Re: LF: VLF

[Gerhard Hickl <gerhard.hickl@aon.at>]

Hello Mal, group!

As far as I know, Markus and Ossi both use multi layer coils. They are
very compact but with the known problems regarding insulation. I think
Markus meanwhile has also a single-layer "stack"-type...some flower pots
building a stack.

My coil is a single layer type with variometer inside. Basically the
same design that Stefan has in use, just a bit bigger.

It is calculated for about 100m vertical wire (=roughly 600pf, pretty
much the same as my fixed antenna has) and the inductance is about 450
to 575mH. DC-resistance is about 140R.

I will have to make some taps for longer wires (kite) but I had no
chance to give it a try.

See the two pictures enclosed.

I was transmitting from about 00:00z today until now on 8969.98 with a
break of about 90 minutes in the early afternoon. I switched to full
power roughly at 10z. The power I used before was about 6db lower in
order to maintain safety while the equipment was unattended. This
produced a nice trace on Paul's receiver.


73
OE3GHB
Gerhard





Am Sonntag, den 20.03.2011, 16:17 +0000 schrieb mal hamilton:
> It looks like all VLF acty has ceased today. No indication about what
> is going on.
> Those using large coils to resonate kites and balloons, are these
> coils single layer or pile wound, multi layer etc 
> A lot of turns would be needed for single layer and insulation
> breakdown could be a problem for pile/lump wound.
> de mal/g3kev
>

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