November 23rd, 2015, 23:47
Obie311 was correct the set indeed predated 1975. By 5 years actually.
The creative atmosphere at King Radio has yielded many important firsts. King brought the first all solid-state transceiver for airline use to the market in 1966, the KTR 900: the first digital ADF for general aviation, the KDF 800, in 1969; and the first low cost all solid-state TSO'd VHF NAV/COMM unit, the KX 175, in 1970.
Found here, in the Ed King story: http://mcguinn1342.blogspot.nl/2006/01/ed-king-story.html