[TowerTalk] Six meter balun

[Grant Saviers]

I don't have installed experimental data but choose to separate the 8 
type 31 large beads on Buryflex from the boom with a strip of 5/8" thick 
HDPE and all were taped to the boom with Scotch 33. 6M5 over 6M5 stack. 
  IIRC the choke measured around 3k ohms on the bench.

Grant KZ1W

On 7/3/2022 05:09, Jim W7RY wrote:
> 
> On 7/2/2022 10:56 PM, Grant Saviers wrote:
>> A minor matter, but RG142 center conductor is SCCS - silver plated 
>> copper coated steel.  That makes it very strong but fatigue prone. 
>> Some are concerned about TFE creep from the solid conductor and 
>> recommend stranded RG400 as a result.  However, I've not had problems 
>> in FT-240 toroid chokes wound 10 years ago with 142 made from Mil 
>> 17/60-RG142 spec cable.
>>
>> Paternack specs their 142 at 2400w average power at 100MHz.  It will 
>> get hot, but the TFE handles it.  Best to provide easy dissipation of 
>> the heat as K9YC recommends.
>>
>> Another possible issue is to keep ferrite toroids away from the boom 
>> and other conductors as the coupling can cause problems.
> 
> 
> 
> _*How far away? *__*
> *_
> 
> _*73, Jim W7RY*_
> 
> 
>>
>>
>> Grant KZ1W
>>
>>
>> On 7/2/2022 16:13, Jim W7RY wrote:
>>> Agreed.
>>>
>>> RG-400 works well to. The only difference between RG-142 and RG-400, 
>>> is that RG-400 has a stranded center conductor. RG-142 has a silver 
>>> plated solid hard drawn copper center conductor.
>>>
>>> 73, Jim W7RY
>>>
>>>
>>> On 7/2/2022 6:09 PM, john at kk9a.com wrote:
>>>> The 50MHz power average rating for RG142 is several kilowatts, why 
>>>> do you
>>>> think it is inadequate?*If it is a balun problem it is most likely 
>>>> connection related.*
>>>>
>>>> John KK9A
>>>>
>>>>
>>>>
>>>> Dave Sublette k4to wrote:
>>>>
>>>> My six element 6M LFA is showing a high SWR and severe loss of receive
>>>> signal.  This happened this afternoon as I was working the band with 
>>>> 500
>>>> watts from my KPA500.
>>>>
>>>> To this point, the antenna was very nicely matched with a 1:1 SWR over
>>>> almost 1 MHz of bandwidth. The antenna is home brew and I made the 
>>>> matching
>>>> balun per the instructions from K9YC using two toroids with six 
>>>> turns each
>>>> of high quality teflon insulated, double shielded silver braid. I 
>>>> think it
>>>> was RG142 purchased new from a reputable vendor in Tennessee. It has 
>>>> worked
>>>> perfectly at the 100 watt level for three or four years.  I had 
>>>> looked at
>>>> the specs on the coax and thought it would be good for 500 watts.
>>>> Evidently not.
>>>>
>>>>
>>>> 73,
>>>>
>>>> Dave, K4TO
>>>>
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