Note
The HD-11 is essentially the same Q multiplier as the older QF-1 but with the addition of a built-in power supply, a pilot light, and the classic Heath two-tone green paint scheme. For additional details and specifications, refer to QF-1. Also see GD-125—the product into which the HD-11 would eventually evolve—still the same basic design.
Tube: (1) 12AX7
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.
