[TowerTalk] A3S tribander gone bad

[Jim Hargrave]

Rob,

You can use the MFJ-259 as a Dipper. All you need is a 2-3 turn loop
soldered to a connector.

I have the MFJ-269 and have used it many times to determine resonance of L/C
circuits. I have a few different diameter loops soldered to a short piece of
coax. This makes it easier to use by getting the loop away from the
analyzer. The loop provides a good link coupling from the analyzer to the
trap. You will get a dip on the meter at resonance. You can even use a piece
of coax with a connector on one end a test jumper cable. Just clip one end
to the center conductor and wrap it around the coil and attach the other end
to the shield. Crude by effective. Put your link near the end of the coil
under test so it does not change the resonant freq too much.

You should remove the traps and measure them without the antenna elements
attached. The resonant frequency will be slightly different with the
elements attached. Either way, you will get readings close enough to tell if
they are matched and in the right places.

     73's Jim
      W5IFP

> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com]On Behalf Of n4zkf
> Sent: Monday, November 15, 2010 10:36 AM
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] A3S tribander gone bad
>
>
> Not so much they are bad. Just in the wrong spot. You can't tell the
> difference between them by just looking at them. They could be just in the
> wrong place.
>
>
>
> You'll need a grid dip to see the difference. I would remove the screw and
> slide the covers off first to make sure they are not burnt, don't
> have bugs
> in them
>
> as mentioned earlier also.
>
>
>
>
>
>
>
> From: Rob Katz [mailto:rob.katz at thelegacycenter.com]
> Sent: Monday, November 15, 2010 11:28 AM
> To: towertalk at n4zkf.com
> Subject: Re: [TowerTalk] A3S tribander gone bad
>
>
>
> Dave,
>
> Thanks for your reply.  Sounds like I need to disassemble the
> beam and test
> the traps to identify the bad one(s) - is that right?  Do you
> know of a way
> to do that test with an MFj259 antenna analyzer?
>
> Thanks and 73,
>    Rob, KA1ARB
>
>
> To:     <towertalk at contesting.com>
> Subject:     Re: [TowerTalk] A3S tribander gone bad
> From:     "n4zkf" <towertalk at n4zkf.co <mailto:towertalk at n4zkf.com> m>
> Date:     Mon, 15 Nov 2010 08:07:15 -0500
> List-post:     <towertalk at contesting.com
> <mailto:towertalk at contesting.com%22> ">mailto:towertalk at contesting.
> <mailto:towertalk at contesting.com> com>
> Sounds like the traps are in the wrong spot and the only way to tell the
> difference is with a grid dip.... Been there, done that....
>
> 73 Dave
> n4zkf
>
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