Note
The Model A-20 Preselector tunes the single range 3.9 to 22.5 MHz. Connected between the receiving antenna and shortwave receiver, the A-20 has a noise figure under 2.0 dB and a gain of not less than 18 dB. The gain is variable with a front panel control from near signal cutoff (–40 dB) to the maximum. A slow motion calibrated dial permits setting the A-20 to the peak of its passband (not less than 200kHz wide at the –3.0 dB points). The
A-20 is powered by 117 VAC with tranformer isolation for safety. Toggle switches are provided for antenna selection and preselector in/out option.
Brief description. Popular Electronics, Jul 1972, p. 88.
Brief description. Ham Radio, Sep 1972, p. 80.