Bulletin:   MT2311
Vendor:     Motorola
Subject:    UHF Mitrek intermitant fix

        Having owned four Motorola Mitrek radios modified for UHF 9600
packet, I was glad to find a simple fix for intermittant preselectors.
The intermittant is usually due to a poor connection between one or more
of the preselector coils and the bottom cover of the preselector
assembly.  All four of my radios had signs of resoldering done here.
This is a common problem that probably started at the factory and was
compounded when techs tried to reflow the joints with standard soldering
irons.  Due to the assembly's heat sink like construction a standard 140
watt iron will just create putty like, cold solder joints prone to fail.
What I found worked best was to shield the bottom of the whole radio
with two sections of double layered aluminum foil, covering everything
except the preselctor cover.  Then using an oxy-acetaline torch with a
very small tip and pencil point flame, reflow the solder spots on the
cover.  This should only take a few seconds per connection (dot) and
should result in a smooth, almost flush solder dot.  Be sure to have the
foil sealed tightly to the edges of the work area to prevent scorching
the rest of the radio.  Standard soldering practices (clean & flux) are
important to preparation as usual.  I hope this helps someone, it did
the trick here.