Seems to me I read a note about W7ZOI starting to build a variation of his
original spectrum analyzer which will cover up to 200 MHz.

http://users.easystreet.com/w7zoi/vhfbpf.html


He expects to use a mini-circuit VCO.

POS-535 VCO from MiniCircuits will sweep from 260 to 460 MHz

Given a first IF of 260 MHz, it all works nicely.

Personally, I'd be inclined to do something like this, using the
minicircuits part, since they tend to be fairly linear tuning MHz/VOLT which
simplifies the sweep circuitry a lot.

I have built broadband tuning range VCOs before, and I know it can be
done, but in a spectrum analyzer, the performance is usually limited by the
first VCO so using a good performance VCO makes sense to me.


Jim
N6BIU