[Milsurplus] AN/ARC-38 and AN/ARR-41

[Mike Morrow]

Jack wrote:

> ...When the two above radios were installed in the same aircraft,
> did they share the same antenna, or did they use separate
> antennas?

Hi Jack,

The manuals and the overall system wiring diagram for the AN/ARC-38 and the associated antenna coupler CU-351/AR indicate no facility for interconnecting the AN/ARR-41 directly to the AN/ARC-38 or CU-351/AR.  Thus, there is no provision for AN/ARR-41 antenna switching, nor has the AN/ARR-41 any muting-on-transmit capability.

I strongly suspect that the AN/ARR-41 utilized a separate antenna.  I suppose that connecting the receiver output of the CU-351/AR to both the R-641 and the RT-311/-594 may have worked acceptably, if only one antenna was available.

I know some USN patrol aircraft after 1960 had both the AN/ARC-38A *and* the later AN/ARC-94 (Collins 618T-2) in place at the same time, plus the AN/ARR-41.  In the pre-AN/ARC-38 era, the AN/ARC-25 that was commonly used in USN patrol aircraft often consisted of one AN/ART-13 transmitter and *two* AN/ARR-15 receivers.  It appears to me that there's always been a need for multiple HF antenna on these types of aircraft.

Some list members have removed components of these systems from aircraft in the Arizona boneyards, so perhaps they can report the actual configutations they have seen.

I've assembled just about everything I need to some day connect up my CW/AMe/USB AN/ARC-38A, CU-351/AR, AN/ARR-41 system.  I consider the AN/ARR-41 to be a integral part of the AN/ARC-38, even though it's not closely tied in electrically.  I also have the earlier CW/AM RT-311/ARC-38 that can be put in place the RT-594/ARC-38A, but I've not been able to find a C-1398/ARC-38 main control box for it.  I suspect that most of them got converted to C-3428/ARC-38A control boxes.  Unfortunately, the manual for the AN/ARC-38 and -38A provides no schematic for the C-3428, and the verbal description of the changes which make a C-3428 from a C-1398 are very hard to follow.  Thus, I don't know how the RT-311 would work if used with the C-3428.

I like these cold war sets.  Although not nearly as large and heavy and oddly-constructed as the USAF's RCA-made AN/ARC-21 and AN/ARR-36 combo from the same era, I think these USN Collins-made systems would give the RCA stuff some good performance competition.  I wonder how RCA won the contract to convert the Collins RT-311/ARC-38 to the Collins/RCA RT-594/ARC-38A.  RCA must have gained the necessary expertise when it came up with the design converting the 145-pound barrel-shaped AM RT-128A/ARC-21 to the USB RT-400/ARC-65.

Mike / KK5F