[Milsurplus] SCR-183/283 junction boxes

[Mike Morrow]

Robert asked:

>Did some of the SCR-183/283 installations have a junction box with
>screw-in connections (cable glands) rather than connectors?  I've never
>actually seen one of the Signal Corps junction boxes but was under the
>impression that they were all similar to the Navy ones.

I've got three different versions of the SCR-*-183 junction box, including the last version, the TM-AH-172.  All are basically mechanically similar to the RU/GF junction boxes, though not interchangable with them electrically.  No screw-in connectors are used.

Most of the SCR-*-183 manuals state that this junction box is not part of the set, and is only to be used if the equivalent circuitry is not provided by the aircraft manufacturer.  All of the TM-*-172 boxes contain 12 vdc relays.  The 24 vdc SCR-*-283 has no equivalent to this juction box, so presumably it was always the aircraft maker's job to provide the interconnections.

It would be interesting to have as detailed a research into SCR-183 and -283 components as there has been for ARA/ATA, SCR-274-N, and AN/ARC-5 components.  There's a lot of odd things about this set.  For example, each version (like AF, AL, AR, AS, etc.) had a different nomenclatured set of tuning coil sets for the transmitter and receiver, even though the coils sets themselves were often otherwise identical between versions.   Many SCR-AS-183 sets (the last version) were made, but I have never ever come across *any* of the receiver coil sets that are specified in the SCR-AS-183 manual.  Every SCR-AS-183 receiver I've seen had coil sets from the SCR-AR-183.  I almost believe that coils sets for the AS receiver were never actually made, especially since a SCR-AS-183 that I bought *still in the unopened original crate* had NO receiver coils supplied at all, nor were there any listed on the packing list.

I've never really warmed up to the SCR-183/283.  I am quite fond of the USN's visually similar RU/GF sets.  I say visually similar, because the later versions differ greatly in electrical design from their USAAF cousins.  For example, the USN's RU-16/GF-11 and the USAAF's contemporary SCR-AR-183 equivalent are very different internally.  As a bonus, it appears that RU/GF vacuum tubes have no audiofool appeal, unlike those in the SCR-183/283 transmitters.  Those are almost always missing the two VT-25 (Type 10) tubes at least.

Mike / KK5F