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INTERNAL BATTERIES GUIDE:
After the cover mounting screws are removed, remove the entire back cover. Battery box is accessed by
removing the AW07A's cover. Place 8× 1.5V (not 1.2V) AA size batteries into the battery box. DO NOT use
external power supply when replacing batteries.
ANTENNA ADJUSTMENT HINTS:
1.Dipoles
Since a dipole is a balanced antenna, it is a good idea to put a balun at the feedpoint. The balun can be
as simple as several turns of coax several inches in diameter, or a complicated affair with many windings on
a ferromagnetic core.
The height of the dipole, as well as it's surroundings, influence the feedpoint impedance and feedline
SWR. Typical heights result in SWR readings below 1.5 to 1 in most installations when using 50 ohm coaxial
cable.
In general, the only adjustment available is the length of the dipole. If the antenna is too long it will
resonate too low in frequency, and if it is too short it will resonate too high.
Remember feedline length, when the antenna is not exactly the same impedance as the feedline, modifies
the impedance along the feedpoint. SWR will remain constant (except for a small reduction in SWR as the
feedline is made longer) if the feedline is a good quality 50 ohm cable. If feedline length changes SWR at any
one fixed frequency, the feedline either has common mode currents that are detuning the antenna or the
feedline is not a true 50 ohm cable. Common mode currents are caused by lack of a balun or other
installation errors, such as a feedline paralleling the antenna.
2. Verticals
Verticals are usually unbalanced antennas. Many antenna manufacturers incorrectly downplay the need
for a good radial system with a grounded vertical. With a good ground system, the SWR of a directly fed
quarter-wave vertical can be nearly 2 to 1. SWR often improves if the ground system (and performance) is
poor, so a low SWR with a directly fed Marconi might be a sign of inefficiency. Verticals are tuned like dipoles,
lengthening the element moves the frequency lower, and shortening the element moves the frequency
higher.
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