[TenTec] More Info Balanced Tuners

[Robert & Linda McGraw K4TAX]

Tapped inductors will work great.  Just a pain to adjust when changing
frequencies or bands or antenna conditions change.  Will take a lot of
patience with finding the correct tap positions the first time through.

73
Bob, K4TAX
----- Original Message -----
From: "denton" <denton at oregontrail.net>
To: <tentec at contesting.com>
Sent: Tuesday, July 15, 2003 9:13 PM
Subject: Re: [TenTec] More Info Balanced Tuners


> I am thinking of building up one of these balanced tuners and am wondering
> if tapped inductors would suffice??
> ----- Original Message -----
> From: "Ken Klinedinst" <kbk at conknet.com>
> To: <tentec at contesting.com>
> Sent: Tuesday, July 15, 2003 4:36 AM
> Subject: [TenTec] More Info Balanced Tuners
>
>
> > More info about the Measures balanced tuner I built.
> >
> > The Richard Measures 1990 article was followed for component values, the
> > choke / balun and layout.
> >
> > 1. PVC pipe
> > White, black has carbon, conductive. I pre-wound the coax to get the
> > correct pipe length, which ended up at about 12" on an outside diameter
> > of +/- 3 ½"
> >
> > 2. Coax
> > RG8X with solid dielectric. Obtained from Radio Works (no commercial
> > endorsement) The coax with foam may collapse. I started with 40' and
> > most was used as the winding. I had one PL259 connected by the coax
> > supplier.
> >
> > 3. For simplicity and individual adjustment of the rollers I eliminated
> > the motors, belts and gears. The reason I wanted individual roller
> > adjustment, my 234' dipole runs through trees which have leaves in the
> > summer and in the winter we have ice and heavy snow here in NH. My
> > concern was, I would have a antenna which at times could become
> > unbalanced and I wanted to be able to compensate for this condition.
> >
> > 4. I used the tuner on a wooden board for several months before
> > enclosing it in a wooden (Wine) box. I am sure the box, because of it's
> > original use, gives the rig more power. Once in the box, I installed
> > counter dials for ease of band changing.
> >
> > 5. The Measures design shows the capacitor being used either on the
> > roller input or output, depending which configuration gives the lowest
> > SWR. With my dipole 160-10 and my 20 meter 8JK, the tuner provides the
> > best match with the capacitor on the roller output.
> >
> > 6. I have temporally installed RF ammeters in each side of the feedline.
> > They read 1.75 RF amps, with key down, 800 watts DC input, on 40 meters.
> > I have not measured the other bands because the meters have not been
> > permanently installed. Frankly, I don't have a clue if 1.75 RF amps
> > means anything, but I think it just another way to ensure a balanced
> output.
> >
> > 7. QST April 2002, Pg 47 has another balanced tuner article, Feb 1990
> > was Measures article with pictures. The author of the April article, has
> > chose not to use the recommended capacitor value and the rollers he had
> > purchased for some other tuner project and I don't find where he stated
> > what their values they are. Point here is try to use the values which
> > Measures uses. I don't have the tech background most of you have so I
> > did not want to fiddle and diddle. There is an excellent picture of his
> > layout on page 50. I followed this layout, except I placed the choke,
> > perpendicular, in back of the rollers. I experimented with the choke
> > location and this was were it fit best for my enclosure. There was no
> > electrical effect if it was along side or in the rear of the rollers. I
> > even considered locating it at a remote location from the tuner.
> >
> > 8. I used Johnson Cat. No. 229-020-001 18uh rollers these have the
> > tapered output turns.
> >
> >
> > _______________________________________________
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> >
> >
>
>
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