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
>
>
>
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