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GAME UP
but see Rik's figures for Belden 8 core cable,
8.5 mA for 300v so 85mA for 3,000v, 850mA for 30,000v, 8.5A for
300,000v
You should be alright about 8A with a safety
margin!! If I see smoke and hear a bang I will know that you mean
business.
You could save yourself a lot of
winding
mal/g3kev
----- Original Message -----
Sent: Tuesday, June 08, 2010 3:59
PM
Subject: LF: RE: RE: Re: RE: COIL WINDING
THOUGHT
I think we?ll do the
single layer route and thus be readily upgradeable, rather than risk setting
fire to Chris? shed and my garage!! B (or perhaps Mal, that was your evil plan
all along?.??!!!! J
)
Just had a look
at a roll of 8 stranded wire (Belden) : it is rated
300Vrms
Assuming
an antenna
capacitance of 500pF (= 35kOhm at 9kHz) you only need 8.5mA through the coil
to generate 300V.
Jim and Co will
hardly be involved with 30kv more like 3kv or less
----- Original
Message -----
Sent: Tuesday, June 08,
2010 2:47 PM
Subject: LF: RE: COIL
WINDING THOUGHT
Beware of the very
high voltages between the strands.
Stefan mentioned
up to 30kV loading coil voltage, I guess even a fraction of this voltage
will cause arcing between the strands
In addition the
high stray capacitance will reduce the Q.
Instead of winding
miles of single strand insulated wire to achive the required inductance, use
instead insulated multi strand wire and series the strands, normally the
individual strands have coloured insulation and convenient to connect in
series.
gather up all the
ferrite cores you can find put into a suitable container and insert into
coil.
The above idea
might save some coil winding time.
another thouight
while I am composing
Get hold of some
old Decca coils ( I have a couple) find the beginning and end and do the
same as above, this however is more difficult although individually
insulated they are all the same colour, but with a meter to identify each
strand it can be done
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