[R-390] Variable-Frequency Oscillator End-Point Adjustment

[Craig C. Heaton]

Talk about working in tight spaces.

	 I needed to slip the veeder root counter after tweaking the VFO, so the
front panel had to move a few inches. There is more than likely a better
way, but I tweaked the VFO, slipped the counter, and then checked to see how
far off the VFO was end to end. After finding the correct direction to turn
the adjustment, it wasn't too bad.

	Got a question for the group. I made my end-point adjustment with the
receiver standing up on its back panel. In this position it was easier to
get the cover nut out of the way and see what I was doing. Would there be
any difference with the receiver in its normal top side up vs. panel side up
while performing the end-point adjustment. Or I'm I picking belly button
lint, almost like discussing the replacement of capacitors.

	I did notice some backlash with the R-390A front panel side up. In other
words, checking 100KHz markers counting up vs. checking the markers counting
down was different. Always had to start at 000, calibrate, and check every
100KHz up to +000, counting up. Once the end-point was as close as I could
get it, I put the receiver front panel on. Today, checking the 100KHz
markers, and the receiver in normal position markers are repeatable going in
either direction.

Craig,

-----Original Message-----
From: r-390-bounces at mailman.qth.net
[mailto:r-390-bounces at mailman.qth.net]On Behalf Of David Wise
Sent: Wednesday, April 27, 2005 1:34 PM
To: R-390A
Subject: RE: [R-390] Variable-Frequency Oscillator End-Point Adjustment


I don't even remove the front panel.

I broke an old metal-tip alignment stick into two
pieces.  The short half is just short enough to
maneuver into place.  It's also just long enough
to turn between thumb and forefinger.

I can't remember how I initially broke the cover nut
loose; I probably took out the VFO.  If you get lucky,
your right-angle screwdriver will have the right orientation
to catch.  I put it back on with the above alignment stick,
which keeps it loose enough to get it back off the same way.
I rock the radio onto its face to drop it out, and
put it on its back to put it back in.  Takes some poking
around, but it still beats (with a stick!) pulling the
front panel, unless you're rack-mounted.

73,
Dave Wise

> From: Craig C. Heaton [mailto:wd8kdg at worldnet.att.net]
>
> 	The other day while performing an end-point adjustment
> I realized there is
> a better way. For those who would like to add a new tool to their
> collection; add a Snap-On SSM5A. It is nothing more than a
> screw starter.
> Used one years ago (about 30 years) for those hard to reach places on
> motorcycles.
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