Galaxy DX-73V, Owner'S Manual

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TUNNING THE ANTENNA FOR OPTIMUM SWR
Since there is such a wide variety of base and mobile antennas, this
section will strictly concern itself to the various types of mobile adjustable
antennas.
Because the antenna length is directly related to the channel frequency,
it must be tuned to resonate optimally all channels of the transceiver. Low
Channel (CH1) requires a longer antenna than High Channel (CH40) because
it is lower in operate frequency.
Due to the various methods of adjusting antennas for proper SWR we
have chosen what we think is the optimum method:
A. Antennas with adjustment screws (set screws)
1. Start with the antenna extended and tightens the set screw lightly enough
so that the antenna can be lightly tapped with your finger for easy
adjustment.
2. Set your transceiver to middle channel (CH 20). Press the PTT (push-to-
talk) switch, and tap the antenna (making it shorten). The S.W.R. meter
will show a lower reading each time the antenna is tapped. By
continuing to shorten the antenna you will notice the S.W.R. reading will
reach a low print and then start rising again. This means that your have
passed the optimum point for channel 20. Extend the antenna a short
distance and again follow the procedure above.
When the lowest point has been reached, switch to Low channel (CH 1)
or high channel (CH 40) and compare S.W.R. readings. They should be
almost equal.
B. Antennas which must be cut to proper length.
1. Follow the same procedure as above, but adjust the length by cutting in
1/8” increments until a good match is obtained.
2. Be very careful not to cut too much at one time, as one it is cut, it can no
longer be lengthed.
3. The whip is easily cut by filing a notch all the way around and breaking
the piece off with pliers.
If you are having difficulties in adjusting your antenna, check the following:
A. All doors must be closed when adjusting the antenna.
B. Make sure the antenna base is grounded.
C. Check your coaxial cable routing (it may be pinched when routed
into the car).
D. Try a different location on your car (keeping in mind the radiation
pattern you wish)
E. Is the antenna perfectly vertical?
F. Try a different location in your neighborhood. Stay away from
large metal objects when adjusting (metal telephone or light posts,
fences, etc.).
EXTERNAL SPEAKER
The external speaker jack (EXT.SPK) on the rear panel is used for
remote receiver monitoring. The external speaker should have 8 ohms
impedance and be able to handle at least 4 watts. When the external speaker
is plugged in, the internal speaker is disconnected.
THE PROPER SETTING IS ACHIEVED WHEN THE SWR IS
1.5 OR BELOW, AND WHEN IT HAS THE SAME READING
FOR LOW OR HIGH CHANNELS.
NOTE
The transceiver will operate into an SWR of 2 to 1 indefinitely
and sustain an SWR of 20:1 for a maximum of 5 minutes at rated
operating conditions.
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NOTE
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