Antenna Connections
The Stryker SR447/497 has a jack in the rear for a standard PL-259 antenna plug. If
you are looking for the most range for your transmission, use a vertically polarized,
quarter-wave length antenna. If antenna height is a problem, you may use a shorter,
loaded-type whip antenna although you can expect some loss of transmission range.
Your antenna should always be adjusted for the lowest possible SWR (1.5 or less.)
To adjust your antenna for best performance you must use a SWR meter, these can be
purchased separately for at little as $12.95 from various retailers. Failure to properly
adjust your antenna(s) will diminish your operational range and could result in damage
to your radio. Damage that results from operating with high SWRs is not
covered under your factory warranty!
Tuning the Antenna for Optimum SWR
Because such a wide variety of base and mobile antennas are available, this section
will concern itself only with the usual types of mobile adjustable antennas.
Antenna length is directly related to signal frequency. Therefore, it must be
tuned to resonate optimally throughout the frequency range of the transceiver.
Lower frequencies require a longer antenna than higher frequencies.
Due to the various methods of adjusting antennas for proper SWR, we have
chosen what we think is the optimum method:
A. Antennas with adjustable screws (setscrews).
1. Start with the antenna extended and tighten the setscrew lightly enough so
that the antenna can be lightly tapped with your finger for easy adjustment.
2. Set your Stryker radio to your desired operating frequency or the center of
the range of frequencies you plan to use. Press the PTT (Press-To-Talk) switch,
and tap the antenna (making it shorter). The SWR meter will show a lower reading
each time the antenna is tapped. By continuing to shorten the antenna, you will
notice the SWR reading will reach a low point and then start rising again.
This means that you have passed the optimum point for the middle frequency.
3. Extend the antenna a short distance and again follow the procedure above.
4. When the lowest point has been reached, switch to the lowest frequency you plan to
operate on and then to the highest and compare SWR readings. They should be
almost equal.
B. Antennas that must be cut to proper length.
1. Follow the procedure as in A above, but adjust the length
bycuttingin1∕8"incrementsuntilagoodmatchisobtained.
2. Be very careful not to cut too much off the antenna at one time.
Once it is cut, it can no longer be lengthened.