The connected balun with an open end added several
pf of capacitance shunted accross the feedpoint. The real
test was when you disconnected it entirely. 2.75/1 vswr with
the antenna setting within 50 feet or so from the ground is probably
a realistic value.
I never found out, but my theory is that the M2 balun may be short
by several beads in covering down to 40 meters. Before we get
carried away into left field; while you have the balun off, connect
your 259B to the balun and a 50 ohm resistor accross the output
terminals and sweep from 6 to 8 mhz to see if the vswr is flat (1.1/1)
If it is, recheck all measuements and connections and hang
the antenna. If it is not flat, exchange the balun with M2, and be
sure to sweep it also before you install it.
(((73)))
Phil, K5PC
-----Original Message-----
From: Jonathan Kaplan <jonk@jskent.com>
To: Phil Clements <philk5pc@tyler.net>; w5ozi <w5ozi@ktc.com>;
towertalk@contesting.com <towertalk@contesting.com>
To: <towertalk@contesting.com>
Date: Sunday, July 04, 1999 4:31 PM
Subject: Re: [TowerTalk] Re: tuning M2's 40m1L antenna
>
>Ok, Guys, we're getting somewhere. I first tried the normal setup (into the
>1:1 balun) with a uncoiled length of RG58 (the only cable of any length I
>could liberate)between the MFJ-259 and the balun. It showed SWR 3+ (5 or
>10?):1, the same as the 9913 jumper I had been using.
>
>Next, I coiled the RG58 as instructed and connected that to feedpoints on
>the antenna--bypassing the balun. When the balun remained connected to the
>feedpoints, the SWR improved only marginally--3.5:1. But when I
disconnected
>the balun from the feedpoints the SWR changed decisively -- 2.75:1. Still
>not great, but maybe that tells us more about what's going on. BTW, what
IS
>going on?
>
>Thanks Again
>
>Jonathan KO6XS
>
>
>-----Original Message-----
>From: Phil Clements <philk5pc@tyler.net>
>To: Jonathan Kaplan <jonk@jskent.com>; w5ozi <w5ozi@ktc.com>;
>towertalk@contesting.com <towertalk@contesting.com>
To: <towertalk@contesting.com>
>Date: Sunday, July 04, 1999 12:50 PM
>Subject: Re: [TowerTalk] Re: tuning M2's 40m1L antenna
>
>>
>>Try this test....remove the balun and connect the coax directly
>>to the antenna. At the feedpoint, roll up the coax into a 8-10
>>turn coil about 10 inches in diameter which makes a choke balun.
>>I agree that there is no way to tune that antenna near ground level,
>>but whatever your readings before the change should remain the
>>same if the problem is in the antenna itself. This at least is a
>>cost efficient way of eliminating the existance of a balun problem.
>>
>>GL!
>>
>>(((73)))
>>Phil, K5PC
>>
>>-----Original Message-----
>>From: Jonathan Kaplan <jonk@jskent.com>
>>To: w5ozi <w5ozi@ktc.com>; towertalk@contesting.com
>><towertalk@contesting.com>
To: <towertalk@contesting.com>
>>Date: Sunday, July 04, 1999 2:10 PM
>>Subject: [TowerTalk] Re: tuning M2's 40m1L antenna
>>
>>
>>>
>>>Pat,
>>> I agree that the freq. of the best SWR will change as the antenna is
>>>raised. But that shouldn't prevent me from getting a good SWR SOMEWHERE
on
>>>the spectrum. Right now, the best I'm getting is 3+:1. Not good! The
only
>>>change I see downward is when I touch one of the linear loading rods. And
>>>that's why I need know what affect my touching the antenna is having.
>>>Maybe, you have a better insight into what might be wrong here.
>>>
>>>Jonathan
>>>
>>>-----Original Message-----
>>>From: w5ozi <w5ozi@ktc.com>
>>>To: Jonathan Kaplan <jonk@jskent.com>
To: <towertalk@contesting.com>
>>>Date: Sunday, July 04, 1999 11:36 AM
>>>Subject: Re: tuning M2's 40m1L antenna
>>>
>>>
>>>>As long as you are holding the antenna right at the mounting plate, it
>>>>shouldn't matter whether it is grounded or not, but if you have to touch
>>>the
>>>>antenna on either side of the mounting plate it will obviously change
>>>>things. Doesn't the instruction manual suggest exact dimensions for
>>>>matching? I cannot imagine that you could set the match at 7 feet AGL
>and
>>>>have it even close when it is up on the tower. Pat
>>>
>>>
>>>
>>>--
>>>FAQ on WWW: http://www.contesting.com/towertalkfaq.html
>>>Submissions: towertalk@contesting.com
>>>Administrative requests: towertalk-REQUEST@contesting.com
>>>Problems: owner-towertalk@contesting.com
>>>Search: http://www.contesting.com/km9p/search.htm
>>>
>>>
>>
>>
>>--
>>FAQ on WWW: http://www.contesting.com/towertalkfaq.html
>>Submissions: towertalk@contesting.com
>>Administrative requests: towertalk-REQUEST@contesting.com
>>Problems: owner-towertalk@contesting.com
>>Search: http://www.contesting.com/km9p/search.htm
>>
>
>
>--
>FAQ on WWW: http://www.contesting.com/towertalkfaq.html
>Submissions: towertalk@contesting.com
>Administrative requests: towertalk-REQUEST@contesting.com
>Problems: owner-towertalk@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
>
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
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Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
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