Thanks Harold. Much of this codeing is new to me and I only got into the workings of audio compression in the last day or so. I'm using ffmpeg. My code can batch process so will run quickly through multiple files I process first through my text editor.

The positive responses posted here on greenkeys encouraged me to add 50 Baud EU FSK audio to the 5bits.net site which may be useful. (And it was easy)

73, John W1AN

On 01-May-25 23:39, Harold Hallikainen via GreenKeys wrote:

They work great! I tested the 45 baud 170 Hz and 850 Hz shift. Both

printed perfectly.

I also ran one of the files through

https://www.maztr.com/audiofileanalyzer and find that you are doing 8

ksps, 16 bits per sample, and through MP3 compression, sending at 20.2

kbps.

Very nice! My New York Time feed ( https://w6iwi.org/rtty/audio/nyt/ )

also runs at 8 ksps but with 8 bit samples and no compression for 64 kbps.

Harold

On Thu, May 1, 2025 11:43 am, John Spigel wrote:

From software I'm creating I've put together a couple of FSK audio

files for outside evaluation of audio and decode quality. The tones

themselves are generated in python. These are large 60M mp3 files. If

able, please open, test and let me know if they are good to go or need

some further filtering. I also may be able to compact further. Audacity

says the noise is about 60db down, but that's not what the real world may

see. There is both 170 and 850 cps shift. Thanks! And I'll have more of

these soon.

https://5bits.net

73, John W1AN

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