[Milsurplus] Old-Age Math and the SCR-183

[Mike Morrow]

Dave wrote:

>Matching parts for the SCR-183 is worlds more challenging than
>doing so for the SCR-274N.

There seems to be a lot of AR and AS version components out there.
But not much by made by A.R.C.

I was fortunate a decade ago to purchase a new-in-unopened crate
SCR-AS-183 set, the last of the SCR-*-183 series, made by Philco.

However, there were NO receiver coils packed with it.  Over the
years I've come to believe that the receiver coils for the AS model
were not originally made available.  Every AS receiver I ever saw
had AR coil sets.  I have only come across one proper AS receiver
coil set, the C-437.  I keep an AR C-379 dual-band coil set with
my unit, but I could now have a 100 percent correct SCR-AS-183 if
I wanted.  

BTW, the transmitter coil sets do not have the same serial numbers
as the transmitter, but they do have a red paint mark with the
transmitter serial number on each of them.

The crate also did not contain the essential TM-AH-172 junction box
since that wiring was supposed to be part of the aircraft manufacturer's
airframe wiring.  I was able to find a new one in Fair Radio's warehouse
in 2002.  There wasn't a 24-vdc version of this junction box, so
SCR-*-283 folks would have to roll their own.

>Connectors I'd like to buy or trade for:

I was able to get all the connectors I needed for my set from William
Perry, for five to ten dollars each.

I like the last 12-vdc USN RU/GF set (RU-16/GF-11) better.  Mine has all
matching serial numbers on each component and came with connectors. But
both the USN and the USAAF sets are interesting, and electrically very
different from each other though superficially similar visually.  All of
these have a definite mid-1930s air about them.  The tubes in the GF sets
haven't become audiofool holy relics as the SCR-*-183/283 transmitter tubes
have become, and even the WECO built RU/GFs appear to have been better
executed than the late SCR-*-183/283 gear.

Mike / KK5F