[AMRadio] Classic Link Coupled Tuner

JACK C. SHUTT w9gt at verizon.net
Mon Aug 17 13:58:08 EDT 2009

Hey Brian,
I wanted to just chime-in and tell you that I had the same sort of experience with my "big" link coupled tuner.  I have been concerned that the tap points for the open wire line seemed very near the center of the coil and seemed to result in much less L than what I expected would be the proper setting.  It appeared that the amount of coil needed was way too small.  I suppose I should have been satisfied that it provided an apparent good match, but I was still concerned about the values being different that what I expected.  I'm using a large 4" diam. Cu tubing coil and a link wound from the (insulated) center conductor of poly-type RG-8U coax wound around the center turns.  I put a large multi-gang loading type variable cap in series with the link to allow tuning it.  The big tuning cap (250 uF) is across the whole coil which is much more L than even what I need for 160M.   Anyway...can't argue with success....it works!
73,  Jack, W9GT

--- On Mon, 8/17/09, WA5AM <ars.w5ami at gmail.com> wrote:

From: WA5AM <ars.w5ami at gmail.com>
Subject: Re: [AMRadio] Classic Link Coupled Tuner
To: "Discussion of AM Radio in the Amateur Service" <amradio at mailman.qth.net>
Date: Monday, August 17, 2009, 12:22 PM

That's a great story John!!

Yep, for the time being I'm going to leave the tuner well enough alone...
We are building a new house down on my east property smack in the woods.
Once the house is complete and ready to move in, I will begin getting my AM
rigs back up and running.  I've got to move this Gates BC-1T too.  It's
going to be a booger.  it will be the first project after the move to get
going on 75 and 160.  Searcy is very close to us.  Only about 35 minutes
from here.  Next time you are up, come by and see the new shack.

By the way, for all interested, always keep an eye on the lookout for these
large old link coupled coils like the one in my photo.  Also for the large
"slip stator" caps.  You can build a tuner for balanced feedline, 450 ~ 600
ohms, that will far surpass the abuse a modern tuner that uses the toroid
baluns can take.  I went to ladder line 10 years ago and never went back to
coax for any lowband antennas.


On 8/17/09, John Coleman <jc at pctechref.com> wrote:
> Hi Brian:
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