Hold your horses till next week when I bring you your ICE filter! (plane leaves
in 8 days but still no visa!!)
John - W2YR
PS - lumped constants in any filter will change the X Y Z reading in the MFJ
----- Original Message -----
Sent: Tuesday, November 02, 2004 13:44
Subject: TowerTalk Digest, Vol 23, Issue 4
Date: Tue, 2 Nov 2004 09:53:16 +0700
From: "Martin Sole" <firstname.lastname@example.org>
Subject: RE: [TowerTalk] My MFJ-259B annoys me.
Content-Type: text/plain; charset="us-ascii"
This is in reply to all the great info and suggestions I received to my
question about the 259B.
Probably what I forgot to put in the original post can be summarised here.
Running on batteries, okay with a selection of resistive loads, tracks
reasonably well - no jittering.
Thanks to Bob, K8IA, who mentioned the use of an ICE BCB filter, and to
John, W0UN, who mentioned using shorted 1/4 wl stubs cut for the band of
interest and T'd at the analyser.
Here's what I know now. The spectrum below 1.5MHz has some BIG signals in
it, my TS940 pins it's S meter on a couple when pluged into the 40m dipole
at 60 feet. Both the quad and the dipole show many signals around 6MHz as
being at the S9+60+++ S meter pinning level.
I have an ICE BCB filter on order as I suspect I have some BC issues anyway,
it should be here with a friend later this month, in the meantime I built a
rough copy of the RX only filter from the handbook. Immediate improvement.
SWR drops to 1:1 and all readings look good with no dancing meter but I did
notice that the 1:1 point is moved about 100 to 150KHz higher compared to
what the meter on the rig says, this has always been fairly accurate, and
still is as far as I know so I guess it's a phase thing with the filter.
This on all the bands tested. Next job will be to try some stubs as per
John's suggestion to see how they work out. I have the bits, just need the
time to put 1 or 2 together.
Thanks for all the suggestions and ideas. Looks like a $5 solution will meet
Martin - HS0ZED
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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