[Top] [All Lists]

[TowerTalk] Current imbalance on 450 ohm Ladder Line

To: <>
Subject: [TowerTalk] Current imbalance on 450 ohm Ladder Line
From: "Garry" <>
Date: Wed, 14 Mar 2007 20:51:40 -0400
List-post: <>
I have a 135' center fed dipole up at 50 feet strung between two trees in
the clear fed with 108' of 450 ladder line. I am using a Palstar BT1500
balanced-L design antenna tuner. I also have an MFJ-835 RF ammeter for
balanced lines. On twenty meters and below, currents are balanced in both
legs of the ladder line. On 17 meters, I have much higher current in one leg
than the other. The first thing I did was reverse the leads from the antenna
at the back of the MFJ-835 to see if the high current would show up on the
other side of the meter. It made no difference. Still had high current on
the same side as before. Next I reversed the leads from the tuner to the
MFJ-835. Now the reading on the ammeter reversed with high current going to
opposite side of the meter.

The tuner tunes up fine on this band but I get reports of RF on the signal.
I could understand if the problem was on the antenna side of the ammeter but
the problem appears to be on the tuner side. I have tried this with a
homebrew T-Network tuner and get the exact same result.

Has anyone run into this before and how did you solve it?

Many thanks,
Garry - WR4R


TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>