hello tom, any time you cut your feed line and that changes the swr 
that just means that the swr still is their all you have done is fool 
the swr bridge andthe really the fool is the person who cuts the 
coax.   like i told you in my earlier posting the only time you 
should cut your feed line is to put on a connector smile.  don't 
listen to all the jail house attorneys.  what is happening to ham 
radio.  get the arrl antenna hand book and read it tom and they can 
maybe explain it better to you then me.  good luck, c u 73 mike w6quv



At 05:42 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.