Message-ID: <670844AA27014CCE88BA2F0F4D83A621@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <D67F7E8F41FE4EBC951C94C6AF8B57E9@AGB> <E61BFB5F4E4543488D6AB72F5C88EA62@AGB> <009c01cbd92e$c4258f70$4001a8c0@lark> <0E0F00B1085A44EB9DE562B4A8BF5FAD@JimPC>
In-Reply-To: <0E0F00B1085A44EB9DE562B4A8BF5FAD@JimPC>
Date: Thu, 3 Mar 2011 00:20:42 -0000
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Subject: Re: LF: Corona Discharge - how to  prevent  ?
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Ok Jim

.....  Interesting  point about  moving the  discharge point round the 
antenna .... may be at the  far end is the  safest place , would not  want 
to  induce evil  spirits  in the  shed ! .. though I suspect  you  refer to 
137  khz and  not  500 , the feed  from the variometer   is quite 'hot'  but 
nothing  'glows' in the  dark

Re the  Bino's  , not  quite  needed as the  end  of the  wire is about 7 
feet  off  the  ground , could be the  reason  for the  discharge , the 
capacity  wire  is inverted  L  shaped , from the  top  loading  coil ..

73 -G..

--------------------------------------------------
From: "James Moritz" <james.moritz@btopenworld.com>
Sent: Wednesday, March 02, 2011 11:54 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: Corona Discharge - how to  prevent  ?

> Dear Graham, Alan, LF Group,
>
> Corona rings as in the attachment have served me well over the years - 
> they
> do seem to substantially increase the voltage at which the onset of corona
> happens. I doubt if multiple rings, spheres etc. will be much improvement,
> since then the maximum potential gradient will then just occur around the
> wire in the middle of the span instead of  at the ends, and the corona 
> will
> move to that point. When I first started fitting them, I found that adding
> the corona ring would get rid of the corona at one end or sharp bend of 
> the
> wire, only for it to reappear at a different point, until all ends and
> corners, and the connection to the loading coil, were so "protected". 
> Make
> sure there are no loose ends of wire hanging out. Also, try to maximise 
> the
> distance between the wire and any other conducting objects, even poor
> conductors like trees, woodwork, masonry, etc.
>
> Cheers, Jim Moritz
> 73 de M0BMU
>