My first crystal radio was the Science Fair model from Radio Shack in the mid 70's and it had long and a short antenna connection. I could only pick up one station with it but I was still impressed as a kid. This 2020 year I have been doing vintage tube radios and decided to play with crystal radios again and built two types and was disappointed in both of them, and then I stumbled across your circuit and it works great. Thank you for your informative videos.
@@MIKROWAVE1I also built an Antenna Loading Coil from your video and it works very well for me because I only have an 50 foot antenna in my attic. I also played with your diode bias circuit and that very interesting also. I will build the regen types in your videos and that should be fun to do this year. Thanks for your great content
I've built this radio and I'm pretty impressed with its performance and simplicity. It's a great tool for experimentation and for learning RF. I made a small change at the coil taps: I divided down each tap from the previous tap by sqrt(2) (~1.414), so the taps are roughly at 88, 63, 44, 31, 22, 16 turns, getting denser at the bottom end. Since the voltage is sqrt(2) lower with each lower stage, the impedance of each tap is exactly the half of the previous tap; this makes impedance matching a bit easier at the bottom end of the coil.
This is a really excellent video! Back in the day, it was a LOT harder to find parts. Most you could make, (any one remember making your own "condensers" -or detectors out of galina, lead crystals, razor blades, oxidized copper -etc?) but the headphones were a big problem. I got some from Lafayette and it took 3 weeks to get them! Now, thanks to the internet, you can get anything you need quickly, easily and relatively cheaply.
For receiving, many folks use #14 stranded or solid copper wire from the hardware store. Copper coated steel wire called "copperclad" can be much thinner like # 20. Bare is OK as long as you use insulators. # 18 "lampcord" would stay up a while but would eventually break.
another great video - I have reticently built some xtal radios and they are tons of fun and lots learning involved - I few comments about them a) It might be better to skip the effort of locating a 2000-5000 ohm headphone and use a Bogen T-725 transformer with modern 16-32 ohm MP3 player headphones - some of them are fairly sensitive for the price. T-725s are found on Ebay for less than 10 dollars. The best coil form I have found is at home depot -4" polystyrene couplers can be had 1.60 USD apiece, they are easy to wind and they have better Q than PVC, cardboard or wood. Lastly got to plug Peter Friedrich's excellent book - Voice of the Crystal - a veritable modern day Morgan!
Found a pair of Baldwin's. In a junk yard. In arcadia ohio. And will not part with come rain or shine and PS I was given by a elmer a radio made 1921. Slider. carried it through my tenure in army and got wjr in fort Hood Texas. It will be 98 years this year. Every fall I listen to foot ball/base ball games. 72/73. De kv4li.
I used to love a certain station in Los Angeles. About 1200 miles away from where I was in Spokane Washington. I could receive it quite easily on the tube based radio in our Volkswagen van. I tried in vain to get the station on any of the radios in our house. Almost all of them were the post tube era radios. I finally found a 1940's era tabletop radio. Then if it was turned in a certain direction. Would receive the LA station. And later, I got a 6 volt Volkswagen radio from a guy who was upgrading to 12 volt. It would also receive the LA station. This was of course during night time hours. During the time I was probably their most long DX fan. I also won two giveaways. Unfortunately one was concert tickets I could not make good on.
In 1979 I interviewed at Motorola for a co-op job in their Arcade NY automotive electronics plant . Girls on the line were building car radios and in back guys were grinding parts for Volkswagen Alternators.
just watchin all vids. after finding your channel.. if you come across this a few vid hints if ok .. 1st. leave text on screen a lil longer. please. i have to puase to read them some.. 2nd. leave images up just a hair longer also and go head talk thru the images. not puasing ur own audio.. above that i think you would have some double killer vids. they are awsome so far tho for sure ty ..
Thank you. I am looking forward to building a clone of yours. Can the antenna have insulation or must it be bare; also does gauge matter? I would suspect 130' strung in the air will need to be thick enough to support it's own weight in the wind, ice and or birds?
A 2 Gang Variable. www.ebay.com/itm/Dual-Gangs-Air-Dielectric-Variable-Capacitor-365X2pf-Crystal-Radio-Ham/164218995441?hash=item263c3702f1:g:U30AAOSwCi5ezDYc
witam i pozdrawiam/podobaja sie Twoje filmy,poprosze o wiencej tego typu filmy/ps;jak zrobic najprowszy odbiornik krotkofalowy na pasmo 80,40...{lampowy}.pozdrawiam....
I'm a little late to the party, but for anyone who might be asking the same question there is a good spot for a screenshot at 19:12 Has all the ratios and tapping points.
@@Inertia888 That data is useless without specifying the copper wire thickness(es) for both coils. Just re-watched to see if I missed them, but he just says everything works between #20-#30 wire.
This was interesting to watch. I've got loads of crystals and was really hoping to see actual crystals used to pick up radio signals.....aren't real crystals used in radio making? I'm a total novice at making anything like this so I'm wondering where the crystals fit in to crystal radio sets? 😎👍
Well kind of. Crystals in the sense that you are talking about, are natural minerals with semiconductive surfaces that can be used to make a crystal diode. This is called a Cat's Whisker Detector. Later, ordinary manufactured Germanium Diodes also began to be called Crystal Diodes. Quartz Crystals are a completely different beast. These are used to establish a single stable frequency in an oscillator such as the crystal in your watch that keeps time or the crystal i your computer or in your cellphone.
The easiest method is to form a loop of about 6 inches where you want the tap. Then twist it until it meets the coil again forming a twisted lead of enamel wire. Then keep winding to the next tap and repeat. When you are done and the two ends are secure, go back and twist each to tidy up and tighten the coil. Finally, scrape and tin the wire right at the coil and on the ends. I will put a picture in my FB page. facebook.com/Mikrowave1/?modal=admin_todo_tour
Well 50Ft will work if it is installed in a good clear area and you have reasonably close AM stations. A small slider type loading coil would help a lot. There is no law that says you can not add more wire to the far end or maybe better, the the down lead end of your kit either, if you are concerned about appearances!
I can use the top of my garage,but that would only be about 50 feet or so. Would that be acceptable? I haven't the room for anything bigger land lord won't allow it. Had to sweet talk him just to use the garage....
Yes it is. The first order of business is to be able to bleed off static build up. A lightning arrester does this. Removing the rig from the antenna lead and grounding the coax is the only real lightning protection. And of course all bets are off with a direct hit.
Headphones are better than earpiece. Why? Earpiece seems a lot less expensive, much easier to find - it's not like you're getting stereo output. I'm not saying you're wrong I just don't care for assertions without reasons.
Crystal earpieces are high impedance and sensitive. A pair (not one) could be hooked up in phase to produce an excellent approach to the headset problem. My promotion of magnetic phones is purely nostalgic.
@@MIKROWAVE1 Thanks for the reply. Can you help me to understand something? High impedance. Crystal radios, working with no external power source, I would think you're talking about very low voltages, so why on earth are high impedance listening devices a good match? I'm picturing myself trying to go up a steep hill on a bicycle. I'd be wishing for a smaller impediment. Obviously I don't understand this concept well. Also, on a related note, I often see a small resistor between the headphone or earpiece terminals, what is that for?
Развлечения
My first crystal radio was the Science Fair model from Radio Shack in the mid 70's and it had long and a short antenna connection. I could only pick up one station with it but I was still impressed as a kid. This 2020 year I have been doing vintage tube radios and decided to play with crystal radios again and built two types and was disappointed in both of them, and then I stumbled across your circuit and it works great. Thank you for your informative videos.
You must do a regen next!
@@MIKROWAVE1I also built an Antenna Loading Coil from your video and it works very well for me because I only have an 50 foot antenna in my attic. I also played with your diode bias circuit and that very interesting also. I will build the regen types in your videos and that should be fun to do this year. Thanks for your great content
Clearly explained and gives the confidence to have a go. I'm collecting parts already! Thanks.
Another new fan to your channel and this series.
Thanks for watching and good luck on your radio build!
I've built this radio and I'm pretty impressed with its performance and simplicity. It's a great tool for experimentation and for learning RF.
I made a small change at the coil taps: I divided down each tap from the previous tap by sqrt(2) (~1.414), so the taps are roughly at 88, 63, 44, 31, 22, 16 turns, getting denser at the bottom end. Since the voltage is sqrt(2) lower with each lower stage, the impedance of each tap is exactly the half of the previous tap; this makes impedance matching a bit easier at the bottom end of the coil.
Nice! And your tap method makes sense.
Thanks for the great video! Looking to have a few winter projects with the kids was thinking some radio circuits would be great.
Outstanding Job on both the video and workmanship !
This is a really excellent video! Back in the day, it was a LOT harder to find parts. Most you could make, (any one remember making your own "condensers" -or detectors out of galina, lead crystals, razor blades, oxidized copper -etc?) but the headphones were a big problem. I got some from Lafayette and it took 3 weeks to get them! Now, thanks to the internet, you can get anything you need quickly, easily and relatively cheaply.
This is my favorite video, so full of great useful information, thank you!!
Nice sir
This is a great explanatory video
I love it! Thanks.
Great great videos. Thank you :)
Very inspirational.
I Do Not Why, But I Adore This Crystal Radio Topic!
I need to get back to some kids projects pronto!
For receiving, many folks use #14 stranded or solid copper wire from the hardware store. Copper coated steel wire called "copperclad" can be much thinner like # 20. Bare is OK as long as you use insulators. # 18 "lampcord" would stay up a while but would eventually break.
Thank you.🌟👍🏻🌟
another great video - I have reticently built some xtal radios and they are tons of fun and lots learning involved - I few comments about them a) It might be better to skip the effort of locating a 2000-5000 ohm headphone and use a Bogen T-725 transformer with modern 16-32 ohm MP3 player headphones - some of them are fairly sensitive for the price. T-725s are found on Ebay for less than 10 dollars. The best coil form I have found is at home depot -4" polystyrene couplers can be had 1.60 USD apiece, they are easy to wind and they have better Q than PVC, cardboard or wood. Lastly got to plug Peter Friedrich's excellent book - Voice of the Crystal - a veritable modern day Morgan!
Great post thanks!
Thanks 👍🏻
Found a pair of Baldwin's. In a junk yard. In arcadia ohio. And will not part with come rain or shine and PS I was given by a elmer a radio made 1921. Slider. carried it through my tenure in army and got wjr in fort Hood Texas. It will be 98 years this year. Every fall I listen to foot ball/base ball games. 72/73. De kv4li.
Fantastic find!
I used to love a certain station in Los Angeles. About 1200 miles away from where I was in Spokane Washington. I could receive it quite easily on the tube based radio in our Volkswagen van. I tried in vain to get the station on any of the radios in our house. Almost all of them were the post tube era radios. I finally found a 1940's era tabletop radio. Then if it was turned in a certain direction. Would receive the LA station. And later, I got a 6 volt Volkswagen radio from a guy who was upgrading to 12 volt. It would also receive the LA station. This was of course during night time hours. During the time I was probably their most long DX fan. I also won two giveaways. Unfortunately one was concert tickets I could not make good on.
In 1979 I interviewed at Motorola for a co-op job in their Arcade NY automotive electronics plant . Girls on the line were building car radios and in back guys were grinding parts for Volkswagen Alternators.
just watchin all vids. after finding your channel.. if you come across this a few vid hints if ok .. 1st. leave text on screen a lil longer. please. i have to puase to read them some.. 2nd. leave images up just a hair longer also and go head talk thru the images. not puasing ur own audio.. above that i think you would have some double killer vids. they are awsome so far tho for sure ty ..
Thank you. I am looking forward to building a clone of yours.
Can the antenna have insulation or must it be bare; also does gauge matter? I would suspect 130' strung in the air will need to be thick enough to support it's own weight in the wind, ice and or birds?
You should add a secondary tube amp to make the set look like it is from the '20s.
Sir I wanted make a redio withe vacuum tube you helped me sir
Muito top em parabéns Maravilhoso
Muito apreciado e obrigado por assistir meus viseos!
A 2 Gang Variable. www.ebay.com/itm/Dual-Gangs-Air-Dielectric-Variable-Capacitor-365X2pf-Crystal-Radio-Ham/164218995441?hash=item263c3702f1:g:U30AAOSwCi5ezDYc
If made a little paperback with the specs ,I for one would buy it,say 6 bucks or so.8 pages or so ,easily mailable.
witam i pozdrawiam/podobaja sie Twoje filmy,poprosze o wiencej tego typu filmy/ps;jak zrobic najprowszy odbiornik krotkofalowy na pasmo 80,40...{lampowy}.pozdrawiam....
Thanks for the video, very well done. How many turns for L1 and L2? I'd like to build the set.
I'm a little late to the party, but for anyone who might be asking the same question there is a good spot for a screenshot at 19:12
Has all the ratios and tapping points.
@@Inertia888 That data is useless without specifying the copper wire thickness(es) for both coils. Just re-watched to see if I missed them, but he just says everything works between #20-#30 wire.
This was interesting to watch. I've got loads of crystals and was really hoping to see actual crystals used to pick up radio signals.....aren't real crystals used in radio making? I'm a total novice at making anything like this so I'm wondering where the crystals fit in to crystal radio sets? 😎👍
Well kind of. Crystals in the sense that you are talking about, are natural minerals with semiconductive surfaces that can be used to make a crystal diode. This is called a Cat's Whisker Detector. Later, ordinary manufactured Germanium Diodes also began to be called Crystal Diodes. Quartz Crystals are a completely different beast. These are used to establish a single stable frequency in an oscillator such as the crystal in your watch that keeps time or the crystal i your computer or in your cellphone.
How are the taps on the round wood connected to the coil itself?
The easiest method is to form a loop of about 6 inches where you want the tap. Then twist it until it meets the coil again forming a twisted lead of enamel wire. Then keep winding to the next tap and repeat. When you are done and the two ends are secure, go back and twist each to tidy up and tighten the coil. Finally, scrape and tin the wire right at the coil and on the ends. I will put a picture in my FB page. facebook.com/Mikrowave1/?modal=admin_todo_tour
I have a 50 foot antenna kit coming, would that be sufficient?
Well 50Ft will work if it is installed in a good clear area and you have reasonably close AM stations. A small slider type loading coil would help a lot. There is no law that says you can not add more wire to the far end or maybe better, the the down lead end of your kit either, if you are concerned about appearances!
I can use the top of my garage,but that would only be about 50 feet or so. Would that be acceptable? I haven't the room for anything bigger land lord won't allow it. Had to sweet talk him just to use the garage....
Sure 50 feet (and a loading coil for best results) will work for many stations.
Is Lightning a danger with an outside antenna wire?
Yes it is. The first order of business is to be able to bleed off static build up. A lightning arrester does this. Removing the rig from the antenna lead and grounding the coax is the only real lightning protection. And of course all bets are off with a direct hit.
I like yora behaviour
I wish my wife liked my behavior more. Thanks for watching!
I'm From ceylon
@@MIKROWAVE1 have nice day for you.
But what about the bodies ??
are you a ham ?
Headphones are better than earpiece. Why? Earpiece seems a lot less expensive, much easier to find - it's not like you're getting stereo output. I'm not saying you're wrong I just don't care for assertions without reasons.
Crystal earpieces are high impedance and sensitive. A pair (not one) could be hooked up in phase to produce an excellent approach to the headset problem. My promotion of magnetic phones is purely nostalgic.
@@MIKROWAVE1 Thanks for the reply. Can you help me to understand something? High impedance. Crystal radios, working with no external power source, I would think you're talking about very low voltages, so why on earth are high impedance listening devices a good match? I'm picturing myself trying to go up a steep hill on a bicycle. I'd be wishing for a smaller impediment. Obviously I don't understand this concept well. Also, on a related note, I often see a small resistor between the headphone or earpiece terminals, what is that for?