[R-390] SSB-Modified R-390A

[Jim DiMauro]

Hi All:

I have a Collins-made R-390A S/N 756 from the very first contract
(14214-PH-51).  It was modified to add SSB capability.  The BFO switch was
changed from the "Off-On" to "LO-UP-AM-BFO" and the dial lock was removed
and replaced with a "VFO Vernier" control.  The mod was very nicely done and
works well, with screened lettering on the front panel, and there are no
immediately obvious circuit additions from looking at the top of the
chassis.  I don't know exactly what type of mod was done, but it's certainly
not a typical hack job normally assosciated with military radio conversions
by amateurs.

I have three questions: where can I find a list and descriptions of known
SSB
conversions for the '390A so I can identify the mod?  Also, were there
commercial
conversions done by/for the government?  This radio came from an estate
which included equipment from a US Army experimental SSB station AN/GRC-108
XC-1, so perhaps this radio was modified for the Army and not by a ham.
Finally, does a "professional" SSB conversion add to or lessen the radio's
value?  I guess
it depends on the type of mod and who did it, but some thoughts along those
lines would be appreciated.

Thanx & 73,
Jim
WA2MER