Note
This general coverage receiver is the forerunner of the GR-64. Its specifications and frequency coverage are similar—500kHz to 30MHz in four bands.
The GR-91 features an illuminated slide rule dial, an S meter, an electrical bandspread, and a transformer operated solid-state power supply. It includes a BFO, an internal speaker, a headphone jack (50Ω to 10kΩ), a switchable noise limiter, and is built on a single PC board. Also included is a rear panel connector for Q-multiplier like the GD-125 (see listing).
Sensitivity and selectivity are not specified and vary depending on mode and frequency. This is typical of the genre. Unlike the GR-64, the GR-91 has no built-in AM antenna. Amateur radio and international broadcast bands are marked on the dial. Refer to Figure 1 for antenna connections.
The GR-91 has a beige cabinet with a beige and green front panel, and white and red dial markings.
Frequency range:
band A: 550 kHz to 1600 kHz
band B: 1.6 MHz to 4.0 MHz
band C: 4.0 MHz to 10.0 MHz
band D: 10.0 MHz to 30.0 MHz
Sensitivity: not specified
Selectivity: not specified
IF: 455 kHz
Power requirements: 120 VAC, 50-60 Hz, 30 watts
Tubes: (1) 12AV6, (1) 12BA6, (1) 12BE6, (1) 50C5
References
Brief description. Popular Electronics, Jan 1962, p. 81.
Photos, general information and specifications from "Heathkit: A Guide to the Amateur Radio Products," by Chuck Penson, WA7ZZE. Used with permission.
