Ok folks, Let me throw this out there for what it is worth. I do remember having an antenna one time which was giving me fits with SWR and a guy who had been around for a long time told me to create an RF coil of a few turns of the coax about 6, or, 8 inches in diameter, just coil a few turns of the coax and secure them in to a coil of sorts. And you know what, it worked.
HTH, 73 Keith-wa9dro
Keith Reedy
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On Nov 17, 2011, at 9:32 PM, Tom Behler wrote:
> Yeah, we do have to be careful of those urban legends, which is why I'm
> tapping into the wisdom of the group once again.
>
> Will see what happens this week-end, I guess.
>
> 73 from Tom Behler: KB8TYJ
>
> ----- Original Message -----
> From: "Pat Byrne" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, November 17, 2011 8:57 PM
> Subject: Re: SWR's continued
>
>
>> Tom,
>> I've never heard any magic about 100 feet. Perhaps it is an urban
>> folk legend!!
>> I don't have anything that will tune 160 at all properly but will try
>> to listen as the saga goes on!!
>> Having a little trouble finding antenna installer support but someday!!
>> Pat, K9JAUAt 07:42 PM 11/17/2011, you wrote:
>>> Guys:
>>>
>>> I unexpectedly had some extra time here tonight, and just got off 160
>>> meters
>>> with some midwest hams, who gave me a real interesting theory about my 160
>>> meter sloper, the excess coax I'm using for a feed line, and why it might
>>> be
>>> throwing my SWR's off.
>>>
>>> Here's the theory:
>>>
>>> They said that using a 100 foot piece of coax as a feed line is never a
>>> good
>>> idea because there is something in that particular length that is known to
>>> throw antenna resonance off. They said there was an article in QST
>>> documenting this fact a number of years ago.
>>>
>>> They said that what I want is either a half wave-length piece of feed
>>> line,
>>> or an eighth-wave length piece of coax. They say I should avoid a
>>> quarter-wave piece.
>>>
>>> If you do the math (i.e. 468 over the frequency in megahertz), a half-wave
>>> piece of coax would be approximately 260 feet long. This is obviously not
>>> very practical.
>>>
>>> However, if one were to use an eighth-wave piece, that would amount to
>>> approximately 65 feet long.
>>>
>>> Since I seem to have about 40 extra feet of coax out in my yard at the
>>> base
>>> of the antenna, cutting that off would almost give me that eighth-wave
>>> length.
>>>
>>> I wonder if this is really what I should now shoot for.
>>>
>>> Of course, I do not have experience soldering pl259's, so I'll have to get
>>> help there, but I'm really thinking this might be worth a try.
>>>
>>> You guys know far more about this stuff than I do, so if you think this
>>> theory is nuts, please don't hesitate to let me know.
>>>
>>> Thanks for the continuing help with this issue, and I look forward to
>>> working at least some of you on 160 meters around 1.845 MHZ tomorrow
>>> night.
>>>
>>> 73 from Tom Behler: KB8TYJ
>>>
>>> ----- Original Message -----
>>> From: "John Miller" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Thursday, November 17, 2011 7:31 AM
>>> Subject: Re: SWR's continued
>>>
>>>
>>>> All I can say is that did happen to me the one time I coiled up about
>>>> 50
>>>> feet of coax, it actually made it try to radiate the rest of the coax
>>>> and
>>>> the SWR went crazy. The coax was fine, I cut off the extra and used it
>>>> elsewhere later on, even uncoiled and thrown all over the place it was
>>>> fine
>>>> but coiled up, it wasn't happening at all. I'm just reminded of that
>>>> which
>>>> is why I say that.
>>
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