Hi Chris,
Here in DL we have cheap access to large PVC tubes, e.g.
https://www.stabilo-sanitaer.de/kg-rohr-dn-250-1000-mm-kgem/a-438342/
Just an example.
I think the situation is not much different in the UK.
PVC is not really the best material. Once arcing has occured on the
surface there is a conducting track which will short cut any HV
arrangement. Anyway, i have good experience with it and i'm using it
some time now (right in this moment! :-) ) on VLF.
You need to keep the coil dry anyway and i really would recommend the
use of Kapton tape directly on the PVC surface where the winding should
be wound.
It is also recommended to do some basic calculations before starting to
wind:
What is the capacity of the antenna? (Try to increase the C and height
of the wire as much as possible. Worth to put some effort in there!)
What is the needed inductance then?
What is the maximum voltage the antenna will hold? (It sould be at least
20 kV!)
Which antenna current can i expect at this voltage level?
Which wire diameter do i need so that my coil can permanently carry this
current.?
Which coil length and diameter do i need to manage the voltage per turn?
(Keep length/diameter < 2, use a diameter as high as possible/practicable)
(Which power do i need to produce that antenna current? (Depends on the
coil and ground losses)).
Which wire length do i need?
What is the distance to Paul Nicholson? :-)
Oh yes, it would be nice to have a signal from the UK -> DL on VLF, it
has always been the other way so far!
Keep us informed, show images and so on :-)
73, Stefan
Am 18.04.2017 13:58, schrieb Chris Wilson:
Hello Stefan,
Tuesday, April 18, 2017
Thanks Stefan, I am toying with having a crack at VLF. I am wondering
where I can find suitable 12 inch plus diameter tube to wind on,
polycarbonate tube is ludicrously expensive in 3mm plus wall thickness
and large diameters. My LF coil is wound around a round and near
parallel sided nylon feed bin. I keep looking about, and although I
have some 12 inch diameter field drain it's ribbed and unsuitable as
is to wind upon. Anyone got any imaginative cheap sources short of
nicking something from a construction site? ;)
Am 16.04.2017 13:48, schrieb Chris Wilson:
I am amazed by pretty much everything Stefan does, I am hope he has
some financial backing, just keeping him in copper wire and toroids
looks like a job fro a wealthy man! Amazing stuff on VLF, simply
amazing.
Many thanks Chris :-)
One day you will decide to join in :-) It's not a miracle to be down
there. The most relevant factor is not money but rather patience, e.g.
for winding a coil...
Your LF signal is one of the best here in the moment! I can see you
daily in LF WSPR and OP32. Good job!
73, Stefan
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