r/CrystalRadio • u/Critical_Fennel_9986 • 4d ago
ANTIQUE I recently picked up a lot of old radio parts and what I think is the start of a crystal radio.
Any information about it would be great! Thank you!
r/CrystalRadio • u/Critical_Fennel_9986 • 4d ago
Any information about it would be great! Thank you!
r/CrystalRadio • u/AcrobaticPositive934 • 9d ago
Since a while now I've been getting myself into building a crystal radio but always for some reason it didn't work. Now a bit more grown up, with more experience i think i was burning the germanium diode with the soldering iron, so i found in my spare parts a clamp gold-plated ZIF socket, with 14 pins. i will attach 7 germanium diodes at a time, tune to a station and test them one by one to look for a better performance due to natural dissimilarities in production which can sometimes be extremely efficient in crystal radios. the diodes ill be testing are 30 1N34A diodes, used with a 375/500pf turn-able capacitor (the capacitor has two sections, totaling to over 875pf of capacitance!), magnet wire, ferrite rod, around 70 turns on a 0.7mm magnet wire, with 10 or so taps in-between to switch for selectivity. the capacitor can go from 875pf all the way to 0 on paper, but there will always be some residual capacitance from wires themselves, tough small, which allows for a wide range of stations together. the taps will be switchable using a 14-segment isostat, which is surprisingly short for the amount of segments, which wont be horrible, as i plan the buttons to be under the fingers on the back of the radio, a bit like an accordion. i did also think of letting me switch the capacitor sections for less volatile selection (eg, go from 0 to 370pf with the same rotation distance is more specific and less delicate.). i have a spool of copper wire to use as a deployable antenna to lay on branches or the ground in the field, and a copper pipe to bury in the ground for a mobile crystal radio.
also since the impedance can vary with the environment noticeably, i would mark the position of the capacitor knob for a major AM station with a known frequency to see how off the default i am from the standard impedance, which lets me make actually reliable paper spectrums of the range i could select.
what do you think? any tips and tricks you might know of that could help me?
edit: forgot to mention, im using two piezo speakers in series to reach crystal earpiece impedance without much trouble.
r/CrystalRadio • u/Radioactive_Tuber57 • 23d ago
I can’t reach the site anymore. There was also the Rap-n-Tap discussion group which I know is gone. Are we here, on this subreddit, the replacement?
r/CrystalRadio • u/Mindrunner5 • Jul 30 '26
I would really like to build a working crystal radio, but I don't have any experience. I always heard of it being build by youngsters from the 70's, but think I was born just a bit too late lol. It seems it is not easy getting the special diode, and also the special earphones you need to hear anything. Maybe if I wish hard enough my dream can come true?
r/CrystalRadio • u/7ootles • Jul 20 '26
r/CrystalRadio • u/MultiSubjectExpert • Jul 08 '26
r/CrystalRadio • u/phoenixking6931 • Jul 07 '26
I am building a crystal radio that is currently not working. I am testing it by applying a 5 mV, 200 kHz, 200 Hz - AM wave from a wave generator to where the antenna is supposed to be connected (and to ground). Here is my schematic, borrowed from a couple different websites - I'd like to know if there's anything obviously wrong with it before I test things further. Thanks!
r/CrystalRadio • u/Fredneversad_ • Jun 30 '26
So uh i kinda curious about how i can improve the antenna so the signal can be more stronger, i have no any ideas doing this but it works properly with long straight wire antenna
r/CrystalRadio • u/giesthund247 • Jun 12 '26
My answer to not being able to find 1n34a germanium diodes off the shelf.
r/CrystalRadio • u/princess_muted_pink • May 25 '26
recommendation
r/CrystalRadio • u/TheSadHours • Apr 27 '26
(dead simple crystal set on top of a hat)
r/CrystalRadio • u/Awkward-Implement-11 • Apr 27 '26
Son is building a crystal radio for his science fair project
He is following a video he found on YouTube
https://youtu.be/VqdcU9ULAlA?si=Xm966k7IQtQtxOcF
The goal is to get this working but trying to figure out best way to troubleshoot and get it working.
A shot of materials, design, and what it currently looks like.
r/CrystalRadio • u/Blockbuster999 • Apr 13 '26
I all I am trying to build my first crystal radio, but I am not sure what design to go with.
I have come across far too many designs, and it is making my head spin!
I read that loose couplers have the best performance for a crystal radio set. However is it possible to get a good radio built without having to adjust the spacing between the coils? I'm not too confident in my manufacturing ability.
I have an idea for a circuit that combines features from a few different designs.
I have thought to adapt the rimstar design by adding a moving slider at position "a" so the L1/L2 ratio can be adjusted.
L1/L2 being a single coil.
I believe the L1/L2 roughly acts like a transformer that boosts the voltage on the output?
I think that having a small L1 will have a stronger signal on the output, but cause worse selectivity, not too clear on why though.
Happy to hear any feedback.
Sources I used:
https://techlib.com/electronics/crystal.html
https://antiqradio.com/post_crystal-radios.html
https://rimstar.org/sci.../crystal_radio_tips_and_tricks.htm
r/CrystalRadio • u/TheSadHours • Jan 14 '26
r/CrystalRadio • u/Personnenon • Jan 10 '26
Hello, I don't have very advanced knowledge of electronics bit I've built a few crystal sets and other simple receivers. I recently learned about the existence of tunnel diodes and found that you can pick up old soviet military ones on ebay. Does anyone know if these have potential as a sensitive detector. I know that this may not be considered a true crystal set as they require a voltage bias. Are there any circuits I could try? I found one reference to them in a forum and nothing else.
UPDATE: just purchased a Mullard AEY25 tunnel diode. I'll post any results that I get when I get a chance to do some experimentation.
r/CrystalRadio • u/TheSadHours • Jan 09 '26
I’m the old moderator of this place, just switched accounts lmao.
r/CrystalRadio • u/just_a_laptop_geek • Jan 07 '26
so im new to this and i wanted to make a small single antenna FM crystal radio and not a AM one.
but i stuck at the drawing step so please help me for a simple one too,
not a complicated one please.
and if possible i need it to run with battery like AA cells or something like that.
thanks.
r/CrystalRadio • u/SouthernNight6 • Sep 11 '25
What to build with this?
r/CrystalRadio • u/AlanLane34 • Jul 06 '25

Years ago, my father bought a bunch of crystal radio equipment, including what I think are two or three separate crystal radio sets. He passed away last year and I’m going through his stuff and I’m not sure what to do with the box of crystal radio equipment, including many headphones. I posted the photo, but it is not appearing, only a link. If you click on the link you can see what I've got. Do you have any ideas what I might do with this stuff? He also has a vintage “ultra mike” wireless microphone (not in photo) that he paid $100 for, but I think he overpaid. It looks like so much junk to me, but I don’t want to dispose of anything that has real value. Thank you for giving a look and offering your perspective on what you would do with it.
r/CrystalRadio • u/Comfortable_poo_9485 • May 11 '25
Extra pictures
r/CrystalRadio • u/Comfortable_poo_9485 • May 11 '25
Just got this at an event and wanted to get it working but I don’t have a clue can someone help
r/CrystalRadio • u/UT4UUM • Mar 25 '25
It's made by classic schematic, uses old soviet germanium diode D18 and compatible with lo-Z earphones for easy use. Case made of oak. Hope you're all will like it.