Note
QST, Jan 1979, p. 149.
QST, Jan 1980 p. 113.
QST, Apr 1981, p. 204.
QST, Jan 1982 p. 209.
The QF-1A replaced the original QF-1 in 1979. There were several refinements.
Four main filter modes for any QRM situation.
Continuously variable main selectivity (to 20 Hz) PEAK CW (or voice) with a 20 HZ bandwidth, but also variable all the way to "flat." Continuously variable main frequency (250 to 2500 Hz, all modes).
Auxiliary Notch rejects 80 to 11,000 Hz! Covers signals other notches can't touch. Reject whistles with the most flexible NOTCH you've heard. Wide or narrow. Depth to 70 dB.
LOWPASS helps cope with SSB hiss and splatter. Skirts exceed 80 dB.
Dual Notch Capabilities: Most above features were in the original QF-1.The "A" model is more selective, adds a HIGHPASS mode for SSB, and a great AUXILIARY NOTCH (35 to 60 dB) to give two notches, notch/peak, notch/lowpass, or notch/highpass.
Power & Build: 115 VAC supply built-in. Filter by-passed when off. Filter supplies 1 watt to fill a room. No batteries required. (12 VDC hookup possible.)
Dimensions & Style: 6x5x2½". Handsome light/dark grey styling. Get yours today!
References
Review. QST, Jul 1980, p. 44.
