VERRRY Interesting! I tried your test this AM. I used a dummy load (the MFJ
264) since I didn't have any bare resistors handy. The sweep showed 2.1:1
from 6Mhz to 7.5Mhz and 2.75:1 from 7.5Mhz to 8Mhz. The resistance showed as
100ohms constant. Since my XYL had me take the antenna down last night, this
test peformed on the ground. I trust this doesn't matter re: balun testing.
If this is a valid test, what does the result ell us about the balun?
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 5:54 PM
Subject: Re: [TowerTalk] Re: tuning M2's 40m1L antenna
>
>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
>Submissions: towertalk@contesting.com
>Administrative requests: towertalk-REQUEST@contesting.com
>Problems: owner-towertalk@contesting.com
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>
--
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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