CMR-312


SINGER ELECTRONICS CMR-312 

The first system used by the Navy to help combat the growing SAM problem in Vietnam was the Singer CMR-312 also referred to by aviators as “Little Ears”. It was a small portable device about the size of a modern automobile radar detector.  The device had two suction cups which attached it to the canopy of the aircraft and a “Y” cable which tied the unit into the aviator’s helmet so he could hear an audible warning of enemy radars in the surrounding airspace. There were different sounds for the different frequencies the radars operated at, so with training and practice the aviator could determine what kind of radars were in the area.


Obviously this system was very limited.  It could not inform the aviator where the radar was in relation to his aircraft (neither direction nor distance), it could not tell if the aviator’s aircraft was the target, nor could it alert the aviator when a missile was launched.  In other words, all it did was heighten the “pucker factor” in an already tense situation in enemy airspace. It was never intended to be anything more than a stop-gap measure to buy some time until a more sophisticated system could be fit into the F-4s.

In his book "USN F-4 Phantom II Units of the Vietnam War 1964-68," Peter Davies writes: "Rear Admiral Smoke' Wilson recalled; We had just installed radar warning receivers in our airplanes - a real "Rube Goldberg" set-up (the Singer CMR 312 "Little Ears' aural system), but it worked. In order to get the capability to have a warning that a SAM radar had locked on, the troops fastened an aluminum bracket on the RIOs glare shield and installed a navigation system antenna on it. It was plugged into a 24-volt utility receptacle. With a phone jack patched in, the high-pitched "deedle-deedle-deedle" that said "Look out! Theres a SAM coming your way!" would be heard by both. John Nash remembered that Little Ears' lasted about two weeks in VF-213 in 1966, although it was in VF-161's F-4Bs in July of that year when a MiG kill credited to Lt Bill McGuigan and Ltjg) Bob Fowler. Nash recalled, They wanted to put it on the RIO's helmet and have him turn his head and scan. They looked pretty queer in the back with those things on. It was effective, but strictly directional and the RIOs were too busy to do that. The device was attached to the canopy by suction cups, with a Y-shaped lead to the RIO's helmet to the provide limited general warning of a SAM launch somewhere in the area."


Revision History: 

  • 17 MAR 2014 - Original Post
  • 03 JUL 2018 - Updated with information from Peter Davies Book.


Sources:
  • Craig Kaston
  • Wild Weasel - The SAM Suppression Story by Larry Davis
  •  First In, Last Out, Stories By the Wild Weasels, by Edward T Rock
  • USN F-4 Phantom II Units of the Vietnam War 1964-68, by Peter Davies