[GreenKeys] NYT Feed

[William Wuttke]

Harold,
My esp32 device decodes the 100 wpm fine. I will keep it running all night.
I had the 60 wpm running all night and ran fine.
Bill
KE3BK

On Tue, Dec 31, 2024 at 22:29 Harold Hallikainen via GreenKeys <
greenkeys at mailman.qth.net> wrote:

> Happy new year! Thanks for the comments on the NYT feed (
> https://w6iwi.org/rtty/audio/nyt/ ).
>
> I found a typo in setting the number of audio samples per bit for 100 wpm.
> That has been corrected, but I'm still not getting great copy out of
> fldigi. I connected a logic analyzer to the loop keying output of my DSP
> TU and got the attached. The DSP TU also does not print the 100 wpm
> correctly, but I suspect there may be an issue in the software uart. I had
> not tested it at this speed.
>
> Looking at the attached logic analyzer plot, we see proper decoding of a
> string of 0x04 characters (space bar at the beginning of my stream).
>
> Marker X is at the beginning of the first start bit. Marker Y is at the
> beginning of D2, so the time from X to Y is 3 bit times (start, D0, D1).
> That time is shown as 39.53666 ms. Since this is 3 bit times, 1 bit time
> is 13.179 ms. It is ideally 1/75 seconds or 13.333 ms. The plot shows us
> running about 1.16% short.
>
> Marker A is at the end of D2. The Y to A time is the duration of D2. It is
> 13.59649 ms or 1.98% long.
>
> The T (trigger) marker is at the start of the start bit of the first
> character. Marker C is at the start bit of the second character. This time
> is 100.16313 ms. This is 7.5 bit times (start, 5 data, 1.5 stop), so the
> bit time is 100.16313 ms /7.5 = 13.35508 ms or 0.17% long.
>
> These timing errors seem quite small and should allow recovery of the data
> (as the logic analyzer did). I have attached the logic analyzer decoded
> characters (Baudot) and hand translated a few to ASCII.
>
> It LOOKS like this should work. Does the 100 wpm NYT feed work for others?
>
> THANKS!
>
> Harold
> https://w6iwi.org
>
>
>
>
> --
> Not sent from an iPhone.
>
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