Topband: MFJ259B QUERY

[Guy Olinger K2AV]

The MFJ can be a blunt instrument on certain tasks. I'm not sure that
the 259 is a good instrument for measuring zero Z crossings.

What I used to do before I got better stuff, was to sweep the
frequency and note the pairs of frequencies where the reactance would
cross X=1, then X=2, then X=3.  I would then compute the center
frequency for X=1 pair, then X=2 pair, so forth.  If those were all in
the same place, that's what I would use.

My AIM 4170 is far sharper and reliable, but requires an attached PC.
It very clearly shows the X=0 crossings, both at halfwave and odd
quarterwave intervals, on the graphic curve presented.

Unfortunately, the good stuff has a way of badly denting budgets.

73, Guy.

On Sat, May 29, 2010 at 11:17 PM, Mr. and Mrs. Magoo <magoo at isp.ca> wrote:
> I'm cutting a couple of 1/4 wave sections on topband and, in tuning for X=0,
> I notice that this value exists over about 30+ khz.  If I "fine tune" for
> R=1 and X=0 there is still a healthy bandwidth of perhaps 20 khz.  This
> complicates cutting the lines exactly where I want them.  Is this a common
> occurrence in using the 259B?  I was not expecting the "dip" to be so broad.
>
> Bill, VE3NH
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>