[Elecraft] Suggestions needed - antenna to tuner
Barry
k3ndm at comcast.net
Tue Feb 13 12:37:51 EST 2018
Chris,
If all else fails, cheat. Probably the very simplest thing you can
do is mount an 17 meter element in parallel to the 80 meter element. It
will be cheaper and no less efficient.
73,
Barry
K3NDM
------ Original Message ------
From: "Chris Hallinan" <challinan at gmail.com>
To: "John W2XS" <jm416 at optonline.net>
Cc: "<elecraft at mailman.qth.net>" <elecraft at mailman.qth.net>
Sent: 2/13/2018 8:55:23 AM
Subject: Re: [Elecraft] Suggestions needed - antenna to tuner
>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
>>
>>
>>
>>--
>>Sent from: http://elecraft.365791.n2.nabble.com/
>>______________________________________________________________
>>Elecraft mailing list
>>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>Help: http://mailman.qth.net/mmfaq.htm
>>Post: mailto:Elecraft at mailman.qth.net
>>
>>This list hosted by: http://www.qsl.net
>>Please help support this email list: http://www.qsl.net/donate.html
>>Message delivered to challinan at gmail.com
>>
>
>
>
>--
>Life is like Linux - it never stands still.
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Elecraft at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
>Message delivered to k3ndm at comcast.net
More information about the Elecraft
mailing list