Loss of the SELCAL Code by the HF 1 System

TASK 23-51-00-810-823-A
Loss of the SELCAL Code by the HF 1 System

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 23-51-00-810-828-A	Loss of the SELCAL Code
ASM 231101
AMM 23-11-33-000-001	Removal of the HF Transceiver
AMM 23-11-33-400-001	Installation of the HF Transceiver
AMM 23-51-00-710-002	Operational Test of the SELCAL System
AMM 23-51-34-000-001	Removal of the Audio Management Unit (AMU) (1RN)
AMM 23-51-34-400-001	Installation of the Audio Management Unit (AMU) (1RN)

3. Fault Confirmation
Subtask 23-51-00-710-050-A

A. Test
(1) Do the operational test of the SELCAL system AMM 23-51-00-710-002.

NOTE: Do this test for each HF and VHF system.

4. Fault Isolation
Subtask 23-51-00-810-072-A

A. If the ground station cannot make a SELCAL call:
(1) During the operational test of each HF and VHF system:

(2) During the operational test of the HF 1 system only:

(a) If the fault continues:

1 If the fault continues:

Do a check and repair the wiring from the XCVR-HF, 1 [3RE1] pins AB/3D, 3C to the AMU [1RN] pins AA/4H, 4J ASM 231101.

Subtask 23-51-00-710-051-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:25:44 UTC