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Cheap and simple marker generator for 2.4 GHz



Hello all,

I just modified a Drake 2880 for use on AO-40 and needed a way to check it
out before seriously trying to hear the bird.  My chief problem is no one in
Abilene has any experience with test equipment in this range, and I don't
want to spend kilobucks on the stuff!!!

During my searches, I noticed several hams had used TTL clock generators in
various projects. So I got to wondering if a clock oscillator would generate
enough harmonic energy to be heard at 2400 MHz.

I had a 40 MHz oscillator module in the junk box (about $2.00 from
Mouser/Digikey/Hosfelt/others), so I hooked it up to 6 volts and pit a 3 cm.
piece of wire on the output pin as a 1/4 wavelength antenna and held it next
to the antenna of the Drake.

I was able to get a very strong signal on the I.F. at 144.980 MHz.  Not too
bad for a non-calibrated downconverter and a signal source that is bound to
be a couple of Hz. off of true!!!

The Drake was also able to pick up the signal at a distince of about 10 feet
from the feed.

LESSONS LEARNED:  We all don't live in large cities where there is lots of
microwave savvy hams and labs available with loads of test equipment.  There
is a great need for simple, dirty, test equipment and other modules
necessary to get on the air ith the new microwave sats that will come.

NEXT:  Can anyone help me come up with a simple way to calibrate signal
strength of the signal generator and a way to attenuate the signal so that
meaningful measurements and be made as to M.D.S and the like?

73,

James,  AA5AO



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