[Elecraft] Suggestions needed - antenna to tuner

[Chris Hallinan]

I have a very similar setup.  K3 -> KPA500 -> MFJ 994BRT 600W autotuner
mounted remote -> Balun Designs 4:1 -> 600 Ohm open wire line to 80 m
doublet.

It works fantastic on 80-20, but will not tune better than about 2:1 on
17.  I cannot use the KPA500 on 17 because the SWR is too high.  Nothing
I've tried works.  I'm wondering if it is simply the tuning
range/resolution of the MFJ-994BRT?  I like the idea of remote mounting, as
I have only a couple feet of coax between the tuner and the balun, thus
minimizing SWR-related feedline loss.

Any suggestions for how to get it to tune on 17?

73
Chris - K1AY
Punta Gorda, FL


On Mon, Feb 12, 2018 at 12:16 PM, John W2XS <jm416 at optonline.net> wrote:

> I replaced my Johnson Matchbox with a Balun Designs tuner balun. The
> biggest
> benefit is that the K3 ATU remembers the settings from band to band so the
> QSY is very rapid. I love watching the DX spots come rolling through on my
> N3FJP logging program and clicking on them to QSY to that frequency and not
> have to tune up again. I use it on 80 through 6 meters with an 80m doublet
> fed with KW ladder line (300 ohm).
>
> My recommendation is to keep the piece of coax from the balun to the rig as
> short as possible.  This is to minimize loss since that line will most
> likely be highly mis-matched on most bands. There was a QST article not
> that
> long ago which detailed the losses in that situation and I was surprised at
> how high they were.
>
> I once had an MFJ balanced RF Ammeter and made measurements of the JMB vs.
> the balun and they compared favorably.  DJ0IP (referenced earlier) has
> kindly put those measurements on his website. (This is in the FWIW
> category!)
>
> I have not tried to substitute the tuner balun with another type but that
> might be a future experiment.
>
> 73, John W2XS
>
>
>
> --
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