Don,  

Did I not see a picture of your shack with a Matchbox, or am I thinking of
someone else?  

As sweet as the link coupling is, I would think a servo controlled box could
be designed as an automatic unit... perhaps Wayne could be talked into
designing one starting at QRP level and eventually designing a QRO linker.

73,
Bill
K9YEQ


-----Original Message-----
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm
Sent: Monday, September 10, 2012 1:46 PM
To: Ron D'Eau Claire
Cc: Elecraft@mailman.qth.net
Subject: Re: [Elecraft] static buildup on antennas

Yes, link coupled tuners will solve a lot of those problems.  There is no DC
path from the antenna to the transceiver.
However, those link coupled tuners have been disappearing from the face of
the earth at a rapid rate.  They are not easily band-switched (the Johnson
Matchbox units were an attempt, but the matching rang was limited)/

73,\
Don W3FPR


On 9/10/2012 2:31 PM, Ron D'Eau Claire wrote:
> It gets tricky when the antenna feed point impedance is several 
> thousand ohms such as I see with my 130 foot inverted L on 80 meters 
> or with the common open wire fed multiband doublets.
>
> In those cases it's common to use a resistance of 100K or more to 
> avoid excessive losses in the resistors.
>
> But, such large resistances require more time to bleed off the 
> accumulated voltage. At some point they can no longer drain the charge 
> as fast as it accumulates and become ineffective.
>
> My favorite "tuner" for such antennas has always been a link-coupled
tuner.
> No direct-current connection between the antenna and the rig and a d-c 
> path to ground for the antenna at all times. But such tuners are not 
> conducive to fast, automatic operation.
>
> 73, Ron AC7AC
>
>
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