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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