VHF CAVITY RECEIVER

Hi
I played around with this idea a little too but only around the FM band and found they work very well.
I am interested in what you come up with too.

Hi,
the cavity resonator itself acts as a high-Q parralel LC circuit. The screw makes it tunable to some extent, so it should not be necessary. If you want to use it as a RF filter, the diode should be removed, too. 
Harry would tell us more, but he is moving and he has not been here for a long time.

BR from Ivan OK1SIP

Hi there Harry! (Or whomever is reading this! ),
I'm trying to build the VHF cavity monitor(http://sm0vpo.altervista.org/use/cavity.htm) and it is acting more like a broadband bandpass filter.






I have tried a few different configurations for the loops. I shortened them up to help the Q. But it didn't.
I don't have the screw in. Is that what is affecting so much? I'll try putting it in tomorrow. Any tips or tricks for getting this to work?
I'm going to also try making the loop long and skinny to make it look similar to commercial notch filters.
(Edit: A notch filter is _not_ what I'm going for)

Thanks for your time!