Specifications

SMARTUNER MANUAL 31

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

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

sure that the grounding point is not insulated from other parts of the vehicle by non-

metallic couplings, bushings, fiberglass panels, etc. Modern vehicle assembly techniques

that use spot welding may not always adequately connect various body parts. Use an

ohmmeter and insure your vehicle is electrically bonded.

Another area to watch is trunk lids and hoods. Because many body parts are dip

painted, they may float above the RF ground when assembled. Use of short heavy braid

to insure all doors and hatches are grounded is good installation practice. Although

this is tedious work, the benefit is that once completed you will have a much superior

radiated signal and lower noise floor on receive.

5.3.2 Marine Grounds

A metal-hulled vessel in salt water provides an almost ideal ground. The coupler

should be connected directly to the hull using the shortest possible ground strap or 2- to

3-inch wide 2 mil copper foil. Make sure that the contact point is free from paint and

dirt. Ensure a good contact area for minimum resistance.

Wooden and fiberglass hulled vessels present more of a grounding problem. It is

normally necessary to bond all large metallic parts such as the stove, fuel tanks, engine,

and propeller shaft; sometimes an external grounding plate should be connected to the

hull. The bonding and grounding plate should be chosen with consideration for the

problems of electrolysis. Severe damage may result if dissimilar metals are connected

together.

Our experience is that sacrificial zincs, which double as radio grounds, may help, but

are not by themselves a complete solution. If you use one (or more) of these devices,

remember to provide for a large physical counterpoise in addition.

In a sailboat installation, we generally place the SMARTUNER in the aft lazaret and

then run at least three runs of foil forward. One runs up the port chine, just below the

waterline, another up the starboard chine below the waterline, and the third up the

center of the vessel.

The center foil is generally connected to the rudder post, transmission, engine, and keel

bolts. The chine foils are attached to through hulls, the stove, tankage and so forth. The

idea is to get as much metal inside the vessel connected as possible. Metal toe rails and

life lines work well as do keel coolers on motorized craft.

Here is a neat trick for attaching foil to keel bolts. When a large keel bolt is exposed,

drill into the keel bolt and tap the hole for a suitable stainless steel machine screw.

Attach with suitable copper washers for a solid electrical connection.

Although it is not mandatory that ground foil be glued into place, we consider it a good

idea to keep the space below decks neat and orderly under all conditions.