Globe Chief 90

john w. king jbkking at BELLSOUTH.NET
Sun Jun 10 08:17:52 EDT 2001

Thanks to Joe and others who replied to my inquiry about low grid drive in
my Globe Chief 90. It dawned on me that the thing might have been modified
for use with a VFO and I have been trying to get it to oscillate with a 40
meter crystal for 7.045 mhz. The book recommends removal of a 33mmf cap
connected between pin 4 and pin 5 of the 6AG7. The cap is still there. It
also recommends connecting a .005 cap from pin 5 to pin 2 of the 6AG7
oscillator for modification for use with a VFO.

Question....will the modification for use with a VFO   make it unusable with
crystals? Will not removing the 33 mmf cap render it unusable with a VFO?

My chief has both the 33 mmf cap from pin 4 to pin 5 of the 6AG7 and ALSO
HAS the 500 mmf cap connected from pin 5 to pin 2 of the 6AG7.

The manual says in THEORY OF OPERATION paragraph 1-6 "The oscillator uses a
6AG7 tube in a controlled regenerative circuit which supplies adequate drive
to the R.F. Amplifier on all bands. REGENERATION IS REMOVED BY

Does that mean that if the cathode is short circuited by C4, the 500mmf cap,
that the regeneration will not take place with a crystal? Removal of the
500mmf cap may restore regeneration or oscillation of sufficient drive to
drive the 807s. Thanks for bearing with me and my atempt to get the old gal
ginning. 73, John, K5PGW

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