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Re: Broken wire in secondary.
From: Phil Chalk[SMTP:phil-at-eagles-dot-com.au]
Sent: Tuesday, November 18, 1997 6:13 AM
To: The TESLA List
Subject: Broken wire in secondary.
Matthew Price, et al
Yes, annoying isn't it ! I broke my wire when winding my second
secondary, smack bang in the middle as it turned out.
I carefully stripped about 10mm insulation from both ends, twisted a
couple of times, soldered, & filed & sanded quite a bit, till smooth &
not much thicker than the original wire. The result is a fairly minor
'lump' in the wire & _slight_ gaps evident either side of the lump in
the finished winding. But basically it looks gorgeous, & under a
squillion coats of poly lacquer (& as many wet&dry sandings) you can't
feel it at all, and it has had no effect on performance. (4.5" coil, &
admittedly at low powers, but I feel confident about it.)
I think lots of polyurethane varnish over your secondary helps a lot.
It gets in, under, & all around your winding & the join & helps to
ensure adequate insulation of the joint. The other important 'point' as
stated is 'No points' Make sure there are no pointy or sharp edges on
your wire joint as they promote corona discharge & breakdown & spark
discharge in general. Spark discharges are nice, but you don't want
them from the middle of your secondary.
But definitely give it a go. You've gone this far & if you're winding
by hand I sympathise with you. It's well worth a try at rejoining your
wire. Do the best you can & if it looks OK to you it'll probably work
fine. (Maybe don't put too many hundreds of kW up it till you feel good
about it.)
Good luck,
Phil Chalk.