Re: LF: Re: VLF Stability and soundcard locking

[M0FMT <m0fmt@yahoo.co.uk>]

OK Stefan

 

I need a "Dope Slap" for my comments below. So impressive that is much better than I had hoped for because its not just slow CW either. There are a lot of potential stations inside that radius in this part of UK.

 

My ferrite rods will be here soon so I can get a front end sorted out.

Roughly worked out I need 650mH tuned with a 0.2-1n variable cap for 8.5 to 9.1 Kc/s. This amounts to 27600mm of wire 0.125mm (I have) on a 9mm diam x 100mm rod covering 80mm means heap winding the ends over approx 16mm the remainder single layer. Link coupled to a low noise fet amp up about 6m. That's the plan.
 

73 es GL Pete M0FMT IO91UX

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From: Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>
To: rsgb_lf_group@blacksheep.org
Sent: Thu, 10 March, 2011 10:06:33
Subject: Re: LF: Re: VLF Stability and soundcard locking

Hello Pete,

Am 09.03.2011 19:36, schrieb M0FMT:

Mal.....  for my ten cents worth.

 

Without being able to add modulation or on-off keying then no QSO is taking place.

 

I suppose you could say if there is a carrier then some one is in the shack but that's not really a QSO.

 

I was hoping at the start of this exercise that a CW or other PSK or similar real time QSO could be carried out over say 10/20kms. From the tests Chris G3XIZ has done the best looks like a real time QSO would only happen over a 1.5km path cross town.

[...]

Remember that i have detected my own CW transmission in a distance of 40.0 km (far field and above 1 Lambda) on 8970 Hz. Listen at http://dl.dropbox.com/u/19882028/DK7FCinCWon8970Hzthe33kmband.WAV
So it is possible to do a CW QSO there. Distance is relative. While it is trivial to do a QSO on 20m in 10000km distance it is something special to reach 10km on VLF or on Laser-TX or 47 GHz and above.
A VLF x band QSO in CW would have been done if there would be stations in that radius of 40, maybe 60 km who would be willing and equipped to receive my signal...

73, Stefan/DK7FC