FLOATING GROUNDS AND HOW THEY WORK ?

[Switch Kit]

I have somewhat of an idea on how they work but IM really not to sure about it ? I know Wilson sells them for some of there mobile antenna's. My question is this , they say that the floating ground (which is basically a long piece of wire) can not touch metal ? I find that strange when the wire is coated to begin with and especially that a vehical is mostly metal ? and could a floating ground also work on some kind of other antenna set up other then a vehical ? How about it Doc ? any Cheers or Jeers on this one ? thanks

 

[W5LZ]

Hmm. If that 'floating ground' is a substitute for a 'real' ground (the other half of the antenna, anyway), then I'd have to say that at 'best', it's a substitute, not going to be as 'good' as the 'real thing'. Will it work? I'm sure it can, but can't say how well, you know? Just depends on the circumstances. Might be a 'marginal' difference, or it could be 'day light and dark'.
As for the touching/near metal thingy, that would change the effective length of it. If that touching or nearness is constant then it can be 'compensated' for. If it's variable... good luck!
So is it a good thing? It -can- be, which doesn't say that it -will- be.
- 'Doc

hows that for an absolute, never wrong, in every case under the sun answer??
(Just about what you paid for it, right?)

 

[Switch Kit]

Thanks for the reply Doc , How good is good and how bad is bad ? Always made be wonder about antenna tuners to a degree as well and how good or bad they were ? I guess if it helps to take care of the transceivers , that would be a major plus to begin with , how much on in and out transmissions would be another "How good or How bad question" Back in the early 90s I did a few installs on fiberglass motor homes , on the roof of these beasts we would use a chrome tape into a X type shape the length of the roof and mount a bracket where we could mount a K-40 on towards the back of the motor home making connections with the chrome tape connected to the X was where we would mount the bracket. Back then the Wilson 1000s wouldn't match out as good as the K-40s would on this step up .but we could get it to match around a 1.3 and usually the customers would be running a little power with the set up. We would use a weather type seal to seal the chrome tape when we were finished. I was very impressed with how well this homemade ground plane worked back then. (Wish I would have taken a picture of it at the time) I truly doubt that any of that has anything to do with a floating ground , it just brought back memories. Wilson's Floating Ground

 

[Cheech]

The idea I got from the floating ground was basically it made a dipole out of the mobile antenna. We ende up making a very similar thing for a guy who lives five stories up in and apartment building. Hes got a 102" whip with a floating ground on his balcony and it works great! We tried to atach the wire to the metal railing but it always threw off the match.

 

[Captain Kilowatt]

Floating ground = Counterpoise

 

[W5LZ]

A little bit 'off topic' but I can't pass this one up!

Tuners and how good/bad they are? Like anything else, it just depends on how well they are adjusted (to a point), and why one is being used to start with. A tuner is a variable impedance transformer, that's all it's meant to do. When you push one past it's limits, then the efficiency goes way down and the resulting end signal does too. If it's used within it's limitations, it's no more inefficient than any other means of transforming an impedance to something desirable, and in most cases it's even more efficient than other means. There will be losses no matter how this transformation is done. The amount of those losses, with a properly used tuner, doesn't amount to a hill of beans. If used improperly, there's very little limit to what 'bad' things can happen (it won't melt the ice in the refrigerator, but that's about it... you don't keep it in the refrigerator, do you, the tuner I mean?).
Tuners are just like people, sort of. If you don't abuse them, they can make pretty good and useful friends. If you give them a hard time, expect the same in return. Then again, there are a few that ought'a be shot.
- 'Doc

 

[Chainsawgang]

This idea is VERY similar to my post re: Mobile antenna counterpoise. Thanks for the link to the Wilson "floating ground" I see that is sort of what I was talking about. I had no idea no one made anything like that . VERY INTERESTING !!!