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From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
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> <FB0006513E634A96AFED8066F7C344C1@JimPC> <4E920BBA.9040200@iup.uni-heidelberg.de> <BA4122BA92D44641A1BE5ED27FD763E5@JimPC> <Pine.LNX.4.64.1110091918360.28918@plato.ucs.mun.ca> <4E934A40.9040204@gmx.de> <Pine.LNX.4.64.1110102003170.6615@plato.ucs.mun.ca> <006c01cc87ab$427234c0$4001a8c0@lark> <Pine.LNX.4.64.1110102222310.10824@plato.ucs.mun.ca> <834DCCD1D3834F4CB4C171B7C30E85B4@AGB>
Date: Tue, 11 Oct 2011 12:31:50 +0100
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Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c.
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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" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
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: <jcraig@mun.ca>
> Sent: Tuesday, October 11, 2011 2:11 AM
> To: <rsgb_lf_group@blacksheep.org>
> 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: <jcraig@mun.ca>
> >> To: <rsgb_lf_group@blacksheep.org>
> >> 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
> >
> >
>
>
>