Gregc The debate if it’s AC/DC is long-standing. In short, some say it’s DC due to a lack of sinusoidal wave. Which is what my thinking was. However, the current is alternating thus, making it AC. NMRA has said that “The DCC signal is an alternating DC waveform”.
NMRA documentation muddies everything up and has referenced it in different ways. LENS has also called the signal Pulse Width Modulation (PWM), but it’s not, it’s Frequency Shift Keying (FSK). The signal doesn’t modulate as the duty cycle never varies. I think they called it PWM to increase their patent scope.
Additionally, there’s the entire ‘zero stretching’. Would this be DC then when it’s in use? Short answer: no - you still have the commands perhaps it’s just considered a DC offset? This is above my pay grade. Perhaps I need correcting here too.
Could you start with a new article that debates both sides of the argument? At the end of the article, you can link to the DCC Power article to learn more about encoding/decoding, etc. From the DCC Power article, you could link to your new article.
Now that I’m thinking, this might be a great place to start and it would help us (mostly me) provide direction throughout the rest of the DCCWiki. Additionally, there are little blurbs of this argument spread throughout the wiki. This would be a great time to consolidate and point to a new article that explains just this point. Not saying to go through the entire DCCWiki to look for these blurbs, just then whenever one is found, we can start pointing to this.
Perhaps you can take components from this article: https://dccwiki.com/DCC_Tutorial_(Power)
and start a new one? Would this be something you would be interested in? This will help you learn the wiki formatting, and get your feet wet (soaked?).
As a quick search, i found this thread interesting: https://ogrforum.ogaugerr.com/topic/is-dcc-high-frequency-ac-or-alternating-dc-based - specifically, a post by Chuck K.