TM 9-2350-275-BD
COMMUNICATIONS SYSTEM
b. If the problem still exists, go to step 5.
Replace KY-57 (KY-38) with a known operational KY-57 (KY-38).
5.
a. If the problem no longer exists, repair the KY-57 (KY-38) using standard
maintenance procedures.
b. If the problem still exists, refer to the troubleshooting procedures in TM 11-
5810-256-OP-4.
Detailed Assessment Steps
1. Check the KY-57 (KY-38) system by attempting to communicate in the PT (plain
text) mode with a distant station.
a.
If PT communication is not possible, refer to paragraph 11-5.
b. If PT communication is possible, go to step 2.
2. Make sure the proper code is being used by zeroing the KY-57 (KY-38) and then
resetting it with the proper code. (Refer to applicable Communications-Electronics
Operation Instructions (CEOI).)
3. Attempt to communicate with a different distant station to make sure the proper
code settings are being used.
a. If communication is restored, attempt to notify the original distant staiton in
PT that he is using improper code.
b. If communication is not established, go to step 4.
4. Make sure the proper pre-operating procedures are being used. (Refer to TM 11-
5810-256-OP-4.)
Make sure the KY-57 (KY-38) system is properly installed by checking all cables.
5.
6.
Replace the KY-57 (KY-38) with a known operational KY-57 (KY-38).
a. I f communication has been restored, repair t h e KY-57 using standard
maintenance procedures.
b . If communication has not been restored, refer to the troubleshooting
procedures in TM 11-5810-256-OP-4.
11-14
