[Amps] Line Isolators for RF feedback

Thu Aug 5 04:29:54 EDT 2004

Hello OT

Use the black ties.
They are special UV resistant .
Used them on my early tower, they were still in good shape after eighteen
years.

Jos on4kj  ( seventy years young black tied  hi hi )

----- Original Message ----- 
From: "R.Measures" <r at somis.org>
To: "Joe Isabella" <n3ji at yahoo.com>
Cc: "Amps" <amps at contesting.com>
Sent: Wednesday, August 04, 2004 2:59 PM
Subject: Re: [Amps] Line Isolators for RF feedback

>
> On Aug 3, 2004, at 9:40 AM, Joe Isabella wrote:
>
> > Good point, Rich!!  I guess I should say "DUUHHH!!!".
>
> Rube Goldberg showed up that high-tech solutions are not always mo'
> bettah.
> >
> > I would imagine that the coax and/or PL-259 would be the weak link in
> > this case though, wouldn't
> > it??
>
> PL-259 connectors are always the weak link because they allow water and
> water vapor to enter the coax.
>
> > Even say RG-400 or RG-303 would give up before they get saturated,
> > right?
>
> Hello, Joe --  Coax doesn't saturate, it melts and/or ignites.  Cores
> saturate.
>
> > Just curious --
> > even if I ran my 3K-A at full bore, it wouldn't kill 'em (given that
> > the dipole is at it's
> > resonant point).
>
> A 3K-A will do about 2-out.  This should not be a problem for small
> coax using SSB, especially because the choke balun is at the center of
> the dipole - so it gets cooled by the breeze.  I make the choke balun
> for a dipole out of the same coax used in the feedline because there
> are no coax splices or connectors out in the weather and because the
> balun would definitely be as capable as the feedline.  Sure, an
> ugly-balun won't win any beauty contests, but it  Will  do the job.  //
>   The main weakness of an outdoor coax choke balun is that UV from the
> sun deteriorates the nylon cable ties that are used to hold the coax to
> the ABS sewer pipe.  A solution is to cover the nylon cable ties with
> black electrical tape.
> end
> >
> > Joe
> >
> > --- "R.Measures" <r at somis.org> wrote:
> >
> >>
> >> On Jul 31, 2004, at 10:21 AM, Joe Isabella wrote:
> >>
> >>> The one I use has ferrite beads stacked on top of each other (about
> >>> 50
> >>> of the little buggers!!) on
> >>> about a 12 inch piece of teflon coax.  Since it isn't a torroid, it
> >>> can't be saturated.
> >>
> >> One wire through the center of a ferrite bead is a one-turn toroid.
> >> And yes, given enough current and freq., they can be saturated.  The
> >> only coax choke device that can not be saturated has an air-core or
> >> powdered-iron core.
> >>
> >>>  It'
> >>> supposed to handle 5kW, but I haven't quite hit it with that much
> >>> power yet ( :-)  ).  It totally
> >>> fixed all my RF woes, and I had plenty!!
> >>>
> >>> Joe,
> >>> N3JI
> >>>
> >>> --- Alek Petkovic <vk6apk at eon.net.au> wrote:
> >>>
> >>>> Ditto for me downunder.
> >>>>
> >>>> The Radioworks line isolators do the trick nicely.
> >>>>
> >>>> You can make your own as they are just coax wound around a ferrite
> >>>> rod. You
> >>>> can also use the coil of coax like Rich suggests.
> >>>>
> >>>> They all work well  but the RadioWorks product is very neat and
> >>>> convenient
> >>>> to use. It is nicely encapsulated with the female connectors on each
> >>>> end.
> >>>> Makes it real easy.
> >>>>
> >>>> 73, Alek
> >>>> VK6APK
> >>>>
> >>>> ps: Their wire antennas are well made and work quite ok as well.
> >>>>
> >>>> At 12:19 PM 30/07/2004, Harold B. Mandel wrote:
> >>>>> Seconding the message below I add my personal endorsement
> >>>>> to Radio Works.com.
> >>>>>
> >>>>> When moving my shack from the 12 month "dxpedition" in
> >>>>> Secaucus, New Jersey to my home in Kentucky, a severe case
> >>>>> of RF feedback plagued the station when activating a linear
> >>>>> amplifier.
> >>>>>
> >>>>> Even though I was ready to plunk down cash for goodies, Jim, W4THU,
> >>>>> took time to speak with me at length, and suggested several tests
> >>>>> to further diagnose the culprit and refused to sell me anything
> >>>>> until
> >>>>> reporting back to him.
> >>>>>
> >>>>> I found out about Radio Works when up in new Jersey, and purchased
> >>>>> line
> >>>>> isolators to cure RF feedback going into the hotel telephone
> >>>>> system.
> >>>>>
> >>>>> Score for Radio Works: AAAAA+
> >>>>>
> >>>>> Hal Mandel
> >>>>> KA1XO
> >>>>> On Tue, 27 Jul 2004 07:34:28 -0500 "Gene Bigham"
> >>>>> <jbigham2 at kc.rr.com>
> >>>>> writes:
> >>>>>> I followed Radio Works recommendations for RF feedback problems.
> >>>>>> Their line isolators and grounding ideas worked to cure a bad case
> >>>>>> here.
> >>>>>> _______________________________________________
> >>>>>> Amps mailing list
> >>>>>> Amps at contesting.com
> >>>>>> http://lists.contesting.com/mailman/listinfo/amps
> >>>>>>
> >>>>>>
> >>>>> _______________________________________________
> >>>>> Amps mailing list
> >>>>> Amps at contesting.com
> >>>>> http://lists.contesting.com/mailman/listinfo/amps
> >>>>
> >>>> http://www.qrz.com/vk6apk
> >>>> http://profiles.yahoo.com/vk6apk
> >>>>
> >>>> _______________________________________________
> >>>> Amps mailing list
> >>>> Amps at contesting.com
> >>>> http://lists.contesting.com/mailman/listinfo/amps
> >>>>
> >>>
> >>>
> >>>
> >>>
> >>> __________________________________
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> >>>
> >>>
> >> Richard L. Measures, AG6K, 805.386.3734.  www.somis.org
> >>
> >> _______________________________________________
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> >>
> >
> >
> >
> >
> > __________________________________
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> >
> >
> Richard L. Measures, AG6K, 805.386.3734.  www.somis.org
>
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