You're climbing a steep hill here James. It is the % change in frequency
that is the problem. Professional spec analysers use a 2 GHz LO with a 2:1
range (to scan 0-2GHz), but I believe that is a magnetically tuned YIG
resonator. If you could get the frequency higher, so the sweep range is
narrower, then mix to the desired freq with a balanced mixer...that would be
an easier VCO design.

Steve
K;9;d;c;i

The punctuation is my feeble attempt at spam-bot blocking.


"James Fenech" wrote in message
...
Hi Roy,

thanks for the suggestion. I am considering buying this book. Can I ask
how
much theory, and how deep does it go? I am an engineer (digital
electornics
and software background) and actually like some theory to help me
understand
what I am doing.

I already have some "real" test equipment, 50MHz CRO, signal generator,
multimeter, etc. So "simple" test equipment may not be too much of an
improvement.

I've looked over the internet, and some books that I have, but found no
real
example circuit on wideband VCOs. The only "sort of close enough" circuit
I
found is at:

http://www.newwaveinstruments.com/resources/rf_microwave_resources/sections/oscillator_vco_theory_design_circuit.htm#Voltage%2 0Controled%20Oscillator%20(VCO)%20Circuits
The second one down - Colpitts. Are there any such examples in this book?

Thanks,
James.


"Roy Lewallen" wrote in message
...
I highly recommend _Experimental Methods in RF Design_, by Hayward,
Cambell, and Larkin. It's published by the ARRL and available from them
and numerous other sources. Besides theory and a lot of real, practical,
tested circuits and projects, it includes simple test equipment you can
build yourself.

Roy Lewallen, W7EL

James Fenech wrote:
. . .
I have the ARRL handbook (1997 or so) but this doesn't have much in
the
way
of theory. Is there any other reference anyone can recommend?
. . .