Message-ID: <ADED38B43E7842348D346BD7F905C943@gnat>
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <51197759.6090001@iup.uni-heidelberg.de>
Date: Tue, 12 Feb 2013 01:09:31 -0000
MIME-Version: 1.0
Subject: LF: Re: Considerations about wide DX experiments on 630m and tonites QRSS-60
Content-Type: text/plain;
	format=flowed;
	charset="ISO-8859-15";
	reply-type=response
Content-Transfer-Encoding: 8bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


Hi Stefan I think that maybe the right approach. I think you may find that 
the "perceived wisdom" on fading rate v QRSS speed is based on relatively 
short paths. I suspect it may well be very different at real DX range, that 
is several hops.......>6000km. There obviously is some sort of a problem 
because the wavelength is much shorter than 136kHz so the phase changes more 
rapidly with ionisation and "apparent refection height" but you need two 
"modes" of nearly equal strength to get extinction. This may not be so 
prevalent at long ranges on 470kHz. The experiment will be very interesting 
if you can start to leave traces on distant grabbers.

Alan
G3NYK
----- Original Message ----- 
From: "Stefan Schäfer" <Stefan.Schaefer@iup.uni-heidelberg.de>
To: <rsgb_lf_group@blacksheep.org>; "Vasily Savchenko" <ua0snv@yahoo.com>; 
"Garry and Linda Hess" <k3siw@sbcglobal.net>; "Douglas D. Williams" 
<kb4oer@gmail.com>; "Andy - KU4XR" <ku4xr@yahoo.com>; "Edgar J Twining" 
<edgarjtwining@virginbroadband.com.au>
Sent: Monday, February 11, 2013 10:57 PM
Subject: LF: Considerations about wide DX experiments on 630m and tonites 
QRSS-60


> MF !!!!!!!!!!!!!!!!!!!!!!! ;-)
>
> Edgar in Tasmania was recently asking if i have some plans about DX 
> experiments on 630m. Well that is a path of > 16000 km. However we do not 
> have real experience if that is easier than 2200m or rather impossible.
>
> At least i know that there was not even a single decode by UA0SNV in my MF 
> WSPR and QRSS tests so far, while it is no problem on LF (OK my MF signal 
> is weaker than my LF signal). Thus i would guess that it is much harder to 
> get some traces of a signal on 630m. We will try anyway!
>
> I'm starting to run a QRSS-60 transmission on 476.172 kHz (+- a few Hz) 
> for the night. Maybe someone across the pond will catch something. We, or 
> at least i still have no experience about the QSB problem on very slow 
> QRSS transmissions on MF. It would be interesting to see a spectrogram.
>
> On air in a few minutes.
>
> 73, Stefan/DK7FC
>
> PS: No, not only beacon transmissions, i've just had a > 1 hour long CW 
> QSO with PA0LCE and DK6SX/p! Also contacts to OK2BVG and S57A.
>