[R-390] First 390A Alignment prep and weak bands

[Dennis Wade]

Hello all,

          I've reassembled my Motorola '390A after recapping the last
deck (AF).  I've had this radio for over 13 years, but this will be
the first alignment I've ever done on it.  No major components were
replaced as the IF deck is a very recent EAC unit.

           Equipment to be used is a Measurements Model 80 sig gen
with assorted 50 attenuators, an HP-410C VTVM  and an Optoelectronics
frequency counter.

           My intent is to align the radio to the conditions I expect
to use it in, i.e. a nominal 50 ohm load fed through a balun into the
balanced antenna terminals.

           I've elected to use Walter Wilson's alignment procedure
(http://r-390a.us/R-390A%20Alignment%20v2.htm) because it avoids
injecting (and loading) intermediate stages during alignment and I'm
much more comfortable with a procedure that doesn't call for injecting
signals into stages.  The one exception maybe to use the calibrator to
stagger tune the IF stages as Dallas Lankford described in the Pearls
of Wisdom.

           When I put the last deck in I fired it up and did a quick
check with the calibrator on all bands.  The signal level was fairly
consistent across all bands with the 2 and 3 mc/s bands being the
notable exceptions.  On these bands, the calibrator was barely
audible..no carrier level meter movement at all while other bands
would be between 20 and 30 db.  When I removed the RF deck for
cleaning and recapping, I did remove the slug racks, but did not
remove the slugs from the racks.  I only replaced the brown beauties
in the deck as I was not experiencing any sensitivity problems below 8
mc/s.

            Any comments, suggestions or wisdom are more than welcome.  

                    Dennis

-- 
Dennis L. Wade
KG6ZI
Carmichael, CA