Apollo TV and MSTV.
Posted: Wed Sep 01, 2021 9:01 pmThe early Apollo moon-missions used a unique and custom TV system, at first in monochrome, later in colour. It was a mish-mash of a system using either 320-lines at a 10Hz frame rate, or a Hi-Def mode of 1280-lines (very familiar now) at 0.625Hz, i.e. 1.6sec/frame. I don't think the HD mode was ever used on actual missions though. In either mode the video needed to be kept within a 500kHz bandwidth, that's all the Moon-Earth link had available for video.
In my mind it's not quite 'TV', nor SSTV, more like a higher resolution version of NBTV, the frame rate isn't that dissimilar. In the absence of any thing else - MDTV (Medium Definition TeleVision), though that could encompass many others.
The fundamental baseband video parameters are below, 'Click' as usual. It used a 'Sync Burst' rather than a pulse, other than the modification of line/frame frequencies , amplitudes and a few other details, it should be quite familiar. This data is only for the monochrome system, aside from the colour system, (same as early US CBS colour), using a RGB motor-driven sequential arrangement I have very little info.
We all remember (though perhaps I should say 'some' now) the quality of the results, not exactly stellar! One day I'll have a go at reproducing 320/10 for no other reason than why not? Maybe then we can see what could have been. Though that's easy to do in no time at all - convert a JPG to monochrome, resize to 428x320 (3:2 aspect ratio) and that's what could have been (without the 500kHz filtering). But that's not fair on those lumbered with the time/cost/reliability/operational constraints.
Steve A.
Also conversion from 320 to 525 had to be done on Earth, then in most of the world 525 to 625, or 405 which is how I saw it live on TV. I was 13 at the time...
In my mind it's not quite 'TV', nor SSTV, more like a higher resolution version of NBTV, the frame rate isn't that dissimilar. In the absence of any thing else - MDTV (Medium Definition TeleVision), though that could encompass many others.
The fundamental baseband video parameters are below, 'Click' as usual. It used a 'Sync Burst' rather than a pulse, other than the modification of line/frame frequencies , amplitudes and a few other details, it should be quite familiar. This data is only for the monochrome system, aside from the colour system, (same as early US CBS colour), using a RGB motor-driven sequential arrangement I have very little info.
We all remember (though perhaps I should say 'some' now) the quality of the results, not exactly stellar! One day I'll have a go at reproducing 320/10 for no other reason than why not? Maybe then we can see what could have been. Though that's easy to do in no time at all - convert a JPG to monochrome, resize to 428x320 (3:2 aspect ratio) and that's what could have been (without the 500kHz filtering). But that's not fair on those lumbered with the time/cost/reliability/operational constraints.
Steve A.
Also conversion from 320 to 525 had to be done on Earth, then in most of the world 525 to 625, or 405 which is how I saw it live on TV. I was 13 at the time...
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