First 2-way Slow-Voce QSO ...slow voice software....where?]

[Andre' Kesteloot]

"'Geri' Kinzel, DK8KW" wrote:

> Hello David and LF-group,
>
> >where might this software be?
> no lf in usa, but 160m can be a bear too !
> david<
>
> today, Markus, DF6NM and I have performed the first succesful 2-way LF QSO
> in slow-voice. Markus used a software named Goldwave (don't know where that
> can be found but Markus said it is shareware, so have a look in the
> Internet search machines ...). I used Cool Edit 2000, that can be
> downloaded at http://www.syntrillium.com (it is also shareware, the demo
> version comes with two functions only, you need to register to have full
> access to all features).
>
> We started at 137.350 to 137.600, where Markus was able to read my signal
> (8 times slower than normal voice) with 57. When I tried to receive him I
> found that the 1.7 kHz filter that I use in my MV62 Level Meter was too
> wide to prevent DCF39 from causing heavy QRM. The build-in 100 Hz filter is
> too narrow for the 250 Hz bandwidth we used. The 250 Hz filter that I use
> in the IC-746 that comes behind the level meter on 200 kHz is narrow
> enough, but it comes too late, the band is already spoiled by the Burg
> transmitter.
>
> The solution was to move 500 Hz further down, with our transmission
> spectrum situated between 136.850 and 137.100 kHz. I hope we did not cause
> any inconvenience to anyone tranmitting there. We have accompagnied our
> slow-voice transmissions with CW to steer the QSO. All in all it took about
> 2 1/2 hours to complete the QSO, whereby my report for Markus was 35,
> however, in a later transmission I could read him better than that
> (probably 45).
>
> The QSO mainly too that long because I had to fiddle around with the
> appropriate adjustments. For the transmission I used macros, so it took
> only one or two minutes to be able to transmit a 3 minute over. For
> reception I did not prepare anything and had to do some experimentation.
>
> For future transmissions we will need to find another way or a better clear
> spot, maybe even further reducing the bandwidt to 100 Hz and make use of
> the narrow filter ...
>
> I know that SSB QSOs have been performed in the band some years ago in the
> U.K., but this slow-voice transmission helps us to
>
> - overcome the bandwidth limitation in Germany (max. 800 Hz)
> - helps to prevent QRM aking best use of the availabel spectrum
> - increases the signal-to-noise ratio relative to the bandwidth used
> - ... and is a lot of fun ... hearing the other's voice clearly readibly
> despite the low signal strength!
>
> I will post some further information on my website (http://www.qru.de).
>
> So, a new field of experimentation. We will conduct further tests and
> improve the operating procedures. Maybe someone who has fun programming the
> Soundblaster card might want to develop a slow-voice software that allows
> more-or-less realtime QSOs ...
>
> Best 73, thanks to Markus, DF6NM for the nice experience, to Walter, DJ2LF
> for his reception report and a very happy New Year 2001 to you all!
>
> Geri, DK8KW (W1KW)
>
>
> Slow-Voice data of the QSO today (December 31, 2000):
>
> - transmitted audio bandwidth 300-2300 Hz (2000 Hz total bandwidth)
> - speed: 8 times slower than the normal voice
> - transmition mode: USB
> - total radio frequency bandwidth 250 Hz with 300 Hz audio equal to the
> lower frequency of the spectrum, 2300 Hz to the upper freqeuncy
> - QSO control by CW in the middle of the spectrum used
>
>