On 2023-01-11 00:13, Dan Smith via chirp_devel wrote:
Hello
Reading what I just wrote during the past hour or so, there is a lot of technical details that may be boring to say the least... Thus you may want to scroll to the end where I tried to address the solution that you proposed, which is quite good IMO.
The manuals for those radios seem to indicate that the behavior on the radio itself is the same, but I can't figure out why their software won't let you choose that. And, even though I can select VW in a separate place in the radio, the FT3 software seems to have zero mention of it.
That seems odd indeed. Then again, Yaesu made quite a number of very odd choices when it comes to Fusion... What happens if you select and store VW on the radio and read out the memory? Does it have the VW flag? Another idea may be to look at another third party programming software made by RT Systems and check if they added the functionality...
Is it possible that Yaesu just didn't implement knobs for the digital settings in their new (at the time) flagship digital radios?
That is possible in the light of what I wrote above... There is also the following tidbit that may have affected such decisions: VW and DN differ from each other in three fundamental ways. One is the way the metadata and the digital voice is multiplexed, as mentioned in my previous E-Mail. The second one is how the digital voice frames are processed and turned into the bit sequence that is actually transmitted, e.g. how and what kind of redundancy is added, how the digital voice bits are scrambled, block-interleaved etc. (although "DN" by itself has two ways of doing that...), and by the way the voice is encoded into the speech model representation. While both DN and VW use the same fundamental speech model, they differ in the number of bits that are used to encode the various parameters of the model. These models and encoding schemes are proprietary and you can buy chips to transcode from PCM and back. Two details are interesting about this: (a) The DN type is actually the same as the one used by DMR (but not stipulated by the DMR standard). This is why it is easy to write software that bridges between DMR and the YSF DN flavour. Also, there is no loss of quality due to transcoding, since you don't have to decode to PCM and re-encode. "VW" may have dropped out of favour because it is (was?) not supported by those bridging solutions. (b) the common chips that you can buy to convert back and forth actually do not support the "mode" used in VW. Yaesu licenses some DSP IP to do that, but this is not something you can do in low quantities, thus there is no easy/legal way for us to homebrew receivers that fully support YSF. While I don't think that Yaesu cares about that, they may have come to the conclusion that it was not smart to use that "special" thing for VW and backtracked a little? Who knows...
Seems to me that "AMS" is really a behavior of the radio
That makes a lot of sense.
Further, "VW" doesn't seem like a mode to me. It's still the same modulation, but with more voice data and less data data, more akin to transmit bandwidth on an HF radio or something.
I would disagree with that statement but without drama. My disagreement is because of the technical detailes outlined above. The differences are much more substantial than just a matter of bandwidth. Yes both are 4FSK, the air packets have the same preamble and header, and indeed they use the same fundamental speech model, but everything else is different. In an odd way, DMR and DN are more similar to each other than DN is to VW. Does that make DMR and DN the same mode? Then again, my point is based on the technical implementation of those things and that may not be what people care for or what makes for the best implementation decision in chirp.
And especially since you don't control whether you receive VW or not (right?)
Correct, that was confirmed by Charlie earlier tonight.
How prevalent is the real-world usage [of VW]?
I have no idea :-). Also there may be regional differences so any particular answer may be biased. Still the solution you proposed below seems like a sensible one to me...
However, users looking at their radio, manuals, and Yaesu's own software will likely not intuitively know what it means.
This is a good point. Everything I wrote is based on the technical details and not necessarily on how people use their radios and software. I should add that I was involved in reverse-engineering the missing parts of the YSF protocol when it was launched. My interest in YSF was mostly in this regard and I have not used any of that in practice...
trainwreck
... aye ...
I kinda wonder if that activity would be a cacophony of people in both modes not really realizing when they're digital or not. Is it actually better in practice?
The difference is pretty clear by the presence of noise vs. the robotic nature of digital voice. There have been issues with people not having AMS turned on and transmitting on top of ongoing contacts because they failed to realize that the frequency was in use. Also, at least some radios disable AMS when you establish a networked connection ("WIRES-X") which adds to the confusion. I practice, YSF has been mostly a novelty thing around here, people try it after purchasing a new radio and then quickly lose interest, for the most part.
So I guess it seems like if we add a DN mode to mean "Yaesu's C4FM format" and then flags for AMS or VW (with a default to Yes and No respectively), that's the right behavior, and keeps DN-supporting radios speaking the same language.
I guess that does make sense. What about the following scenarios, though:
- Would there be a difference between 'FM' plus AMS checked and 'DN' plus AMS checked? Because according to this logic, that should be the same setting. How would we deal with people who program FM & AMS and once they read back their programming, chirp displays that as DN & AMS (or vice versa)? Would that cause confusion? Would users know what to select if they actually want the AMS setting? I wouldn't really know if I had to select 'FM' or 'DN' along with the AMS checkbox to get that...
- What about the combination FM, no AMS and VW? That would not make sense. Is there a way to gray out the VW checkbox in that case? Then again, this may be similar to the RX-Tone column when TSQL is not used..
I hope that helps, and apologies of the verbosity of my post
Matt