Date: Tue, 05 May 2009 14:14:35 +0200
To: rsgb_lf_group@blacksheep.org
From: Rik Strobbe <rik.strobbe@fys.kuleuven.be>
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Subject: RE: LF: RE: rtty test
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Hello Gary,

I had a closer look at the 23Hz shift option of MMTTY and it seems to 
run at 45Bd what is on the edge regarding the shift/baudrate ratio. 
That is most likely the reason why it is not so robust.
Using 45Bd at 85Hz shift would exceed the 100Hz bandwidth limit.
I guess the best option for RTTY would be a shift around 50Hz and a 
lower baudrate (say 20Bd) what would well fit within the 100Hz 
bandwidth and would have a sufficient shift/baudrate ratio to provide 
a robust signal.
I will see if I can get such signal out of MMTTY and - if time 
permits - run some tests tonight.

73, Rik  ON7YD - OR7T

At 12:22 5/05/2009, you wrote:
>Hi Rik,
>
>You have experienced the same as I did with 23Hz shift, the signal needs to
>be very strong to decode. It was in the last 2 minutes that I got the
>partial decode.
>
>A much better shift to use is the 85Hz which will fit into your spec.
>
>I have had good QSO's with Chris G3XIZ in Biggleswade both of us using 85Hz.
>
>Give that a try next time & I believe I will get a much better decode
>judging by the strength of your signal.
>
>73
>
>Gary - G4WGT.
>
>-----Original Message-----
>From: owner-rsgb_lf_group@blacksheep.org
>[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Rik Strobbe
>Sent: 04 May 2009 22:37
>To: rsgb_lf_group@blacksheep.org
>Subject: Re: LF: RE: rtty test
>
>Hello Gary,
>
>call the is almost right, locator completely.
>But not really impressive for 500mW ERP.
>I could see my signal on your grabber, some slow QSB but strong for
>the last 2 minutes or so.
>I used MTTY with the profile "23Hz RTTY (MTTY)" without any further
>changes, not sure that this is the best mode.
>So any advice is welcome.
>I have also installed MultiPSK, but am still overwhelmed by the colors
>and options.
>I am allowed to use any digital mode as long as I stick to max. 100Hz
>bandwidth.
>
>73, Rik  ON7YD - OR7T
>
>
>
>Quoting Gary - G4WGT <g4wgt@tiscali.co.uk>:
>
> > Hi Rik,
> >
> > This is the best I could do, it looks like almost your call sign & locator
> > :-
> >
> > RHTQHTST DE TC(TIOJ7T OR1T JO20IX
> >
> > 73
> >
> > Gary - G4WGT.
> >
> > -----Original Message-----
> > From: owner-rsgb_lf_group@blacksheep.org
> > [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Rik Strobbe
> > Sent: 04 May 2009 21:10
> > To: rsgb_lf_group@blacksheep.org
> > Subject: LF: rtty test
> >
> > dear all,
> >
> > I will run a short (10 minute) rtty test (23Hz shift) on 503.500 at 21UTC
> > Reports and/or reply welcome.
> >
> > 73, Rik  ON7YD - OR7T
> >
> >
> >