Hat tip to @mathew - I just learned that France had a graeter than 720i broadcast standard in the 1940s!
That's Astounding.
I gotta find some old french gear, I guess.
HD broadcasting in 1948!
https://www.earlytelevision.org/grammont.html
The sets were 4:3 of course, but basically they were 4:3 720i black and white.
(in practice it was actually more like 816×736 px vs 720's 960×720, but also it was analog so the minor differences were probably lost anyway.)
The standard was used in to the 80s, but I'm having a really hard time finding any information about it.
If you're french, and you know what this was called in france, please let me know!
Here's a thread where some folks are driving 819 line sets from a VGA cable: https://www.vintage-radio.net/forum/showthread.php?t=167674
and from a converter box that doesn't appear to be sold anymore.
I wrote a blog post summarizing the things I learned about HD broadcasting in the 40s:
The big takeaway from the blog post is that I need a Teleavia P111, and that I need to rig up a board that converts 720P HDMI to the ~730i RF signal that this thing would be expecting.
And a power supply.
@djsundog I've got the "submit offer" dialog open in the next tab.
@djsundog But like ... I haven't entered any numbers.
@ajroach42 if this one https://newatlas.com/teleavia-type-p111-high-definition-tv-1958/13026/ went for 2400 pounds in 2009 (in better condition arguably) I'd say they're lucky to get US$3,000 for theirs imo but ymmv yolo etc
@djsundog So, they accepted, and now I have to make it work.
@ajroach42 woohooooo! congrats, I can't wait to meet it and then get my grubby lil fingers into it ;)
@djsundog Right? We're going to have our work cut out for us, I imagine.
@ajroach42 that's where the fun is!
@ajroach42 I could see it. it's not like they've got people beating a path to their door at 10k lol