The current version of the long line of HRO receivers -- the 50Kc to 54Mc
double conversion HRO-60. Standard equipment is every electronics
laboratory in the country because of its enormous frequency range, low
noise, and absence of spurious signals or images. Take another look at
the 1934 HRO "Senior" -- There aren't many such designs with a 30 year
life!
Over ten years ago, National's AM-FM Criterion tuner (shown in rack model
monitoring version) incorporated a number of firsts -- a drift-free
oscillator that eliminated the need for AFC ... FM squelch ... The first
binaural tuning [stereo with one channel on the FM band and the other on
the AM band] ... The first wide band detector.
National's famous AN/MRC-80 is a tactical, transportable, self-contained
two-way tropospheric scatter facility for radio-telephone, CW, or teletype.
The MRC-80 is used by the U.S. Army for reliable field communications when
terrain or military considerations do ot permit telphone links.
National's "Dream Receiver", the NC-300, was probably the fastest selling
deluxe amateur receiver ever manufactured. Double conversion, the NC-300
covered all ham bands from 160 through 10 meters, with separate slide rule
dial scales and converters for the 6, 2, and 1 1/4 meter bands.