Understanding and Building Crystal Radio Sets
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- Опубліковано 15 сер 2022
- New Jersey Antique Radio Club August 2022 meeting
Understanding and Building Crystal Radio Sets
By Al Klase
New Jersey Antique Radio Club Meeting "Tech Talk"
August 12, 2022 - Розваги
Wonderful presentation. Enjoyed it!
Excellent presentation. I'm in my 70s and been building sets since about age 12. I always learn something new listening to another talk about radios.
A great primer on crystal sets, with quite a lot of detail for those wanting to take it further. Thank you for telling folk not to bother with the really simple beginner circuit where both the antenna and diode detector are connected to the top of the coil. That circuit alone must have been responsible for so many people completely writing off crystal sets as a mere novelty. Great talk. Thank you Al!
Every time I think I understand crystal radios pretty well, I watch something like this and realize there's even more for me to learn. Thanks so much for posting this!
On a lark this came up in the algorithm. Really great presentation and brought back some memories. I had made a crystal radio after following many designs and improvements from the "braindead" one. I was fortunate enough to have a great antenna and ground. Listening in the winter after dark from eastern Canada I was able to listen to a Washington Capitals hockey game!
10/9/23 Crystal Radios.
Thank you for your presentation on Crystal Radios. I built several of them in elementary school and purchased one of those rocket crystal radios. I loved your ideas on impedance, matching and wish I would’ve known about that when I was building them as a child.
I started in Radios, when I was four years old toddling behind the Sears Silvertone TV that my dad bought in 1954. I was trying to see how howdy Doody got in my TV. I knew he came in through the rabbit ears on the top since I had to twist it all around to get a good signal. when I look through the holes in the fiberboard on the back and could see glowing orange things. I figured those must be responsible for putting howdy duty on the screen. By eight years old. I understood how tubes worked and by 12 I had my radio amateur license WN6INX
And that time I was living in San Diego & sending Morse code and receiving QSL cards from across the United States &South America using a homebrew transmitter with 6146 output tubes and a converted arc5 world war II airplane receiver. Also using a long wire dipole antenna that could be tune to the 40m and 80m amateur band.
That was a really good presentation.
Thanks for doing it.
Thank you so much , I grew up in the 1970's as a boy these were at the Local Confectionary and the five and dime . Sears , Radio shack etc. . I wish that more youngsters today Used and Understood the fun of all of this and building on the Technology , Thank you , Liked and Shared :) QC
thats wonderful.....
I built my first crystal set when I was 8. I used a germanium diode. The coil was experimentally wound. I bought the variable capacitor from a local repair shop I later worked at as a an after-school job. I lived in an area with a single AM station and nothing else for over eighty miles.
The 3DQ also sounds better because it is turned on for a greater portion of the wave cycle.
This is great! Thanks Al.
Always fascinated with crystal ' no power ' radios.
I had a schematic for Crystal set that used a transistor to slightly amplify the output where the transistor was powered by input signal. I lost it, I haven't seen any others.
The fellow that goes by ' glasslinger ' on youtube who makes vacuum tubes was building a crystal set that was amplified by two 6AU6 tubes and it worked really good. The crystal receiver part seemed extremely sensitive as he drove across the dial ( variable capacitor ) and tuned in at least four totally separate stations.
I don't know what the circuit was called but it had variable volume control between antenna and coil similar to circuit on my 34 Philco radio.
AFAIK, _"Sound Powered Phone"_ systems are still used on US Navy and US Coast Guard ships and cutters.
I was in the USCG, and for about my first two years in was stationed aboard a Cutter. They employed both the headphone/microphone devices {which I never used}, and the telephone handset devices which I did use on occasion.
I was also in the USN before the USCG, but was never aboard any Navy vessel {I did Aviation..👍}.
My electronics career started in 1951 with a Cub Scout Radio kit. Catwhisker and a half inch wide strap slider across the tuning coil. Not successful. Ended up building a set with a double gang cap, two loopsticks, inductively coupled, with added windings for the antenna and detector (1N34). Telephone operator headset much more sensitive than surplus headsets of the time. listened to WWL from 300 miles away when local WDDT went off the air at night. KK6IL
Fantastic thanks!
Absolutely, a metal bed frame, the kind with springs, is a real good crystal radio antenna.
The best i have is my Dad's, w5ewf (sk ) set. Dual pancake tuned circuits and taps on last rf and first rf coils plus hi z to low z phone socket via transformer. Detector also drove a 10 uA meter with sensitivity pot. In Chicago suburbs had to use that pot to keep from WGN burning out meter. Even better in Jefferson City, MO with a 240 ft wire 60 ft up. Amazing tuning indicator. Only time i have seen a meter on a xtl set. Takes a while tune in a station. Headphone vol with my old hi Z phones could be heard 10 ft away. Got stations across midwest,Texas, Mexico and Canada. Even NYC late. Still have it. Doing regens at moment, but going back to pretty up Dad's set soon. QTH in west cent FL now. 73 karl wa2kbz
if you get a standard pair of 2k magnetic headphones you can dramatically improve them by getting a modern strong niobium magnet and experimentally positioning it on the back of the earpiece.
And then there is Mike Tuggle and his Liondyne Super Set !
I use a double sided tape on several places parallel to to axis of the coil to help to fix the wire while I am making the coils and after that I use nail polisher along the line parallel to the axis to hold the wire.
Notwithstanding that these things can be made to pick up FM, I shouldn't think there'd be much point to making a crystal set as a kids' (or grown ups') project these days, where I live (Rep. of Ireland), as, sadly, AM broadcasting is deader than flares!
I did actually make one of these as a kid (under the direction of my 'nerdier' buddy, who had at least some kind of idea what he was doing. In order to skip all that tedious winding, we used some kind of coils salvaged out of cars; I don't know whether it was an ignition coil or an alternator coil, not really looking like either, but it looked like one of those toilet roll - core jobs. Perhaps it was one of those RF suppressor coils, which would have been mildly ironic, I guess! Do cars even _have_ those, any more? Probably to the surprise of no~body here, wherever I would clamp on to it, I could only get the one station; but to be fair, that was a pirate station less than ½ a mile up the road putting out on 5kW, and which was known to come out over the Tannoy in the local church - you can imagine; "We believe in God, the Father Almighty, Creator of *>`krsstk!’
When I was a boy I grounded my crystal radio on the electric outlet neutral (there were no 3 pins electric outlets then). I tried a band-saw partially buried on ground, too and I discovered a few volts difference between the two. Took me a while to understand why. It was a nice learning. And yes you are right my crystal radio could only receive a an FM radio that was very powerful.
Yes they can receive FM too putting them a little out of tune to transform FM on an AM signal on the edges of the cutoff of the LC tuner.
Great
37:20 Is 2.5x Diameter really correct? Those look more like 2.5x RADIUS??? That would align more with the 'make them square' motto as well...
I have to wonder, to what degree is the pocket protector an ironic accoutrement or does he use it completely unselfconsciously.
Pls refresh my memory: why transistor radios dont need grounding and crystal sets do. Thanks.
I am NOT an expert on this topic.
That said, having a power source allows transistor radios to contain the stuff and/or perform the functions that must be done by an external antenna and ground on a crystal set.
Amplification. Without the long antenna and good ground, a crystal set will struggle to produce enough signal to hear from all but the strongest local transmitters. A transistor set can take a tiny signal, much too small to drive an earphone directly, and amplify it hundreds or thousands of times so it's strong enough to drive a speaker. At that point the ground connection would be superfluous.
Well I guess I have another project...
Sooooo did I miss antenna talk, ?
22:04 neuralink, coming soon. ;p
that baldwin headset looks like you could clip an amp on the line, and it’d work as poor quality mic. 😮 like, talk into the earpiece. 😅
No, PVC is very low loss anything cardboard or wood is very high loss and lowers the queue tremendously. Even Glass is very bad.
No funcionan los subtítulos
Eso no sucede automáticamente. Alguien tendría que hacer ese trabajo. ¿Estarías dispuesto a hacerlo por nosotros?
This is too advanced.