S 865-004

 (2)  
Make sure the applicable circuit breakers on the overhead circuit breaker panel, P11, are closed:

 (a)  
11G8, HF COMM LEFT

 (b)  
11G34, HF COMM RIGHT (IF INSTALLED)

 F.  HF Operational Test
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 S 715-002

 WARNING:_______ DO NOT OPERATE THE HF COMMUNICATIONS SYSTEM WHILE PERSONS
 REFUEL OR DEFUEL THE AIRPLANE.  AN EXPLOSION CAN CAUSE INJURIES
 TO PERSONS AND DAMAGE TO THE AIRPLANE.

 WARNING: MAKE SURE PERSONNEL STAY A MINIMUM OF 6 FEET AWAY FROM THE
_______ VERTICAL STABILIZER WHEN THE HF SYSTEM TRANSMITS. RF ENERGY FROM THE HF COMMUNICATION ANTENNA CAN CAUSE INJURIES TO PERSONNEL.
 (1)  Do the HF Operational Test as follows:
 (a)  
Set the mode selector switch to the AM position on the left HF communication control panel (P5).

 (b)  
Set the frequency selectors to an AM frequency between 2.8 MHz and 23.999 MHz (or between 2.000 MHz and 29.999 MHz on airplanes with wideband frequency operation enabled).

 (c)  
Make sure the left HF communication transceiver blower fan operates during the test.

 (d)  
Connect the headset to the PHONE jack on the left transceiver front panel.

 (e)  
Connect the hand microphone to the MIC jack on the left transceiver front panel.

 (f)  
Push and hold the SQL/LAMP TEST switch on the left transceiver front panel. 1) Make sure all three status lights on the transceiver front

 panel come on and stay on. 2) Make sure the squelch is removed and you can hear background noise in the headset.

 (g)  
Release the SQL/LAMP TEST switch. 1) Make sure all the status lights go off.

 NOTE: If a status light stays on after the
____ SQL/LAMP TEST switch is released, a fault condition is shown.
 (h)  Push and release the hand mic PTT switch. 1) Listen for a 1 kHz tune-in-progress tone in the headset.
 NOTE: A continuous or pulsed tone indicates that the
____ coupler is tuning to a new frequency. The coupler tune tone will sound no longer than 15 seconds. The average coupler tune time is 1 to 7 seconds.
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 NOTE: Some coupler types are able to tune quickly when
____ previously used frequencies are selected, in which case the tune tone may be only a momentary beep.
 2)  Make sure none of the status lights on the transceiver front panel come on.
 (i)  Push and hold the PTT switch.
 1)  Make sure none of the status lights on the transceiver front panel come on.
 NOTE: A 1 kHz tone will be heard while the PTT switch
____ is pushed if an out of range frequency is set.
 (j)  Release the PTT switch.
 G.  Right HF Operational Test (Dual HF system installations only)
 S 915-008
 (1)  Do the HF Operational Test again with the right HF communication system (if it is installed).
 H.  Restore the Airplane to Normal
 S 865-009
 (1)  
Remove the headset and the hand mic from the jacks on the transceiver front panel.

 S 865-010

 (2)  
Set the mode selector switch to the OFF position on the left and right (if installed) HF communication control panels.

 S 865-013

 (3)
Remove electrical power if it is not necessary (AMM 24-22-00).

 TASK 23-11-00-735-014
 3.  System Test - HF Comm System
____________________________
 A.  General
 (1)  This test does a check of the left HF communication system and the right HF communication systems (if installed). It includes all system adjustment specifications necessary for the best performance.
　
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