[ARC5] RE: ARC-5 Plugs

[Morrow, Michael A.]

> I am a volunteer at the Museun of Flight in Seattle, where we are =3D
> restoring the T-Square 54, a WWII B-29 which flew out of the Marianas.
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> We have the ARC-5 transmitters and modulator and receivers=20
> for her, but are without the associated cables.

I hope it's a USAAF/Army Signal Corps SCR-274-N (BC-442, -450, -451, =
-453 through -459, etc.) set, and NOT an AN/ARC-5 set that you're =
restoring for a B-29.  I don't think there's any evidence for the normal =
use of the AN/ARC-5 sets by any service but the US Navy.  It is =
inconceivable that a USAAF B-29 would have had an AN/ARC-5 installation.

As an added bonus, now-a-days SCR-274-N components are much easier to =
accumulate (i.e., more common) than all the proper AN/ARC-5 components =
would be. =20

Actually, it would really really surprise me that **any** HF **command** =
set would be carried on a B-29.  I'd think that the VHF command set =
AN/ARC-3 would be far far more likely instead.  At least one B-29 at the =
US Air Force Museum had an AN/ARC-3 in it.  If in fact an HF SCR-274-N =
was installed, it would likely have had most of its components in the =
natural unpainted aluminum finish of most of the late WWII SCR-274-N =
components.

William Perry Company of Louisville, KY, has a good selection of most =
SCR-274-N connectors, at least as of last August.  The plugs you'd need =
for a typical SCR-274-N two-transmitter, three-receiver installation =
are:

                                       Quantity
PL-147-A  28 vdc to FT-220-A    2-pin    1
PL-148-A  28 vdc to BC-456-E    3-pin    1
PL-151-A  BC-456-E to FT-220-A  6-pin    2
PL-152-A  BC-450-A to FT-220-A  8-pin    6
PL-153-A  BC-451-A to BC-456-E  18-pin   2
PL-154-A  BC-456-E to FT-226-A  12-pin   2
PL-156-A  BC-442-A to FT-226-A  5-pin    2

Non "-A" plugs work too.  They have a backshell that the "-A" plugs do =
not.

The following is a listing of **all** other components of a typical =
SCR-274-N two-transmitter, three-receiver installation:

BC-442-A  Antenna Relay
BC-450-A  Control Box, for Three Receivers
BC-451-A  Control Box, for up to Four Transmitters
BC-453-B  Receiver  190 to 550 KC
BC-454-B  Receiver  3.0 to 6.0 MC
BC-455-B  Receiver  6.0 to 9.1 MC
BC-456-A, B, or E  Modulator, Transmitter
BC-457-A  Transmitter  4.0 to 5.3 MC  *
BC-459-A  Transmitter  7.0 to 9.1 MC  *
DM-32-A   Dynamotor, Receiver  (On receiver, three needed)
DM-33-A   Dynamotor, Modulator
FT-220-A  Rack, Three Receivers
FT-221-A  Shock Mount for FT-220-A
FT-222-A  Mount for BC-450-A
FT-225-A  Shock Mount for BC-456-E
FT-226-A  Rack, Two Transmitters
FT-227-A  Shock Mount for FT-226-A
FT-228-A  Mount for BC-451-A
FT-229-A  Shock Mount for BC-442-A
FT-230-A  Adapter, Receiver Remote Control  (Part of each receiver)
MC-211-A  Coupling, Right Angle for Tuning Shaft  (Three needed, =
optional)
MC-212-A  Control Box Dial  190 to 550 KC  (Part of BC-450-A)
MC-213-A  Control Box Dial  3.0 to 6.0 MC  (Part of BC-450-A)
MC-214-A  Control Box Dial  6.0 to 9.1 MC  (Part of BC-450-A)
MC-215-A  Tuning Shaft, Flexible (Length as required, three needed)

* Or BC-458-A 5.3 to 7.0 MC, or BC-696-A 3.0 to 4.0 MC

Don't forget the manual:

T.O. 08-10-50  SCR-274-N Operation and Maintenance Instructions


Mike / KK5F



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