[MRCA] RS-6 (RA-6) Connection to GN-58

[Tim]

Mike -
Good find - that's the connector needed for the Genny- RA-6 connection.
WA5CAB said he used to have a couple of those cables but still not clear if
they were contract - supplied or locally fabricated/modified cables.  That
1953 addendum sure indicates a local mod was acceptable.

Regarding its use, I'm pretty sure it was *not* designed for military
service.  In its era, the GRC-9 would have served that purpose, the GRC-109
possibly later on.  Its complete lack of weatherization or otherwise
"ruggedization" is pretty clear evidence that it was not designed for
military comms.  Other evidence is an apparent lack of a standard Technical
Manual or reference to it in any other Army manuals that I can find.
Pretty clearly intended for CIA "briefcase" type usage, not in a combat
environment.  Clean examples are rare, well-worn examples seem to be the
norm in my experience.  These were not shelf queens.

One website quotes a Special Forces guy who routinely used them
operationally in Germany in the 1950's.  SF people and today's Special Ops
folks have a lot of lattitude in the gear they can obtain and use.
Possibly the case he described.

Looking at serial number data and making some guesses, probably thousands
were made.  Would like to know if USAF SAC had some others built for them
or if they just requisitioned them from the supply system as needed.

It's true, harmonic suppression would be pretty poor.  A simple series
inductor in the output line, working with the output loading capacitor
makes a reasonable "L" network low pass filter to reduce the harmonics.  I
need to measure mine when I get the chance.  Pretty easy to do. Yes, a
low-pass tuner would be recommended.

Hopefully some new references or operator anecdotes will surface but they
seem to be rare these days.
73,
Tim
On Sun, Apr 8, 2012 at 12:32 PM, Mike Morrow <kk5f at earthlink.net> wrote:

> Al asked:
>
> > What goes between the GN-58 and the RS-6?
>
> A recent posting cited a pdf for the RS-6 manual, to be found at:
>
>
> ftp://server.thestaffychronicles.com/mirrors/nj7p.info/Common/Manuals/PDFs/Military/RS-6%20Manual%20Unk%20NJ7P%20AS.pdf
>
> Also at that server is a pdf for the 10-page addendum from 1953:
>
>
> ftp://server.thestaffychronicles.com/mirrors/nj7p.info/Common/Manuals/PDFs/Military/RS-6%20Errata%2015%20May%2053%20NJ7P%20AS.pdf
>
> On page two of the addendum, it states:
>
> 1 Female socket connector to adapt hand generator to filter
> accessory unit.  (Original connector must be unsoldered from
> generator cable and new connector substituted.)
>
> On page ten of the addendum, it adds this connector as:
>
> S08   409A122       CONNECTOR, PLUG:  6 female contacts
>
> I've had a very good condition RS-6 for 15 years, complete with rubberized
> bags, interconnect cable, antenna insulators, and battery clamps.  As
> expected, all the unit serial numbers are different.
>
> I've tried to like the RS-6, but I just can't escape the feeling that this
> is a real half-assed jury-rig set that probably should not have seen any
> real production.  It seems to lack all qualification as a satisfactory
> military-service unit (but then, so did the AN/FRC-93 [KWM-2A]).  I wonder
> why most examples look as if they have seen a lot of use.  But surely they
> have not seen much or any use...at least as a radio set. :-)
>
> Judging from the transmitter's output network, I suspect that any signal
> that the RT-6 emitted could be copied from long distance almost as well
> on second and third harmonics.  It would not seem wise to operate the RT-6
> today unless it's feeding a resonant antenna (though that won't help third
> harmonics) through an antenna tuner, to provide at least some pretense at
> spurious emission reduction.
>
> 73,
> Mike / KK5F
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