Receiver Output Adjustments

TM 11-5820-509-35

3-22. Receiver Output Adjustments (fig. 3-94, 3-106)

(a) KILOCYCLES indicator to 2225.

a. Preliminary Procedures.

(b} CW-FSK/VOICE: switch to VOICE.

(1) Remove the RT-671/PRC-47 from its

case using the procedures of paragraph 3-11.

(d) VOLUME control to maximum

(2) Connect the primary power source to the

clockwise stop.

POWER connector on the front panel of RT-671/PRC-

(e) POWER-LIGHTS switch to POWER

47.

ON.

(3) Connect the output meter, signal

b. Adjustment Procedures.

generator and frequency counter to the receiver-

(1) Observe the output meter and adjust

transmitter as shown in figure 3-106.

A1R54 (fig. 3-94) to obtain a reading of 1000 milliwatts

(4) Set the output meter IMPEDANCE switch

(18 volts in 300 ohms).

to 300 ohms, and adjust the meter multiplier for 5000

(2) Return the POWER-LIGHTS switch to

milliwatts full scale.

POWER OFF and disconnect the test equipment.

(5) Adjust the signal generator to 2226 kHz

(3) Return the RT-671/PRC-47 to its case

and set the output level to 1000 microvolts.

using the procedures listed in paragraph 3-11 if no

(6) On the front panel of RT-671/PRC-47, set

further adjustments are required.

the controls as follows:

Figure 3-106. Receiver Audio Output Adjustments, Test Equipment Setup.

3-23. Receiver AGC Circuit Adjustments

(fig. 3-94, 3-107)

(d) POWER-LIGHTS

switch

a. Preliminary Procedures.

POWER-ON.

(1) Remove the RT-671/PRC-47 from its

b. Adjustment Procedure.

case using the procedures listed in paragraph 3-11.

(1) Observe the multimeter and adjust A1R52

(2) Connect the primary power source to the

(fig. 3-94) until a further counterclockwise adjustment

POWER connector on the front panel of RT- 671/PRC-

has no effect on the meter reading, but a clockwise

47.

adjustment increases the meter reading.

(3) Connect the dc probe of Multimeter ME-

(2) If step b (1) is unsuccessful, adjust A1R52

26A/V to test jack A1J15 (fig. 3-94).

to its clockwise stop and then vary the output of the

signal generator between 0.1 and 1.6 microvolts. The

(4) Connect the signal generator and

agc threshold must occur between 0.6 and 1.2

frequency counter to the ANTENNA terminal of the

microvolts.

receiver-transmitter as shown in figure 3- 107.

(3) Return POWER-LIGHTS switch to

(5) Adjust the signal generator to 2226 kHz

POWER OFF and disconnect the test equipment.

and set the output level to 1 microvolt.

(4) Return the RT-671/PRC-47 to its case

(6) On the front panel of RT-671/PRC-47, set

using the procedures of paragraph 3-11 if no further

the controls as follows:

adjustments are required.

(a) KILOCYCLES indicator to 2225.

(b) CW FSK/VOICE switch to VOICE.

3-125