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

[Andre' Kesteloot]

g3kev wrote:

> Dave wrote:
> > Dear all,
> > Assuming that we're sticking to 1W erp then what does it matter how big the
> > antenna is as long as the power is sufficient to  give the required erp?
>
> There is a big difference in the radiation pattern and angle of take off between
> a high vertical antenna and a very low antenna given the same rf power to the
> antenna. 1 Watt erp from a dummy load or low horizontal wire is hardly the same
> as 1 Watt erp from a vertical antenna at 120 ft. There is also the RX
> consideration especially on long haul signals. At LF the delivery system ie
> ANTENNA is the most important factor. Even with large towers, and high elaborate
> antennas, which are still physically small relative to 137 khz and a limit of 1W
> erp, one has to realize the limitations, but at least there might be a chance.
> 73 de Mal/G3KEV
>
> >
> > CFH peaks 33dB above the noise regularly (in 100Hz filter). If its erp is
> > around 8kW as rumoured then a 4W erp signal would be on the noise level,
> > normal good copy, and a 1W signal would be 6dB down. No problem for
> > Spectrogram.
>