73, Sep 1963, p. 65.
The MT-75A is an updated version of the Mars MT-75 Thunderbird. It includes a number of cost saving changes, mostly in the form of less expensive components, changes the oscillator from a 12AU7 to a 12BY7, and adds an oscillator tuning control.
Extremely rare.
From the ad:
The popular MARS Mobile re-appears in a new dress and improved design. Bandswitching 75-40 with 18 watts input and plenty of good audio. Measures only 3½ x 5 x 7. Switches to either 6 or 12 volt operation. Requires 300 volts at 150 mills. Completely wired ready to operate less crystal mike and power supply.
Tube Lineup
– (2) 6AQ5
– 12BY7
Power output: 3–4 watts
