Stop sand before it stops you: AN/GRC-103 radio ...

Sand in cooling air filter makes the ventilation fan work harder and harder to suck in cooling air. The transmitter overheats and the OVERHEAT lamp comes on and stays on. The transmission signal degrades or the signal goes out altogether.

That's just the beginning of your problems. Components begin to bum up--like driver tubes, the RF amplifier, frequency generating circuits and the transmitting section of the duplexer.

In a desert environment, you must check the filter before, during and after every operation to make sure it's dean and stays that way. Blowing sand might require several "during operation" checks.

If the filter is sandy, remove it from the transmitter by loosening the captive screws. Use an air hose, if you have one, to blow the sand out of the filter. Direct the airflow from the inside of the filter to the outside. But don't use the air hose unless you have an air gun, NSN 4940-00-333-5541, to attach to it. (The air gun limits the outlet pressure to 30 psi, a safe level that won't damage the filter or injure you.)

If you don't have an air hose or the air gun, tap the filter and shake the sand out. If your mission permits, wash the filter in warm water and a mild detergent. Let it air dry away from blowing sand before reinstalling it. If you install it wet, sand will stick to it and cause even greater problems.

Sand also collects on the recessed area and the metal screen where the filter fits on the transmitter. Use a cloth to wipe them clean.

Also wipe down the transmitter frequently to keep sand away from the ventilation fan.