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.
>
| --------------------------------------------------------------------
---
> |
> | -----
> | FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> | 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
> Administrative requests: towertalk-REQUEST@contesting.com
> 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.
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