Note
QST, Jan 1965, p. 119. (910A)
QST, May 1965, p. 119.
QST, May 1966, p. 119.
QST, Aug 1968, p. 5.
Sometimes called the GSB-VI or GSB-6.
The Gonset Model 910A Sidewinder is a 6-meter transceiver designed for SSB, AM, and CW operation across the 49.975 to 54.025 MHz frequency range. Released in the mid-1960s, it stands out for its early hybrid architecture—combining solid-state transistorized receiver and oscillator circuits with vacuum tube final transmit stages to maintain a compact footprint.
The transceiver utilizes solid-state circuitry throughout the receiver, audio stages, low-frequency VFO, and high-frequency crystal oscillators. Vacuum tubes are reserved strictly for the transmit mixer (6EA8 pentode section), driver stage (12BY7A), and final RF amplifier stage (6360 dual tetrode operating in Class AB1).
The 910A operates with a power input of 20 watts PEP on SSB, 20 watts on CW, and 6 watts on AM.
The receiver employs double conversion across all modes. The first IF operates across a 14.5 to 15.5 MHz bandpass range, followed by a second IF at 9 MHz using a high-selectivity crystal lattice filter.
The receiver features a dedicated product detector for SSB/CW signals and a diode detector for AM, backed by a Class B push-pull audio amplifier delivering 2.5 watts of audio power. Receiver sensitivity is rated at 0.5 uV for a 10 dB signal-plus-noise to noise ratio, with image rejection of –50 dB.
A four-position "Sector" switch divides the 6-meter band into four distinct 1-MHz segments (50–51 MHz, 51–52 MHz, 52–53 MHz, and 53–54 MHz).
Main frequency control is provided by a stabilized 5.5 to 6.5 MHz VFO. Alternatively, the unit can be crystal-controlled using fundamental-mode crystals operating between 5.5 and 6.5 MHz. Sockets are provided for up to four crystals—one accessible directly on the front panel and three housed internally.
For transceiver operation, the unit includes an offset tuning that allows the receiver to be fine-tuned ±1.5 kHz independently without shifting the transmitter.
A front-panel pull-switch on the RF Gain control cuts filament power to the transmit tubes and dial lamps, reducing current drain during long monitoring sessions in mobile setups.
Power Supplies & Accessories: The 910A requires an external power supply housing the system speaker and high-voltage T/R relay. Gonset offered the Model 911A for 120 VAC fixed-station operation and the Model 912A for 12 VDC mobile applications. The unit was also designed to drive the matching Gonset 913A RF linear power amplifier.
