Hello David,
I did read your blog entry, the associated WeNet presentation, and the Wenet github page. It all sounds fascinating but it was very high level on the TX side (just highly brushed over). I'd love to see a higher throughput solution out there and I have questions like:
- Which FSK TX board were you using? It looks like it's based on a RFM98W RoRA board which might be soldered onto another Rpi HATT board (hard to tell from the 2016_11_wenet_presentation.pdf but maybe that's the FSK modem sitting on top of another Hab Supplies board? - This design seemed to be uni-directional but do you think it would be hard to make bidirectional? The current design seems to take a picture, apply FEC, etc. and then send in batch.
- Did you ever measure the current draw when transmitting?- There is very little detail on the antenna you used. Did you just use a dipole? Maybe more of a panel design? - Thanks for all the work in publishing the details at https://github.com/projecthorus/wenet
--David KI6ZHD On 03/11/2017 11:53 PM, David Rowe wrote:
100's of kHz wide. For FSK you need about the symbol rate spacing between tones, so for 2FSK at 115 kbit/s, the tones are spaced at 115kHz-ish, plus a bit more, think we use 400 kHz separation in practice. Yes we only managed these fine results through very careful engineering, and deliberately avoiding the common trap or re-using legacy FM radio kit. Cheers, David
------------------------------------------------------------------------------ Announcing the Oxford Dictionaries API! The API offers world-renowned dictionary content that is easy and intuitive to access. Sign up for an account today to start using our lexical data to power your apps and projects. Get started today and enter our developer competition. http://sdm.link/oxford
_______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
