Thread: Tube-based 40M VFO
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Old December 16th 06, 11:58 PM posted to rec.radio.amateur.boatanchors
Edward Knobloch Edward Knobloch is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 113
Default Tube-based 40M VFO
wrote:
I've been having a lot of fun the past few weekends with my "new" Eico
720 and a couple of 40M crystals and a dipole strung between two trees.

But now I'm tired of QRM'ing the same frequencies all the time and want
to build a VFO. I've got some random variable capacitors, a couple of
nice dials, and would love to spend a weekend punching holes in a
chassis and putting something together.

I look in the 50's and 60's era handbooks and am a little confused. The
"SSB exciter" construction articles almost exclusively use a Vackar VFO
made out of a twin triode. Looks really straightforward and simple. But
the cookbook section inevitably shows pentodes in usually both grid-
and plate-tuned circuits, and then with extraordinary amounts of
buffering (say, a cathode follower AND a buffer amp).

snip

Hi,

You might look at the matching Eico 722 VFO manual on BAMA:
ftp://bama.sbc.edu/downloads/eico/722/


73,
Ed Knobloch
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