CB antenna junk again
 

Ok, one for the techies, Beastmaster, a good one for you;)

So, I have a Midland CB with a Wilson 1000 antenna. Worked great, loved it. Now I have the Gobi stealth added and have run the antenna all the way to the rear (it's a magnet mount) with it resting on the roof of the truck. It's a base load antenna. I take the mast of the antenna off and on as required due to it's height

Now the Gobi is not really grounded, right? Should I ground the rack (even though the antenna is not attached in any way to it) or should I leave the rack relatively un-grounded?

I know there is some ground-plane BS stuff that I am supposed to think of but before I complete all of the wiring, I though I should consider what would be best for reception/transmission. BTW, the majority of the antenna mast is above the rack, there is a plastic coil or whatever that would be below the level of the rack.

Re: CB antenna junk again
 

Got a pic to show how it's mounted? I suspect that I know what the problem is, but I need to see how you've got everything.

-Steve

Re: CB antenna junk again
 

well, No, not right now. there's really no problem. I'm just not sure if I should ground the rack or leave it out of ground. The way the rack mounts to the top, it's not really grounded well to the truck.

The regular roof panel of the truck offers a ground plane and now I have added this mesh and tubular rack on top. I don't have everything wired up, to get a meter on or to test in any way and don't want to disturb the PC on the rack if it would be better for the rack to not be grounded to the truck.

Think of it this way. The base of the antenna is just below the bottom of the rack, which shouldn't make much difference except it's a base-loaded antenna. I have that rack that covers all of the roof and the antenna is centered at the rear-most part of the truck. Should I ground the rack to the truck ground.

Re: CB antenna junk again
 

That's what I thought. Here's the problem that I see.

Bottom loaded coils on low frequency transmissions will have a tendency to emit more radiation from the coil on upward.

So, if the coil is under the roof rack grid, the majority of the signal will end up being bounced between the ground plane of the roof and the roof rack grid.

If you were to look at a normal vertical antenna from the side, it would emit in a pattern similar to what you would see in a McDonald's arch logo, or similar to a bagel being cut in half abd you create an "m" shaped thing out of it.

When you have the coil between the grid, the propogation will end up getting cut off and you'll end up with only a transmission pattern that is aimed pretty much upward.

The funny thing - grounding the rack will merely add to transmission woes in theory, since you're sandwiching the coil part of the antenna between two actual ground planes.

So, I'd see if I could put the magmount on the grid of the rack, and ground the rack.

Re: CB antenna junk again
 

I don't like you ;)

I was thinking along those lines and was hoping that if the rack wasn't grounded it might offer some difference.

The antenna base stays well protected like it is, but doesn't serve me very well if it's severely limiting my range. Guess it's up on the rack.

Re: CB antenna junk again
 

Is this really a fit it in the garage without scraping up the door issue?

Re: CB antenna junk again
 

No not really. I don't run with the antenna on the base all of the time.

The way the antenna is made (and the way I drive off-road) a nice limb would slice it right off at the base because it would wedge at the rear of the rack, even though it's magnetic. I've already tried to tear the old cross bars off a couple of times on the sides of trees. So I am trying to think pro-actively and have the antenna protected, before there was nothing to "hold" it and a limb would just knock it loose and all I would have to do is put it back in place.

But, alas, I get too anal about stupid things like this and overcomplicate it. I should have just stuck it on the rack to begin with and not worried about it. :mad:

Re: CB antenna junk again
 

Sorry, that was all I caught from your post, but sweet. When did you get the Gobi?

Re: CB antenna junk again
 

after we got back from K-rocks

Re: CB antenna junk again
 

I would ground the rack and mount a fire stick antenna (on a spring) to the side of the rack with a quick dissconnect so when it was removed the mount would be below rack level.

Maybe teh whole rack would act as a ground plain?

Re: CB antenna junk again
 

Paragon, not sure if something like this would interest you or not.

Firestik ? II
"No-Ground Plane", CB Antenna Kit


http://www.elcovaforums.com/forums/s...t=16764&page=2

Re: CB antenna junk again
 

Don't you own an H2? Doesn't Beast own an H1? Oh, nevermind. I see a shortbus in Beast's avatar. Man, I thought you were all drunk posting here.;)

Firestik just like mine. It rattles off the McDonald's drive thru all the time. They love it.;) :D

Re: CB antenna junk again
 

You know I get range out the wazooo with my antenna. I can't give up on my Wilson.

Yeah, since Steve is venturing in here more, I had to come down here and bug him about it........ did you even read my dilemma? nevermind we solved it;) :D