[Collins] 32S-3 drive issue

[Dr. Gerald N. Johnson]

On Sun, 2008-04-06 at 10:51 -0700, Glen Zook wrote:
> It has been my experience with the 32S-3 series that
> the 20 meter positions do require a substantial
> increase in the gain control when compared to the
> other bands.  However, having to run the gain control
> "wide open" is generally not necessary.
> 
> The indication on the meter in the tune position is
> necessary to get the exciter tuning correctly
> adjusted.  However, as Gerald has pointed out, you do
> not want a grid meter reading when operating the
> transmitter.
> 
> One thing that I have noticed is that quite often it
> is necessary to adjust the receiver preselector when
> tuning the transmitter.  This is an indication that
> the receiver alignment is not quite "right on". 
> Frankly, I find it helpful to align the receiver with
> the connections to the transmitter in place.  When the
> 100 ohm "dummy plug" is inserted in the jack for the
> heterodyne oscillator output it does a fairly good job
> of approximating the load presented by the 48 inch
> long section of RG58/U cable used to connect the
> receiver to the transmitter.  However, it is not
> "perfect" and "touching up" the alignment when the
> receiver is connected to the transmitter often helps
> with the drive problems.
> 
> Glen, K9STH
> 
> Website:  http://k9sth.com
> 
And the gain of the transmitter mixer is a function of the LO drive
voltage to the mixer. So low LO means low transmitter output.

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer