When should a bit test be performed on the PRC 149?

A bit test, or Built-In Test, is crucial for ensuring the proper functionality of the PRC 149 radio before any operation. Performing this test when the switch is in any position other than off is essential since it allows the user to verify that the radio is operational and free from faults at that time. This is particularly significant in a tactical environment where communication reliability can be critical.

Testing only before every use would not effectively guarantee that the radio works correctly under operational conditions if it's activated or adjusted later. Conducting the test after every 20 uses may not catch potential issues promptly, and relying on damage as a trigger for testing could lead to failures during critical communications. Therefore, conducting the bit test when the switch is not in the off position ensures that the system is continually monitored for optimal performance, enhancing safety and operational readiness.