DD8SFAug 28, 2025
WebSDRs are very nice tools in #AmateurRadio :
Especially for experiments in digital modes it is quite hard to find a partner to experiment.
A SDR on 2m just enabled me to run my very first test using 16-DAPSK modulation to transmit a 1600bit/s speech signal on less than 600Hz bandwidth.
Everything worked like simulated in #gnuoctave . It looks like a good basis for further experimentation.
Show threadDD8SF

I just repeated my 16-DAPSK experiment using the EnCodec audio codec. Everything went perfect, all packets received.
The audio quality suffers using 1500bit/s EnCodec.

The sample I did with 3000bit/s EnCodec on M17 was much better:
https://mastodon.radio/@DD8SF/113553261736504519

DD8SF (@[email protected])

Attached: 1 video Today, I took some time to investigate the cause of the clicking sounds in my #M17 transmission using EnCodec and Vocos models as the codec. After 5 minutes, I realized that I had forgotten to update the software on the receiver side. That’s why the local echo tests worked well while the transmission did not. Here is a sample with the correct software versions running: @m17_project #hamradio Voice: LibriSpeech - CC BY 4.0 - https://www.openslr.org/12/

Mastodon.Radio
Sep 1, 2025 at 10:06pmWeb