Note
The 51 J-1 was introduced by Collins as a superior receiver at a premium price. The 16-tube, double-conversion superhet tuned from 0.5 to 30.5 MHz in 30 bands, each spanning 1 MHz. Frequencies in the lower dial window were marked in 1 kHz increments. It had an IF crystal filter and selectivity from 200 Hz to 3 kHz.
The 51J-2 successor was identical except for the addition of an "Input/Output" switch next to the S-meter and a front-panel adjustment screw for the 100 kHz calibrator; $875.00.
