/diy/ - Do It Yourself

>>1620479
OK, some ideas in random order
- do something more than present digital modes
- for instance avoid global sounders
- eliminate "need" for Internet reporting nodes
- provide reliable relaying
- add cognitive radio features

- start by A calling CQ
- B responds, with signal strength report and report on adjacent occupied frequencies that B can hear
- A reports back the frequencies that A can hear
- if A or B has had an earlier QSO with someone nearby the other, reuse earlier sounding data
- A does a quick sounding at different strengths on all frequencies that are unoccupied as far as A and B both can hear, within a limited scope (we don't want to fill all bands with junk)
- B does a quick sounding back
- having characterised this section of the band, agree on best frequency for this QSO
- from the above chose a constellation, bandwidth, data rate and forward error coding
- offer relay-QSO for previous QSO for A and for B
- A and B exchange sounding and contact data for earlier QSOs, so that propagation data is exchanged over the air rather the Internet
- if either has an L5-capable GPS receiver, report ionospheric delay (see if this correlates with contact data)

One of the days there will be a more extensive setup:
https://youtu.be/abapFJN6glo

Perhaps I could use Bell 103 mode

They are 300 bps fast, and duplex

Since radio is half duplex, I could use the sender and receiver frequencies at the same time, getting 600 bps or 75 bytes per second.

Quoting wikipedia:

>The originating station used a mark tone of >1,270 Hz and a space tone of 1,070 Hz.

>The answering station used a mark tone of >2,225 Hz and a space tone of 2,025 Hz.

The only issue I see here is that each "tone" will be 3.3333 ms long, and considering that I will be recording the audio samples @ khz, that gives me 26.6666 samples per symbol.

in DTMF I had 200 samples per symbol, or 7.5 times as much samples per symbol.

Also, the sound is even more anoying in 300 bps than DTMF @ 20/5