> From:
[email protected]> To:
[email protected]> CC:
[email protected]> Date: Sun, 17 Jun 2012 15:26:39 +0000
> Subject: LF: Re: Re: Further MF impressions
>
> Alan
> I work both 160 metres and 600 metres and find both similar. Daytime range
> and night time similar.
> but you must compare like with like power and antenna wise.
> I use a 1/4 wave inv L on each band up at 100 ft vertical, but naturally the
> 600 metre antenna is less efficient than the 160 metre therefore one has to
> adjust the power on 160 to get the same erp for comparison purposes. In my
> case 10w erp on each band
> For those fiddling about with 400w pep on 160 and a variety of antennas and
> unknown erp and those with a few watts on 600 metres and often very small
> antennas you cannot draw any rational comparison
> I can work over the same distances daytime on 160 or 600 and after dark the
> same applies to dx locations.
>
> de mal/g3kev
>
>
> ----- Original Message -----
> From: "Alan Melia" <
[email protected]>
> To: <
[email protected]>
> Sent: Sunday, June 17, 2012 2:54 PM
> Subject: LF: Re: Further MF impressions
>
>
> > Stefan, the groundwave does not change, but what you have is varying
> amounts
> > of skywave and daytime "fading" The wavelength is only a quarter of that
> at
> > 136kHz so it only tales a quarter of the change in (apparent) reflection
> > height to give the same sort of constrctive and destructive interference.
> > 500kHz does not travel over land so well as the surface "roughness" is
> > bigger wrt a wavelength ( but even rough seas are generally less "rough"
> > than land ) Yes 500k is an interesting frequency and quite different to
> both
> > 136 and top-band. There are times of the day when the fading can be
> vicious
> > at relatively short range Also with the shorter wavelength most antenna
> > height limited stations can have up to 16 times more ERP than at 136kHz
> >
> > Enjoy the new "playground" :-))
> >
> > Alan G3NYK
> >
> > ----- Original Message -----
> > From: "Stefan Schäfer" <
[email protected]>
> > To: <
[email protected]>
> > Sent: Sunday, June 17, 2012 3:03 PM
> > Subject: LF: Further MF impressions
> >
> >
> > > MF,
> > >
> > > I just thought my receiver isn't working correctly. I thought the xtal
> > > does not start to oscillate due to the higher ambient temperatures in
> the
> > > afternoon. But later i found that the band noise on MF is significantly
> > > lower than in the evening, at least 20 dB. So now i see that the band
> > > noise is about 5 dB above my soundcard noise with the current setup.
> > >
> > > What do others know about the ground wave range in summer and in the
> > > afternoon? When does the band open? Similar to LF?
> > >
> > > BTW thanks to DF6NM for the grabber. Nice tool to get some experience in
> > > these first days...
> > >
> > > 73, Stefan/DK7FC
> > >
> >
> >
>
>
