on the part of operators, a training program is needed.
Field expedients
are not a substitute for maintenance and training. If the cause for poor
communications is some physical hindrance, a field expedient may correct the
problem. Some problems which may indicate the use of field expedients are:
Great distance between sets.
Unfavorable terrain (mountains, hills, and dense foliage areas).
Poorly chosen sites for antennas.
Insufficient battery power.
Noise and interference.
b. Operating hints.
Frequently, these causes can be overcome by
adjusting radio sets, or applying sound operating techniques. Common sense
measures frequently preclude the use of more involved field expedients.
When signals are weak, use a headset instead of a loudspeaker (this
should reduce local noise).
When transmitting, allow a few seconds for the transmitter to warm
up before transmitting. Speak slowly, directly into the microphone.
Ensure that battery voltage is normal. (It may be necessary to keep
the vehicle running to maintain battery voltage.)
Move the antenna.
Frequently a move of only a few feet improves
Reorient the vehicle toward the distant station.
NOTE:
The AN/VRC-12-series of radios uses center-fed, half-wave
antennas which are not appreciably affected by the mass of a
vehicle.
25. IMPROVISING ANTENNAS. If these hints do not improve communication, or
if whip antennas have been broken, it may be necessary to improvise an
emergency antenna. When preparing an expedient antenna, keep in mind:
Copper or aluminum wire is the best for fabricating or repairing
antennas. In an emergency, use whatever is available.
The exact length of most antennas is critical. Fabricated antennas
must have the same physical length as the antennas replaced.
Improvised guys used to support antennas may affect antenna
operation.
To ensure that guy wires do not interfere with
communication, cut them into several short lengths, and connect the
pieces with insulators.
46
Previous Page
