HY-2 VOCODER (Voice Coder)

Designed in 1961, this device was used for converting speech into a form compatible for encryption by a general purpose key generator  (ie KG-13) and transmission over a narrowband radio or telephone channel. It was a 16-channel, 2400-bps system using Flyball color-coded modular logic to reduce the weight to 100 pounds.The HY-2 was widely deployed in Vietnam but according to NSA web documents, President Johnson refused to use the HY-2 because of its poor "Donald Duck" sounding  quality. Its wide deployement is confirmed by its use in AUTOSEVOCOM I, a worldwide secure voice network used by the US government in the 1960's.
The  HY-2  was  the last generation of channel vocoder technology in the US.
hy02.jpg
This example of the HY-2 can be found in the National Cryptologic Museum. (Photo by  Doug Eyre)
hy02_02.jpg
Another view. (Photo by Vin Simmons)

 
 
 
hy02_03.jpg
Closeup of front panel. The meter face indicates it was made by Honeywell.  
hy02_04.jpg
Closeup of National Cryptologic placard.
Both images in this table are deratives from Ralph Simpson's photos. 


Credits and References :

1) Doug Eyre, Hewitt, TX
2) A History of Secure Voice Coding  http://www.nsa.gov/publications/publi00048.cfm
3) Vin Simmons  <vinsimmons(at)aol.com>
4) Ralph Simpson <ralphenator(at)gmail.com>
 

Back To Menu Page
Apr 1/12