Return-Path: Received: from mtain-mb02.r1000.mx.aol.com (mtain-mb02.r1000.mx.aol.com [172.29.96.22]) by air-md10.mail.aol.com (v129.4) with ESMTP id MAILINMD104-8b9f4d6ecc3c398; Wed, 02 Mar 2011 18:01:16 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mb02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7D0CD380000BE; Wed, 2 Mar 2011 18:01:14 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Puv1d-0002wc-Oj for rs_out_1@blacksheep.org; Wed, 02 Mar 2011 23:00:09 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Puv1c-0002wT-Ak for rsgb_lf_group@blacksheep.org; Wed, 02 Mar 2011 23:00:08 +0000 Received: from out1.ip02ir2.opaltelecom.net ([62.24.128.238]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Puv1a-0007fu-23 for rsgb_lf_group@blacksheep.org; Wed, 02 Mar 2011 23:00:08 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AvMAABVabk1Z8+BA/2dsb2JhbACULYNtjlh0vliFYQSBbI4U X-IronPort-AV: E=Sophos;i="4.62,255,1297036800"; d="scan'208,217";a="357495980" Received: from unknown (HELO TraceyPC) ([89.243.224.64]) by out1.ip02ir2.opaltelecom.net with SMTP; 02 Mar 2011 22:59:58 +0000 Message-ID: From: "Tracey Gardner" To: References: In-Reply-To: Date: Wed, 2 Mar 2011 22:59:53 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18197 X-MIMEOLE: Produced By Microsoft MimeOLE V6.0.6002.18263 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Corona Discharge - how to prevent ? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0715_01CBD92D.8AEB8E40" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_40_50,HTML_MESSAGE, MISSING_OUTLOOK_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-sid: 3039ac1d60164d6ecc39707a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_0715_01CBD92D.8AEB8E40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I recall that you can get copper cistern ball floats in various sizes,= as large as 12 inches diameter, would that be of any use? Regards Tracey ----- Original Message -----=20 From: Graham=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Wednesday, March 02, 2011 10:26 PM Subject: Re: LF: Corona Discharge - how to prevent ? Thanks Alan , John. Yes that seems to be the solution , may be a ball would do th= e same thing ?.. I was wrangling with the charge distribution angle= .. as to the best way , assuming a sharp point on the ring woul= d still produce the same corona ?=20 The double stacked ring looked a good idea , but is only = in 'one plane' what happens at 90 deg ie in front and behind= ... ? The tube has possibilities, I have some copper brake pipe , that= should do the job ..... Pity to quench it, it looks quite impressive in the night ! ,= (not sure what its doing to the local medium wave reception though...) tnx - G..=20 From: Graham=20 Sent: Wednesday, March 02, 2011 8:32 PM To: rsgb_lf_group@blacksheep.org=20 Subject: LF: Corona Discharge - how to prevent ? Corona Discharge - how to prevent ? Running into corona problems with a small loaded antenna , te= rminating as a wire at the far end=20 Q has any one addressed this problem and found a suitable solut= ion ? Apparently more prevalent on 136 khz , this is presenting on= 500k , I can find reference to rounded objects and rings , one= being two sets of ring's the second being insulated to reduce= the v/mm stress , but these where part of a high voltage insulat= or with the far end earthed , not so in this case, the wire en= ds in free space .. Increasing the surface area will distribute the charge , but= will not reduce the stress as this is a generated field as opp= osed to a static build up ? Links / ides ? Tnx - Graham .. ----------------------------------------------------------------------= -------- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1204 / Virus Database: 1435/3477 - Release Date: 03/02= /11 ------=_NextPart_000_0715_01CBD92D.8AEB8E40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
I recall that you can get copper cistern ball floats in vari= ous sizes,=20 as large as 12 inches diameter, would that be of any use?
 
Regards
 
Tracey
 
----- Original Message -----
From:=20 Graham
Sent: Wednesday, March 02, 20= 11 10:26=20 PM
Subject: Re: LF: Corona Disch= arge - how=20 to prevent ?

Thanks  Alan , John.
 
Yes that  seems  to be th= e solution ,=20 may be a  ball   would  do  the  same= thing ?..=20 I was  wrangling with the charge  distribution angle .. as= to=20 the  best  way  , assuming a  sharp point on the=  =20 ring  would  still  produce the  same  coro= na  ?=20
 
The  double  stacked = ; ring =20 looked a  good  idea  , but  is  only = in 'one=20 plane'  what  happens  at  90  deg  ie=   in=20 front  and behind ...  ?
 
The tube  has possibilities,= I have=20 some  copper brake  pipe , that   should = do the job=20 .....
 
Pity to  quench it, it&nb= sp;=20 looks  quite impressive  in the  night  <= FONT size=3D2 face=3DArial>! , (not  sure what its doing to= the =20 local
medium wave reception =20 though...)
 
tnx - G..

From: Graham
Sent: Wednesday, March 02, 2011 8:32 PM
Subject: LF: Corona Discharge - how to prevent ?

Corona Discharge - how to  pre= vent =20 ?
 
Running  into  corona pro= blems =20 with  a  small  loaded  antenna , terminating&nb= sp; as=20 a  wire  at the far  end
 
Q has any one  addressed = this =20 problem and  found a  suitable solution ?
 
Apparently  more  prevale= nt on=20 136  khz , this  is  presenting  on 500k , I can=  =20 find  reference  to rounded  objects and  rings= ,=20 one  being  two  sets  of ring's the  secon= d =20 being  insulated to  reduce the  v/mm stress , but th= ese =20 where  part of a  high  voltage insulator  with= the =20 far  end  earthed , not so  in this  case, the&n= bsp;=20 wire  ends in free  space ..
 
Increasing the  surface = area =20 will  distribute  the  charge , but  will = not =20 reduce the stress  as this  is  a generated  fie= ld as=20 opposed to a  static build up ?
 
Links / ides ?
 
Tnx - Graham ..



No virus found in= this=20 message.
Checked by AVG - www.= avg.com
Version: 10.0.1204 / Virus=20 Database: 1435/3477 - Release Date: 03/02/11

= ------=_NextPart_000_0715_01CBD92D.8AEB8E40--