QST, Sep 1969, p. 121.
QST, Feb 1971, p. 5. ("transceiver of the 70s")
Hamtronics ad: "National is back." First seen QST, Nov 1976, p. 131.
QST, Jan 1977, p. 147.
The NCX-1000 makes a comeback? Along with NCL-2000 and HRO-500.
The ads ran until May 1977.
