What connections need to be made to the radio for the SGC coupler to operate?
SGC couplers require only 12 volts, and the RF signal from the radio. There are some optional control circuits and status indicators available.
Can I install the SGC antenna coupler outdoors?
Several of the SGC couplers are waterproof, and are designed to operate in extreme environments. We do ask that you provide a cover or shield for protection from direct sunlight and perhaps large hailstones. Some couplers are not provided with protection and require that you provide extra protection if installing outside. (See individual specifications.)
How do I install my coupler and antenna on my boat?
In general, power boats use whip antennas and sailboats use back stay or triadic antennas. The placement of the antenna is not critical except that it should be kept at least 3 feet away from the rigging.
Please refer to the following diagram for sailboat antenna placement information:
SGC recommends that the top insulator be placed 4 feet down from the top of the mast to reduce the risk of lightning striking the radio antenna. In addition, we recommend placing the lower insulator as close to the deck as possible and covering the exposed backstay with a piece of small diameter plastic pipe (or a slip-on shroud cover) to prevent risk of an RF burn if the antenna is touched while transmitting.
Can I use a CB ball mount?
No. CB ball mounts have been designed for 5 Watt CB transceivers and will not sustain 10,000 Volts RF. SGC's SG-303 will sustain 20,000 Volts RF isolation. Second, the coupler you used before probably did not allow you to tune the antenna for maximum efficiency. Note: VSWR readings are for the best match but not necessary for best antenna efficiency. Also, as much as 10,000 Volts are developed on a 9-foot antenna at frequencies below 7MHz when the antenna is efficiently set.
What about unstable installations?
The most common problem with Smartuner installations is an insufficient RF ground, especially in mobile installations. If the coupler is performing intermittantly, this is usually the cause. It is best to use a balanced antenna whenever possible, and to insure you have an adequate RF ground. Read our recommendations for grounding here.
I have a good antenna and ground system but still have unstable conditions. Why?
If you have unstable conditions, then there is still a deficiency in your installation which may or may not be related to your antenna or ground system. Good radiation but poor or unstable conditions may have nothing to do with the coupler's performance. The better job you do in radiating power, the greater chance you have that some of that power is radiated back. The power supply, radio, microphone, coiled power supply A/C input cable, radio power supply DC cable, and more seriously, the radio to coupler cable are all sensitive to RF. If any of these do capture RF, it can make the system highly unstable. Analog or switching power supplies themselves are highly susceptible to RF. A few millivolts of RF in the power supply can create an instability which could lead to a catastrophic failure. We never recommend regulated or switching power supplies because no one can predict when RF is upsetting the power supply and all installations differ in characteristics.
SGC Inc., Tel:
425-746-6310 Fax: 425-746-6384
Email: sgc@sgcworld.com SGC reserves the right to change specifications, release dates and price without notice.