Operational Test of the Very High Frequency (VHF) System

TASK 23-12-00-710-803-A
Operational Test of the Very High Frequency (VHF) System

WARNING: MAKE SURE THAT ALL THE CIRCUITS IN MAINTENANCE ARE ISOLATED BEFORE YOU SUPPLY ELECTRICAL POWER TO THE AIRCRAFT. UNWANTED ELECTRICAL POWER CAN BE DANGEROUS.

NOTE: During this test, the aircraft must be in an open area.

NOTE: The transmission and reception test of the VHF system is the same for all crew stations. You must do the test at each station.

ZONE: 210

1. Reason for the Job
To make sure that the reception and transmission from each station operate correctly.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	BOOMSET 600 OHMS

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)

3. Job Set-up
Subtask 23-12-00-860-059-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(2) Connect a BOOMSET 600 OHMS to the applicable jack panel at the crew station where you do the maintenance.

Subtask 23-12-00-865-055-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	COM/RMP/1	2RG1	G10
49VU	COM/VHF/1	2RC1	G09
49VU	COM/INT/1+2	9RN	G08
49VU	COM/AUDIO/ACP/F/O	5RN	G07
49VU	COM/ACP CAPT/SELCAL/INT 1 AUDIO/AVNCS	4RN	G06
121VU	COM NAV/VHF/3	2RC3	L05
121VU	COM NAV/VHF/2	2RC2	L04
121VU	COM NAV/SELCAL	8RN	M04
121VU	COM NAV/ACP/THIRD/OCCPNT	6RN	M02

4. Procedure
Subtask 23-12-00-710-053-A ** ON A/C NOT FOR ALL

A. Operational Test of the VHF System

NOTE: This test is for the system 1. For the other system(s), use the indications between the parentheses.

ACTION	RESULT
1.On the RMP1:	On the RMP1:
Set the ON/OFF selector switch to ON.	The RMP shows the last frequencies and the last function used.
Push the VHF1 (VHF2, VHF3) pushbutton switch.	The green LED on this pushbutton switch comes on. The SEL indicator light (amber LED) comes on only for the VHF2 system.
In the STBY/CRS display window, with the dual selector knob, set the frequency of a station that transmits.
Start this frequency. To do this, push the transfer pushbutton switch (double arrow) between the two display windows.	The frequency set comes into view in the ACTIVE display window.
2.On the ACP of the station on which a maintenance is in progress:	On the ACP:
Push the VHF1 (VHF2, VHF3) transmission pushbutton switch.	The green bars on the VHF1 (VHF2, VHF3) transmission pushbutton switch come on.
Push and release the VHF1 (VHF2, VHF3) reception pushbutton switch.	The reception pushbutton switch comes on.
Make sure that the reception in the boomset is correct.
Smoothly turn the VHF1 (VHF2, VHF3) reception pushbutton switch clockwise.	The reception you can hear must change smoothly without interference.
Set the INT/RAD switch to RAD and hold it in this position (You can do this operation on the PTT switch of the sidestick controller at the CAPT. or F/O station).
Speak in the boomset microphone.
Make sure that the transmission is correct.
Release the INT/RAD switch (or the PTT switch on the sidestick controller at the CAPT. or F/O station).	The INT/RAD switch comes back to the center position.

5. Close-up
Subtask 23-12-00-860-060-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) On the ACP, push the VHF1 (VHF2, VHF3) transmission pushbutton switch and the VHF1 (VHF2, VHF3) reception pushbutton switch.
(2) On the RMP1, set the ON/OFF selector switch to OFF.
(3) Disconnect the boomset at the crew station where you do the maintenance.
(4) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 05:20:00 UTC