continue the process moving the whip down 1/8 ю 1/4 inet i ai a time u ri ti i the lowest reading is
obtained. If the SWR is higher, raise the whip 1/4 to 1/2 irich the first time and 1/8 to 1/4 inch
thereafter until the lowest SWR is obtained. Note, if the reading continues falling but you hâve
reached farthese point down that you can go with the whip, the whip may be too long. To
verify this, put the Channel Dial to Channel 1 and measure Lite SWR, Next, put the channel dial
to Channel 40 and measure the SWR. IF THE SWR WAS LOWEST ON CHANNEL 1 AND
HIGHEST ON 40 THE WHIP SECTION IS ТОО LONG. Carefully eut 1/4 to 3/8 inch from the
whip section and re-measure Channels 1, 20, and 40. If the SWR is still lowest on Channel 1
continue trimming the whip by removing 1/8 to 1/4 inch at a time until the lowest SWR is
obtained on Channel 20. DO NOT G ET OVERANXIOUS. YOU CANNOT REPLACE A
SECTION ONCE IT IS CUT OFF. If you exceed slightly the best tuning for Channel 20, the
whip may be raised 1/8 to 1/4 inch at a time to obtain the best SWR on Channel 20.
WARNING: DO NOT CUT THE WHIP USING THE "POWER OUTPUT METER TUNING
METHOD". YOU MUST USE AN SWR METER ТО ACCURATELY DETERMINE THE SWR.
Every six months or so, re-check the SWR. Car washes, rod grime, and Chemicals can eftect the
mechanical connections of an antenna and corrode them. This corrosion can cause poor
electircal connections and lead to high SWR. The correction of this problem is usually
accomplished by cleaning of the metal connection parts with a wire b rush.
HELPFUL HINTS
1.
High SWR robs you of range and puts a strain on your output transistor.
ALWAYS TUNE A NEW ANTENNA.
2.
Never tune your antenna in a closed area (garage, under a metal car port, etc.) as
may resuit.
3.
MAKE SURE A L L MECHANICAL CONNECTIONS ARE TIGHT.
4.
DON'T SMASH OR SHARPLY BEND THE COAX CALBE - it should remain generally round
to do its job properly.
5.
TIGHTEN YOUR PL-259 CONNECTOR OCCASIONALLY - road vibration has a tendency to
loosen it which can cause output transistor'Problems.
6.
PERIODICALY (every 6 months) re-check your SWR. Corrosion and road grime may rob you
o f performance.
7.
PERIODICALLY check your coax cable fo r wear. A broken or loose wire could cause RF
output transistor failure.
This information was produced to help you understand the installation and maintenance of your
antenna and cable feed system. Many field problems hâve been traced to Problems such as the above.
They can lead to eventual failure of the RF output transistor in your transceiver. Careful installation
and maintenance can prevent these problems.
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