Hello Rajiv -
I've read with interest your report on your experiences with the "big
W2DU" current balun.
It concerns me for several reasons:
1. Your words imply that W2DU makes baluns for sale and that they are
poorly made - he does not, and if those you have are of poor quality,
W2DU is not at fault. He did, however, write the book on the principle.
2. Electrically, this type of balun, introduced in 1983 (+/-), has an
excellent track record in our hobby and in commercial use. The principal
is not necessarily new or unique, but W2DU's research and development has
made it an almost generic description of a very popular and effective
device.
3. We have, under W2DU's (Walt Maxwell) explicit approval, made a great
many of a wide variety of "W2DU-" type "baluns" with great pride and 100%
warranty for their designed use and purpose. We react immediately when a
blanket negative report on the "big W2DU" appears, especially when it
concerns construction only - unrelated to the electrical design.
This style of current balun is now manufactured commercially by more than
the two companies who made them at the start - with or without W2DU's
approval. Properly made, they should last indefinitely, and if they fall
apart or otherwise fail mechanically, the manufacturer should be notified
promptly and given the opportunity to learn from the error and solve it,
both for the user and for future business.
For the record, then, I would respectfully suggest that constructive
criticism of your problems should include the resolution of the
difficulty and how it was handled by the manufacturer, and who it was -
for the benefit of all of us - that's the way it works on this reflector
-- a legitimate manufacturer should be able to take it.
Further, I again emphasize the point that your unfortunate experience was
clearly with construction and not with the W2DU principle which has
proven to be a highly valuable help to the amateur radio community. The
fine Force 12 item is also a "W2DU" type, and we are proud to have made
some of their early, smaller models.
Finally, as one of the two original producers of W2DU type devices, I
will say that if anything that we put on the market self destructed in
the manner you've described and we hadn't heard from the buyer
immediately, I would have been amazed, and truly disappointed.
Sincerely,
Press Jones, N8UG, The Wireman, Inc., Landrum, SC, 29356
Sales (800)727-WIRE(9473) or orders@thewireman.com
Tech help (864)895-4195 or n8ug@thewireman.com
http://www.thewireman.com and the WIRELINE news
and bargain page. Our 22nd year!
On Mon, 20 Sep 1999 13:42:07 -0400 "Rajiv Dewan, N2RD" <n2rd@arrl.net>
writes:
>
> I have had very bad luck with the big W2DU current balun.
>
> Three years ago I bought four of them for different wire antennas
> that I
> slung from trees.
>
> Two of them have already busted.
>
> 1. One had an intermittent short. Would check ok with ohmeter on
> ground
> and not
> work in the air. After much scratching of my head, I discovered
> that the
> short developed
> only when I had a pl259 attached. Upon opening, I discovered that
> the
> shield was not
> dressed well and when the pl259 was attached, it pushed the center
> pin a
> little into
> the connector and shorted the center and shield. Very irritating.
>
> 2. This occured a couple of weeks ago. I have a 2 element relay
> switched
> 40m wire beam.
> It suddenlys stopped working. With so many working parts, I did not
> suspect
> the balun.
> Checked the relay, etc., to find that it was fine. Eventually
> worked may
> way up the
> feed line to find that the balun was busted. It had an open
> circuit. I cut
> it open to find
> a clean fracture of the center conductor and a near fracture of the
> shield.
> Fatigue is my
> guess. I think that there is a design fault. The beaded teflon
> cable is
> not well supported
> in the inside. The only support consists of the soldered joints.
> The 50
> ohm teflon thin
> coax has a thin stiff (20 or 22 swg) solid center conductor and I
> guess
> that the swaying
> of the wire beam (one year old) flexed the choke assembly in the
> balun
> enough to cause
> a fatigue fracture. (BTW, unlike the first one, the shield in this
> unit was
> dressed fine.)
>
> Changing the balun was a bit of work. My wire beams are supported
> by four
> ropes in trees, and are
> over structures. It was a pain to get it down to work on and again
> get it
> back up. Changing a
> balun on a yagi installed on a tower and mast, with driven element
> near one
> end of boom seems
> even worse. Ugh.
>
> I recently put up the Force 12 C3SS tribander and used their balun.
> It is
> extremely well built.
> Some special features:
> 1. It has a rubber o-ring at the so239 to seal with the pl259
> 2. It is vaccuum potted with silicone. Absolutely nothing shakes on
> the
> inside.
> 3. They claim that instead of using a bulkead mount so239 (as w2du
> does),
> they use
> a crimp on so239 to crimp the shield.
> It seemed really well built. (And I though that the W2DU's were
> well built
> when I
> bought them.)
>
> Time will tell.
>
> Regards,
> Rajiv, N2RD
>
>
> ----- Original Message -----
> From: <W4nf@aol.com>
> To: <towertalk@contesting.com>
> Sent: Monday, September 20, 1999 12:09 PM
> Subject: [TowerTalk] Balun for 40-2CD
>
> >
> > I read several posts that stated they used the W2DU beam balun on
> the
> 40-2CD.
> > I was wondering what experiences people have had with this type
> balun. I
> > have always just used a coax wound balun on all my yagis as I have
> looked
> at
> > baluns as an additional point of failure of an antenna system.
> Where I
> have
> > never had a coax wound balun fail I have been involved at several
> times
> where
> > the balun was the failed part on the system.
<snip>> >
> > FAQ on WWW:
> http://www.contesting.com/towertalkfaq.html
> > Submissions: towertalk@contesting.com
> > Administrative requests: towertalk-REQUEST@contesting.com
> > Problems: owner-towertalk@contesting.com
> > Search:
> http://www.contesting.com/km9p/search.htm
> >
Press Jones, N8UG, The Wireman, Inc., Landrum, SC, 29356
Sales (800)727-WIRE(9473) or orders@thewireman.com
Tech help (864)895-4195 or n8ug@thewireman.com
http://www.thewireman.com and the WIRELINE news
and bargain page. Our 22nd year!
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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