at two millihertz of bandwidth, you could transmit a 30-pixel line in only 7500 seconds, so you could transmit an entire 30×30 frame in 225 000 seconds, less than three days
but plausibly the millihertz notation was an error and megahertz was meant
Full blown color NTSC managed with 6mhz channels! Digital broadcasts have a terrible user experience: Instead of providing the same channel they always did, but to vastly more receivers in much more marginal conditions using advances in digital signal processing and encoding power and methodology, broadcasters were allowed to cut up their frequency into 6 "subchannels", so they crunch the streams to the shittiest quality they can (as low as 3mb/s, DVD is 10!) legally get away with, provide almost zero redundancy in the broadcast, so now TVs that were well in the broadcast area of analog signals are straining to get every last bit out of the digital stream so it can hope to recover a picture.
They did this because 6 channels that most people cannot actually receive over the air gives them more advertisement slots than the 1 previous channel. Good old enshittification.
Not only did it manage, it looked fantastic, at least at the source. Back in the 80s I had a chance work with high-end analog video gear at a broadcast production studio. You wouldn't believe the detail and color fidelity of a full 6 Mhz composite video signal coming straight out of a broadcast studio camera through a Grass Valley video switcher to a studio reference monitor. It had a lot of the subjective character audiophiles use to describe tube amplifiers like: depth, warmth, etc. After being recorded on a 2-inch broadcast quad tape machine (the size of a dishwasher!), the playback looked identical to my eyes.
Of course, by the time these pristine images lost several generations through editing and dubbing, were sent through RF distribution, up a transmitter, down an antenna and through 75 ohm coax house cable, they could look decidedly less amazing. :-)
In the 90s, analog component video looked even more impressive still and we could record and dub it digitally on D1 digital VTRs with no generational loss (and no compression!). Since so much of the analog standard definition TV historical footage we see today was recorded post-edit & dubbing and then captured on VHS or 3/4-inch U-Matic tape air checks, it doesn't reflect the remarkable quality we had back then. And worse, much of what we see today of analog video is also not properly de-interlaced during digital conversion and then is further degraded through over-compression for streaming or broadcast. The worst of all worlds...
To your point, the quality we had back then makes the peggish mess created by today's over-compression all the more egregious. I have a high-end 4K HDR10 home theater with top notch components all properly interfaced, calibrated and tested - and yet, outside of 4K Ultra HD discs, much of what I see on OTA broadcast, cable, satellite and streaming looks pretty awful.
> and yet, outside of 4K Ultra HD discs, much of what I see on OTA broadcast, cable, satellite and streaming looks pretty awful.
And that's why I keep my grandfathered Netflix 720p subscription. Shitty compression with low resolution vs shitty compression with higher resolution means the same amount of artifacts anyway.
It's sad that no Scophony set survives. High resolution and 24 inch screens in 1938.
[1] http://earlytelevision.org/mechanical.html