[Milsurplus] VRC-12 and other stuff

[Mike Morrow]

Ken wrote:

> I also looked for PRC-74 stuff, and the same thing occurs.

The RT-794B/PRC-74 was made by Hughes...the B-model came out in 1968...prime Vietnam War gear.  It is all solid-state, supports USB and CW, and covers 2 to 17.999 MHz.  Earlier models are 2 to 11.999 MHz.  It used the same batteries as the AN/PRC-25.

> I thought the PRC-77 was a CW only transceiver, crystal controlled, and not used much by 
> the military, but so far have found nothing on that.

The RT-841/PRC-77 (30 to 76 MHz FM) came out in 1968 to replace the RT-505/PRC-25, with which it was absolutely identical in outside appearance.  However, the RT-841 supported wide-bandwidth X-mode reception required for use with the TSEC/KY-38 Nestor voice encryption set (as big as the RT-841 itself), and eliminated the RT-505 PA vacuum tube and increased the transmitter power output.  It's prime Vietnam War gear that remained in US service until the early 1990s, and in reserves until a few years after 2000.  The USN and USMC continued using the RT-505, instead of the RT-841, well into the early 1970s.

It's been noted already that you are thinking of the very early 1960s RT-654*/TRC-77 (2 to 8 MHz 8-channel crystal controlled, CW-only transmission).  There was also a USB and CW transmission-capable version during the same time known as the RT-655*/TRC-88. (I have one, serial number 9)

The confusion between the AN/PRC-77 and AN/TRC-77 possibly lead to the glaring error in the third document dated 2005 that Tom Bryan cited in his posting.  At one point that document states that in 1965 a LRRP team in Vietnam would be provided with an AN/PRC-25 or AN/PRC-77 with AN/GRA-71 code burst keyer.  The AN/PRC-77 did not exist in 1965, and could not have been used with the AN/GRA-71 if it had.  Obviously, the author meant "AN/PRC-25 and AN/TRC-77 with AN/GRA-71".  It's interesting that one of Tom's 1963 articles notes that the shortwave spectrum was extremely crowded in SE Asia in 1963 (time of testing in Thailand), allowing sometimes only one of the eight channels of the AN/TRC-77 or -88 to be of use, due to interference.  Another evaluated set with a synthesizer was much more usable.  That was the Hughes HC-162 (USB, CW, 2 to 11.999 MHz in 1 kHz increments) that soon became the RT-794/PRC-74.

Mike / KK5F