Note
QST, Apr 1962, p. 127.
The TELco SB-50 is a 6-meter heterodyne transmitting converter manufactured by Tapetone Electronic Laboratories, Inc., introduced in 1962. It was designed to allow amateur radio operators to get on the 6-meter band using their existing 20-meter transmitter without buying a standalone 6-meter rig.
The transmitter circuitry takes up only half of the internal cabinet space, leaving room inside to install a matching TELco 201 6-meter receiving converter for a self-contained setup.
The front panel features a single tuning knob ("One-Knob tuning") alongside a multi-function panel meter.
Input Requirements: 14 to 18 MHz at 50 ohms impedance (VSWR under 1.06:1). Drive power requires 5–10 watts for AM, FM, or CW, and 2–5 watts for SSB.
Output: Approximately 30 watts output (any emission mode) into a 50-ohm load.
Tube Complement:
– 6U8 (Crystal Oscillator & Multiplier)
– 5763 (High-Level Mixer)
– 6146 (Linear Amplifier)
Power Requirements: Requires external power supplies delivering 300–600 VDC at 150 mA, 200–265 VDC at 40–50 mA, and 6.3 VAC at 1.3 A. Tapetone noted it could run off the host transmitter's power supply or a Heathkit HP-20.