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 video showing off an absolutely beautiful Teleavia type P111 that pulled the french standard 819 line signal.
He does not show the set in operation, and spends most of the video talking about a book, but he does show the swiveling head and the design.
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 wikipedia's write-up covers the basics (line frequency, bandwidth, etc) - not in any great detail, but given its dearth of external references, there just might not be much out there
@ajroach42 hmm. given that you don't have to worry about colour, i wonder if you could pull some cnlohr-like tricks to get a microcontroller to broadcast a signal to an 819-line set?
@millihertz @ajroach42 There are also more technical details on the French wiki page: https://fr.wikipedia.org/wiki/819_lignes
Basically, it says that the actual picture resolution would actually have been lower than 720p (but still higher than the 625-line SECAM color signal that replaced it). Furthermore, the public French TV archives (https://ina.fr) doesn't seem to be hi-def at all (or upscaled maybe?).
I guess @fenarinarsa may know a little about this topic?
@ajroach42 $10k non-functioning in North Hollywood CA lol
@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 That was my thought exactly.
Figured maybe 2500 (on the assumption I can fix it and generate signals for it.)
@ajroach42 woohooooo! congrats, I can't wait to meet it and then get my grubby lil fingers into it ;)
@piggo It's very much the Mid-century modern look that fallout took inspiration from, yeah.
I always see fallout more in the predicta than in the european models, but this TV looks so overwhelmingly inspired by american cars that the line gets blurry.
@ajroach42 That "cabinet" is absolutely gorgeous, even without TV functional that would be an incredible design piece. Sounds like a steal!
@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.
@ajroach42 Now I know where Boston Dynamics got its design inspiration for their robot dog. Just look at those gams!
@ajroach42 Can I just remind you that the most important thing about TV repair is the FUCKING HIGH VOLTAGES - be careful.
A social network for the 19A0s.