I have several UHF "bugs" and I wish to understand several things:
All the bugs I have work on the 433MHz band. SMD components.
Several use a simple metallic case crystal, U49, and several use SMD, and I suppose they work on the third overtone and then doubled, meaning I think the crystals are around 87MHz. The SMD ones have 4 "legs" - no idea which kind of crystal is this one, or it may be even an oscillator I cannot debug it to know which kind of device is it. I need your help, maybe someone may know this device: 4 legs - one from each side, black, about 6mmx4mm. All I could do is to measure the frequency with a counter - at 3 legs it showed me 433.9MHz - but I'm not 100% sure it's not from the PCB. I'll be very thankful for any help - maybe a link to similar device.
As well, I'd like to know if when I order a crystal, I have to mention it's for the 3rd overtone.
Regards,
Nina [/u]