IF. ATTENUATOR MODULE A4900 (HOMING MODE).

TM 11-5820-670-30

1-51. RF CONTROL ASSEMBLY P/O MODULE A4500 (HOMING MODE). (CONT)

The rf attenuator circuit operates only in homing mode and is controlled by agc voltage from the homer

rf agc amplifier.

When low level homing signals are applied from the diode switch to the rf attenuator, agc voltage from

the agc amplifier increases, allowing signals to pass with no attenuation. As the homing signal level

increases, agc voltage decreases causing the attenuator output level to decrease.

The rf attenuator has a signal loss approaching 40 db with low agc input voltage. The 40 db attenuation

of the homing signal is sufficient to prevent overload under the strongest signal operating conditions.

Rf signals from the rf attenuator circuit are applied through energized relay K4502 to the antenna

tuning and protection circuits.

1-52. IF. ATTENUATOR MODULE A4900 (HOMING MODE).

EL1AT127

The if. attenuator attenuates signals only in homing mode and is controlled by agc voltage from the

homer if. agc amplifier.

When low level homing signals are applied from the mixer to the if. attenuator, if. agc voltage

increases to approximately 10 volts which causes the if. homing signals to pass with minimum attenu-

ation. As the homing signal level increases, the agc voltage decreases, causing the attenuator output

level to decrease. With low agc voltage applied to the attenuator circuit, the attenuator has a signal

loss of approximately 40 db.

11.5 MHz if. homing signals from the if. attenuator are applied to filter FL4001.

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