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Content preview: ykes I forgot that and at 1 watt I believe Bill was able to generate a ;ot of current at your power level I would expect any discontinuity in the loop would be a flash point or at least a potential one [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [64.136.55.36 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (riese-k3djc[at]juno.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-Scan-Signature: 310131a5e532565f108a820138314750 Subject: Re: LF: Fire in the wire Content-Type: multipart/alternative; boundary=--__JNP_000_746a.1104.20d4 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: *** X-Spam-Status: No, hits=3.6 required=5.0 tests=FORGED_JUNO_RCVD,HTML_20_30, HTML_MESSAGE,NO_REAL_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mtain-de03.r1000.mx.aol.com ; domain : juno.com DKIM : pass x-aol-sid: 3039ac1d40cb517b29681924 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ----__JNP_000_746a.1104.20d4 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit ykes I forgot that and at 1 watt I believe Bill was able to generate a ;ot of current at your power level I would expect any discontinuity in the loop would be a flash point or at least a potential one HAR Bob K3DJC On Fri, 26 Apr 2013 19:28:51 -0400 Warren Ziegler writes: Hi Bob, Yes but Bill always worked at the 1W level. I forget the exact numbers but the loop has an inductive reactance of 100-200 ohms, when you multiply that by a loop current of 50A you can get 10kV. BTW, my RG-11 loop was put up by Bill and I in 2005 - no complaints! 73 Warren On Fri, Apr 26, 2013 at 7:14 PM, wrote: Thought the loop info Bill Ashloch developed pointed to high currents in the loop so a large conductor needed ,, but low voltage and I remember ( ? ) his idea of pushing soft plumbing copper through trees and just supporting the CU on the branches hi voltage on verticals .low current hi current on loops low voltage Bob K3DJC On Fri, 26 Apr 2013 19:44:01 +0200 =?ISO-8859-1?Q?Stefan_Sch=E4fer?= writes: > Warren, > > What is the voltage between the tree (GND) and loop? I thought that > the > voltages are rather small, i.e. below 100V, especially when a large > loop > is used. Isn't it possible to ground the loop? > > 73, Stefan > > Am 26.04.2013 19:21, schrieb Warren Ziegler: > > > > Just a quick report on a failure mode for LF TX antennas. > > Last Fall my original TX loop made up of approximately 500 feet of > > > RG-11 coax suspended from trees went open circuit (both center > > conductor and shield), some time later part of the wire actually > came > > down. I had thought that abrasion from contact with the trees had > > > eventually worn through it. > > > > What I found was a little more interesting. Looking at the downed > end, > > it appeared that the insulation had melted for a considerable > distance > > and there were burn marks further up the cable. My hypothesis is > that > > the outer insulation was abraded away and the coax shield came > into > > contact with the tree limb causing the burning/melting. > > Will try to get some pictures this weekend and put them up on my > website. > > > > Long term if one wants to operate at the kW level either better > > insulation or a better way of supporting the antenna than trees > would > > be required! > > > > -- > > 73 Warren K2ORS > > WD2XGJ > > WD2XSH/23 > > WE2XEB/2 > > WE2XGR/1 > > > > -- 73 Warren K2ORS WD2XGJ WD2XSH/23 WE2XEB/2 WE2XGR/1 ----__JNP_000_746a.1104.20d4 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: quoted-printable
ykes  I forgot that and at 1 watt I believe Bill was able to = generate=20 a ;ot of current
at your power level I would expect any discontinuity in the loop would= be a=20 flash point
or at least a potential one
 
HAR
 
Bob K3DJC
 
On Fri, 26 Apr 2013 19:28:51 -0400 Warren Ziegler <wd2xgj@gmail.com> writes:
Hi Bob,
    Yes but Bill always worked at the 1W level. 
I forget the exact numbers but the loop has an inductive reactance = of=20 100-200 ohms, when you multiply that by a loop current of 50A you can get= =20 10kV.

BTW, my RG-11 loop was put up by Bill and I in 2005 - no=20 complaints!

73 Warren



On Fri, Apr 26, 2013 at 7:14 PM, <riese-k3djc@juno.com> wrote:
Thought the loop info Bill Ashloch developed pointed = to=20 high currents in
the loop
so a large conductor needed ,, but low= =20 voltage and I remember ( ? ) his
idea of pushing
soft plumbing = copper=20 through trees and just supporting the CU on the
branches
hi = voltage on=20 verticals .low current
hi current on loops low voltage

Bob=20 K3DJC



On Fri, 26 Apr 2013 19:44:01 +0200=20 =3D?ISO-8859-1?Q?Stefan_Sch=3DE4fer?=3D
<Stefan.Schaefer@= iup.uni-heidelberg.de>=20 writes:
> Warren,
>
> What is the voltage between the= tree=20 (GND) and loop? I thought that
> the
> voltages are rather= =20 small, i.e. below 100V, especially when a large
> loop
> is= =20 used. Isn't it possible to ground the loop?
>
> 73,=20 Stefan
>
> Am 26.04.2013 19:21, schrieb Warren Ziegler:>=20 >
> > Just a quick report on a failure mode for LF TX=20 antennas.
> > Last Fall my original TX loop made up of=20 approximately 500 feet of
>
> > RG-11 coax suspended = from=20 trees went open circuit (both center
> > conductor and shield)= ,=20 some time later part of the wire actually
> came
> > = down. I=20 had thought that abrasion from contact with the trees had
>
&= gt;=20 > eventually worn through it.
> >
> > What I found= was=20 a little more interesting. Looking at the downed
> end,
> &= gt;=20 it appeared that the insulation had melted for a considerable
>=20 distance
> > and there were burn marks further up the cable. = My=20 hypothesis is
> that
> > the outer insulation was = abraded=20 away and the coax shield came
> into
> > contact with = the=20 tree limb causing the burning/melting.
> > Will try to get = some=20 pictures this weekend and put them up on my
> website.
>=20 >
> > Long term if one wants to operate at the kW level = either=20 better
> > insulation or a better way of supporting the = antenna=20 than trees
> would
> > be required!
> >
>= >=20 --
> > 73 Warren K2ORS
> >        = ;=20         WD2XGJ
> >       &= nbsp;=20         WD2XSH/23
> >      = =20           WE2XEB/2
> >    = =20             WE2XGR/1
>=20 >
>
>




--
73 Warren K2ORS
        &= nbsp;=20       WD2XGJ
           = =20     WD2XSH/23
            &= nbsp;=20   WE2XEB/2
               = ;=20 WE2XGR/1

 
 
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