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Date: Mon, 04 Feb 2019 09:47:52 +0100
From: DK7FC <selberdenken@posteo.de>
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Subject: Re: LF: TXing WSPR/MF on an indoor loop, part 2 / VLF in VK?
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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
> <dhchurch@lineone.net>  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
>>
>>      
>>>        
>>      
>