[Top] [All Lists]

Re: Topband: Newbie question

To: "Mark Lunday" <>
Subject: Re: Topband: Newbie question
Date: Mon, 23 Aug 2010 15:33:17 +0200 (CEST)
List-post: <">>
> So I decided to start a serious investigation.  Using an MFJ-259 tonight at
> the base of the antenna, I see 1 ohm of resistance and 400 ohms of
> at 1.8 MHz, for a length of 174 feet of wire.   At 3.5 MHz, I see 25
> resistance and 85 ohms reactance.
>>From the readings, I have the following thoughts.
> *     I would expect a higher resistance with the longer wire above ¼
wavelength on 160, say around 100 ohms, because an end-fed ½ wavelength
> should be seeing 5000 ohms.  Why the low resistance?

Something must be seriously wrong there. Either the MFJ-259 or some
feedpoint error. I would suspect the tuner or its connections. 1 ohm is
impossible as resistive part of the impedance at that length of wire. Did
you measure with or without the tuner in line?

73 de Lars/SM3BDZ

UR RST IS ... ... ..9 QSB QSB - hw? BK

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