Yes I enjoyed working with the Phillystran...easy to cut and much lighter to
pull up the tower.
Getting the big grips to seat at the end was a little more difficult but not
too bad after my learning experience putting big grips on ehs.
Mark N1UK
----- Original Message -----
From: "Roger (K8RI)" <K8RI-on-TowerTalk@tm.net>
To: <towertalk@contesting.com>
Sent: Tuesday, 05 October, 2010 11:29 PM
Subject: Re: [TowerTalk] Tower Detuning
>
>
> On 10/5/2010 8:10 PM, Mark Robinson wrote:
>> If he hung some capacitance hats off the top of the tower, would that
>> work.
> Replace those conductive guy lines with Phillystran?
>
> 73
>
> Roger (K8RI)
>> Maybe something to try.
>>
>>
>> Mark N1UK
>>
>>
>> ----- Original Message -----
>> From: "David Gilbert"<xdavid@cis-broadband.com>
>> To:<towertalk@contesting.com>
>> Sent: Tuesday, 05 October, 2010 3:59 PM
>> Subject: Re: [TowerTalk] Tower Detuning
>>
>>
>>>
>>> Well, as Jim pointed out (and as I should have) the operating frequency
>>> was much higher (12 to 15 times higher), and we used three clamp-ons
>>> instead of one. To a first order approximation (I didn't look at the
>>> material curves)that's 40 times the choking action of the single
>>> identical clamp at 1.8 MHz. We would have used more clamp-ons except
>>> that it was already getting kind of expensive and it made sense to see
>>> if there was any improvement at all before spending money on more of
>>> them. As it turned out, the three clamp-ons for each guy worked well
>>> enough that K9RX was satisfied with that.
>>>
>>> 73,
>>> Dave AB7E
>>>
>>>
>>>
>>>
>>>
>>> On 10/5/2010 11:33 AM, Michael Baker wrote:
>>>> OK, well that raises another question.
>>>> If a clamp on bead works with a single cable and a single turn, why
>>>> doesn't
>>>> it work with a Tower? Granted, on zig zag reinforcing on the tower,
>>>> they
>>>> would also have to get a bead to break up the path but why not work? If
>>>> I
>>>> can clamp on one each to each leg of an overhead power source to keep
>>>> RF
>>>> off
>>>> the service entrance, why not a tower leg?
>>>> It is still a single turn?
>>>>
>>>> Section (cut in half with a diamond wheel) Mix 31 toroids and band them
>>>> around the leg. If 5 to 7 work as chokes for coax it should work for
>>>> the
>>>> leg.
>>>>
>>>> What have I missed? (OK< yes, the guys also must be done as well AND
>>>> all
>>>> cables descending down the tower.
>>>>
>>>> Just curious.
>>>>
>>>> Michael Baker K7DD
>>>> k7dd@cox.net
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: towertalk-bounces@contesting.com
>>>> [mailto:towertalk-bounces@contesting.com] On Behalf Of David Gilbert
>>>> Sent: Tuesday, October 05, 2010 10:11 AM
>>>> To: towertalk@contesting.com
>>>> Subject: Re: [TowerTalk] Tower Detuning
>>>>
>>>>
>>>> I agree ... one turn through a core is insufficient on 160m.
>>>>
>>>> Using clamp-ons can be useful in other semi-similar situations, though.
>>>> A couple of years ago afriend of mine, K9RX, was having significant
>>>> detuning issues with his 3-stack of KT34XA's. He could see the effect
>>>> on SWR (and presumably pattern) on either 15m or 10m (I don't remember
>>>> which band .. maybe both) as he rotated the stack. He was convinced
>>>> he
>>>> was getting interaction with the top sections of each guy even though
>>>> he
>>>> had them split with insulators per the usual recommended lengths. We
>>>> put three Mix-31 clamp-ons from DX Engineering on the top section of
>>>> the
>>>> guys out as far as I could reach from the tower at each level and the
>>>> situation dramatically improved.
>>>>
>>>> 73,
>>>> Dave AB7E
>>>>
>>>>
>>>>
>>>>
>>>> On 10/5/2010 9:28 AM, Jim Brown wrote:
>>>>> On 10/4/2010 3:00 PM, Michael Baker wrote:
>>>>>> How about using the Giant Clamp on Beads made my Fair-Rite?
>>>>>> Clamp one or more on each leg and the descending cables.
>>>>> Sorry, that will NOT work -- the impedance of a single turn through
>>>>> these parts are FAR too small to have any effect on 160M.
>>>>>
>>>>> 73, Jim Brown K9YC
>>>>> _________________
>>>> _______________________________________________
>>>>
>>>>
>>>>
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