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Old November 19th 05, 09:04 PM posted to rec.radio.shortwave
Telamon
 
Posts: n/a
Default Drake R8B VFO adjustment

In article ,
David wrote:

On Sat, 19 Nov 2005 20:14:08 GMT, Telamon
wrote:

In article ,
dxAce wrote:

Telamon wrote:

The VFO is a little off and I would like to touch it up.

In CW mode and the 2.4 filter and receiving WWV it is easy to tell that:
5 MHz is spot on
10 MHz is 20 Hz low
15 MHz is 30 Hz low

I haven't been getting the 20 MHz transmission very well so I was
thinking of centering the adjustment on either 10 MHz or 15 MHz.

The synthesizer board is on the bottom of the unit and I don't know what
to adjust. On the bottom board there is a tube type crystal with a cap
trimmer next to it behind the volume control as one possibility and one
of the large metal covered cans has a hole in it for a coil adjustment
in the middle of the side of the bottom board behind the tone control as
another likely place to adjust the main VFO oscillator. The rest are
individual coils that can be adjusted.

If you can clearly indicate which of the many coils or the one cap
trimmer to adjust I would appreciate it.

If you can't get an answer here you might want to go to
http://www.qth.net/ and sign up to the Drake mailing list and post
the question there.


Thanks for that tip dxAce.

L56 adjusts the 35 Mhz reference oscillator.


I don't have the service information and the circuit board is not
labeled on the component side facing the bottom of the cabinet so can
you indicate, which one of the possible 13 coil adjustments is "L56."

--
Telamon
Ventura, California