Re: {Collins} SSB tuning question



Glen,
I did not do a good job of describing the process.  I thoroughly warmed up
the equipment and then aligned the crystal calibrator for what I thought was
the center of 15 Mc.  I then went to the closest 100 kc division on the dial
and set the fiducial so that I was right one the zero beat of the calibrator
at the 100 kc mark.

The problem occurred when I then went to tune in some nets, including CCA
and was low on the readout each time.

My concern is that when tuning to WWV and aligning the calibrator, should I
be in the AM or USB mode when attempting to zero beat?  I do the alignment
in AM mode.  If it is done in the AM mode, is there an offset when switching
to USB and attempting to zero beat?

Thank you

Jeff, K1YLV

-----Original Message-----
From: Glen Zook [mailto:gzook@xxxxxxxxx] 
Sent: Thursday, July 28, 2011 11:23 AM
To: 'Jerry O. Stern'; collins@xxxxxxxxxxxxx; 'Grayson Evans'; Jeff Wayne
Subject: RE: {Collins} SSB tuning question

That is what the movable fiducial is for (the little black knob in the upper
right-hand corner of the escutcheon - black plastic with the model number).
You turn on the crystal calibrator, adjust the PTO knob for zero-beat, and
then move the fiducial to the correct frequency.  The chances of one of the
heterodyne oscillator crystals to be on the exact frequency tolerances of
another is astronomical and the chances of all the crystals are not on the
exact frequency tolerance is even greater.

You have to adjust the ceramic trimmer marked 100 KC adjust to calibrate the
crystal calibrator for zero-beat to WWV.  Then that is the standard by which
you calibrate the dial for all of the other bands.  That is, you set the
fiducial for the nearest 100 kHz on the dial.

Glen, K9STH

Website:  http://k9sth.com


--- On Thu, 7/28/11, Jeff Wayne <wayne4@xxxxxxxx> wrote:

While we are on the subject, how do you calibrate your frequency using WWV
and a 75S3-B?  This has become quite a challenge for me.  I know that it is
a simple process, but after I think that I am right on at 15 Mc., I go back
to 20 meters and am slightly off.







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