A very well done presentation. Thank you. I now live about 40 miles from NIST station WWVB, but when I lived in MI I built a 3' diameter Styrofoam coil form that I wound with 35 lbs of 8 gauge copper wire coupled with a very large air-variable capacitor to act as a high Q antenna for WWVB. To reduce noise, I put the coil in a basement that lacked electrical wiring. It received WWVB beautifully. Extremely high Q resonant circuits are an almost magical thing, as Nick Tesla learned many years ago.
This is also what most seem too not check out, my first crystal set worked but not well at all with the 2 kohm Brandes matched tones I got. I skipped the most important part really, I didn’t even shot for the highest Q I could have gotten just went for it. It works with a high gain amplifier so I was happy with just that! Soon I plan to push for High Q
VERY nicely done presentation.... 50+ years ago I could have fun with some crystal set DXing. The local station on 1060 went off at sunset. Eventually two other stations came on the air and run 24/7 except for Sunday at midnight once a month. My house is 0.9 and 1.6 miles between 4 & 5 KW stations on 1060 and 1190.... Tried dual traps and a few other things, but the stations still are deal killers.... Consider yourself lucky.... For those in a more RF friendly environment that have never given crystal set building a try and then graduate to higher performance, I can testify that it can be a fun challenge....
Crystal radio was a right of passage. When I got to my army classes. I got as sack w/ parts. Radio So as i waited for the classes. I was to assemble this kit. And be creative. So as I advanced to microwave and multiplex modes I grew out of my kit. But it taught me about soldering, coil winding, and antenna math. A good return for students. Still have one around and at ft hood Texas I got wjr Detroit Michigan and listened to several foot ball games over the years tks om good show. odn-1
Hello! I achieved the best sensitivity - when I used a RF mosfet, for example BF998 as a synchronous detector. A gate was connected to "hot" wire of coil (antenna), a drain to 1/4-1/5 part of windings. A drain connected to RF block capacitor 0.02micro Farads, and to 250Ohm earphone - through an electrolytic capacitor.
Grounding through a water pipe was much more reliable back in the day. Now even if the house has metal pipes, the supply up to the house might be PVC or pex.
I've been doing some research on the Selectivity Enhancement Circuit (SEC) mentioned in this video. On this page: www.theradioboard.com/rb/viewtopic.php?t=2989 Dave from "Dave's Crystal Radio" mentions that the 27mH value is not critical. On this page www.hobbytech.com/Practical%20Tips%20for%20Crystal%20Radios.htm Jim suggests a 10mH-27mH choke, and on this page www.hobbytech.com/crystalradio/crystalradio.htm he mentions it should be between 7.5mH - 10mH for maximum performance at the low end of the band. Have you found that 27mH is the ideal value for the choke?
The 27mH value is not critical. You should be able to use anywhere from 10mH to 47mH. Shortwave chokes such as 2.5mH are not suitable at broadcast band frequencies.
@@baikushex0et682 Thanks for the nice comment. My radio websites might not be gone forever. I don't want to be involved in the. hosting of websites anymore. If someone offered to host the sites, I would be interested in uploading them.
I remember crystal radio my friend and I used to build a radio i love to listen to it back in my days when i was younger back in my early 40s😊
Thanks for the video. It reminds me the hours of fun listening to self built receivers when I was a teen and, why not, builing a crystal set again!
Für diesen wertvollen Filmbeitrag vergeben wir von maximal 10 erreichbaren Bewertungspunkten: 10. Sehr geeignet für Bildungseinrichtungen.
Mr Day, this video was exceptional and demystified crystal radio systems very well. It has inspired me to build one myself
Only at 11 min and loving this enough to share! Thank you so much for your time and love for XTAL RF. :)
A very well done presentation. Thank you.
I now live about 40 miles from NIST station WWVB, but when I lived in MI I built a 3' diameter Styrofoam coil form that I wound with 35 lbs of 8 gauge copper wire coupled with a very large air-variable capacitor to act as a high Q antenna for WWVB. To reduce noise, I put the coil in a basement that lacked electrical wiring. It received WWVB beautifully. Extremely high Q resonant circuits are an almost magical thing, as Nick Tesla learned many years ago.
This is also what most seem too not check out, my first crystal set worked but not well at all with the 2 kohm Brandes matched tones I got. I skipped the most important part really, I didn’t even shot for the highest Q I could have gotten just went for it. It works with a high gain amplifier so I was happy with just that! Soon I plan to push for High Q
Best video on crystal radios I've found so far. Amazing stuff. I'm working with wireless electricity.
VERY nicely done presentation.... 50+ years ago I could have fun with some crystal set DXing. The local station on 1060 went off at sunset. Eventually two other stations came on the air and run 24/7 except for Sunday at midnight once a month. My house is 0.9 and 1.6 miles between 4 & 5 KW stations on 1060 and 1190.... Tried dual traps and a few other things, but the stations still are deal killers.... Consider yourself lucky.... For those in a more RF friendly environment that have never given crystal set building a try and then graduate to higher performance, I can testify that it can be a fun challenge....
Crystal radio was a right of passage. When I got to my army classes. I got as sack w/ parts. Radio So as i waited for the classes. I was to assemble this kit. And be creative. So as I advanced to microwave and multiplex modes I grew out of my kit. But it taught me about soldering, coil winding, and antenna math. A good return for students. Still have one around and at ft hood Texas I got wjr Detroit Michigan and listened to several foot ball games over the years tks om good show. odn-1
🎉😂😂😂😂😂😂😂😂
Ok, thanks very much for your reply and results of your experiments.
Thanks! Very interesting crystal radio circuits.
I made TRF receiver with earth battery - earth spike antenna. Circuit runs with 0,6V.
Thank you! Fantastic introduction!
Really good presentation. I had a Remco crystal radio years ago
Thank you for the concise and clear explanations.
Hello
You can view my simple crystal radio from my small apartment in Bishkek kyrgyzstan
Just click my user name
16:00 is the BEST idea, man! KUDOS!!!!
Great video! Hope you have some more of these in the pipeline 🥳
Great video dave !
Awesome video!! 👍 ❤
Thank you for sharing.
Hello! I achieved the best sensitivity - when I used a RF mosfet, for example BF998 as a synchronous detector. A gate was connected to "hot" wire of coil (antenna), a drain to 1/4-1/5 part of windings. A drain connected to RF block capacitor 0.02micro Farads, and to 250Ohm earphone - through an electrolytic capacitor.
30:00 was another banger! This is great!
very interesting, thank you!
Thanks 👍. Great Video
David Day I had a cystatal set radio Receiver when I was a kid
👏👏👏👏👍
42:09 ...... Amazing.
I have picked up shortwave with just a simple crystal radio with just a coil variable capacitor crystal germanium diode and crystal earphone
😊
Very thorough and informative, thank-you! 🖕
Grounding through a water pipe was much more reliable back in the day. Now even if the house has metal pipes, the supply up to the house might be PVC or pex.
David Day this instresing about cystatal seat radio reciver histotory this cool
40:00 my stylr._ :) The Franken Class
The small improvements in crystal radio do make a big difference.
Unlike hifi.
David Day when I had crystal set radio Receiver I hear shortwave on my crystal seat radio Receiver
David Day when my mom and dad wore alive my dad me and dad build a shortwave radio Receiver from a kit from radio shack
One would think that if you can bias the diode fairly in a contest, then all designs would have bridge rectifiers.?
Oh, yes, this is a super great video!
David Day my hobbys are painting pictures and lisining to shortwave and ssb iam thinking about getting my ham license I have 4 shortwave receivers
I've been doing some research on the Selectivity Enhancement Circuit (SEC) mentioned in this video. On this page: www.theradioboard.com/rb/viewtopic.php?t=2989 Dave from "Dave's Crystal Radio" mentions that the 27mH value is not critical. On this page www.hobbytech.com/Practical%20Tips%20for%20Crystal%20Radios.htm Jim suggests a 10mH-27mH choke, and on this page www.hobbytech.com/crystalradio/crystalradio.htm he mentions it should be between 7.5mH - 10mH for maximum performance at the low end of the band.
Have you found that 27mH is the ideal value for the choke?
10 is more than enough
I've tried it and didn't see much if any change with or without rfc
The 27mH value is not critical. You should be able to use anywhere from 10mH to 47mH.
Shortwave chokes such as 2.5mH are not suitable at broadcast band frequencies.
@@daveschmarder-1950 Thanks Dave. I have learnt a lot from your website. Regards Grant
@@daveschmarder-1950
Dave really appreciated all your work
Wonderful talent you have
I miss your web sites
@@baikushex0et682 Thanks for the nice comment. My radio websites might not be gone forever. I don't want to be involved in the. hosting of websites anymore. If someone offered to host the sites, I would be interested in uploading them.
Good technical level😅.
His best was
Hawaii to turks and caicos
5600 miles ...
15:12 my placeholder, i will delete it
Makeradio.com is now gone.