Rajiv,
Yes, I too experienced all kinds of problems with some commercial W2DU baluns.
So, here is what I did to solve the problems. I use one of those center
insulators, the HQ-1 available from Radio Works at the center of the
antenna. Then I take a piece of RG-303 50 Ohm Teflon coax about 2 feet
long, string on the right type and number of ferrite beads, and then hold
the beads in place on the coax with a piece of heat shrink tubing. The heat
shrink is probably not necessary but it makes sure they stay in place and
don't get any problems with freezing and cracking in New England winters.
Then I put connectors (I use UHF crimp types) on each end. It works like a
charm.
73,
Joe, W1JR
At 11:53 PM 2/4/2002 +0000, Rajiv Dewan, N2RD wrote:
>Indeed. I have had very bad experiences with commercially available
>W2DU baluns for around $20 or so. All kinds of problems ranging from
>broken solder connection inside the pvc tube, broken beads, to ferrite
>beads shorting the connector on the inside. I use then primarily for
>wire antenna strung between trees and they have very limited life. It
>really takes a beating on the wire antennas. Impregnating them helps
>at the cost of limiting their ability to dissipate heat.
>
>There are good ones that are vaccuum impregnated. F12 and CalAv labs
>have these. I always wonder about heat stress on these at lower
>frequencies. And, they are rather expensive - almost $50 each.
>
>I now build them myself using kits (about $10 or so) available from a
>number of sources. Before sealing up the PVC tube, I fill them with
>self expanding foam (available in hardware stores for insulation
>purposes) that comes in aerosol cans. I use a vaccuum cleaner to suck
>from the other end of the tube as I fill it to get it into all nooks
>and crannies. The ones I built have been in use for over 3yrs,
>compared to fewer than 2 for some of the commercial ones I tried.
>
>Regards,
>Rajiv, N2RD
>
>----- Original Message -----
>From: "Jim" <w7ry@earthlink.net>
>To: "Rich Hallman - N7TR" <rich@n7tr.com>; <towertalk@contesting.com>
>Sent: Sunday, February 03, 2002 10:16 PM
>Subject: Re: [TowerTalk] W2DU Balun's?
>
>
> >
> > Well made an W2DU CANNOT be used in the same sentence!
> >
> >
> > I have had MANY problems with them. The failure was the solder
>connections
> > on the lugs that connect the coax to the studs/eyes. The ends of the
>coax
> > did not have a good mechanical connection. (Remember your Heathkit
> > instructions ?) The center conductor was just stuck through the hole
>in the
> > lug and little bit of solder applied.
> >
> > No much fun when the balun is mounted on end of the boom on your 2
>element
> > 40 meter beam....And you cannot reach it unless you take down your
>tribander
> > and the 40 meter beam.
> >
> > Better to make your own with a torroid core and some Teflon coax
>RG-142 or
> > RG-400 and an outdoor PVC electrical box.
> >
> > 73
> > Jim W7RY
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > From: Rich Hallman - N7TR <rich@n7tr.com>
> > To: <towertalk@contesting.com>
> > Sent: Sunday, February 03, 2002 13:52
> > Subject: [TowerTalk] W2DU Balun's?
> >
> >
> > |
> > | Who is commercially selling a well made version of the W2DU Choke
>Balun
> > for
> > | Dipoles? Looking for a 160-10 Meter version.
> > |
> > | Thanks...
> > | Rich
> > |
> > | ******************************
> > | Rich Hallman - N7TR
> > | Reno, Nevada
> > | http://www.n7tr.com
> > |
> > | N7TR DX-Cluster Access:
> > | telnet://dxc.n7tr.com
> > |
> > |
> > |
> > |
> > |
>______________________________________________________________________
>__
> > | Where do you get ICE bandpass filters & beverage matching boxes?
>The
> > | same place that pays for the hosting of this list: The eHam
>Store.
> > | Order online at http://store.eham.net.
> >
>| --------------------------------------------------------------------
>---
> > |
> > | -----
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> > | Submissions: towertalk@contesting.com
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> > | Problems: owner-towertalk@contesting.com
> > |
> >
> >
> >
> >
>______________________________________________________________________
>__
> > Where do you get ICE bandpass filters & beverage matching boxes?
>The
> > same place that pays for the hosting of this list: The eHam Store.
> > Order online at http://store.eham.net.
> > --------------------------------------------------------------------
>---
> >
> > -----
> > FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> > Submissions: towertalk@contesting.com
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> >
> >
>
>
>________________________________________________________________________
>Where do you get ICE bandpass filters & beverage matching boxes? The
>same place that pays for the hosting of this list: The eHam Store.
>Order online at http://store.eham.net.
>-----------------------------------------------------------------------
>
>-----
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________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
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