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I had one of these in the 1950's when I was a kid. My bed was next to a window, and I ran a wire outside the window and wrapped it around a screwdriver I stuck in the ground. I used the window screen for an antenna. I would then lay in bed and listen to The Fleetwoods and The Coasters. With the ear plug my parents thought I was asleep. There is nothing like listing to "Dream Walk" by Santo and Johnny at 1:00am on a summer's night.
I built a crystal radio with my dad when I was about 8. He had one in the army and he strung the antenna on the clothes line outside the barracks so the sergeant would not notice it. My antenna stretched out my window and across the back yard. It was a circuit with a variable capacitor for tuning and I loved to tune it to different stations and hear music and talking from all over. We were near enough to Canada to get French stations which to me sounded so foreign and mysterious! To this day, I fall asleep with one ear bud in my ear listening to Podcasts. Brownie - a trick I learned once was that you could make a diode using a safety pin and a quarter. You screw the clasp of the pin to the board so that the elbow sticks up in the air and the point comes back down onto the center of the quarter, held there by the spring of the pin. The surface effect makes it somewhat of a diode at higher frequencies. You can hook the wires by twisting one onto the pin clasp and the other underneath the quarter. You might try this on your kit there. Someone below mentioned a similar trick with a razor blade and a pencil lead. Thanks for the cool video and the wonderful memories!
Thank you for your stories. I've not heard of the pin and quarter, will have to try that. I used to use galena (lead mineral) and a pin, but now I'm lazy! ;)
I remember getting a crystal radio kit as a Christmas gift when I was 8 years old. If my memory serves me correctly, the tuning-coil came pre-wound, so I didn't have to fart-around with that. It came with a very long antenna, that my father ran from his bedroom window, all the way to our clothes-line pole in our back-yard. (Unfortunately, my own bedroom window faced our front-yard.) After its assembly and antenna connection, it received most, if not all of the local AM stations clearly; mind you, at that time, I lived in a small city of approximately 100,000 residents, so there weren't many stations to receive. I had a lot of fun with it, nevertheless. :)
Made one when I was 10, from a kit. Wound the wire, etc. Had a small antenna wire, could pick up local stations. Outside my bedroom window was a sycamore tree, about 30 feet tall. Ran an antenna wire about 20 feet up the tree. I could pick up Mexican radio stations at night. Pretty cool stuff.
3 things will cause your crystal radio to NOT WORK. 1. You must have a long wire for an antenna. 2. You must connect the ground to a good metal water pipe or other metal going into the ground. 3. you must use a PIEZO or CRYSTAL earphone.... not one of those modern magnetic wire earphones. Also be sure to scratch off the enamel paint on your copper wires AS HE explains in his video. I made one of these in the 5th grade back in about 1965
Magnetic headphones work fine if the impedance is 2k or higher. Of course these are not widely made anymore, and the modern 4-32 ohm impedance won't work at all, UNLESS you also use a matching audio transformer such as the Bogen T725.
I love these guys who are trying to learn the world something. Only a shame that the final demonstration, there where the magic starts to happen, is so short.
He mentioned in another comment string that he originally put some off the air audio into his video and he got a notice from RUclips to remove it. Apparently putting off the air content on RUclips is a potential copyright violation.
@@joevignolor4u949I used to make these radio crystal radios when I was a kid back in the 70's. Pretty sad that RUclips has nothing more important to worry about considering some of the things on it. What a f'd up world we live in.
RUclips and the rich people doesnt want you to know that it is possible to get such a clear sound from an energy free radio or else the business goes down
Nice build. I made one of tgese with my grandfather in the 80s, he made one as a child in the mid 30s. It was a great memory for both of us. Ultimately, building this simple am crystal set with him sparked a lifelong interest in electronics. I went to school for electronics engineering, but ended up only working in the field for a few years. Still love to see people build cool things and watch the amazment of children at mnaking suchva seemingly complicated thing with so few parts. Everyone should build one, just for the experience.
Dave Leland I would love to know how they sourced the Parts, I personally knew 3 extremely Senior Pows and spent time with them over the years talking about being in the Hanoi Hilton, I never herd one mention a crystal receiver. Two of them were hams also. Just saying!😁🛫
@@TheFalconJetDriver Well, I don't know about your 'senior POWs' or the "Hanoi Hilton", BUT this is the information I have... en.wikipedia.org/wiki/Foxhole_radio, hackaday.com/2016/04/21/hacking-when-it-counts-pow-canteen-radios/, www.radiosurvivor.com/2009/07/06/home-brew-radio-in-a-wwii-pow-camp-shows-radios-survivability/. So you see I think I have reliable information that they did BUILT them in the POW camps.
When I was a kid My brother made a crystal Radio and I was amazed. I always think these kind of projects can come in very useful if your'e in a situation like war or somrthing like that.
Cool! I got a crystal kit for X-mass in 1962 and my dad who knew all about them kept telling me it will not need batteries to make run as we put it together. I thought it was all a joke and was waiting for the gotcha as he had be put the ear phone in my ear and ta da ! WSB am came it clear as a bell. Tuned it a little and WQXI came it too. I will never forget this and wish I had a picture of the look on my face as I heard my first crystal radio work.
+ufoengines Thanks for the comment. I made one out of the boy scout book and was also amazed it could work. I guess EverReady had us all brainwashed. ;)
to tsbrownie; I just completed 25 kits for a class to assemble your radio design. I posted a question earlier and the prototype worked great. Thanks again for an elegant simple design that works! We are thrilled.
God bless tsbrownie for being so patient in answering the same questions over and over. This is ancient technology(over 100 years old) that obviously works. Follow the instructions and it will work. No it won't pick up FM or short wave etc. If you have an antenna, a ground, a coil, a diode and headphones it will work. It's like a miracle you have built with your own hands. Try to appreciate that miracle. No it won't blow you away with fidelity and volume. It is what it is. A good antenna and a good ground are important. In a darkened room you can strike the antenna and ground wire together and see a spark....or put both wires on your tongue and feel the electricity you are capturing from the air. Follow the instruction in the video. In fact, I have made some down and dirty(quick and ugly) versions that also work. Forget the overkill about spring clips and screws and washers...just strip some insulation from the ends of the wires and twist the wire ends together to make a connection. I'm not advocating sloppy craftsmanship...just saying...if you get the connections made, it will work. Appreciate it for what it is.
@@morphenominal Copyright violation probably. It's getting so bad that you can't even pass gas without YT says you violated some copyright or something. :)
@pjd412 They are ultra-safe when it comes to protecting themselves. I can't afford the time to re-do things they take down then force me to prove it's "fair use". And they won't review it until it gets thousands of hits, so once burned, many times shy. Oh, and if the copyright owners complain youtube gives them 100% of the few dollars I get for a video, now the owners want 110% of the take.
@@dleland71 yep, YT is so inconsistent... porn, full movie and TV show videos stay up but a little bit of an am radio broadcast to illustrate how this radio works? CEASE AND DESIST!!! Ridiculous....
We used to build these when i was about 7 years old and now maybe with this video todays generation can experience the same magic that I had as a child.
I was 6 or 7 in the1950s and my dad had the how to build one out of his Boy Scout manual. I don't have any idea how old the Scout manual was. I loved this back then it was a s great as X box is today. Thanks for bringing back great memory's.
I too had good memories of building one of these "magic" devices and it turns out there are a lot of us. I'm glad I could help bring back recollections of those good times.
It might make it easier to wind the coil if you put a piece of double face Scotch tape down the length of the form, maybe even two on opposite sides of the tubing. Also, a spot of hot glue to secure the ends to the form when you are done. I built my first one about 65 years ago as a Cub Scout.
I still like playing with a crystal radio. Built my first in the 1970s. It was magical to listen to radio stations by connecting the antenna to a pipe. It is still magical. I built a shortwave version several years ago.
I agree. It is magical. People I show it to, from engineer friends to my son's science teacher are amazed by it. It's like getting something from (almost) nothing.
I knew a guy who built a radio powered crystal set. He used the rectified dc power from a strong station (WMAL) to power a germanium transistor and a 12" speaker. Very clever invention.
The time has come for those who has knowledge, wisdom and information about how to do. they will go far away with respect to those whose every day passing same. thanks for sharing this info about how to make a free radio (; I am a new subscriber now
Great job. Amazing how simply these radios can be constructed and still work pretty well. This is exactly how I started with crystal radios and then eventually went to double tuned "tuggle" type tuners, and sound powered phones. I am currently into large loop crystal radios which don't use external antennas or grounds and can be seen on my channel. Keep up the good work!
I built a number of these in the 50s. A couple of years ago I even picked up a few galena pieces at a rock and gem shop to do it again. That modest beginning led to a full career in electronics.
When I was 12 I made one using a 1N34A diode ,a 400 microfarad capacitor. The coil was a 5 inch 2x2 wood block with the corners rounded off in a lathe. I used the lathe to wind the wire on the wood . sprayed shellac on it to keep the wire coil together Mounted the coil with 90 ° metal corner brackets at each end so that one corner of the coil was on top. the wiper was a piece of galvanized metal strip with a copper wire solder along the length of it . mounted on a block of wood level with the top of the coil. the most important part was the antenna..I used 200 feet of wire strung between the house and a power pole on the other side of the neighbor's yard. the antenna will be more directional in the opposite the end picking up stations that way. if it goes east to west and if end is west of your radio stations east of you will be stronger.
The old crystal earphones required that 400 uF cap to work. The new crystal earphones are actually piezoelectric and come with a lot (almost too much) capacitance built in so that's no longer needed (in fact it keeps the radio from working). Sounds like you did a very nice job on building it.
You did a great job! When I was a kid a guy that worked with my dad built a radio like this and I remember he used an old spice deodorant stick to wind the coil. I wish I had asked him for it, those were the good ole days.Thanks again, I might build one myself.
Try double sided tape along the PVC before you start the winding. It won't be too sticky, but it will help hold the wire into place. Thank you for such and interesting and informative video! Most people don't know about this kind of thing.
I always thought all devices made are impossible to make without a circuit board or advanced tech. This has got be the simplest one done! From scrap to finish. Radio that runs without battery or electric power! I would love to see it tune more frequencies. Gratitude!
I'm in school for robotics and this never crossed crossed my mind even after watching mythbusters do a similar project! this is your first video I've watched and im subscribing hope you continue to make innovations to inventions
This knowledge is important to have because you can never know what circumstances may be in the future. You may find yourself having to MAKE this because you have no alternative. Remember, radios have been CONFISCATED by authorities in the past.
I have watched a lot of videos on the fox hole radio this evening and yours was by far the coolest one. I'm going to use your design for sure. Thank you.
I won't lie to you, the coil is the hardest part. Keeping it tight and "beautiful" helps, but it will likely still work. Maybe you can find a relative or neighbor? These radios are almost magical. Oh, and the antenna is important. It can just be a long wire (stay away from electric lines for safety and to prevent buzzing) running parallel to the ground. I use wire from an old transformer.
Nice video. Thanks! More theory would have been really helpful, though. You went into deep detail on the easiest part (assembly), but I would have loved to hear more about what each component actually does.
Wow! cool video,when a was young,i receive a kit of radio cristal but he never made a single noise but now i m gonna build one like your's and it gonna work!!thanks for your expertise!
just came across your channel and am truly amazed . Sir if you don't mind could you post another video of just listening to your home built radio . I'm looking forward to building my own and learning more in how it works . Thanks again for this video .
4:00 he was sitting on the toilet seat while filming this and ran out of toilet paper😅😅😅 only joking buddy. Love your work on the crystal radio and very well explained 😎👍
Cool. I've had people tell me that a different coil can do it. Have not tried it. I don't think there are any nearby shortwave stations, so I have not prioritized that project.
My mother had a friend who was stationed in Burma during WW II. He said that the soldiers who had new or newer rifles would use a section of the barrel that had good bluing for the detector section instead of a galena crystal and cat's whisker or the germanium diode used today. Obviously not during battle. Some would use Gillette super blue razor blades. The bluing on both, when dry, forms a conductive crystal structure that can exhibit semiconductor properties. I don't know if today's gun barrels are coated chemically the same way that they were 80+ years ago though. Another setup, he said, was instead of the coil wiper, they would whittle some of the wood back off the end of the end of a pencil, twist the wire tightly around the graphite pencil "lead" near the wood and use the pencil point as the detector / wiper, again, replacing the diode. Graphite also has a crystalline structure that can exhibit semiconductor properties. Before the late 1950's There were no semiconductor diodes or transistors. Regular radios used vacuum tube diodes as the detector. Soldiers had to get creative if they wanted news or music in their down time and the above is what some came up with. I was born and raised in downtown Rochester N.Y. 5 miles from the hill where the bulk of our radio and TV transmitters were. Crystal radio reception was LOUD AND PROUD to say the least. One time, using an AM radio tuned loopstick antenna, for those who don't know, it is a factory wound, center tapped coil of wire about 2 1/2 inches long and a little wider than a pencil with a ferite slug inside with a threaded rod molded in to screw in and out of the coil. Rather than using a wiper on a bulky coil to tune the radio, you would solder a 100 pF disk capacitor across the 2 outside contacts, connect the germanium diode to one side, connect the antenna to either the same side as the diode or the center tap, which ever works better, connect a 50 pF disk cap across the open end of the diode and the coil contact opposite the diode then your crystal earphone across the 50 pF cap. Connect the ground to the coil contact opposite the antenna. Screw the ferite slug in or out to tune. The radio above I experimented with a bit. Instead of the 2,000 ohm earphone, I connected a 2,000 to 8 ohm miniature audio output transformer and speaker out of a pocket transistor radio. I mounted the whole circuit on a small piece of perf circuit board and put it in a cassette tape box. Being 5 miles away from a 5,000 watt transmitter, I had to install a volume control on the transformer to cut down on distortion and volume enough to understand speech and music. I didn't actually need an antenna but the only thing keeping it from being a truly portable radio was the need for a good earth ground like a water pipe or the 3rd prong of an electrical outlet. It was loud and clear enough to set on a dinner table for anyone to hear. Where I live now in West Virginia, the nearest AM radio station is 28 miles away so this circuit wouldn't work here. When my son was young, we built basically the same circuit but using the crystal earphone. 50 feet of wire strung in the trees bought us only static. He got a kick out of trying though.
I'm sure the pencil thing would still work but I don't know anyone that still makes blue blades anymore. With the advent of 137 bladed razors, I don't even know if you could get double edged razor blades outside of an antique shop. Maybe Amazon or E bay? If you do locate some, they can't just be blue painted. The bluing that they used to use on guns and razor blades was for rust prevention so you may have to try an antique shop for the original Gillette super blue blades. The area of the blade that you want to use can't be rusty so be aware of what you are buying. Other companies may have made them but the old Gillette TV commercials sticks in my mind. getting senile I guess. Also, with the pencil thing. If you don't get results the first try, try different hardness of pencil lead. Number 2, 3, 4, 5 up to drafting pencil lead. Pencil makers add clay to their lead formula to control hardness. Number 1 and 2 are soft and usually required for lottery ticket computer read order slips, multiple choice tests and such. Number 3, 4 is harder and usually for people who do a lot of forms where it isn't convenient to stop and run to a pencil sharpener often. Number 5 and up is used by draftsmen where their hands or arms may sweep across a drawing while still in progress. Lead this hard won't come off a technical drawing and smear making it look more like a pastel pencil portrait. Which way that the clay content swings, I don't know so trial and error may apply. Good luck.
Or for added realism use an actual crystal. I bought two in metal boxes, Hertzite and Cymosite and one in a cardboard box, a Dr. Cecil. You might find them at radio rallies as I did with Dr. Cecil or smaller electronic shops where I got the the other two. The Dr. Cecil came with a small piece of gold coloured wire. Wrap the xtal in tin foil leaving the xtal exposed on top and attach a wire to the tin foil, then fix a stiff wire onto a sewing needle and attach the other ends as shown in the video. By probing around with the needle a sensitive spot can be found and stations heard. It works but is tricky. The old sets had an arm to adjust the spot and hold it there. I like this kind of stuff. Thanks for showing it tsbrownie. It was only later I made a crystal set after starting with a one valve kit, H.A.C, Hear All Continents aged 13. I later made mullti valve sets in my teens, moving onto transistors then i.c.'s. Got the amateur licence and made my own h.f. tx/rx. Took thing back a few years ago and made a one valve transmitter using a crystal. Bill, G4GHB.
The old cub scout model that I first build had you cut a piece of 1/2 inch copper pipe to put a mount tab on the bottom and a set screw in the side. It worked.
That's a clean radio ,well done ,now if someone could make a apartment crystal radio ,that would be cool for me ,I got all the parts ,except after seeing your video ,I no now I need to buy some brass washers and brass screws,and I going to buy heaver that's megneti c wire i think it works better and looks better too ,some of your ideas work for me ,I like soldering things together,when I can ,I no it makes a better connection.thanks for letting me barrow some of your ideas.
to many complaints that it doesn't work. Morons! it does at 20:51 to 20:54 you didn't bother to wait till the end. no patience. i made one in 7th grade 1975. Thumbs up. i Like, OLE!
Anybody remember razor-blade radio receivers using a Blue Gillette blade? The device was shown in a 1950's Superman annual. I could also pick up "The Third Programme" transmitted by The BBC by clipping a pair of headphones to the hot and cold water pipes in the airing cupboard.
Mid to late '50's KIX cereal had them for I think two box tops & $.50 and they sent you in the mail. I remember it came with an alligator clip which all you had to do was ground it like the center screw of an outlet cover or the finger stop on rotary phones. The good ole daze!!!!! It was 2" long and like 3/4" square. Came with an ear piece.
I remember doing the same lead . . . . . empty toilet paper roll with about 120 turns of #24 bell wire with graphite from a pencil over the razor blade to tune !!!
there are numerous detectors possible. 1n34, oa91, aa143, FO-215 or similar germanium diodes. modern shottky diodes; 1n5711, HP5082-2835, HSMS281. even some minerals form "diodes" with cats whisker (point of graphite, copper, silver), Galena (lead sulfite ore), iron-pyrite, magnetite, copper-pyrite, calcopyrite (peacock ore), zincsite, stenite... Rusted nail, tarnished ccopper or silver, blued steel (gun barrel, razorblade...). Here are more crystalradio.net/minerals/index.shtml www.crystal-radio.eu/endiodes.htm
This is amazing! I've been thinking about building a low cost v2 crystal radio, (I've built from a kit before v1), I'm going to build one from your demo, I'll post results.. Thank you!
I want to help my 12 year old grandson how to make a crystal radio, I have a Philmore VC1000 that and uncle gave my when I was 10 years old (1966) we put it together and strung bell wire all over our 1 acre yard trying to make the best antenna I could. A neighbor gave me a two pieces of u channel aluminum one 6 feet tall the other 4 foot. I made cross with them and screwed them to a skinny Poplar tree in my back yard about7 feet off the ground and that became my antenna and it worked well. I sanded the aluminum and cleaned the copper 23 awg bell wire ran a screw around the wire and the aluminum and I spray painted it with enamel paint for corrosion protection. In 1976 my parents moved from that home. In 2018 I visited the area where I grew up. The aluminum antenna parts were 60 feet in the air to my knowledge it is still there. Of course the bell wire is long gone. 😁🛫
Probably not. There's no issue in storing electricity, it's all a careful balancing act so overdoing one part won't help. BUT it never hurts to experiment. You may find you can receive other bands and such.
The details are in the description. The capacitor is not used with modern piezoelectric earphones. But you may need one if you have one of the models from mid 1900's and before.
Awesome. Very easy to understand this. You are the master explainer! I have a question about the coil used for tuning. Is it a variable capacitor or what manner of component is that? All good wishes.
+Anton Nym Thank you very much. That's a good question. Most people think of the coil as an inductor, but in fact it also has significant capacitance. In this model when you move the wiper you are making 2 changes: on the left you are changing the inductance / capacitance with the antenna, and on the right side you are changing the inductance / capacitance of the tank (resonant) circuit. For example: if you move the wiper to the left, the antenna side inductance and capacitance gets smaller, while on the right side (tank circuit) the inductance and capacitance increases.
Please Mr. If you don't mind i really appreciate your work and i really want to do it, but i need you to write the measures of the resistences and diods and the names of all elements so that i can look for them.
The parts details are in the description. The how it works is found under "tank circuit" or "resonant circuit". There's lots of information on those already, so I won't repeat all that. The wiper divides the coil into 2 parts, the unused left side and the "radio" part on the right side where you are hearing the stations. By moving the wiper, you change the resonant frequency of the circuit filtering out all the undesired frequencies. It's a bit like moving a stethoscope around on a large, ringing bell and hearing the different pitches it rings at.
Everything fine with my radio except the reception. How do I receive signals from a distance 50-55 miles from the station, how long antenna do I need for that and, how should it be installed. There are two nearest Am radios nearby one is situated at 55 miles away from my house and the other 150 miles away from my house. Both of the stations can be tuned with crystal clear sound in my AM radio Transistor of Philips.
I have a video on antennas. How they are made, the length, and how they are orientated makes a lot of difference, especially for weaker stations. ruclips.net/video/G8AsgZbncW4/видео.html
When I was just a wee lad, we made crystal radios, but it seems to me that we actually used a crystal then a brass pin to connect to touch the crystal. But basically the same way.
This is a modified version that was in my Wolf Scout handbook. (They had a mistake in the drawing that kept it from working!) We used a piece of galena (lead ore) and a brass safety pin as well. The diode is much more reliable and gives a clearer output.
Very nice.I don't think Radio Shack has sold germanium diodes for many years though. You can make your own detectors that work well, or buy the germanium diodes online though.
Use a 1N34 - it's commonly available and it's germanium. Better yet, after you build this, work your way up to a regenerative receiver. They are simple and sensitive, and there's a bunch of reasonably priced kits around.
A bit of zinc, heated red hot and left to cool so that it oxidizes on its surface, makes an excellent detector in light contact with lead or copper wire. Very nearly as good as the old factory made germanium diodes...but you have to search for the sensitive spots. Steel that has been turned to a bluish surface by heating (and allowing to cool) also works well in light contact with a little piece of copper wire.
I imagine that the glue might also cause a short by insulating the wire so that no signal can be heard too. I’d be afraid to use glue for that reason too.
Great memories come back after I saw your video, thank you so much. I have a question, I used a Galena crystal when I was a little boy, I can't remember if the galena rock goes where the diode is on yours, or do I need both?
56 years ago when I built my first I also used galena. As you know it requires searching around on the galena to find a good spot. It would replace the diode. Thank you for watching and for your comment.
Hello my name is Tom Murphy i am 61 years old and know very little of volts or amps ie Imust say i really enjoy how you break the build down very good ! one thing i have a question on is resistor i got some that amazon said who work my question is this how what does a resistor due and i notice you can get a station with out them how can i tell if they are working , my next question how to drop var cap into a radio love your info god bless tom
Hi Tom, we're about the same age. Electricity acts a bit like water in a pipe. A resistor acts like a constriction in a pipe; it introduces "friction". The resistor is needed to funnel some (but not too much) electricity around the earpiece. For a variable cap radio I have a different design here: ruclips.net/video/AaNpFYe5dSo/видео.html
Love the bike spoke wiper. Dump the resistor. Short it out! No idea where he got that idea! Connect a .001 Capacitor...or condenser (any style) between the earpiece end of the diode and earth/ground. That takes the radio waves out of the system, when you've finished with them. After the diode, you HAVE finished with them
+MauriatOttolink These new "crystal earphones" are not like the old day types, these are piezoelectric and the resistor is needed. In fact the earphone has lots of capacitance so the capacitor is no longer needed. I built it from my old wolf scout handbook and it did not work well at all. Made the "modern" changes to account for the piezoelectric earphone and sound jumped out of it. They taught this old dog a new trick.
@@MauriatOttolink This is what I like to see and rarely see nowadays - "It looks like you just taught this even older dog a new trick". In todays world we rarely see this, especially on RUclips - everyone wants to argue and antagonize everyone else. Good on you. (I also am an older dog)
@@chumleye1112 Wow...3 years ago...I'd quite forgotten. I put it in non tech terms as Xtal sets are usually built by complete beginners In fact the capacitor is an RF decoupler although I believe that it's not required when using Hi Z crystal ear pieces but a high Ω resistor IS required to complete the D.C. path. Using high Z moving-iron phones, the audio really does increase when the rf decoupler is connected. Thank you for your message.
Very easy to follow! But I don't remember if you mentioned it needs a "germanium diode". If you did I missed it. Either way, this is a very good video! Your explanations and methods are very nicely done! thanks!
Thank you. Yes, I always emphasize it has to be a 1n34a. Also say it in the description. Lots of people write and ask and I emphatically emphasize it MUST be that diode!
What's the radio shack part number for the diode? Is it germanium or some non-silicon based diode? Also I guess the self-capacitance of the coil and circuit is enough to work for the tuning. I have seen other schematics for this sort of rig and they have separate tunable caps. Very nice video! I enjoyed it.
TechnoW1zard Thanks for the compliment. The diode is a 1N34A. RS 276-1123 but I would not use RS unless I really had to. You can get the 1n34A from Amazon. I've also heard second hand (but never tried them) ECG109 (Sylvania) and SK3090 (RCA) will work. The boy scout manual lists a home made capacitor and we made 2 and tried them in the circuit (along with factory made ones) and in this circuit we can't hear a difference. I'd guess there's a significant capacitance in the coil and come to think of it I might be able to measure it indirectly. A rainy day project!
Thanks for a great video with excellent commentary and clear enunciation. Q: Where is the capacitor that is needed to form the resonant circuit? In other words, what gives the C of the required LC to get the necessary resonance? Thanks.
Thanks. A: Components from wire to transistors to coils to caps have all the properties of resistance, inductance and capacitance. Most of the time you can ignore the less significant ones, but in this case not. The coil has both inductance and capacitance in significant amounts. The AC in the windings (wires separated by insulation) acts as capacitance. It's not a lot, but enough.
Theoretically you can receive any AM band given the right coil. The limitation is in distance - most cities have AM commercial stations relatively close by, so it works. It will not pick up lower power stations or stations really far away, so you will not get BBC in the US. But if you were near the BBC AM station, then given the right coil, it should work.
this is great! i am going to build one just like yours. Could you also in your next video put another presentation with a 10watts amplifier, even if it is two or multiple stages will do. I want to build this with two stage mono or stereo amplifier with 10 watts of power max. Thank you for the video.
it seems like with that big coil you will be able to get long wave also your design is best big size simple wiring I will build this one first then experiment with other things can various crystals be used to change the frequency. thanks
The AM band covers roughly 500KHz to 1.6MHz, but that varies a lot with how a radio is actually built: number of turns, size of wire, etc. The details for this one are in the desc.
You can limit your soldering by using a 16 gauge metal ring terminal squeezed on the end of the 16 gauge wire "wiper" rod, then use a wire to the ground and one to the diode. :)
Built one of these from a kit when I was about nine years old very handy knowledge to have.Do you have the values on the resistor and diode or doesn't it make a difference?
I had one in the early 1960’s. I think it was something I got off of the back of a cereal box. I’d listen to Cincinnati Reds and Royals games on WLW at night.
Hi, please excuse me if this has been asked before; what does the resistor do? I’ve built crystal radios that don’t use a resistor. Thank you for posting.
tsbrownie The resistor discharges the capacitance of the earpiece. Without it you get little sound and will hear a popping. I did not believe that the resistor would make much difference (my boy scout radio I used a "real" crystal earphone and not an piezoelectric modern one and it behaved differently) so I tried this new earpiece without the resistor and the volume was very low.
It’s been a while since you made this. I had a few questions mainly about the variables. To start, what would the effect be if you used a smaller gauge wire? Secondly, does the high amount of turns of coils mean you have more frequencies that you can visit or does it allow certain frequencies to expand over more of the wire? Lastly (for now), I read in a comment from a few years back you said the diameter of the coil affects the amount of frequencies allowed. I was hoping you could elaborate on that. And on that same comment you said most AM channels. What would need to be done to higher the frequency to FM? Sorry if I’m asking too much, I’m self taught in all this by research and reading and quite interested
The questions about wire gauge and coil size can be seen best (and most fun) by playing with the apps in this video: ruclips.net/video/Fw9eb-aB-XU/видео.html The wire diameter changes the turns per distance which changes the inductance which changes the resonant frequency. Ditto the more turns. The size (all measurements) of the coil changes the inductance. Again, the apps will show you that. It's a lot of fun to play with. Check the description in this video for the basic parameters you can use as a starting point.
Not getting anything in the earpiece. What is the significance of the diameter of the bottle, you use to wrap the wire. I used a smaller bottle with only 40 rounds. Should I use a bigger(in diameter) and longer bottle to be able to coil around more wire ?
+Anurag A. 40 turns is rather few, but you should get something. The usual problems (in order): 1) did you use the correct type of earphone. ONLY a crystal earphone will work. 2) did you take the enamel paint off the wire where there are connections? On each end of the wire and where the wiper touches the coil. 3) Do you have AM stations in your area? (This is a problem in India where they don't have many). I just made another, different style yesterday and even before it was completely done I could get 1 station!
+tsbrownie I'm in US about 100 miles N of DC. I got the crystal earphones(Philmore Crystal earphone high impedance n. 748 Japan) from amazon exactly like yours. the only suspect is the antenna now. I connected a roughly 15 ft magnetic wire(same wire I used to coil around the bottle) to a satellite dish outside my house. For a very short period this morning I heard a KRRRRRRRRRRR..., but that also went away quickly. Now it is absolutely blank.
The antenna wire can not touch anything metal. You can use string or plastic or such to tie it up. Make sure the enamel paint is off he end that connects to the radio. Is your diode a 1n34a? Other diodes won't work. If you can, make a close up video of what you have, post it and I can look at it.
+Anurag A. From your video: Your windings look OK. You used just 1 set of windings, yes? The earphone looks like the right one. I can not clearly see the diode or resistor, I will assume the values are OK. The big problem I see is the wiring. I do not think that is right. The circuit is a big "U". One the right side of the "U" at the top is the antenna coming in. Then the coil. The bottom of the "U" is the resistor with the earphone across the resistor. The left side of the "U" is the diode and above the diode is the wiper (or jumper in your case) and at the top of the left side is the ground. To test your diode and antenna you can put the antenna on one side (does not matter which) and the ground on the other. Put the earphone across the diode (no resistor, just diode and earphone). You should hear the loudest station (no tuning obviously). The antenna can not be in contact with metal or be inside or under a metal roof or similar. Final comment on wire: you must be very careful to remove all the enamel (green) coating all the way around the wire. Also some of your connections look loose. The currents you are working with are very, very tiny. Small resistances add up and will kill the signal. Make sure the connections are tight / strong. If you are using steel screws or plated screws they may have oxide and/or not connect well. I strongly recommend stainless or brass screws and washers. If you can solder connections that is best (requires brass, stainless won't solder with normal solder). Use only rosin core solder (not acid). It appears you have all the right parts, it's a matter of connecting them well and in the right sequence.
For all the crystal radios that I've made over the years, I never tried using a 4 germanium diode bridge for full-wave rectification. That should give double the output. That would have be insane back when diodes were expensive, but I have dozens in a parts drawer.
I just built my first example of this radio. I used 22 gauge wire on a 2 inch PVC pipe. I used some magnet wire for an antenna and I was getting some static and popping. This was before the 10k resistor came in. After I put the resistor on and bought some 8 gauge wire 16 feet long for an antenna I got nothing at all. My tuns with the 22 wire was 128. The magnet wire was a bit over your your specs. I used the exact resistor and diode you have in the spec. I refurbish fans so I am aware of magnet wire for choke coils and the like. I used a OHMs meter to test continuity and its fine. If I can use the Magnet 22 G magnet wire I may get the bigger pipe in your specs. But my turns were short compared to yours. My wiper is Brass and its about 6 gauge stiff brass. I also used a spring on the base of the wiper to keep pressure on the wiper. Any guidance would be appreciated. Thanks for the videos.
I have a video just for you. Since you already work with wire, some of it will be a repeat. ruclips.net/video/kCxQ8iPQx4s/видео.html I don't think you need a total redo, it sounds like you're almost there. If you have a station within 10 miles, you should be getting something. You did not mention your earphone, is it the same? Other types won't work. What's the number on your diode? What are you using for a ground? Also how are you making connection to the wiper? If you can post a video of your device, leave a link here and I'll look at it.
@@tsbrownie I watched that already. There are a couple of things that may be the issue. What I will do is make a video of the radio I made and you can tell me if anything looks wrong.
I haven't seen a crystal radio where the ground wire is attached to the tuning rod before. Which way works best , antenna attached to the base of the tuning coil and earth attached to the tuning rod, or the antenna attached to the tuning rod and the earth attached to the base of the coil.
+woodcoast50 Excellent question. I have 1 more design where there are a couple subtle differences and I plan to build that and test them side by side. This design is from the Wolf Scout handbook from when I was a kid, I had built it before and knew it would work. Odd that so many years later i remembered there was an error in their drawing and there was 1 wire too many. I guess we remember a lot more about what we learn as kids than we think.
@@tsbrownie No. I built such receivers in my youth, and it doesn't work that simple. The output power is not enough for such an ordinary earphone. If so, it only works with a high-resistance part such as an earpiece on the phone. And even then you can only hear the station that is closest to your own location. The selection and filtering of such a device is far too weak and imprecise
In the old days with real crystal earphones they needed a capacitor. But the piezo electric earphones already have (too much) capacitance. Adding more causes problems.
TSBrowinie...I thought antennas needed their own ground, like an outdoor tv antenna. I know the set is grounded because it’s needed to make it function, but what about for real grounding purposes? Ie: when the set is brought inside, the antenna is left out there all alone without the set/ground, what happens when struck by lightning? If set is 24/7 hooked to antenna and always indoors, even if grounded, aren’t you inviting the strike to come inside the house and go thru our internal ground system? Thanks
Not sure what you mean by "real grounding purposes." To get the max signal for a radio/TV, you typically need to have the signal pass from antenna through the device to a ground. SOMETIMES with crystal radios the ground is actually a hindrance. Not sure why, I just know from experience. The signals are very weak and just having objects nearby can influence the quality of the signal - hands, body, table, appliances, ... so the tiny signals may be going to "ground" just by dissipating in the radio or its surroundings. Too much ground in these circumstances changes the "tuning" such that it does not work as well. Just a guess. I don't understand your "IE: when the set is brought inside..." If all the antenna wire is outside, if lightning strikes the wire, the lighting will not have an artificially supplied path into the house. "If set is 24/7 hooked to antenna...." Yes, having the wire inside the house can channel a strike into the house. Lightning does not need you to supply a ground, it will find one by itself. It travels kilometers though the air, if it hits your antenna and travels along it, the strike will have no trouble emerging from the wire and continuing on by itself. If the wire is all outside, the lightning will not have a human supplied path into the house. This is why I say that I deal with lightning suppression by putting ALL of the wire outside the house and lay the end on the ground (or tied to a ground rod) when I am not using the radio or when there's a storm any where near. If lightning strikes the antenna, it will be destroyed, however you will not be giving the lightning a path inside.
Hi again. As you may have surmised, I know nothing of the topic, but I do have a home built crystal set I’d like to hook up Clarification, the antenna remains in a 50 ft straight line from post to post at all times, even when unused. From there I pigtail a dangling outside wire that I hook from one end of antenna into my Antenna terminal on the radio when in use. All other times I unhook it & toss it out the window where it either: rests on the earth; or I tie it to a ground rod Right? Can the rod serve as having 2 purposes... it’d be a single point of contact to have 2 wires: one going to the grounding terminal on the radio and the other wire goes to the suspended antenna
No variable tuning cap? I would think a simple slider foil variable cap would increase selectivity. A lot of the Xtal sets use a 150 or 240 micro Henry coil with a 365pf variable cap for tuning. creates an oscillating tank circuit to select the carrier frequency and squelch other frequencies as I understand. Not to be confused with the cap that sometimes is use for the earpiece.
I thought the same. I saw the same in many diagrams on the internet, but no one actually made one. So I did. It did not work. It got 1 station well, a weak second one. A germanium diode by itself will get 1 station! (I made videos on both of these.) I've been looking at transistor radios that use a 365 var cap, and they use a few very small coils BUT they also use part of the ferrite antenna in the turning circuit. Don't have it totally figured out yet, need to spend some more time with it. ruclips.net/video/i2PITPUg2vI/видео.html ruclips.net/video/GdvKDFz9Xi4/видео.html
The Antenna supplies the necessary capacitance, and the variable inductance tunes the two together. This is how the earliest sets worked before tuning caps were available. But you do need a big antenna and an Earth.
Updated Video: Best/Easiest DIY Crystal Radio - No Batteries, No External Power 2023 (4K)
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I had one of these in the 1950's when I was a kid. My bed was next to a window, and I ran a wire outside the window and wrapped it around a screwdriver I stuck in the ground. I used the window screen for an antenna. I would then lay in bed and listen to The Fleetwoods and The Coasters. With the ear plug my parents thought I was asleep. There is nothing like listing to "Dream Walk" by Santo and Johnny at 1:00am on a summer's night.
I used the gutter of the house for an antenna and used to listen to baseball games when I was supposed to be sleeping. Good times indeed!
I built a crystal radio with my dad when I was about 8. He had one in the army and he strung the antenna on the clothes line outside the barracks so the sergeant would not notice it. My antenna stretched out my window and across the back yard. It was a circuit with a variable capacitor for tuning and I loved to tune it to different stations and hear music and talking from all over. We were near enough to Canada to get French stations which to me sounded so foreign and mysterious! To this day, I fall asleep with one ear bud in my ear listening to Podcasts.
Brownie - a trick I learned once was that you could make a diode using a safety pin and a quarter. You screw the clasp of the pin to the board so that the elbow sticks up in the air and the point comes back down onto the center of the quarter, held there by the spring of the pin. The surface effect makes it somewhat of a diode at higher frequencies. You can hook the wires by twisting one onto the pin clasp and the other underneath the quarter. You might try this on your kit there. Someone below mentioned a similar trick with a razor blade and a pencil lead.
Thanks for the cool video and the wonderful memories!
Thank you for your stories. I've not heard of the pin and quarter, will have to try that. I used to use galena (lead mineral) and a pin, but now I'm lazy! ;)
I remember getting a crystal radio kit as a Christmas gift when I was 8 years old. If my memory serves me correctly, the tuning-coil came pre-wound, so I didn't have to fart-around with that.
It came with a very long antenna, that my father ran from his bedroom window, all the way to our clothes-line pole in our back-yard. (Unfortunately, my own bedroom window faced our front-yard.)
After its assembly and antenna connection, it received most, if not all of the local AM stations clearly; mind you, at that time, I lived in a small city of approximately 100,000 residents, so there weren't many stations to receive. I had a lot of fun with it, nevertheless. :)
Made one when I was 10, from a kit. Wound the wire, etc. Had a small antenna wire, could pick up local stations. Outside my bedroom window was a sycamore tree, about 30 feet tall. Ran an antenna wire about 20 feet up the tree. I could pick up Mexican radio stations at night. Pretty cool stuff.
3 things will cause your crystal radio to NOT WORK. 1. You must have a long wire for an antenna. 2. You must connect the ground to a good metal water pipe or other metal going into the ground. 3. you must use a PIEZO or CRYSTAL earphone.... not one of those modern magnetic wire earphones. Also be sure to scratch off the enamel paint on your copper wires AS HE explains in his video. I made one of these in the 5th grade back in about 1965
Magnetic headphones work fine if the impedance is 2k or higher. Of course these are not widely made anymore, and the modern 4-32 ohm impedance won't work at all, UNLESS you also use a matching audio transformer such as the Bogen T725.
What if you can't get those earpieces ?
@@QIKUGAMES-QIKU you can use a amplifier
I love these guys who are trying to learn the world something. Only a shame that the final demonstration, there where the magic starts to happen, is so short.
He mentioned in another comment string that he originally put some off the air audio into his video and he got a notice from RUclips to remove it. Apparently putting off the air content on RUclips is a potential copyright violation.
@@joevignolor4u949I used to make these radio crystal radios when I was a kid back in the 70's. Pretty sad that RUclips has nothing more important to worry about considering some of the things on it. What a f'd up world we live in.
RUclips and the rich people doesnt want you to know that it is possible to get such a clear sound from an energy free radio or else the business goes down
Nice build. I made one of tgese with my grandfather in the 80s, he made one as a child in the mid 30s. It was a great memory for both of us. Ultimately, building this simple am crystal set with him sparked a lifelong interest in electronics. I went to school for electronics engineering, but ended up only working in the field for a few years. Still love to see people build cool things and watch the amazment of children at mnaking suchva seemingly complicated thing with so few parts. Everyone should build one, just for the experience.
Great video, very informative, thanks. FYI, POWs used to make these to hear 'the truth' about the war. It gave morale a huge boost!
Dave Leland I would love to know how they sourced the Parts, I personally knew 3 extremely Senior Pows and spent time with them over the years talking about being in the Hanoi Hilton, I never herd one mention a crystal receiver. Two of them were hams also. Just saying!😁🛫
@@TheFalconJetDriver Well, I don't know about your 'senior POWs' or the "Hanoi Hilton", BUT this is the information I have... en.wikipedia.org/wiki/Foxhole_radio, hackaday.com/2016/04/21/hacking-when-it-counts-pow-canteen-radios/, www.radiosurvivor.com/2009/07/06/home-brew-radio-in-a-wwii-pow-camp-shows-radios-survivability/. So you see I think I have reliable information that they did BUILT them in the POW camps.
When I was a kid My brother made a crystal Radio and I was amazed. I always think these kind of projects can come in very useful if your'e in a situation like war or somrthing like that.
Cool! I got a crystal kit for X-mass in 1962 and my dad who knew all about them kept telling me it will not need batteries to make run as we put it together. I thought it was all a joke and was waiting for the gotcha as he had be put the ear phone in my ear and ta da ! WSB am came it clear as a bell. Tuned it a little and WQXI came it too. I will never forget this and wish I had a picture of the look on my face as I heard my first crystal radio work.
+ufoengines Thanks for the comment. I made one out of the boy scout book and was also amazed it could work. I guess EverReady had us all brainwashed. ;)
to tsbrownie; I just completed 25 kits for a class to assemble your radio design. I posted a question earlier and the prototype worked great. Thanks again for an elegant simple design that works! We are thrilled.
Glad you found it useful. Thanks for the feedback.
God bless tsbrownie for being so patient in answering the same questions over and over. This is ancient technology(over 100 years old) that obviously works. Follow the instructions and it will work. No it won't pick up FM or short wave etc. If you have an antenna, a ground, a coil, a diode and headphones it will work. It's like a miracle you have built with your own hands. Try to appreciate that miracle. No it won't blow you away with fidelity and volume. It is what it is. A good antenna and a good ground are important. In a darkened room you can strike the antenna and ground wire together and see a spark....or put both wires on your tongue and feel the electricity you are capturing from the air. Follow the instruction in the video. In fact, I have made some down and dirty(quick and ugly) versions that also work. Forget the overkill about spring clips and screws and washers...just strip some insulation from the ends of the wires and twist the wire ends together to make a connection. I'm not advocating sloppy craftsmanship...just saying...if you get the connections made, it will work. Appreciate it for what it is.
Never knew they would spark. Cool! Have to try that. Thanks!
Wow, I really wanted to hear you tune in at least a few stations after that lengthy build lesson.:-)
Me too. In video version 1.0 I did that and youtube sent me a take down notice.
tsbrownie why?
@@morphenominal Copyright violation probably. It's getting so bad that you can't even pass gas without YT says you violated some copyright or something. :)
@pjd412 They are ultra-safe when it comes to protecting themselves. I can't afford the time to re-do things they take down then force me to prove it's "fair use". And they won't review it until it gets thousands of hits, so once burned, many times shy. Oh, and if the copyright owners complain youtube gives them 100% of the few dollars I get for a video, now the owners want 110% of the take.
@@dleland71 yep, YT is so inconsistent... porn, full movie and TV show videos stay up but a little bit of an am radio broadcast to illustrate how this radio works? CEASE AND DESIST!!! Ridiculous....
Me and my pops built a crystal radio like such back when I was a kiddoe, I always found the concept fascinating
We used to build these when i was about 7 years old and now maybe with this video todays generation can experience the same magic that I had as a child.
This is the best how-to crystal radio I have found on youtube. Thanks for the clear and concise instructions!
Aghast Thank you for the compliment!
I was 6 or 7 in the1950s and my dad had the how to build one out of his Boy Scout manual. I don't have any idea how old the Scout manual was. I loved this back then it was a s great as X box is today. Thanks for bringing back great memory's.
I too had good memories of building one of these "magic" devices and it turns out there are a lot of us. I'm glad I could help bring back recollections of those good times.
It might make it easier to wind the coil if you put a piece of double face Scotch tape down the length of the form, maybe even two on opposite sides of the tubing. Also, a spot of hot glue to secure the ends to the form when you are done. I built my first one about 65 years ago as a Cub Scout.
This is probably the best video I've seen on this subject thank you
Thank you. This is an updated version of it
ruclips.net/video/fLVCqZGpv3U/видео.html
I still like playing with a crystal radio. Built my first in the 1970s. It was magical to listen to radio stations by connecting the antenna to a pipe. It is still magical. I built a shortwave version several years ago.
I agree. It is magical. People I show it to, from engineer friends to my son's science teacher are amazed by it. It's like getting something from (almost) nothing.
I knew a guy who built a radio powered crystal set. He used the rectified dc power from a strong station (WMAL) to power a germanium transistor and a 12" speaker. Very clever invention.
The time has come for those who has knowledge, wisdom and information about how to do. they will go far away with respect to those whose every day passing same. thanks for sharing this info about how to make a free radio (; I am a new subscriber now
My dad had one of these when he was a kid and listened to the Grand Old Oprey on Saturday night.
Great job. Amazing how simply these radios can be constructed and still work pretty well. This is exactly how I started with crystal radios and then eventually went to double tuned "tuggle" type tuners, and sound powered phones. I am currently into large loop crystal radios which don't use external antennas or grounds and can be seen on my channel. Keep up the good work!
I built a number of these in the 50s. A couple of years ago I even picked up a few galena pieces at a rock and gem shop to do it again. That modest beginning led to a full career in electronics.
When I was 12 I made one using a 1N34A diode ,a 400 microfarad capacitor. The coil was a 5 inch 2x2 wood block with the corners rounded off in a lathe. I used the lathe to wind the wire on the wood . sprayed shellac on it to keep the wire coil together Mounted the coil with 90 ° metal corner brackets at each end so that one corner of the coil was on top. the wiper was a piece of galvanized metal strip with a copper wire solder along the length of it . mounted on a block of wood level with the top of the coil.
the most important part was the antenna..I used 200 feet of wire strung between the house and a power pole on the other side of the neighbor's yard.
the antenna will be more directional in the opposite the end picking up stations that way.
if it goes east to west and if end is west of your radio stations east of you will be stronger.
The old crystal earphones required that 400 uF cap to work. The new crystal earphones are actually piezoelectric and come with a lot (almost too much) capacitance built in so that's no longer needed (in fact it keeps the radio from working). Sounds like you did a very nice job on building it.
You did a great job! When I was a kid a guy that worked with my dad built a radio like this and I remember he used an old spice deodorant stick to wind the coil. I wish I had asked him for it, those were the good ole days.Thanks again, I might build one myself.
Thank you. Old Spice tube, that's interesting. You should build one. They are not hard or expensive. Let me know how it goes or if you have questions.
Try double sided tape along the PVC before you start the winding. It won't be too sticky, but it will help hold the wire into place. Thank you for such and interesting and informative video! Most people don't know about this kind of thing.
The thin stuff would probably work. I was always concerned it would make the surface lumpy.
I always thought all devices made are impossible to make without a circuit board or advanced tech. This has got be the simplest one done! From scrap to finish. Radio that runs without battery or electric power! I would love to see it tune more frequencies. Gratitude!
Hello jaz
I've uploaded videos
I have a small apartment in Bishkek kyrgyzstan
And a simple crystal radio
Just click user name
I'm in school for robotics and this never crossed crossed my mind even after watching mythbusters do a similar project! this is your first video I've watched and im subscribing hope you continue to make innovations to inventions
You don't need to burn power on a downlink! ;) Kind of like RFID.
This knowledge is important to have because you can never know what circumstances may be in the future. You may
find yourself having to MAKE this because you have no alternative. Remember, radios have been CONFISCATED by
authorities in the past.
I have watched a lot of videos on the fox hole radio this evening and yours was by far the coolest one. I'm going to use your design for sure. Thank you.
Thank you. Let us know how it goes.
Well Done. I think i will give it a try. I may just try to purchase one all ready made , the coil may be the problem for my 75 year old hands.
I won't lie to you, the coil is the hardest part. Keeping it tight and "beautiful" helps, but it will likely still work. Maybe you can find a relative or neighbor? These radios are almost magical. Oh, and the antenna is important. It can just be a long wire (stay away from electric lines for safety and to prevent buzzing) running parallel to the ground. I use wire from an old transformer.
Nice video. Thanks! More theory would have been really helpful, though. You went into deep detail on the easiest part (assembly), but I would have loved to hear more about what each component actually does.
Wow! cool video,when a was young,i receive a kit of radio cristal but he never made a single noise but now i m gonna build one like your's and it gonna work!!thanks for your expertise!
Please watch my video on antennas. You also need an AM radio station in your area. And it gonna work!
Wonderful instructions my dad made radio receivers for fun my kids not too so. What a great simple receiver. Thanks
just came across your channel and am truly amazed .
Sir if you don't mind could you post another video of just listening to your home built radio .
I'm looking forward to building my own and learning more in how it works .
Thanks again for this video .
Thank you. I can not play what is on the radio because under US intellectual property law, that is not allowed, and youtube will take down the video.
4:00 he was sitting on the toilet seat while filming this and ran out of toilet paper😅😅😅 only joking buddy. Love your work on the crystal radio and very well explained 😎👍
Naw, my butt's a little wider than that.
i modified the circuit a little to receive shortwave band without ground but it kinda works
Cool. I've had people tell me that a different coil can do it. Have not tried it. I don't think there are any nearby shortwave stations, so I have not prioritized that project.
Very well done ! Your explanation was spot on. Thank you for sharing.
All the best.
Bobby
My mother had a friend who was stationed in Burma during WW II. He said that the soldiers who had new or newer rifles would use a section of the barrel that had good bluing for the detector section instead of a galena crystal and cat's whisker or the germanium diode used today. Obviously not during battle. Some would use Gillette super blue razor blades. The bluing on both, when dry, forms a conductive crystal structure that can exhibit semiconductor properties. I don't know if today's gun barrels are coated chemically the same way that they were 80+ years ago though.
Another setup, he said, was instead of the coil wiper, they would whittle some of the wood back off the end of the end of a pencil, twist the wire tightly around the graphite pencil "lead" near the wood and use the pencil point as the detector / wiper, again, replacing the diode. Graphite also has a crystalline structure that can exhibit semiconductor properties.
Before the late 1950's There were no semiconductor diodes or transistors. Regular radios used vacuum tube diodes as the detector. Soldiers had to get creative if they wanted news or music in their down time and the above is what some came up with.
I was born and raised in downtown Rochester N.Y. 5 miles from the hill where the bulk of our radio and TV transmitters were. Crystal radio reception was LOUD AND PROUD to say the least. One time, using an AM radio tuned loopstick antenna, for those who don't know, it is a factory wound, center tapped coil of wire about 2 1/2 inches long and a little wider than a pencil with a ferite slug inside with a threaded rod molded in to screw in and out of the coil. Rather than using a wiper on a bulky coil to tune the radio, you would solder a 100 pF disk capacitor across the 2 outside contacts, connect the germanium diode to one side, connect the antenna to either the same side as the diode or the center tap, which ever works better, connect a 50 pF disk cap across the open end of the diode and the coil contact opposite the diode then your crystal earphone across the 50 pF cap. Connect the ground to the coil contact opposite the antenna. Screw the ferite slug in or out to tune.
The radio above I experimented with a bit. Instead of the 2,000 ohm earphone, I connected a 2,000 to 8 ohm miniature audio output transformer and speaker out of a pocket transistor radio. I mounted the whole circuit on a small piece of perf circuit board and put it in a cassette tape box. Being 5 miles away from a 5,000 watt transmitter, I had to install a volume control on the transformer to cut down on distortion and volume enough to understand speech and music. I didn't actually need an antenna but the only thing keeping it from being a truly portable radio was the need for a good earth ground like a water pipe or the 3rd prong of an electrical outlet. It was loud and clear enough to set on a dinner table for anyone to hear. Where I live now in West Virginia, the nearest AM radio station is 28 miles away so this circuit wouldn't work here. When my son was young, we built basically the same circuit but using the crystal earphone. 50 feet of wire strung in the trees bought us only static. He got a kick out of trying though.
Thanks for the comment. Lots of good stuff there. I have to try the pencil and razor blade things one of these days.
I'm sure the pencil thing would still work but I don't know anyone that still makes blue blades anymore. With the advent of 137 bladed razors, I don't even know if you could get double edged razor blades outside of an antique shop. Maybe Amazon or E bay? If you do locate some, they can't just be blue painted. The bluing that they used to use on guns and razor blades was for rust prevention so you may have to try an antique shop for the original Gillette super blue blades. The area of the blade that you want to use can't be rusty so be aware of what you are buying. Other companies may have made them but the old Gillette TV commercials sticks in my mind. getting senile I guess.
Also, with the pencil thing. If you don't get results the first try, try different hardness of pencil lead. Number 2, 3, 4, 5 up to drafting pencil lead. Pencil makers add clay to their lead formula to control hardness. Number 1 and 2 are soft and usually required for lottery ticket computer read order slips, multiple choice tests and such. Number 3, 4 is harder and usually for people who do a lot of forms where it isn't convenient to stop and run to a pencil sharpener often. Number 5 and up is used by draftsmen where their hands or arms may sweep across a drawing while still in progress. Lead this hard won't come off a technical drawing and smear making it look more like a pastel pencil portrait. Which way that the clay content swings, I don't know so trial and error may apply. Good luck.
Or for added realism use an actual crystal. I bought two in metal boxes, Hertzite and Cymosite and one in a cardboard box, a Dr. Cecil. You might find them at radio rallies as I did with Dr. Cecil or smaller electronic shops where I got the the other two. The Dr. Cecil came with a small piece of gold coloured wire. Wrap the xtal in tin foil leaving the xtal exposed on top and attach a wire to the tin foil, then fix a stiff wire onto a sewing needle and attach the other ends as shown in the video. By probing around with the needle a sensitive spot can be found and stations heard. It works but is tricky. The old sets had an arm to adjust the spot and hold it there.
I like this kind of stuff. Thanks for showing it tsbrownie.
It was only later I made a crystal set after starting with a one valve kit, H.A.C, Hear All Continents aged 13. I later made mullti valve sets in my teens, moving onto transistors then i.c.'s. Got the amateur licence and made my own h.f. tx/rx. Took thing back a few years ago and made a one valve transmitter using a crystal.
Bill, G4GHB.
I remember reading somewhere the special wire was phosphor bronze and 'Wood's Metal' used to hold the crystal.
Bill, G4GHB.,
I looked it up. I wonder if just lead would work. Galena comes from around lead mines.
Bill.
I used galena on my first radio and it does work, but now I'm lazy and use the diode. It is less fussy! I should do a demo of it.
The old cub scout model that I first build had you cut a piece of 1/2 inch copper pipe to put a mount tab on the bottom and a set screw in the side. It worked.
@@tsbrownie Yes, that would be good to show, and how tricky it is.
Sandpaper for the enamel works best with some grit to it. Neat trick my father taught me
That's a clean radio ,well done ,now if someone could make a apartment crystal radio ,that would be cool for me ,I got all the parts ,except after seeing your video ,I no now I need to buy some brass washers and brass screws,and I going to buy heaver that's megneti c wire i think it works better and looks better too ,some of your ideas work for me ,I like soldering things together,when I can ,I no it makes a better connection.thanks for letting me barrow some of your ideas.
I Always Wondered what that Spool on the Wall was for.
Excellent, thank you for sharing your knowledge.
You are welcome.
Really enjoyed it, going make myself one and thank you.
@@hugominnee3678 Thank you. Let us know how it goes. I have a much newer video that is better.
ruclips.net/video/fLVCqZGpv3U/видео.html
to many complaints that it doesn't work. Morons! it does at 20:51 to 20:54 you didn't bother to wait till the end. no patience. i made one in 7th grade 1975. Thumbs up. i Like, OLE!
Anybody remember razor-blade radio receivers using a Blue Gillette blade? The device was shown in a 1950's Superman annual. I could also pick up "The Third Programme" transmitted by The BBC by clipping a pair of headphones to the hot and cold water pipes in the airing cupboard.
happy plucker I built one in the late 50s.
@@dwighthebert4052 First published in Superboy #6 (1950) ...
Mid to late '50's KIX cereal had them for I think two box tops & $.50 and they sent you in the mail. I remember it came with an alligator clip which all you had to do was ground it like the center screw of an outlet cover or the finger stop on rotary phones. The good ole daze!!!!! It was 2" long and like 3/4" square. Came with an ear piece.
You can dispense with the diode as they may be hard to find, you replace the Diod with a safety pin and a razor blade.
An important detail would be the value of the resistor. I'm guessing >2K ohm ?
@@kenschmidt6522 Details are in the description. I usually use 10k to 40k ohms.
I remember building one back in 60s only instead of a crystal we used a razor blade and peice of graphite pencil lead
I remember doing the same lead . . . . . empty toilet paper roll with about 120 turns of #24 bell wire with graphite from a pencil over the razor blade to tune !!!
I would like to see that. Have you built one recently or do you have a diagram?
I used a 1n34 crystal diode.
there are numerous detectors possible.
1n34, oa91, aa143, FO-215 or similar germanium diodes.
modern shottky diodes; 1n5711, HP5082-2835, HSMS281.
even some minerals form "diodes" with cats whisker (point of graphite, copper, silver), Galena (lead sulfite ore), iron-pyrite, magnetite, copper-pyrite, calcopyrite (peacock ore), zincsite, stenite...
Rusted nail, tarnished ccopper or silver, blued steel (gun barrel, razorblade...).
Here are more
crystalradio.net/minerals/index.shtml
www.crystal-radio.eu/endiodes.htm
As kid I made a razor blade detector with a sewing needle. It worked but was not dependable like a diode was that was about 1965 in Chesapeake, VA
This is amazing! I've been thinking about building a low cost v2 crystal radio, (I've built from a kit before v1), I'm going to build one from your demo, I'll post results..
Thank you!
Look forward to it.
That thing is really nice. Bomb proof.
They are tough and pretty much foolproof.
I want to help my 12 year old grandson how to make a crystal radio, I have a Philmore VC1000 that and uncle gave my when I was 10 years old (1966) we put it together and strung bell wire all over our 1 acre yard trying to make the best antenna I could. A neighbor gave me a two pieces of u channel aluminum one 6 feet tall the other 4 foot. I made cross with them and screwed them to a skinny Poplar tree in my back yard about7 feet off the ground and that became my antenna and it worked well. I sanded the aluminum and cleaned the copper 23 awg bell wire ran a screw around the wire and the aluminum and I spray painted it with enamel paint for corrosion protection.
In 1976 my parents moved from that home. In 2018 I visited the area where I grew up. The aluminum antenna parts were 60 feet in the air to my knowledge it is still there. Of course the bell wire is long gone. 😁🛫
This is the best of the easy designs. Let me know if you have questions.
I was wondering if you salvaged a Large capacitor off a board from say a washing machine were in the circut would it go to increase the out put?
Probably not. There's no issue in storing electricity, it's all a careful balancing act so overdoing one part won't help. BUT it never hurts to experiment. You may find you can receive other bands and such.
What gauge of wire, how long, what diode model, what value of capacitor (that you're missing, BTW), what value of resistor?
The details are in the description. The capacitor is not used with modern piezoelectric earphones. But you may need one if you have one of the models from mid 1900's and before.
Awesome. Very easy to understand this. You are the master explainer! I have a question about the coil used for tuning. Is it a variable capacitor or what manner of component is that? All good wishes.
+Anton Nym Thank you very much. That's a good question. Most people think of the coil as an inductor, but in fact it also has significant capacitance. In this model when you move the wiper you are making 2 changes: on the left you are changing the inductance / capacitance with the antenna, and on the right side you are changing the inductance / capacitance of the tank (resonant) circuit. For example: if you move the wiper to the left, the antenna side inductance and capacitance gets smaller, while on the right side (tank circuit) the inductance and capacitance increases.
Please Mr. If you don't mind i really appreciate your work and i really want to do it, but i need you to write the measures of the resistences and diods and the names of all elements so that i can look for them.
It is all in the description.
It worked well.
You picked up Radio India by the sounds of it.
LOL
how many wraps and why,, same goes with the other parts? Like to hear the science and math of why this would work.
The parts details are in the description. The how it works is found under "tank circuit" or "resonant circuit". There's lots of information on those already, so I won't repeat all that. The wiper divides the coil into 2 parts, the unused left side and the "radio" part on the right side where you are hearing the stations. By moving the wiper, you change the resonant frequency of the circuit filtering out all the undesired frequencies. It's a bit like moving a stethoscope around on a large, ringing bell and hearing the different pitches it rings at.
Everything fine with my radio except the reception. How do I receive signals from a distance 50-55 miles from the station, how long antenna do I need for that and, how should it be installed. There are two nearest Am radios nearby one is situated at 55 miles away from my house and the other 150 miles away from my house. Both of the stations can be tuned with crystal clear sound in my AM radio Transistor of Philips.
I have a video on antennas. How they are made, the length, and how they are orientated makes a lot of difference, especially for weaker stations. ruclips.net/video/G8AsgZbncW4/видео.html
It is awesome!! Thanks for showing how to make a simple radio.
When I was just a wee lad, we made crystal radios, but it seems to me that we actually used a crystal then a brass pin to connect to touch the crystal. But basically the same way.
This is a modified version that was in my Wolf Scout handbook. (They had a mistake in the drawing that kept it from working!) We used a piece of galena (lead ore) and a brass safety pin as well. The diode is much more reliable and gives a clearer output.
Very nice.I don't think Radio Shack has sold germanium diodes for many years though. You can make your own detectors that work well, or buy the germanium diodes online though.
+Rob T You are probably right. I bought boxes of stock from a couple that were going out of business for a few bucks a box!
Use a 1N34 - it's commonly available and it's germanium. Better yet, after you build this, work your way up to a regenerative receiver. They are simple and sensitive, and there's a bunch of reasonably priced kits around.
I have been able to get them on ebay and jameco electronics. A schottky might work, too. Those are everywhere.
A bit of zinc, heated red hot and left to cool so that it oxidizes on its surface, makes an excellent detector in light contact with lead or copper wire. Very nearly as good as the old factory made germanium diodes...but you have to search for the sensitive spots. Steel that has been turned to a bluish surface by heating (and allowing to cool) also works well in light contact with a little piece of copper wire.
built one of these as a kid in the 60s. Toilet paper roll, wire wrap, crystal, diode, and the earpiece
Me too. This is just an updated version of what was in the Wolf Scout handbook.
I imagine that the glue might also cause a short by insulating the wire so that no signal can be heard too. I’d be afraid to use glue for that reason too.
You have to sand off the enamel and the glue comes off also.
Great memories come back after I saw your video, thank you so much. I have a question, I used a Galena crystal when I was a little boy, I can't remember if the galena rock goes where the diode is on yours, or do I need both?
56 years ago when I built my first I also used galena. As you know it requires searching around on the galena to find a good spot. It would replace the diode. Thank you for watching and for your comment.
Thank you, thank you
Hello my name is Tom Murphy i am 61 years old and know very little of volts or amps ie Imust say i really enjoy how you break the build down very good ! one thing i have a question on is resistor i got some that amazon said who work my question is this how what does a resistor due and i notice you can get a station with out them how can i tell if they are working , my next question how to drop var cap into a radio love your info god bless tom
Hi Tom, we're about the same age. Electricity acts a bit like water in a pipe. A resistor acts like a constriction in a pipe; it introduces "friction". The resistor is needed to funnel some (but not too much) electricity around the earpiece. For a variable cap radio I have a different design here:
ruclips.net/video/AaNpFYe5dSo/видео.html
It will work for the foreseeable future. With MW stations moving off and others just going dark MW probably won’t be around in the next 40 years.
Love the bike spoke wiper.
Dump the resistor. Short it out! No idea where he got that idea!
Connect a .001 Capacitor...or condenser (any style) between the earpiece end of the diode and earth/ground.
That takes the radio waves out of the system, when you've finished with them.
After the diode, you HAVE finished with them
+MauriatOttolink These new "crystal earphones" are not like the old day types, these are piezoelectric and the resistor is needed. In fact the earphone has lots of capacitance so the capacitor is no longer needed. I built it from my old wolf scout handbook and it did not work well at all. Made the "modern" changes to account for the piezoelectric earphone and sound jumped out of it. They taught this old dog a new trick.
tsbrownie Thank you..It looks like you just taught this even older dog a new trick.
Woof!
Thank you.
We old dogs gotta look out for each other! ;)
@@MauriatOttolink This is what I like to see and rarely see nowadays - "It looks like you just taught this even older dog a new trick". In todays world we rarely see this, especially on RUclips - everyone wants to argue and antagonize everyone else.
Good on you. (I also am an older dog)
@@chumleye1112
Wow...3 years ago...I'd quite forgotten.
I put it in non tech terms as Xtal sets are usually built by complete beginners In fact the capacitor is an RF decoupler although I believe that it's not required when using Hi Z crystal ear pieces but a high Ω resistor IS
required to complete the D.C. path.
Using high Z moving-iron phones, the audio really does increase when the rf decoupler is connected.
Thank you for your message.
Did I miss it? What kind of resistor is it? I can't see the lines...(even if I do, don't know how to read them)...:)
Did not see your comment from so long ago! It's a 10k ohm resistor. Specs are in the description.
Very easy to follow! But I don't remember if you mentioned it needs a "germanium diode". If you did I missed it. Either way, this is a very good video! Your explanations and methods are very nicely done! thanks!
Thank you. Yes, I always emphasize it has to be a 1n34a. Also say it in the description. Lots of people write and ask and I emphatically emphasize it MUST be that diode!
Thanks! i figured I just missed it. You did a great job!
Damn those coil wrapping skills!!!
I'm working on a new one that has only 32 turns. It's a lot easier!
What's the radio shack part number for the diode? Is it germanium or some non-silicon based diode? Also I guess the self-capacitance of the coil and circuit is enough to work for the tuning. I have seen other schematics for this sort of rig and they have separate tunable caps. Very nice video! I enjoyed it.
TechnoW1zard Thanks for the compliment. The diode is a 1N34A. RS 276-1123 but I would not use RS unless I really had to. You can get the 1n34A from Amazon. I've also heard second hand (but never tried them) ECG109 (Sylvania) and SK3090 (RCA) will work. The boy scout manual lists a home made capacitor and we made 2 and tried them in the circuit (along with factory made ones) and in this circuit we can't hear a difference. I'd guess there's a significant capacitance in the coil and come to think of it I might be able to measure it indirectly. A rainy day project!
A 'Macgyver' radio, always useful!!
Thanks for a great video with excellent commentary and clear enunciation.
Q: Where is the capacitor that is needed to form the resonant circuit? In other words, what gives the C of the required LC to get the necessary resonance?
Thanks.
Thanks.
A: Components from wire to transistors to coils to caps have all the properties of resistance, inductance and capacitance. Most of the time you can ignore the less significant ones, but in this case not. The coil has both inductance and capacitance in significant amounts. The AC in the windings (wires separated by insulation) acts as capacitance. It's not a lot, but enough.
@@tsbrownie Thanks for the clarification. It was a good learning experience.
Exceptional video. Simple to understand, clear and concise explanation. Thanks for taking the time :O)
+sandpiper9988 Thank you!
Is there a way to make this crystal radio shortwave?
Theoretically you can receive any AM band given the right coil. The limitation is in distance - most cities have AM commercial stations relatively close by, so it works. It will not pick up lower power stations or stations really far away, so you will not get BBC in the US. But if you were near the BBC AM station, then given the right coil, it should work.
this is great! i am going to build one just like yours. Could you also in your next video put another presentation with a 10watts amplifier, even if it is two or multiple stages will do. I want to build this with two stage mono or stereo amplifier with 10 watts of power max. Thank you for the video.
it seems like with that big coil you will be able to get long wave also your design is best big size simple wiring I will build this one first then experiment with other things can various crystals be used to change the frequency. thanks
The AM band covers roughly 500KHz to 1.6MHz, but that varies a lot with how a radio is actually built: number of turns, size of wire, etc. The details for this one are in the desc.
You can limit your soldering by using a 16 gauge metal ring terminal squeezed on the end of
the 16 gauge wire "wiper" rod, then use a wire to the ground and one to the diode. :)
Good idea.
Built one of these from a kit when I was about nine years old very handy knowledge to have.Do you have the values on the resistor and diode or doesn't it make a difference?
Sorry, I missed your comment. All the values are in the description.
@@tsbrownie Thanks ,found it later,my bad.
I had one in the early 1960’s. I think it was something I got off of the back of a cereal box. I’d listen to Cincinnati Reds and Royals games on WLW at night.
Don't tell my mom, but I used to do the same, but it was Chicago. Do you mean the KC Athletics? ;)
@@tsbrownie no. The Cincinnati Royals was an NBA team. Oscar Robertson was their point guard before they traded him to Milwaukee.
Any particular diode and any particular resistor?
The details are all in the description. There are diodes that work much better than others, like the 1n34a and the D9K.
Hi, please excuse me if this has been asked before; what does the resistor do? I’ve built crystal radios that don’t use a resistor. Thank you for posting.
tsbrownie
The resistor discharges the capacitance of the earpiece. Without it you get little sound and will hear a popping. I did not believe that the resistor would make much difference (my boy scout radio I used a "real" crystal earphone and not an piezoelectric modern one and it behaved differently) so I tried this new earpiece without the resistor and the volume was very low.
It’s been a while since you made this. I had a few questions mainly about the variables. To start, what would the effect be if you used a smaller gauge wire? Secondly, does the high amount of turns of coils mean you have more frequencies that you can visit or does it allow certain frequencies to expand over more of the wire? Lastly (for now), I read in a comment from a few years back you said the diameter of the coil affects the amount of frequencies allowed. I was hoping you could elaborate on that. And on that same comment you said most AM channels. What would need to be done to higher the frequency to FM? Sorry if I’m asking too much, I’m self taught in all this by research and reading and quite interested
The questions about wire gauge and coil size can be seen best (and most fun) by playing with the apps in this video:
ruclips.net/video/Fw9eb-aB-XU/видео.html
The wire diameter changes the turns per distance which changes the inductance which changes the resonant frequency.
Ditto the more turns.
The size (all measurements) of the coil changes the inductance. Again, the apps will show you that. It's a lot of fun to play with. Check the description in this video for the basic parameters you can use as a starting point.
Not getting anything in the earpiece. What is the significance of the diameter of the bottle, you use to wrap the wire. I used a smaller bottle with only 40 rounds. Should I use a bigger(in diameter) and longer bottle to be able to coil around more wire ?
+Anurag A. 40 turns is rather few, but you should get something. The usual problems (in order): 1) did you use the correct type of earphone. ONLY a crystal earphone will work. 2) did you take the enamel paint off the wire where there are connections? On each end of the wire and where the wiper touches the coil. 3) Do you have AM stations in your area? (This is a problem in India where they don't have many). I just made another, different style yesterday and even before it was completely done I could get 1 station!
+tsbrownie I'm in US about 100 miles N of DC. I got the crystal earphones(Philmore Crystal earphone high impedance n. 748 Japan) from amazon exactly like yours. the only suspect is the antenna now. I connected a roughly 15 ft magnetic wire(same wire I used to coil around the bottle) to a satellite dish outside my house. For a very short period this morning I heard a KRRRRRRRRRRR..., but that also went away quickly. Now it is absolutely blank.
The antenna wire can not touch anything metal. You can use string or plastic or such to tie it up. Make sure the enamel paint is off he end that connects to the radio. Is your diode a 1n34a? Other diodes won't work. If you can, make a close up video of what you have, post it and I can look at it.
+Anurag A. From your video: Your windings look OK. You used just 1 set of windings, yes?
The earphone looks like the right one. I can not clearly see the diode or resistor, I will assume the values are OK. The big problem I see is the wiring. I do not think that is right. The circuit is a big "U". One the right side of the "U" at the top is the antenna coming in. Then the coil. The bottom of the "U" is the resistor with the earphone across the resistor. The left side of the "U" is the diode and above the diode is the wiper (or jumper in your case) and at the top of the left side is the ground.
To test your diode and antenna you can put the antenna on one side (does not matter which) and the ground on the other. Put the earphone across the diode (no resistor, just diode and earphone). You should hear the loudest station (no tuning obviously).
The antenna can not be in contact with metal or be inside or under a metal roof or similar.
Final comment on wire: you must be very careful to remove all the enamel (green) coating all the way around the wire. Also some of your connections look loose. The currents you are working with are very, very tiny. Small resistances add up and will kill the signal. Make sure the connections are tight / strong. If you are using steel screws or plated screws they may have oxide and/or not connect well. I strongly recommend stainless or brass screws and washers. If you can solder connections that is best (requires brass, stainless won't solder with normal solder). Use only rosin core solder (not acid).
It appears you have all the right parts, it's a matter of connecting them well and in the right sequence.
For all the crystal radios that I've made over the years, I never tried using a 4 germanium diode bridge for full-wave rectification. That should give double the output. That would have be insane back when diodes were expensive, but I have dozens in a parts drawer.
+Felix Automaton Interesting idea. Will have to put that on my list of things to try! Thanks.
My question is where is the negative side of diode to be place direction?
This is a very rare case where diode direction does not matter.
La de da! still amazing how this old tech works.
I just built my first example of this radio. I used 22 gauge wire on a 2 inch PVC pipe. I used some magnet wire for an antenna and I was getting some static and popping. This was before the 10k resistor came in. After I put the resistor on and bought some 8 gauge wire 16 feet long for an antenna I got nothing at all. My tuns with the 22 wire was 128. The magnet wire was a bit over your your specs. I used the exact resistor and diode you have in the spec. I refurbish fans so I am aware of magnet wire for choke coils and the like. I used a OHMs meter to test continuity and its fine. If I can use the Magnet 22 G magnet wire I may get the bigger pipe in your specs. But my turns were short compared to yours. My wiper is Brass and its about 6 gauge stiff brass. I also used a spring on the base of the wiper to keep pressure on the wiper. Any guidance would be appreciated. Thanks for the videos.
I have a video just for you. Since you already work with wire, some of it will be a repeat. ruclips.net/video/kCxQ8iPQx4s/видео.html
I don't think you need a total redo, it sounds like you're almost there. If you have a station within 10 miles, you should be getting something. You did not mention your earphone, is it the same? Other types won't work. What's the number on your diode? What are you using for a ground? Also how are you making connection to the wiper? If you can post a video of your device, leave a link here and I'll look at it.
@@tsbrownie I watched that already. There are a couple of things that may be the issue. What I will do is make a video of the radio I made and you can tell me if anything looks wrong.
@@jaybabcock4557 OK, let me know.
Great instructional vid. Thanks for sharing.
Thank you. This is the new and updated version.
ruclips.net/video/fLVCqZGpv3U/видео.htmlsi=iXN2sxawUr4UdWn4
I haven't seen a crystal radio where the ground wire is attached to the tuning rod before. Which way works best , antenna attached to the base of the tuning coil and earth attached to the tuning rod, or the antenna attached to the tuning rod and the earth attached to the base of the coil.
+woodcoast50 Excellent question. I have 1 more design where there are a couple subtle differences and I plan to build that and test them side by side. This design is from the Wolf Scout handbook from when I was a kid, I had built it before and knew it would work. Odd that so many years later i remembered there was an error in their drawing and there was 1 wire too many. I guess we remember a lot more about what we learn as kids than we think.
What sense does a recipient make. the one without electricity, works when you need an amplifier?
No amplifier is needed. No electricity is needed.
@@tsbrownie No. I built such receivers in my youth, and it doesn't work that simple. The output power is not enough for such an ordinary earphone. If so, it only works with a high-resistance part such as an earpiece on the phone. And even then you can only hear the station that is closest to your own location. The selection and filtering of such a device is far too weak and imprecise
It's missing a capacitor across the coil but it still works??
In the old days with real crystal earphones they needed a capacitor. But the piezo electric earphones already have (too much) capacitance. Adding more causes problems.
TSBrowinie...I thought antennas needed their own ground, like an outdoor tv antenna. I know the set is grounded because it’s needed to make it function, but what about for real grounding purposes?
Ie: when the set is brought inside, the antenna is left out there all alone without the set/ground, what happens when struck by lightning?
If set is 24/7 hooked to antenna and always indoors, even if grounded, aren’t you inviting the strike to come inside the house and go thru our internal ground system? Thanks
Not sure what you mean by "real grounding purposes." To get the max signal for a radio/TV, you typically need to have the signal pass from antenna through the device to a ground. SOMETIMES with crystal radios the ground is actually a hindrance. Not sure why, I just know from experience. The signals are very weak and just having objects nearby can influence the quality of the signal - hands, body, table, appliances, ... so the tiny signals may be going to "ground" just by dissipating in the radio or its surroundings. Too much ground in these circumstances changes the "tuning" such that it does not work as well. Just a guess.
I don't understand your "IE: when the set is brought inside..." If all the antenna wire is outside, if lightning strikes the wire, the lighting will not have an artificially supplied path into the house.
"If set is 24/7 hooked to antenna...." Yes, having the wire inside the house can channel a strike into the house. Lightning does not need you to supply a ground, it will find one by itself. It travels kilometers though the air, if it hits your antenna and travels along it, the strike will have no trouble emerging from the wire and continuing on by itself. If the wire is all outside, the lightning will not have a human supplied path into the house. This is why I say that I deal with lightning suppression by putting ALL of the wire outside the house and lay the end on the ground (or tied to a ground rod) when I am not using the radio or when there's a storm any where near. If lightning strikes the antenna, it will be destroyed, however you will not be giving the lightning a path inside.
Hi again. As you may have surmised, I know nothing of the topic, but I do have a home built crystal set I’d like to hook up
Clarification, the antenna remains in a 50 ft straight line from post to post at all times, even when unused.
From there I pigtail a dangling outside wire that I hook from one end of antenna into my Antenna terminal on the radio when in use.
All other times I unhook it & toss it out the window where it either: rests on the earth; or I tie it to a ground rod Right?
Can the rod serve as having 2 purposes... it’d be a single point of contact to have 2 wires: one going to the grounding terminal on the radio and the other wire goes to the suspended antenna
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No variable tuning cap? I would think a simple slider foil variable cap would increase selectivity. A lot of the Xtal sets use a 150 or 240 micro Henry coil with a 365pf variable cap for tuning. creates an oscillating tank circuit to select the carrier frequency and squelch other frequencies as I understand. Not to be confused with the cap that sometimes is use for the earpiece.
I thought the same. I saw the same in many diagrams on the internet, but no one actually made one. So I did. It did not work. It got 1 station well, a weak second one. A germanium diode by itself will get 1 station! (I made videos on both of these.) I've been looking at transistor radios that use a 365 var cap, and they use a few very small coils BUT they also use part of the ferrite antenna in the turning circuit. Don't have it totally figured out yet, need to spend some more time with it. ruclips.net/video/i2PITPUg2vI/видео.html
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The Antenna supplies the necessary capacitance, and the variable inductance tunes the two together. This is how the earliest sets worked before tuning caps were available. But you do need a big antenna and an Earth.