Radio Shack TRC-445 - Adjusting the Standing Wave Ratio

10
ADJUSTING THE STANDING WAVE RATIO
Most antennas are factory tuned. How-
ever, you can usually improve radio per-
formance by tuning your antenna
system to the CB’s RF output power us-
ing the SWR meter on this radio.
Once you have installed the antenna ac-
cording to its instructions, follow these
steps to adjust the standing wave ratio
to your equipment.
Note
: You cannot change the SWR on
some mobile and base-station anten-
nas.
1. Turn on the CB by turning
OFF/VOL-
UME
clockwise until it clicks.
2. Set
S/RF/SWR/CAL
to
CAL
.
3. Hold down the microphone’s talk
button and adjust
SWR CAL
so the
SWR/RF/signal meter’s needle
points to
CAL
t
(on the top SWR
scale).
4. Release the microphone’s talk but-
ton.
5. Set
S/RF/SWR/CAL
to
SWR
.
6. Press the microphone’s talk button
again and read the meter’s needle
on the top SWR scale for the
antenna’s actual SWR measure-
ment. Refer to the Standing Wave
Ratio Chart on Page 11 to interpret
the SWR meter readings.
The SWR is keyed to the actual frequen-
cy of the RF signal transmitted. There-
fore, you will get a different SWR
reading from one CB channel to anoth-
er. Almost all the CB transmissions usu-
ally fall within an acceptable range.
However, for optimum radio perfor-
mance, we recommend you “fine tune”
the antenna’s system to the most com-
monly used CB channel. If you have no
particular channel preference, set your
antenna’s SWR for maximum perfor-
mance on Channel 19.
Illustration
Figure 13
Illustration
Figure 13
Illustration
Figure 13 and
Figure 19
21-1573.fm Page 10 Thursday, August 5, 1999 9:22 AM