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Re: [TowerTalk] Reactance at end of feedline

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Reactance at end of feedline
From: Pete Smith N4ZR <n4zr@contesting.com>
Date: Mon, 07 Oct 2013 08:31:19 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Hi Paul - no, the MFJ does not give you the sign, just R and un-signed X.

73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.

On 10/7/2013 8:23 AM, Paul Christensen wrote:
Pete,

Does your MFJ 259B separate out reactance and provide the sign (complex R+jX rather than only Z magnitude)? I thought some MFJ models only read magnitude of the impedance.

If the 259B reads complex Z, did you observe a point where reactance went from one sign to the other as it crossed zero? If we knew the feedpoint Z and type of line (we know the line length), we could then easily calculate the Z at the input end of the line, including sign of the reactance and compare it against your results.

Paul, W9AC

----- Original Message ----- From: "Pete Smith N4ZR" <n4zr@contesting.com>
To: "TowerTalk" <TowerTalk@contesting.com>
Sent: Monday, October 07, 2013 7:53 AM
Subject: [TowerTalk] Reactance at end of feedline


Us history majors sometimes need to ask elementary questions, so please be kind.

Yesterday I was refurbishing my 80M lazy-vee dipole array, measuring the center frequencies to adjust as needed. On my MFJ259B, the reactance at the end of the 88-foot feedlines reached a minimum of only about 45 ohms before starting back up. Does this value reflect the inductive reactance of the feedline?


--
73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.

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