The problem just may be the measurement system.
I tried this very same thing once with my MFJ antenna analyzer.
There was so much rf that the meter was useless.
We forget about all the different radio frequency signals out there.
----- Original Message -----
From: E. Glenn Wolf, Jr. <egwolfjr@cegi.net>
To: <towertalk@contesting.com>
Sent: Wednesday, September 29, 1999 8:11 PM
Subject: [TowerTalk] Cushcraft XM-240 problem
>
> I posted this for Vitaly ... please reply to him direct... email is at the
> bottom.
>
> I working to figure out why it isn't working.
>
> glenn
>
>
> Hi All,
> Just finished assembly and test of my XM-240.
> On the roof of the house it was resonating @ about 6.9 MHz with low SWR
> and impedance close to 50 ohms (measured with digital frequency
> counter).
> Now it is up on the tower at 66'. Measurement at this hight shows
> resonance at 7.07 MHz and lowest SWR of 2.5:1!!! SWR goes to 3:1 at 7.0
> and 7.25 MHz. Reading is very unstable (SWR metre is moving up and down
> a little).
> The only difference between the first and second measurement is the coax
> cable (100' of RG-8U).
> I've connected it to my FT-1000D and with 200 Watts made a few contacts
> with good reports (one with Ukraine & 599 from the side of the beam as
> antenna is not rotating yet and is pointing Florida.). The SWR (tuned
> with internal tuner) is 1.1:1 @ 7.0 MHz to 1.4:1 @ 7.3 MHz and stable!
> This antenna can not be so flat across the band?!
> Now the question:
> Matching Network (MNXM) that comes with the antenna, is it a balun? What
> is the DC resistance it measures? My shows open circuit.
> Owners of the antenna, please measure the DC resistance across your
> cable and let me know the results.
> Am I transmitting on a tuned feed line?
> Please reply direct.
> Thank you.
> 73! Vitaly (VE6JO)
>
>
> Please reply direct to .....MARKV@SNC-LAVALIN.COM
>
>
>
> --
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>
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