(c)
Do the COMM TEST on the VHF-L comm control panel: 1) Push and hold the COMM TEST switch.
a) Make sure you hear a tone in the headset. 2) Release the COMM TEST switch.
(d)
Set the frequency selectors on the VHF-L comm control panel to two approved test frequencies.
(e)
Push the PTT switch on the captain's audio selector panel or control wheel.
(f)
Make a communication with a test radio.
(g)
Use the TFR switch on the VHF-L comm control panel, and make sure the transmission and reception on both frequencies is clear. 1) Make sure there is an audio sidetone during the
transmissions.
(h)
During the voice communication, adjust the VHF-L volume (on the audio selector panel) along the full range. 1) Make sure the audio level changes smoothly with no change
in the voice quality.
(i)
At each remaining audio selector panel, set VHF-L MIC SELECTOR and make a voice transmission.
(j)
Make sure of the conditions that follow:
1) The audio sidetone is satisfactory.
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2) The audio level changes smoothly along the full range of VHF-L volume control.
I. Right VHF Communication System Test
S 715-011
(1) Do the VHF Communications Test again for the VHF-R.
J. VHF Communications Antenna Test
S 765-081
(1) AIRPLANES WITH BENDIX RTA-44A TRANSCEIVERS; Do the steps that follow to do the VHF Communications Antenna Test:
(a)
Open this circuit breaker on the overhead circuit breaker panel, P11, and attach DO-NOT-CLOSE tag: 1) 11C3, VHF COMM LEFT
(b)
Install the thruline wattmeter between the left VHF comm antenna and the transceiver at D41721, on the E4 rack.
(c)
Remove DO-NOT-CLOSE tag and close this circuit breaker on the overhead circuit breaker panel, P11: 1) 11C3, VHF COMM LEFT
(d)
With the wattmeter, make sure the transmitted power is larger than 18 watts.
(e)
Make sure the reflected power is less than 25 percent of the transmitted power value.
(f)
Open this circuit breaker on the overhead circuit breaker panel, P11, and attach DO-NOT-CLOSE tag: 1) 11C3, VHF COMM LEFT
(g)
Disconnect the wattmeter from D41721.
(h)
Remove DO-NOT-CLOSE tag and close this circuit breaker on the overhead circuit breaker panel, P11: 1) 11C3, VHF COMM LEFT
S 765-016
(2) Do the VHF Communications Antenna Test again for VHF-R.
(a) Use the VHF COMM RIGHT (11G31) circuit breaker on P11 and D41731 on the rear of E4.
K. Put the Airplane Back in Its Usual Condition
S 865-010
(1) Remove electrical power if it is not necessary (AMM 24-22-00/201).
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VHF COMMUNICATION TRANSCEIVER - REMOVAL/INSTALLATION
____________________________________________________
1. General_______
A. The left, right, and center (if installed) VHF communication transceivers M188, M189 and M190, are located in the main equipment center on equipment rack E4. The removal/installation procedure is the same for each of the VHF transceivers.
TASK 23-12-01-024-004
2. Remove the VHF Communication Transceiver________________________________________
A. References
(1) AMM 20-10-01/401, E/E Rack Mounted Components
B. Access
(1) Location Zones
119/120 Main Equipment Center
C. Procedure
S 864-002
(1) Open the applicable circuit breaker on the overhead circuit breaker panel, P11, and attach a DO-NOT-CLOSE tag:
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