Midland 79-290, Owner'S Manual

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antenna is shortened. 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 Channel
20. Extend the antenna a short
distance and again follow the procedure above.
B. Antennas which must be cut to proper length.
1.
Follow the same procedure as above, but adjust the length by cutting 1/4 in.
increments until a good match is obtained.
2. Be very careful not to cut too much at a time, as once it is cut, it can no
longer be lengthened.
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 posts, buildings, or fences).
WARNING: The transmitter may be damaged if operated into a bad antenna
system. When adjusting antenna only operate the transmitter as short a time as
possible.
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 disabled.