Hi Dimitris,
Thanks, very kind. If your's is even larger and has just 1 nF, then it
will be just adequate :-)
Another radio amateur from Germany offered me two capacitors wich will
be suitable. They seem to be already on the way in the post.
I wonder how this indoor loop performs as an RX antenna. Of course it
will depend on the neighbours QRM but maybe it is not as bad as
expected. Then, i could try to arrange a JT9 QSO or maybe QRSS... If the
other station is 20 dB stronger, then i could have a higher QRM level...
What about your VLF experiments, what is the next step? What was the
locator of your 120m antenna? Could you build a longer antenna? Maybe
you like to try a ground loop? Did you follow the recent experiments
from my 900m long antenna on 8270 Hz? It is the best experimentation
field that VLF amateur radio offers these days :-) My recommendation :-)
73, Stefan
Am 04.02.2019 06:54, schrieb Dimitrios Tsifakis:
Hi all,
I have a few mica capacitors that came from a MW broadcaster, similar
to this one (in fact I have one that it bigger than this one).
Stefan, I think this is probably your best bet and pity you are not
closer otherwise I would be happy to lend you a couple to do your
experiments :-)
https://rustys.net.au/products/large-ducon-transmitter-honey-pot-capacitor
(this is smaller than the ones I have, most are about 1 nF capacitance)
73, Dimitris VK2COW
Στις Πέμ, 31 Ιαν 2019 στις 10:01 μ.μ., ο/η dhchurch
<[email protected]> έγραψε:
Hello Dimitrios
Polypropylene capacitors can actually self-heal to such an extent that there's
little left of them. The melting point of polypropylene is not very high and
they can end up as just a liitle blob of plastic.
Don't worry though, I still use them suitably rated for the frequency in use
and most of them are 600Vac or more.
73, Hugh, M0DSZ
----- Receiving the following content -----
From: Dimitrios Tsifakis
Receiver: rsgb_lf_group
Time: 2019-01-31, 00:25:55
Subject: Re: LF: TXing WSPR/MF on an indoor loop, part 2
Hi Stefan,
In my experience these polypropylene capacitors when they fail, they
just lose some capacitance. I think they call it 'self healing', maybe
they imply that when they fail there is no short circuit?
I have some really nice silver mica capacitors (ex MW broadcast stuff)
that would be perfect for this task...
Anyway, I am slowly gearing up for some VLF action over here. The
other day I did some tests at 16.72 kHz into an ugly loop (very
roughly 120 metres by 3 metres, single turn) and I was able to receive
my signals using an unoptimise ferrite antenna at a bit over 2 km from
the TX. I don't think I am in the near field at that distance, am I?
:-)
73, Dimitris VK2COW
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