[GreenKeys] ITTY/RTTY Sampling tests

[ad7i]

With the 8K sampling, how many bits per sample were used per sample?

The reason I ask is because the 1970s T1 systems did sample at 8000 sps and
transmitted 8 bits per sample, but those 8 bits represented a compressed
(compandered) value.  Although I've forgotten the specifics, the entry on
Wikipedia for uLaw coding seems to indicate that the compander transformed
the data from 14 bits uncompressed to 8 bits compressed, and vice versa at
the RX end.

Paul, ad7i


On Thu, Sep 23, 2021 at 8:54 PM Paul Heller <phearvada at gmail.com> wrote:

> It was definitely sampled at 8K. As I said, sampling at 11K and 22K were
> fine. It only dropped when sampling at 8K.
>
> The streaming software does not know about sample rates - it just sends it
> out.
>
> It’s a puzzle
>
> Paul
>
> > On Sep 23, 2021, at 6:04 PM, Harold Hallikainen <harold at w6iwi.org>
> wrote:
> >
> > I don't know what the combination of hardware and software is, but is it
> > possible that the audio was being sampled at a higher rate than 8k, then
> > being streamed at 8k? This would explain the frequency drop and bit rate
> > drop. But, it seems like the transmit buffer would eventually overflow.
> >
> > Harold
> >
> >
> > ______________________________________________________________
> > GreenKeys mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:GreenKeys at mailman.qth.net
> >
> >>>> Jordan Spencer Cunningham's GreenKeys Search Tool:
> https://teletype.net/gksearch
> >>>> 2002-to-present greenkeys archive:
> http://mailman.qth.net/pipermail/greenkeys/
> >>>> 1998-to-2001 greenkeys archive:
> http://mailman.qth.net/archive/greenkeys/greenkeys.html
> >>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:
> http://comcents.com/tty/greenkeyssearch.html
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to phearvada at gmail.com
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
> >>> Jordan Spencer Cunningham's GreenKeys Search Tool:
> https://teletype.net/gksearch
> >>> 2002-to-present greenkeys archive:
> http://mailman.qth.net/pipermail/greenkeys/
> >>> 1998-to-2001 greenkeys archive:
> http://mailman.qth.net/archive/greenkeys/greenkeys.html
> >>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:
> http://comcents.com/tty/greenkeyssearch.html
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to ad7i at ad7i.net
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20210923/5c5ab850/attachment.html>