QST, Jun 1962, p. 164.
QST, Jul 1962, p. 154. (description)
QST, Dec 1963, p. 175.
QST, Apr 1964, p. 160.
QST, Mar 1966, p. 144.
TM-1 for cathode keying.
TM-1G for grid block keying.
Disappeared from advertising for 6 months beginning in July 1963, but returned in December as the Model B.
TM-1 squelches receiver output and injects adjustable side-tone into headphones for monitoring of keying.
– TM-1 can be used for code-practice and AM reception.
– Fully transistorized.
– Handles up to 300 volts at key terminals.
TM-1 for cathode-keyed rigs
TM-1G for blocked-grid keying
The "B" version includes several improvements. Sidetone generator has full frequency range; battery drain has been reduced greatly; and provides better impedance matching between the Monitor and your phones.
