Hat tip to @mathew - I just learned that France had a graeter than 720i broadcast standard in the 1940s!
I gotta find some old french gear, I guess.
HD broadcasting in 1948!
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:
Followup on yesterdays ramblings about a 70+ year old french High Definition TV standard:
I found a Teleavia P111 for sale, submitted an offer for 1/4 of the listing price, and the offer was accepted.
In a few weeks, I'll have a mid-century french HD TV to start experimenting with.
I guess it's time to join an old TV forum and actually read my "Handbook of Television Repair" from 1952.
@ajroach42 I think you'd probably have a much easier time using a computer with a VGA card as in the post you linked to rather than trying to start from HDMI, because HDMI is digital and the timings will be wrong, so you'd have to go through a framebuffer anyway. The easiest way to get there from HDMI is probably to use an HDMI capture card attached to a computer.
@ajroach42 It occurs to me that if it's not easy to bypass the receiver and feed it a baseband signal, the easiest way to get an RF signal might be via SDR. The HackRF and BladeRF both appear to have sufficient bandwidth.
A social network for the 19A0s.