[AMPS] fixed output caps

KL7RA Fairbanks Alaska kl7ra@icefog.gcgo.nasa.gov
Tue, 22 Apr 97 01:32:01 utc


> Which is better - air/vacuum variables or fixed value capacitors 
> in the output circuit?

Gary
You can use fixed caps in the output if you use a roller inductor.
I have a commercial service amp that uses a motor driven inductor
and large ceramic band switch to make automatic freq changes.

I have several other commercial types that use a "channel" system
with both fixed and a variable caps in the output. You use a
screwdriver to tune each channel. Although you would think its a
tune and forget thing different antennas/freq combinations keep
forcing you inside the box.

Tuning one of the "channel" amps became so annoying that I removed
all the tank circuits (six) and installed variable caps and roller
inductor.  

Rich KL7RA

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