Collins 75S-1 Receiver Specifications

75S-1 Receiver.

The 75S-1 receives single-sideband, CW, or AM signals in all amateur bands between 3.4 and 30.0 mc.

Frequency Coverage.

The receiver coverage is in 14 bands, each 200 kilocycles wide. With the crystals furnished, they cover the entire amateur bands of 80 meters, 40 meters, 20 meters, 15 meters, and a 14.8- to 15.0-mc band including WWV, and the 28.5- to 28.7-mc portion of the 10-meter band. The two remaining crystal sockets may be used for crystals selected to provide two additional 200-kc bands within the 10-meter band. Other crystals may be substituted for those furnished to place the receiver at other frequencies throughout the range.

Requirements for Operation.

The receiver requires a 110-volt, 50- to 60-cps, a-c power source and consumes approximately 90 watts of power from the line. It may be operated mobile from a d-c power supply by using the proper connector. In this service, the receiver requires a +150 volts d-c at 125 ma, -70 voltes d-c at 5 ma, and 6.0 voltes d-c at 5.5 amperes, or 12.0 to 14.0 volts d-c at 2.75 amperes, or 24.0 to 28.0 volts d-c at 1.375 amperes. The 75S-1 should be connected to a speaker with 4-ohm voice coil. Any type headphones may be used.

Specifications.

Frequency range	3.4 to 30.0 megacycles. With crystals furnished, bands are as follows: 3.4 to 3.6 mc, 3.6 to 3.8 mc, 3.8 to 4.0 mc, 7.0 to 7.2 mc, 7.2 to 7.4 mc, 14.0 to 14.2 mc, 14.2 to 14.4 mc, 14.8 to 15.0 mc, 21.0 to 21.2 mc, 21.2 to 21.4 mc, 21.4 to 21.6 mc, and 28.5 to 28.7 mc.
Mode	Single sideband (selectable), CW, or AM.
Sensitivity	One microvolt for 15-db signal-plus-noise to noise ratio for SSB operation.
Selectivity	SSB: 2.1 kc at 6 db down, 4.2 kc at 60 db down. CW: 0.5 kc at 6 db down, 1.0 kc at 60 db down. (with accessory filter) AM: 4.5 kc at 6 db down, 25 kc at 60 db down.
Spurious response	Image rejection better than 50 db. Internal spurious signals below one microvolt equivalent antenna input.
Frequency stability	After warmup, stable to within 100 cps.
Dial accuracy (after midband calibration)	Better than one kc on any band.
Dial backlash	Less than 50 cycles.
Output level	0.25 watt at avc threshold. 1.8 watts maximum.
Size	6-9/16 inches high, 14-3/4 inches wide, 11-1/2 inches deep.
Weight	20 pounds.