Re: RF Clipper Diode Design


goscickiw
 

I think it's sort of solved with the 100.9MHz signal. I had automatic IF gain set, the signal became better after I changed it to manual.
In case of other weak signals, I tried with a 4-20dB variable attenuator and they became much worse or disappeared, while the strongest signals stayed just as good. Same situation when I use a short piece of wire or a smaller antenna.

These signals come from different transmitters so a directional antenna would help, but the problem here is space. I can't put a 5 element FM Yagi on a wall.

Also something I should have mentioned, my antenna doesn't have a direct line of sight to the transmitters because of location - surrounded by higher buildings. Putting it on the roof would probably help, but would require much convincing of other residents. It's a vertical folded dipole.

Here is how the signals look like on the spectrum in normal conditions - no attenuator.


When I increase the RF gain by 1, the spectrum becomes this mess:


With an attenuator:
 

I'm not sure why this subject expanded in this direction... Originally I wanted to protect my HackRF One, that I use just for testing stuff like modulators and usually don't connect an antenna to it, from accidentally giving it signal stronger than its nominal -5dBm... Then I started talking about receiving FM. WTF brain.

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