Specifications

SMARTUNER MANUAL 28

SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA

E-Mail: sgc@sgcworld.com Web Site: www.sgcworld.com

5.0 General Notes on Antennas and Couplers

1. The longer the antenna, the generally better the antenna performance. By

doubling the length of the antenna, an improvement of 3 to 6 dB can be

expected in your radiation or receiving characteristics. This is the equivalent of

transmitting with 400 watts, when actually you are using only 100 watts.

2. A ground for end-fed antennas can be effectively created by running radial

wires from the coupler point and burying them in the ground. We recommend

for a good ground that 12 radials should be used and they be about 1/3 longer

than the antenna length. The number of radials can be reduced; however, you

need at least one. Efficiency pattern and radiation will decrease in proportion.

3. Antennas will always perform better if the wire is of a large gauge. Never use

anything less than gauge 16. If gauge 6 is used, an improvement of 6 dB can be

expected over the 16 gauge. The radial ground wire should be at least the same

size as of the antenna wire.

4. The SMARTUNER coupler can handle antennas beyond the specified mini-

mum range of 8 to 80 feet and should be extended as much as possible. In some

cases, the antenna can be 300 feet or longer. In this situation, you may find

some tuning holes. The antenna can be made a little shorter or longer to

overcome the tuning hole on the frequency band you may have wanted to use.

5. Always install the antenna system as far away as possible from any electrical or

industrial noise source. Electrical appliance, electric motor, or fluorescent

lighting noise may cover up weak or even strong signals.

6. A remarkable antenna coupler, the SMARTUNER will tune practically any an-

tenna—good or bad. Keep in mind that it is not the coupler that will radiate the

RF energy, it is the antenna. Therefore, use only good size wire and long

antennas.

7. Never use a feed line or coaxial cable at the output of the antenna coupler. The

coupler functions to couple the radio to the antenna, not to act as a mid point

connector. Because the antenna system starts at the output of the coupler, the

lead end from the coupler to the hypothetical antenna is part of the antenna

system. Avoid having the lead end wire touch any other metal structure: it will

capacitively short your antenna to ground.

8. The backstay of your mast is the only viable antenna on a sailboat. The

SMARTUNER coupler is specifically designed to be used for such applications.

9. For vehicular installation, do not use any inexpensive CB antennas and/or

mounts. These antennas will not perform well from 1.8 to 10 MHz even though