[Milsurplus] ARR-41 Info

[Mike Morrow]

Ray wrote:

>Couple questions, one if the ARR-41 was paired for use with the ARC-38
>family why was their never a SSB conversion for that receiver? I wonder
>if their may have been a application for the ARR-41 for teletype use?

It was definitely used for RATT service on some aircraft, but a USB-modified AN/ARR-41 could have performed the same role as a RATT receiver, if there had been some value to having a USB AN/ARR-41.  I believe the real answer is that it wasn't worth the effort to make a USB version of the R-648/ARR-41.  The USB conversion of the RT-311 was developed and performed by RCA (not Collins) around 1961, about the time that the much smaller, much lighter, much higher powered, much more versatile, much easier to use, full HF coverage 618T and its military versions like the AN/ARC-94 and -102 were appearing in quantity.  The USB coversion was essentially an add-on life-extending kludge to old, existing, in-place installations that were otherwise about to become completely obsolete.  There wouldn't be much point in the USN spending the effort and money to upgrade an HF auxillary receiver like the R-648, which in fact can do a reasonably good job of USB reception as-is.  The USB mod for the RT-311 must have cost an arm and a leg.

The contemporary equivalent USAF system was the AN/ARC-21 and its auxillary receiver AN/ARR-36.  When most of the AM AN/ARC-21 sets were converted to USB AN/ARC-65 sets in the late 1950s/early 1960s, there was no USB upgrade developed for the AN/ARR-36.  The USAF apparently adopted the same outlook as the USN, with respect to spending money on the auxillary receivers of soon-to-be-outmoded systems.

>the 618S1-4 manual has several paragraphs about use of the 618 for
>teletype operations and in many larger Navy aircraft tactical teletype
>receive circuits may have been common.

The 618S-1 and the 618S-4 were, AFAIK, not bought under the civilian model number by the US Navy.  Every military-use 618S-1 I've ever seen had USAF contract numbers on the name plate.  The US Navy seems to have progressed from the AN/ARC-38 to the AN/ARC-38A to the AN/ARC-94 in most instances.

Mike / KK5F