Total posts : 45366
Howdy BC Man…
Because your ground conductivity may be poor out there in CA, judging by the FCC map, a 1/2 mile range seems quite good for your area.
Adding a second ground wire will halve your inductance, making the ground looking twice as close. But it generally will have the opposite effect except to put more power into the antenna.
Shotgunning your ground wires will distort your radiation pattern. What you should do, after peaking up the tuning, is to drive around and determine your contour. The range in some directions may be better or worse than what you’ve already found. Too, there may be hot spots well beyond the contour.
It’s best to use a radio other than a car radio. Car radios are more sensitive than the usual radio a listener would use.
I recall you have a Rangemaster. What do you have it mounted on? I would ground to the support and then ground the support to the ground rod. That would make it more legal-seeming, too. If there are any unbolted joints in the support, they should be jumped with a wire.
You might look at the Transmitter/Antenna Installation info at my Web site;
My SSTRAN will be configured similar to that of a Rangemaster.
One other thing… Ungrounded metal absorbs transmitted energy. But, grounded, it will then act as a reflector or a director and thus affect the radiation pattern.
Bill in SE Texas
Bacliff Radio (still UC)