Re: LF: VLF - G3XIZ

[Chris Osborn <g3xiz@yahoo.co.uk>]

Many thanks Stefan,

I believe that Jim is about 38 km distant and I will check.
The signal Jim received was certainly on the correct frequency and the right time to have been me

That's a good idea about using the inverted 'L' and balloon aerial in parallel; I shall try that.

My big concern with balloon aerials here is that should the wire touch a neighbour's TV aerial
I imagine that his TV, radio, stereo etc will go zap!
The balloons soon deflate and the wire starts to sag so I have to keep a constant watch on it.
I am pretty much surrounded by tall trees or houses and the wind is constantly varying in direction.

I may try more balloons next time and get a bit more lift.
They were not especially expensive and 50 balloons and a disposable canister of helium gas was
only £32 on E-Bay.

73 Chris
G3XIZ

---

From: Stefan Schäfer <schaefer@iup.uni-heidelberg.de>
To: rsgb_lf_group@blacksheep.org
Sent: Fri, 31 December, 2010 17:01:17
Subject: Re: LF: VLF - G3XIZ

Congratulations to the new record Chris, Jim,

What is the exact distance? Some 10 km i think. http://no.nonsense.ee/qthmap/

Chris, can't you use the inv-L and the balloon antenna in parallel? This lowers the voltage and needed L, so less losses. And you can make QRO without increasing the HV problems. If you come back to the same antenna voltage, you will surely improve the ERP! And the resonance is rather less affected by the vertical antenna movement due to wind since the inv-L part stays constant!
If you increase the wire length to 60m (limit in UK) you would increase the efficiency by up to 50% and lower the voltage by 20%!
Nice success just some minutes before 2011 :-)

73, GL, Stefan/DK7FC




Am 31.12.2010 14:54, schrieb James Moritz:
> Dear Chris, LF Group,
>
> I seem to have a trace on your frequency - see attachment. SNR is currently around 15dB with 1.5millihertz FFT resolution. It definitely wasn't there before ;-)
>
> Cheers, Jim Moritz
> 73 de M0BMU