[Motorola] Luggie Talkie

[Glen Zook]

Moving the frequency of plated crystals of which those
in the HC6/U, HC48/U, and so forth, is very difficult
to do.  This is unlike the old FT-243 types that can
be moved by removing material from the blank.  If the
holder is soldered in place (not welded as is the case
of many of these crystals today) you can carefully
unsolder the top of the holder to get to the crystal
itself (which usually connects to the pins by small,
but very "stiff", wires).

You can move a plated crystal slightly lower by
carefully dragging a piece of 60/40 solder across the
surface and you can move it slightly higher by using a
pencil eraser to remove a little bit of plating. 
However, it is very easy to "kill" the crystal by
doing either and just how far you can move the
frequency is very limited.

Glen, K9STH


--- Gene Smar <ersmar at verizon.net> wrote:

The kids rubbed pencil lead on the crystal face to
lower the freq a bit, then reassembled the holders to
test.  To raise the freqs, they gently rubbed the
crystal across a piece of fine grit sandpaper a few
times, rinsed it in alcohol, then reassembled.
 
Since then I've read in several Ham sources about
changing the nominal freqs of such crystals in similar
manner.  I have never done this myself, but it sounds
doable.  The trick is the crystal holders have to be
the ones that are screwed closed, not crimped like
most crystals from ICM, Bomar, etc.









Glen, K9STH

Website:  http://k9sth.com


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