Thanks, Lloyd.
This is why I asked the question.
I don't know as much as I'd like to about these sorts of things, so am
willing to consider varying opinions.
That is what this is all about, in my view.
Thanks very much.
73 from Tom Behler: KB8TYJ
----- Original Message -----
From: "Lloyd Rasmussen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, November 17, 2011 11:43 PM
Subject: Re: SWR's continued
> I think that that theory is nuts. Moving the coil to a different
> place along the length of the cable might change something. But if I were
> you, I might just leave it alone, because it is working and you can tune
> it
> over much of the band. I don't see much value in cutting the coax
> shorter.
> Having said all that, I suspect that the coax is probably part of the
> radiating portion of the antenna, so ,if there's a problem with RF in the
> shack, the coil should be closer to the antenna than to the rig.
>
> Lloyd Rasmussen, Kensington, Maryland
> Home: http://lras.home.sprynet.com
> Work: http://www.loc.gov/nls
>
>> -----Original Message-----
>> From: For blind ham radio operators
>> [mailto:[log in to unmask]]
>> On Behalf Of Tom Behler
>> Sent: Thursday, November 17, 2011 8:43 PM
>> To: [log in to unmask]
>> Subject: Re: SWR's continued
>>
>> 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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