A Wide-Bandwidth Medium-Frequency Receiver

Radio-frequency signals of relatively wide bandwidths are being transmitted in the communications-frequency spectrum which extends approximately from 15 kc to 30 Mc.A countermeasures receiver must have sufficient bandwidth to accept all of the transmitted sideband frequencies if itis to present all of the information that was transmitted.An experimental tuned-radio-frequency amplifier and detector has been developed with a fractional bandwidth often percent of the center frequency. It is tunable through a frequency range of 500 kc to 2 .5 Mc and maintains practically constant gain. The receiver skirt selectivity measured at the 60 and 6 db points is approximately 3. 75to 1. The receiver is composed of flat-staggered quintupler-f stages, in which both capacitance and inductance aretuned, and a push-pull detector followed by two de-coupled cathode-follower video filter stages.