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Re: Topband: MFJ 259B on 160M

To: Glen <>
Subject: Re: Topband: MFJ 259B on 160M
Date: Mon, 28 Sep 2009 13:39:58 +0000 (UTC)
List-post: <">>

The problem with using a filter ahead of your "wideband" MFJ-259 analyzer is 
that the filter will transform the impedance of the load you're trying to 

You have a better chance of measuring the impedance in the presence of a strong 
signal. with a "narrorband" vector network analyer such as the N2PKVNA (kit) or 

If you do need a filter both units enable you do perform a "OSL" calibration 
with open, shorted and 50 ohm load calibration with a filter inserted in front 
of the input.

In general, I find my MFJ-260 unit handy in determing the lowesr SWR but I 
doubt it's accuracy when the load deviates to far from 50 ohms.

If you want accurate readings I'd take a look at the N2PKVNA:

and AIM4170:

Here is a good write up on analyzer accuracy:


Mike N2MS

> Hello,


> Has anyone made an effective AM broadcast filter (HB) for their analyzer?


> I have to feel that my lack of readings on the unipole may stem from AM

> interference.

> I have a station here in town, or close on 1400khz.


> 73's


> Glen K4KV

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