Page 11 - May 2023 Track N Times
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TECHNICAL TRAINING
Antennas By Donald Dougherty, Senior Technician
Two-Way Radio Antennas
Today’s radio transceivers are highly reliable units that in themselves require very
little maintenance. If the transceiver has good power and antenna connections,
and clear of interfering structures, it should be able to send and receive messages
over considerable distances, especially the “base units” mounted in the cabs.
When a radio is having trouble reaching out to a station that is more than a mile
or so away, it is quite often the fault of the antenna.
If you can hear the “traffic” (spoken words and phrases) clearly from the suspect
radio on another that is “close-by”, that radio and microphone are most likely
working properly.
Another way to test the radio and antenna is to attempt to monitor weather
channels. Depending on your area, you should be able to pick up at 1-2 weather
channels clearly. If you cannot, try tightening the silver connector on the back of
the radio. If that doesn’t do the trick, further inspection of the cables, connector,
and the antenna itself are in order.
Antenna Whip and Ground Plane Checks:
Use and ohmmeter to test continuity between the outside “shield” of the antenna
connector, chassis ground or the Ground-Plane surface. This test should show
“zero-ohms” or a very low resistance.
An ohmmeter check between the Center Pin of the Antenna Connector and the
outside shield or Ground Plane. This test should show a very high resistance. If
this is okay, safely access the antenna for inspection. Look for loose or corroded
parts. If all seems in order, use an extension wire to check continuity between the
center pin of the Antenna Connector and the Antenna Whip itself. This
should show a very low to zero-ohm reading. If these “fixes” do not improve
radio system performance, it will be the necessary to call in a radio technician
who has specialized tools to troubleshoot the problem.
NEW—Email Address to Contact Tech Services for general
and non-emergency inquiries:
OPStechhelp@loram.com
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Page 9 MAY 2023
