Laurence KL1X wrote:
Im hoping to erect a reasonably large but lightweight temp 60m
vertical here in the near future but need to keep the insulator weight
down to the minimum - I see toothbrushes have been used in the past at
the 400W level (?) but Im going to be around that level and concerned
over corona _ive made some lightweight corona rings up but still
concerned. I dont think Im going to be able to top cap load so looking
like something around 365pF and perhaps >3.5mH to resonant
I've used fiberglass rods. Several sources: ~10 mm - electric fence
post, ~6 mm - bicycle flag mast, ~3 mm from dead pool umbrella spreaders.
Also I've found some weed eater line to be a very good insulators with
high voltage at LF. However the last type I bought sure wasn't. After
reading the packaging I found the line to contain some titanium!
Here's a picture of an insulator made with a section of an electric
fence post connected to plastic electric fence insulators. A hole the
diameter of the rod was drilled in one end of the plastic insulators.
Then rod was inserted and pined with small brass nails. I tested this
one with 200 pounds dead weight. The umbrella spreader size rod would
be lightweight.
http://www.w4dex.com/lf/part5/xko_insulator.JPG
Dex, W4DEX / WD2XKO
http://www.w4dex.com/wd2xko.htm
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