ANTENNA TUNING AND PROTECTION MODULE A1100.

11-5820-401-34-3/0967-LP-432-3060

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CRS HUNT DISCRIMINATOR A3600, CRS PHASE DISCRIMINATOR A3700, AND REFERENCE

OSCILLATOR A2000. (CONT)

Assume that the radio is set to 30.00 MHz and the local oscillator is misalined, thereby causing it to

operate at 41.550 MHz. The output of the limiter 5.70 MHz, is 50 kHz higher than it would be if the

oscillator were exactly on frequency.

The two signals entering the phase discriminator are 5.65 MHz from the reference oscillator, and

5.70 MHz from the Limiter A3500. Because of the difference in frequencies, the phase discriminator

outputs a dc voltage. This positive dc voltage is measurable at TP3001.

ANTENNA TUNING AND PROTECTION MODULE A1100.

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Frequency-modulated rf signals from the antenna are fed to the Al 100 tuning circuits which consist of

tuned tank circuits. The resonant frequencies of the tank circuits are varied by altering the inductance

when the MC-TUNE-KC control is rotated, and by changing their overall LC ratio when the band is

The bandwidths of the resonant tank circuits allow passage of signals of the selected frequency while

unwanted frequencies are rejected.

The overload protector consists of a neon lamp which fires, shunting excess rf signal strength to

ground. From the overload protector, the rf signals are applied to the tuning circuits in the first rf

amplifier.

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