Using a mobil antenna as a base

[Nightshade]

For cost reasons alone I'd like to use a Wilson 1000 mag mount as BOTH a base and mobil antenna. My goal is to install the Wilson on my Suburban when we take trips 4 or 5 times a year then leave it on a post (with a steel plate) outside the rest of the year as a base antenna.

That brings me the root question.......Does a mobil antenna require the steel body of the vehicle to work properly for a radiating a signal?

 

[longhaireddwb]

Don't quote me on this but from my understanding you need 9 ft of ground plane in two directions from the base of the antenna for it to work. But to work better you need 9 ft of metal in four directions for the ground plane. You might be able to get away with something else but...

If I were you I'd buy a A-99 antenna from Sparkys for around 60.00 you would be much better off!

 

[Nightshade]

Sigh! I kinda thought so. I'll have to save my pennies now for an A-99.:mellow:

 

[W5LZ]

No idea where you might buy one, but a "groundplane", or the other half of that antenna isn't difficult to make at all. If you plan on sitting that antenna on top of a post, and if that post is metal and part of a fence, for instance, and if that fence is metal, then you've got a "groundplane" already... the fence. Even if there is no metal fence, you'd need is at least one wire to act as a 'counterpoise', or basically the 'other half' which a vehicle's metal body does. Making that wire something on the order of 9 feet long is a good starting point. From there you 'trim' it till the SWR get's reasonable. You'd have to hav a metal plate on top of that post for the magnet to stick to and that would be a good place to make a connection with that wire. You need at least one, but more will work too.
As far as that goes, you could make the whole antenna out of wire and leave that mag-mount on the car. You'd need about 27 feet of wire and an insulator of some kind. Hang the thing in a tree. It'd look like an upside-down 'Y'. About 9 feet of wire straight up and the two 'legs' would be about 9 feet too. And like any antenna, you could tune it by shortening that straight up piece of wire. If you can't make one like that, at about a 1/10th the cost of an 'A99', you just ain't trying. If that home-made antenna is at least as high as that mobile antenna would be, it'll out perform it.
- 'Doc