I forgot to mention to apply tape on the PVC openings - decreases bird nests
and such ! :)
I misread your first sentence - yes, it is a coil OF coax. :)
73, Jamie
WB4YDL
Sent from my iPad
> On Aug 1, 2014, at 2:14 PM, "James C. Hall, MD" <heartdoc@nwtcc.com> wrote:
>
> Is it a coil or coax ? Yes and yes ! :) I use lightweight 3 1/2" sewer PVC
> and use it as a form for wrapping the appropriate number (depending on
> frequency) turns of coax (I had Buryflex on hand). You have to drill a few
> holes in the PVC and use zip (cable) ties to hold the coax while wrapping.
> Then tape it up nice with Scotch 33 or 88 and put PL259 connectors on each
> end. I use a Budwig (center dipole connector) and solder ring lugs on the
> wire terminals and bend them forward for your yagi connection. The SO259
> connector of the Budwig makes it easy to connect to and waterproof. Of course
> you can just break out the two conductors of the coax and put lugs on
> directly, I just found its more contained to add connectors.
>
> As to the proper number of turns of coax -
> http://www.k1ttt.net/technote/airbalun.html . Interesting reading.
>
> 73, Jamie
> WB4YDL
>
> Sent from my iPad
>
>> On Aug 1, 2014, at 12:59 PM, "L L bahr " <pulsarxp@embarqmail.com> wrote:
>>
>> What is that, Jamie? Are you using a coil of coax? That is what I think
>> I'll be using.
>> Lee, w0vt
>>
>> ----- Original Message -----
>> From: "James C. Hall, MD" <heartdoc@nwtcc.com>
>> To: towertalk@contesting.com
>> Sent: Friday, August 1, 2014 12:21:10 PM
>> Subject: Re: [TowerTalk] Recommendations for Purchasing a short 2 Element 40
>> Meter
>>
>> I quit using the old B-1 balun. I use the "Ugly balun" on all antennas.
>> Works extremely well with no heat degradation.
>>
>> 73, Jamie
>> WB4YDL
>>
>> Sent from my iPad
>>
>>> On Aug 1, 2014, at 11:36 AM, "Dale Drake" <daleaa1qd@gmail.com> wrote:
>>>
>>>
>>> I had a recent bad experience with the Cushcraft XM-240. The present
>>> manufacturer had changed the U channel design from the original when it was
>>> made by the NH company. The original design ( according to the guy that
>>> actually designed it) used a heat treated aluminum channel but the "new"
>>> design uses a thinner channel formed from sheet in a brake ( not heat
>>> treated).
>>>
>>> Mine was of the newer design and the wind ( 40-50MPH gusts from the remnants
>>> of Bob) tore the 1/4" hex head cap screw heads right through the U channel
>>> on one side and left the element dangling. I called the manufacturer in MS
>>> who said they had never heard of that failure but they sent me a new U
>>> channel for free. I put large stainless fender washers under the heads of
>>> the 1/4" cap screws this time to spread the stress out more and so far so
>>> good. If I was to do it over I would replace the less rugged U channel with
>>> something more like the original design.
>>>
>>> If you want to see the pics email me directly aa1qd@arrl.net
>>>
>>> Also if you plan on 1.5KW AM I would not use the stock balun as it is like
>>> to fail with that much heating from what I've heard from other hams.
>>>
>>> Dale
>>> AA1QD
>>>
>>> _______________________________________________
>>>
>>>
>>>
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>>> TowerTalk@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
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>>
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> _______________________________________________
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