UHF Crystal Radio

Ramussons

Joined May 3, 2013
798
The "Crystal" radios can be used only for receiving a simple AM signal. AM on VHF and above is RARE and definitely not on UHF.
What are you trying to pickup?
 

alfacliff

Joined Dec 13, 2013
2,458
actually crystal radios can be used to listen to fm, but wide band fm broadcast, by tuning off center (slope detection) narrow band fm has too little deviation, the tuned circuits have to have very high "Q" to get anything.
 

alfacliff

Joined Dec 13, 2013
2,458
am at 900 mhz, probably a remote control, or something similar. quite a few simple transmitter/reciever pairs use am because they also use regenerative recievers, which dont respond well to fm. an fm radio (88-108 mhz) cavity is not very large, a metal coffee can has been used before for that. a;lsp,, an lc circuit should have enough Q if you use thick wire, around #12 or so.
 

KL7AJ

Joined Nov 4, 2008
2,225
Yes Alfacliff, but the high Q required would be possible only with cavity resonators. The enormity of the task, to fabricate a cavity resonator for the 88 - 108 MHz band, would definitely put off the average homebrewer!

Regards,

Nandu.
Achhh...I can build one with a garbage can and some coat hangers. HI!
 
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