[Milsurplus] Manual for RD-142/UN?

[Bruce Gentry]

On 2/18/13 10:32 PM, Brad Hernlem wrote:
> I am trying to find the manual (or identify it, at least) for the 
> RECORDER-REPRODUCER, SOUND RD-142/UN
> This is a vacuum tube based tape recorder that uses 2" recording tape.
> Is there another mil designation for equipment of which this is a part?
> Any help is greatly appreciated.
>
> Brad
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I can't help with a manual, only some recollections of  this interesting 
recorder. It works on a principle very similar to old video recorders, 
the head wheel scans the heads across the slowly moving tape to lay down 
the track. I never saw one in actual use, just got to fool with one in 
the store room at Griffiss AFB 43 years ago.  They were probably from 
the early 1950s for logging air traffic control conversations. Others on 
this group are very welcome to correct me. The few people I met who had 
worked with them hated them and refused to share any information with me.
    There was an even more unusual audio recorder from the 1950s that 
embossed an analog mechanical sound groove   on an endless plastic tape 
in a big cardboard cassette. I only saw the cassettes, the person who 
had them would not describe the equipment any further. Considering the 
competition and patent catfights over audio recording at the time, there 
are probably even more unusual systems that are fading or have faded 
into oblivion.

      Bruce Gentry, KA2IVY