[Lf] [Fwd: LF: Re: Transatlantic beacon tests]

[Andre' Kesteloot]

Rik Strobbe wrote:

> I think that Andy's (G4JNT) approach to go to milli-Hz bandwidth will be
> very usefull in exploring the limits of what we can do with our small
> antennas and 1 Watt ERP limit. It may also give us some interesting
> information on propagation.
> But due to the very narrow bandwidth the 'speed' will also be extremely low.
> Practise has learned us that a basic QRSS QSO at 3 sec. dot length takes
> about 30 minutes. As 1mHz bandwidth corresponds to a dot length of 1000
> seconds a minimal QSO (exchange of calls and 'TMO' report) will take about
> 16 hours. The question is if we will have a 16 hours long period of
> ionospheric propagation over a 4000km long path ? Otherwise we will need to
> rely on the surface wave and the disadvantge of this is that it has a
> 'coaxial cable like' attenuation of 2 to 3 dB per 100km. This means that
> you need 40 to 60dB more power (or better SNR) to cover a 4000km path
> compared to a 2000km path.
>
> My opinion is that we should try all possibilities, going from normal-speed
> CW over QRSS and DFCW to the milli-Herz techniques that Andy is developing,
> in our attempt to cross the pond.
> Even within a small community as our 'LF world' there are different groups
> of interest. But I see this as a benefit, not as a problem.
>
> 73, Rik  ON7YD