If that's a 26U, try here,

http://www.collinsradio.org/26U-1-_07-58_.PDF

Otherwise try here

http://www.collinsradio.org/html/manuals.html

Especially check out the Specifications Data section where they specify audible noise as "none." For comparison purposes, forty-some years later Outlaw only claims a 102dB S/N ratio for the 950 :-).

[This message has been edited by gw10nt (edited July 10, 2003).]