Galaxy DX-73V Owner's Manual - Page 4

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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.

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.

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.

NOTE

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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.).

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.

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.

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