Copper Talk » Open Forum » Archived Messages » 2002 » Archived Messages 02/01/2002 to 04/31/2002 » Antenna SWR Problem « Previous Next »

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john
Posted on Sunday, January 20, 2002 - 12:42 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I have an old A99 antenna that has not been used for over a year, when it was used last it had a 1.5:1 SWR now it is just under 3:1. Nothing has changed since that time same everything,coax,and radio. What will cause the jump in SWR? Any help is appreciated.
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Marconi
Posted on Monday, January 21, 2002 - 1:00 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

John, do you have the documentation that came with your antenna? If you do read the section about checking the A99 with an V\OHM meter.

If it worked before, then there should be nothing wrong with the antenna unless it is damaged. 1.5:1 is higher than I would expect but the 3:1 is out of the question.

How did you check it and have you Ohm'ed out your line?

Even if you had the rings all the way up or down, I don't think you could get this type of reading.

Marconi
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ChillyDog
Posted on Monday, January 21, 2002 - 2:29 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

john,

Another possibility is corrosion on the coax connectors.

Sometimes just unscrewing and then reconnecting is enough to improve the contact. If the connectors need cleaning, I've had good results using one of those pink erasers. You can cut pieces to fit into the connector and polish off the crud.

Bob
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Vernonott
Posted on Monday, January 21, 2002 - 7:03 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I did have a A99 somehow or another fill up with water a few years ago.
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Marconi
Posted on Tuesday, January 22, 2002 - 12:15 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

You are exactly right Vern. There is a little hole right next to the SO-239 that is supposed to let water out that gets in. The docs even caution you about caulking this area. John, stick a small wire up in that hole and see if it is stopped up. Water will do as Vern says. If it does not appear to be stopped up, sling the bottom section around towards something that would show water. I bought one for $15 dollars that was said to be bad. I still use that one. Water dried up and it was OK.

BTW, here is a tip. Every time I remove coax from an antenna that has been up long enough to get rained on real good, I swing about two feet of the antenna end of the coax towards my hand to see if water comes out.

Marconi
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ninoblue
Posted on Saturday, February 02, 2002 - 12:31 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I have a pontiac trans-sport van. It has totally upset everything i thought i knew about antennas. does anyone know or has anyone been able to get an swr match on this vehicle????
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ncrebel
Posted on Saturday, February 02, 2002 - 3:57 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey,from what i know about those vans,a lot of the body is made from fiberglass instead of metal.
The fenders and the hood might be metal but not the some of the other parts.That might be why it's not grounding.Another this is that you may have to trim off some of the antenna like I did.

*Unit 168 "Timberwolf"*
Eastern North Carolina