On 2023-01-10 02:32, Dan Smith via chirp_devel wrote:
Hello
I can try but don't want to claim correctness on this, nor to know how things should be done best. And I don't want to fight over this :-). The radio that I played with could be set to one of: FM, DN, VW, AMS. This is the interactive setting used when operating; I am not sure whether this also corresponds to the choice available when programming (I'm not using any of those digital modes). AMS is the automatic mode that picks the "right" one of the other tree. I find this to be a sensible choice for multimode repeaters, but not everybody agrees: Some people only want to hear the digital traffic, others only the analog traffic and they would set their radio accordingly. AMS is also a bit annoying since it changes your transmit mode to whatever was last used on the repeater. This is cool because you are automatically responding in the same mode that somebody used for calling, but then again if you want to call, you always have to check your settings first to ensure you are on the desired mode. There is, however, a setting that allows you to set the default for that. (E.g. RX AMS, TX always FM). I don't remember if this is per-channel but that works for me.
As for the DN vs. VW thing: These are different ways the voice is encoded into a representation of the speech model and further treated with the usual techniques (whitening, interleaving etc.). In DN, a voice data "packet" and a metdata "packet" containing the call sign, GPS coordinates and other stuff are transmitted in an alternating fashion. IN VW, there is some kind of metadata pilot package in the beginning and then it's just voice data all the way, thus more of the channel's bandwidth is used for voice data -- in fact, all of it vs. half, which allows them to use a better speech model and the audio quality is supposed to be better. The tradeoff is that a receiving station doesn't see the call sign on late entry or if that pilot packet got crippled. Hence, I believe, the names "Digital Narrow" and "Voice Wide".
All that said, I'd have to check what happens if somebody has his radio set in DN and some VW is incoming, or vice versa. I guess it would still decode but not change the current TX setting? But in any case, I always thought of the VW and DN to be two modes that are more or less separate from each other. Offering them as individual choice would reflect that. With the flag/extra property instead, somebody's though process while programming the radio would go like 'Oh yeah, I want digital on that channel of course... ah yeah, and I want that to be in "Voice Wide" [with the trade-off mentioned above]'. That would also work, I guess. Thus the options/schemes are:
['FM', 'AMS', 'DN', 'VW'] or ['FM', 'AMS', 'YSF'] with the extra flag for improved 'VW' voice. That one would work according to the aforementioned thought process, but I don't like it because:
- Using a checkbox for DN vs. VW imposes some kind of default and I don't see why chirp should suggest one over the other. - In "Fusion", the "F" in "YSF" refers to fusing digital and analog into one thing. This was one of the marketing lines when the system was introduced, allowing for a smooth transition to digital and all that. As such, it was meant to describe the whole "digital plus analog together" idea. Using that term to discriminate the digital part from the analog part thus sounds wrong... But one could use 'Digital' instead of 'YSF' in the second scheme.
I hope that helps somewhat
Matt