[ARC5] AN/ARC-4, -4X, -4A Variations, and Some AN/ARC-1 and -12 Info Too

[Mike Morrow]

Jay wrote:

> ... my AN/ARC-4 is not available. I've got too many years 
> getting it together to let it go. As it is I do not have
> the correct mount and only the remote control head, not
> the pilot's control head.

There can only be *one* control box in any AN/ARC-4* installation.
Both versions are "pilot" control boxes.

It sounds like you have the simplified control box C-52/ARC-4A that
is part of the AN/ARC-4A, rather than the full control box C-51/ARC-4
that is part of the original AN/ARC-4.  The later AN/ARC-4A is designed
for use on aircraft where power, fusing, an audio controls and jacks
are "part of the airplane", not the radio set itself.  The original 
AN/ARC-4 is a stand-alone system that provides all RT controls on the
C-51, and power fusing circuits on the J-23.

Next are listings of the components in the AN/ARC-4, -4X, and -4A. 

---The AN/ARC-4 consists of:
C-51/ARC-4     Control Box - Full control includes Reception Channel 
               (Guard Mode) Select, Transmission Channel Select, Power,
               Interphone, Volume, Microphone Jack (1), and Headphone
               Jacks (2).
DY-9/ARC-1     Dynamotor - 24 vdc only (Part of RT-19)
J-23/ARC-4     System Junction Box (Power, Fusing, and Control)
RT-19/ARC-4    Receiver-Transmitter
MT-80/ARC-5(2) Mountings for C-51 and J-23
MT-101/ARC-4   Mounting for RT-19

---The AN/ARC-4X is the same as above, except for:
DY-10/ARC-4X   Dynamotor - 12 vdc or 24 vdc (Part of RT-19)

Notes:
(1)  The MT-101/ARC-4 has two integral cable and plug assemblies that
     connect to the J-23 junction box.  If the MT-230/ARC with
     CX-182/ARC-4X is substituted for the MT-101, two new cable 
     assemblies (one to the C-51, and one to aircraft power, fusing,
     and interphone circuits) must be connected to the CX-182.  The
     J-23 is eliminated, so fusing must be provided as part of the
     power connections.

---The AN/ARC-4A consists of:
C-52/ARC-4A    Control Box - Limited control includes Reception Channel 
               (Guard Mode) Select and Transmission Channel Select only.
CX-182/ARC-4A  Cable/Connector Assembly (Adapts MT-230 mount to RT-19)
DY-9/ARC-1     Dynamotor - 24 vdc only (Part of RT-19)
RT-19/ARC-4    Receiver-Transmitter
MT-80/ARC-5    Mounting for C-52
MT-230/ARC     Mounting for RT-19

Note:
(1)  The J-23 is eliminated in the AN/ARC-4A.  A simplified control box
     is employed.  Power, fusing, and audio controls and connections
     are provided by circuitry that is part of the aircraft.
(2)  There is no official AN/ARC-4AX, but a DY-10/ARC-4X may be used
     in place of the DY-9/ARC-1 in the AN/ARC-4A.

As a side note, the Western Electric 233A set did not get its JAN nomenclature
until well after the JAN system was adopted in February 1943.  Before that,
the WE component nomenclature designations were:
233A       RT unit
702B-1     RT mount
39A        Control Box (Full)
5A         Junction Box
KS-10085   Dynamotor
703A       Dual Crystal Unit

The Operating Instruction Handbook for AN/ARC-4 Series:  AN 08-10-245.
The Maintenance Instructions Handbook for AN/ARC-4 Series:  CO AN 08-20-6.

There are other variations and ad-mixtures possible, of course, but
those above seem to be the canonical configurations.

I suspect for the PT boat, the original AN/ARC-4 configuration may be
most appropriate, rather than the AN/ARC-4A variant.

Many AN/ARC-4* major components are fairly common, especially the RT-19,
DY-9, C-52, and MT-230 with CX-182.

Other components are *not* very common, especially the  MT-80, MT-101, C-51,
J-23, and DY-10.  The MT-80/ARC-5 is also the transmitter control box mount
in the AN/ARC-5 system, as well as for some other similar-sized controls,
and is thus in high demand for that set.

The manuals are rather hard to find, especially the Maintenance Instructions.
Early versions of the Operating Instructions are untypical, because they
include a full schematic of the system.  That was eliminated by 1945.

Now, to the AN/ARC-1 stuff.

> The mount for the AN/ARC-1 looks the same but the power connector is upside
> down compared to the ARC-4 and the wiring is all different. There is also a
> warning tag to that effect on the mount.

The original AN/ARC-1 mount for the RT-18/ARC-1 is the MT-100/ARC-1.
The original AN/ARC-4 mount for the RT-19/ARC-4 is the MT-101/ARC-4.

> ... but the power connector is upside down compared to the ARC-4 and the
> wiring is all different.

True on both accounts.

But before the end of WWII, the RT mechanical mount became the MT-230/ARC,
common to both the RT-18/ARC-1 and the RT-19/ARC-4.  The CX-181/ARC-1 or
CX-182/ARC-4A cable/connector assembly has to be installed at the rear to
make the MT-230 appropriate for the set to be used.

> There is also a warning tag to that effect on the mount.

You'll find that on the MT-230, but probably not the MT-100 or MT-101.

> It could possibly be re worked with effort.

I doubt that it would be worth the effort.  If you have the wrong mounting,
the thing to do is get the much better RT-18/ARC-1 for it.  Even better,
find a RT-58/ARC-12 **UHF** set for it!  The RT-18 is very common, but
unfortunately the RT-58 is not (even though Fair Radio sold them 45 years
ago).

Mike / KK5F