[Fwd: LF: 136KHz]

[Andre' Kesteloot]

Steve Olney wrote:

> G'day All,
> I have read with interest the comments about stations on 136KHz.  My
> particular interest is using FFT software I have written to detect tones
> buried in noise.  Using SSB receive mode, measurements indicate that I can
> detect a carrier heterodyne down to about -57dB S/N ratio. This is using a
> maximum of 8,388,608 points (about 761 seconds @ 11025Hz sampling rate).
> This gives a bin BW of 0.00134Hz.  The 136Khz stations sound like ideal
> real signals to test my system on down under.  To do this I would need:
> 1.  The Mark and Space frequencies.
> 2. The assigned carrier frequencies.
> It would be helpful to have these to an accuracy of better than +/- 10ppm.
> Are the Mark and Space frequencies AM modulated (ie, carrier plus two sets
> of two sidebands) or SSB-like (no carrier plus one set of sidebands -
> either upper or lower)?
>
> If I had the above information I could set my receiver to the carrier
> frequency and search for the Mark and Space frequencies.
>
> Regards,
> Steve VK2ZTO
> -------------------------------------------------------------------------
> -       "Your point of view always depends on
> -               where you are standing"
> -
> -                    Steve Olney
> -                  North Richmond
> -                     Australia
> -
> -      email:  ollaneg@zeta.org.au
> -      Web Page:  http://www.zeta.org.au/~ollaneg
> -------------------------------------------------------------------------