Would that FCP work with my 43' vertical, three 25' top loading wires that drop
at a 45 degree angle (patterned after the NORD antenna model) and have a 160
meter loading coil that I put in series with an auto tuner at the base???
Using a less than complete counterpoise "field" - about 40 radials, not
symmetrical and not even in lengths. Max power is 20 watts out of a Ten Tec
Argonaut V 516 but run QRP most of the time.
Thank you, in advance, for comments, suggestions or escape plans!
72, Jim Rodenkirch, K9JWV
> Date: Fri, 30 Dec 2011 20:50:48 -0500
> From: olinger@bellsouth.net
> To: rgarrett5@comcast.net; w0uce@nc.rr.com; topband@contesting.com;
> press@thewireman.com
> Subject: Topband: K2AV 160m Folded Counterpoise (FCP), parts and
> winding for isolation transformer.
>
> As requested.
>
> Parts:
>
> http://thewireman.com/wirep.html#631 #635 Double polyimide insulated
> #14 AWG, 15 feet.
>
> https://www.amidoncorp.com/categories/15 #12 AWG standard wall teflon
> tubing, 15 feet.
>
> https://www.amidoncorp.com/items/26 T300A-2 #2 material powdered iron
> toroid.
>
> You can also use Micrometals T300-2D, or a PAIR of Micrometals T300-2
> stacked and taped together with fiberglass tape, which are the same as
> Amidon T300A-2. You can often find the Micrometals cores on eBay.
>
> Note: The core material, bifilar winding turn count, and core dimensions
> are chosen to facilitate a "simple" 160 installation that has approximately
> 1/4 wave wire, a toroid wound balun-sized isolation transformer feeding the
> coax, and a folded counterpoise attached, that delivers an impedance that
> is close enough to 50 ohms resistive to reasonably use regular coax as a
> feed. If you change the turn count, or the core material, or core
> dimensions, this balance for the "simple solution" is defeated, and the
> conditions which were tested in our two year research period no longer
> apply. You might substitute configurations which we put up ourselves,
> tested, and specifically rejected for cause. Like burned it up, was lossy,
> wouldn't stay tuned, was worse than the original antenna, etc, etc
>
> You can't use a stack of smaller diameter cores with the same total of A
> sub L numbers because you can't get the required 20 bifilar turns on the
> inside diameter of the smaller cores. 20 turns fills up the inside diameter
> of the T300x-x form factor. If you don't use 20 turns, then you will get
> less inductive reactance to cancel the FCP's capacitive reactance for the
> simple installation and need more wire in the radiator to compensate.
> Dropping only one turn on the core will add 12 or 13 feet to the "pruned"
> length for resonance you would have had otherwise.
>
> The #2 powdered iron core material has been very carefully chosen for 1.8
> MHz QRP and QRO, drawing on advice and published work by W2FMI. Do not
> substitute ferrite or other powdered iron materials. #2 powdered iron cores
> are always painted red and easily identified. A core without paint or a
> different color will not work.
>
>
> Winding:
>
> First, have a look on W0UCE's site for a good picture of one of these
> correctly done . (Pix worth 1000 words and all that...)
> http://www.w0uce.net/K2AVantennas.html
> Scroll down for the pictures. Note the appearance of the bifilar pair when
> done right. Think of the bifilar pair as an exotic "zip cord". You will
> be winding the PAIR as if you were winding with zip cord.
>
> The professionally wound version from Balun Designs with enclosure and
> hardware can be seen at:
> http://www.balundesigns.com/servlet/the-108/1-cln-1-High-Isolation-Balun/Detail
>
>
>
> Cut wire and tubing in half and slip the wire inside the tubing to create a
> pair of parallel 7.5 feet teflon-sleeved wires. Some find it easier to
> handle the wires in winding if you tape them together.
>
> Tightly wind twenty bifilar turns around the core. This will use all the
> space in the inner diameter. Keep the bifilar pair turns separate and
> uniformly spaced on the outside. ALL the wires should be laying flat on
> the toroid, with NO twist flips where the wires do an "over-under".
>
> IMPORTANT: When properly connected there is NO connection between the
> antenna/FCP side and the coax side. CAUTION: If you get that WRONG when
> you hook it up, you will STILL be able to hear on it, but the system won't
> work right and you will loose valuable dB's.
>
> !!! VERIFY THE SEPARATION !!! with an ohmmeter BEFORE you start pruning the
> antenna wire or hurling electronic curses at dog, family, neighbors, or me.
>
> To wind one of these for a 16+16 version FCP for 80 meters, and you are
> doing the "simple" version with 67 feet or so radiator above the FCP,
> evenly space *fifteen* bifilar turns around the toroid.
>
> 73, and I'm looking forward to a lot more 160 QSO's in the contests,
>
> Guy K2AV
>
>
> On Sat, Dec 10, 2011 at 1:38 PM, Bob Garrett <rgarrett5@comcast.net> wrote:
>
> > Hello Guy,
> >
> > When the dust settles, will you post a list of parts and sources so we can
> > duplicate this antenna and the unique matching network? 73, Bob K3UL
> >
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
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