Re: LF: GPS Locked test transmission

[Scott Tilley <sthed475@telus.net>]

Hi Alan and other clicklockers...

All should be fine if the CFH stuff is not exactly on 137.00000000ish

The clicklock alg. can easily resolve in the sub mHz region so seeing 
around QRM should be easy.
Even the Russian loran line shouldn't really cause QRM if your careful 
in the interpretation of the data if you switch phase on the amateur 
signal for the same reason a PSK31 signal produces two lines in its idle 
mode.  Our early experiments used this feature to produce unique 
sequences based on the phase switching time so that QRM such as loran 
lines could be excluded and the real amateur signal identified.  I 
modified my DDS software to allow phase switching in 11 degree ish 
increments to play with this concept and had lots of fun pulling my clip 
leads radiated signals from across the yard out of the noise.  I believe 
the ZLs also evolved this to a higher degree in their experiments. 

Depending on the version of the alg you're using they may need to use 
certain freq that the DDS can produce which are rational numbers.  
Peter's 'spinfreq' adaption allowed for using irrational numbers but the 
absolute GPS phase reference gets lost if I recall.  Of course Peter had 
a solution to that as well involving some real fancy stuff to get it 
back using the loran pulses if my memory serves me well...
I'd suggest breaking out Excel and play with the FFT feature and create 
your own methods to extract the signal and you may be surprised.  I have 
a template around here somewhere that could be used for experimenting if 
you need something to start off with.  Peter may have something more up 
to date...
73 Scott


Alan Melia wrote:
> Hi Uwe, i would think it would be better fot Andy to avoid exact frequecies
> like that also I wonder if you were receiving a line from CFH which is
> centred there and has been active the last few nights. It is not so strong
> at the moment but is visible on Spectran here, as a noisy 200Hz wide band.
> (GMSK)
> Cheers de Alan G3NYK
>
> ----- Original Message -----
> From: <uwe-jannsen@versanet.de>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: 13 October 2006 23:51
> Subject: Re: LF: GPS Locked test transmission
>
>
>   
> > Zitat von Alan Melia <alan.melia@btinternet.com>:
> >
> >     
> > > Hi Uwe, you are receiving this through the CFH "noise" as well??
> > > Cheers de Alan G3NYK
> > >
> > >       
> > Yes, Alan, I did. but, but, but, home agn at midnight I switched on the
> > equipment and do see nothing. possibly I registrated the carrier Markus
> > mentioned and not the transmission of G4JNT.
> >
> > Andy, is your transmission off the air?
> >
> > regards
> > Uwe/dj8wx
> >
> >
> >     
>
>
>