Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dc03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 6668C38000159; Tue, 11 Oct 2011 08:11:11 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RDbAB-0003jZ-4q for rs_out_1@blacksheep.org; Tue, 11 Oct 2011 13:10:27 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RDbAA-0003jQ-LS for rsgb_lf_group@blacksheep.org; Tue, 11 Oct 2011 13:10:26 +0100 Received: from smtp5.freeserve.com ([193.252.22.128]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RDbA8-0003lc-Aa for rsgb_lf_group@blacksheep.org; Tue, 11 Oct 2011 13:10:26 +0100 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3419.me.freeserve.com (SMTP Server) with ESMTP id 8754D1C00094 for ; Tue, 11 Oct 2011 14:10:18 +0200 (CEST) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3419.me.freeserve.com (SMTP Server) with ESMTP id 72E421C00095 for ; Tue, 11 Oct 2011 14:10:18 +0200 (CEST) Received: from AGB (unknown [2.26.46.67]) by mwinf3419.me.freeserve.com (SMTP Server) with SMTP id 45B861C00094 for ; Tue, 11 Oct 2011 14:10:18 +0200 (CEST) X-ME-UUID: 20111011121018285.45B861C00094@mwinf3419.me.freeserve.com Message-ID: From: "Graham" To: References: <4E91694C.8060900@orange.fr> <4E9169AD.8090609@wanadoo.fr> <4E918C0E.30401@freenet.de> <4E918FF1.1010407@iup.uni-heidelberg.de> <1318166502.15085.YahooMailNeo@web28106.mail.ukl.yahoo.com> <1849736542-1318171189-cardhu_decombobulator_blackberry.rim.net-208700020-@b1.c11.bise7.blackberry> <4E920BBA.9040200@iup.uni-heidelberg.de> <4E934A40.9040204@gmx.de> <006c01cc87ab$427234c0$4001a8c0@lark> <834DCCD1D3834F4CB4C171B7C30E85B4@AGB> <004801cc8809$63378d50$4001a8c0@lark> In-Reply-To: <004801cc8809$63378d50$4001a8c0@lark> Date: Tue, 11 Oct 2011 13:10:18 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Antivirus: avast! (VPS 111011-0, 11/10/2011), Outbound message X-Antivirus-Status: Clean X-Spam-Score: 0.2 (/) X-Spam-Report: autolearn=disabled,RCVD_ILLEGAL_IP=0.234 Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=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-SCOLL-SCORE: 0:2:508808128:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40834e94325f1a19 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Yes engineering wise it quite possible to produce a actuated Knife switch but , that path may be a little problematic ? I would be surprised, if say 3 of the 6Kv relays in series flashed over , as each contact 'set' is 6Kv , that would give ~ 36 Kv working , I use the smaller relays with the moving contacts linked to provide a no/nc 'two contact' path .. very rarely have any flash problems .. over heating may be but that's a different matter ... G. -------------------------------------------------- From: "Alan Melia" Sent: Tuesday, October 11, 2011 12:31 PM To: Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. > > Hi Joe in theory 50kV will need about an inch ....25mms but this is always > a > try it an see thing in my mind. I reckon it "non-linear" on you strike an > arc you can increse the gap a lot before it goes out....so if you can > prevent an arc starting?? It is a strage situation...... maybe you do need > a > big gap at that voltage....a solenoid operated short?? A door closer > solenoid or a rotary one should have enough throw, and you can always use > some mechanical "amplification" for a bigger gap ?? > > Alan > > > ----- Original Message ----- > From: "Graham" > To: > Sent: Tuesday, October 11, 2011 12:17 PM > Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. > > >> Joe.. >> >> There are some 'good' rf relays at :- >> >> http://www.surplussales.com/Relays/rfopen.html >> >> Ive used the small open frame one's for some time on the HF >> bands >> may be a couple of the 6 Kv open frame in series would work ? >> >> G.. >> >> >> >> -------------------------------------------------- >> From: >> Sent: Tuesday, October 11, 2011 2:11 AM >> To: >> Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. >> >> > >> > Hi Alan, Group. >> > >> > Thank-you for the reply. Multiple contacts in series were considered... >> > but the gap has to >> > increase by orders magnitude! How much gap will I need for 50 kV? >> > >> > Your spiral pie story was most enlightening. My pies are ~35 turns of >> > 4mm litz about 37 cm diameter with L=0.24 mH. A stack of 4 yields >> > 3mH. Each pie has ~23 metres of litz. Do you think this is will give >> > the most L for the least length of litz? >> > >> > VX9MRC is still sending the 8 WPM beacon as yours truly looks at a >> > fried >> > relay... >> > >> > Cheers >> > Joe >> > >> > On Tue, 11 Oct 2011, Alan Melia wrote: >> > >> >> Hi Joe, why not stick two sets of normal contacts in series....doubles >> >> the >> >> gap :-)) >> >> >> >> Alan >> >> >> >> ----- Original Message ----- >> >> From: >> >> To: >> >> Sent: Monday, October 10, 2011 11:54 PM >> >> Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c. >> >> >> >> >> >>> Hello Hartmut, Group. >> >>> >> >>> Good to hear from you again, Hartmut. Thank-you for the report. >> >>> >> >>> The beacon is on again, but there was some trouble: to use the tower >> >>> on 160m the 500 kHz tuning coil (0.2 mH) is shorted by a relay. The >> >>> N.O. contacts on this relay arced over. Perhaps a high voltage > (vacuum) >> >>> relay would help? >> >>> >> >>> This problem will be much worse on 137.777 kHz with the higher > voltage. >> >>> I have some spiral wound 4mm (Decca) litz to make up the 3 mH for >> >>> that >> >>> project. (The spiral winding was inspired by G3NYK's experiments >> >>> with >> >>> tuning coils on his web page.) >> >>> >> >>> 73 >> >>> Joe >> >>> >> >>> On Mon, 10 Oct 2011, Hartmut Wolff wrote: >> >>> >> >>>> Am 2011-10-09 23:50, wrote jcraig@mun.ca: >> >>>>> Dear Group, >> >>>>> Reports on the 8 WPM CW beacon will be appreciated! >> >>>>> 73 >> >>>>> Joe VO1NA >> >>>> >> >>>> Attached a screenshot of the 8wpm signal. The signal came up at >> >>>> about >> >> 23:20 >> >>>> and faded out at about 7:35. The strongest part was between > 04:00-06:00 >> >> UTC >> >>>> -- >> >>>> 73 >> >>>> Hartmut >> >>>> www.h-wolff.de >> >>>> Locator: JO52hp >> >>>> >> >>> >> >>> This electronic communication is governed by the terms and conditions > at >> >>> >> >> > http://www.mun.ca/cc/policies/electronic_communications_disclaimer_2011.php >> >>> >> >> >> >> >> >> >> > >> > This electronic communication is governed by the terms and conditions >> > at >> > > http://www.mun.ca/cc/policies/electronic_communications_disclaimer_2011.php >> > >> > >> >> >> > > >