[Milsurplus] ARC-5 Transmitter Crystal Summary

[C Whitaker]

de WB2CPN                  2004.10.30

There was no "standard", but there was some pattern
to the crystal frequencies.  I was USAF back then, and
the crystal was used to calibrate the transmitter
frequency by adjusting the dial for a minimum angle
in the eye, then noting the error on the dial's
frequency markings.  There was an errata sheet on
the transmitter.  The calibration wouldn't hold that
close all the way to the ends of the dial, so some
crystals were picked which were in or near a band
of frequencies which were common to many users.  The
4000 - 4600 range and 8200 was common in USAF.  As you
Milsurplus guys know, procurement proceedures varied
greatly even within a given service.  The Navy appears
to have selected a crystal on an operating frequency
more so than the USAF.  Some crystals were half way
between top and botton XC wise.  So the three patterns
I see are frequencies near the frequency band, crystals
on the operating frequency, and crystals that were in
between high and low frequencies on a transmitter.
Also, one factor to consider, quartz was in very short
supply, so perhaps any left overs could be tweeked and
used for these things.

73  Clete