The simple meter I had been using wasn't sensitive enough at VHF unless I held it right next to the antenna so I decided to build an amplified FSM that is dedicated to the broadcast FM frequency range.
Built into an old 1.44Mb floppy disk container and using a random Vu meter I had laying around...
As you can see it's very simple. Would be a piece of cake to build for anyone with a little bit of knowledge on soldering and basic electronics design.
I used a 2SK19 FET since I have a bunch of them laying around. I am sure just about any FET would work fine. The 6 turn coil I used made the meter most sensitive right around 90-100MHz.
With my FM transmitter running at 5 watts I am able to peg the meter around my whole property! Good thing it has a variable control to turn down the sensitivity which makes it more useful for high power transmitters.
Using a tiny MP3 player FM transmitter I have to put it right next to the meter at full sensitivity to make the meter budge. Goes to show the huge difference between microwatts compared to watts of power! ;D
Anyone experimenting with FM broadcasting really should have one of these. It helps greatly for tuning up antennas and getting an idea of your antenna pattern and any directivity it may have.
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