I've considered your notion of sending compressed speech slowly to get around that 300 baud thing on HF with non-linear amps.
It would be interesting to experiment with, there might even be some good use cases.
But seems phone modes are mostly for folks who want to communicate as they normally do.
I prefer packets of text, even if it's not coming over slowly.
Which is why I'm here in the forum and not in some SSB roundtable discussion about modulation methods.
Jerry, KE7ER
On Sat, Oct 16, 2021 at 07:01 AM, Tom, wb6b wrote:
This is all interesting information. I'm back in the reading mode exploring the things that have come up in the posts.?
One would think that "advanced multi-band excitation coding" (AMBE) being invented so long ago would be easily improved upon. But, sometimes the fundamental design is well done and not a compromise that was realizable with the technology of the time (circa 1990), that it stands the test of time. Certainly would not need the expensive custom codec chips; now that it can be implemented in software on current microprocessor chips.?
One thing that occurred to me might be a sort of "earth-to-mars" mode. Where each operator's voice, in a conversation, is stored/buffered and sent at a significantly lower bit rate to the destination. This could allow for having voice conversations under significantly reduced signal to noise ratios, facilitating better DX communication. Albeit with a turnaround delay for each side to pick up on their side of the conversation. Maybe would give each side some time to think a bit before they start speaking again to reply. Would also produce sort of an intriguing feeling of suspense, waiting for the data stream, in the noise, to end so you can listen the reply from the distant other location.?
So are the folks experimenting with D-Star on HF just kind of flying under the radar?
Tom, wb6b
