Post-war military requirements demanded R & D leadership -- and National
pioneered tropspheric scatter techniques for ultra-reliable military
communications. Shown is the 10KW final amplifier of National's
This 50KW transmitter is part of NATO's main communications trunk -- the
"Ace High" tropo system.
The popular NC-125 incorporated the famous "Selectoject" variable audio
filter -- a boon to the CW man!
National's FSK-4 is a 30-65Mc tropospheric scatter RTTY system. The FSK-4
and similar earlier National tropo systems are in active use in U.S. Army
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