[ARC5] Re: [Milsurplus] SCR-183 question
Mike
[email protected]
Sat, 20 Apr 2002 08:37:27 -0500
Mike Feher wrote:
> Theoretically, due to tracking concerns, none of the receiver coil sets were
> interchangeable, unless they had the same serial number as the set. Each was
> individually aligned for the set and the serialized.
I know that for the USN RU/GF sets, this is true. I have seen a couple
of RU/GF sets in which every component bears the same serial number, and
I assume that it was intended that serial numbered coil sets be matched
to the receiver or transmitter. I have a GF-11 with all matching
serialed components.
I paid an arm and a leg last year for a NOS SCR-AS-183 still in the
unopened (since 1943) wooden crate. The original packing list stated
the serial numbers of each component, and each component agreed with the
packing list. But guess what? NONE of the serial numbers on any of the
components (even coil sets) were the same! There IS an ink stamp INSIDE
the coil units that states that the coil was calibrated for use with a
particular serial-numbered transmitter or receiver.
That leads me to think that the SCR-*-183/283 coil sets in any given
installation were very unlikely to bear external serial numbers that
matched each other or the unit into which they plugged.
> The biggest problem was BFO tracking, where a LO was used to provide BFO
> injection as there was no IF.
That would seem to the the most critical alignment problem, but since
the SCR-*-183/283 had no BFO for CW receive capability, that would make
the USAAF set more tolerent of coil swaps, compared to the USN's RU/GF.
For those who haven't done so, you would likely find it interesting to
compare the manual and equipment for a RU/GF set versus a SCR-*-183/283
set. The USN set is *grossly* different electrically, and in a few
aspects mechanically, compared to the USAAF set. The RU/GF is much more
refined. The two sets are, IMO, very different radio designs that just
happen to be in similar looking external packages. For years I had
thought that the RU/GF was mainly just an SCR-*-183/283 in USN clothing.
Mike / KK5F