[ARC5] SCR-274-N test sets

[telegrapher at att.net]

Back in the late 80's i bought out the remaining stock of "I" model command set test sets from ARC.  Among them were the I-85A, I-85-B, I-85-C, I-85-D, I-84-B and I-155-A.

After wondering what went where with what, i set down this am and did a stare and compare between what i have left and what the  manuals indicate.

The I-84-B unit i have is a receiver Test set and connects between a control head and the test adapter which slides onto the back of the receiver where the receiver would normally plug into a rack.  It has to "tel" jacks on the bottom along with a connector for going to primary power and then from the 2nd connector to the "special test adapter" into the back of the receivers.  The special test adapters are only indicated as part of Cord CD-706 (for the receiver)and CX-33/GRM-1 (for the transmitter) in TO 08-10-195, Dated 15 April 1944 on page 140.  I haven't found a regular illustration of the adapter for the receivers and transmitters although i do have 2 of them.

In the "Instruction Book for Radio Set SCR-274-N, no date, Order number 1470-NY-41, Figure 30 illustrates the Test Sets RC-54-A and RC-55-A.  The I-84-A is shown as a 5 meter receiver test set so i'm suspecting that the I-84-B unit i have is the newer version having one meter but being switchable and also more portable.  The I-85-A transmitter Test set was then replaced by the I-85-B, C and D, those being smaller, switchable and more portable as well.

I have 3 of the I-85C units, 1 of the I-84-B, 1 ea of the I-85-B and 1 ea of the I-85A units remaining along with 1 ea cable CX-34/GRM-1 and 2 of the test adapters that slide onto the back of the receivers/transmitters.

As ARC-5 receivers are interchangeable with the SCR-274-N receivers, so either the ARC-5 TS #7369 or the RC-54 system, I-84-A/B test sets should work.  Interconnect cords for the RC-54-A system would be the: CD-531, CD-532 or CD-533.  CD-533 terminates in "special Plug and fixture #7845".

The interconnect between the I-85-A, B, C, D and the transmitter under test is the CD-530 with special plug #7844.

Along with this is a "note 2" which states that "articles to which this note applies were were procured per Specification RE-13A-597A, of the Bureau of Ships, Navy Dept, as modified by exceptions thereto covered by Note of Contract".  This note applies to the cables with the "special plug and fixture"  Now if one were to locate this Spec., would that tell him how this Special plug and fixture is made or show a drawing or it?

Interesting stuff.  This list has been to quiet.  yeah, know the server stuff has been inop for awhile.  Hope it stirs up some discussion.

Larry
W0OGH