VSSTV

Forum for discussion of SSTV topics. Slow Scan television (SSTV) is a picture transmission method used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or colour.

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VSSTV

Postby Steve Anderson » Sun Apr 18, 2021 7:31 pm

...a new one to me, and the following link is very mechanical in nature...

https://www.gebseng.com/02_vsstv/vsstv_english.pdf

Anyone interested in having a go at it? (Very Slow Scan Television).

The website referred to (Vsstv.com) seems to be down...brings you to some Asian site...though quite a few links are thrown up in a search on Vsstv, but I've found nothing of any real substance so far...

No, I'm not going down this path...ordinary SSTV is fine for me...

Though some of the Hi-Res current modes could be called VSSTV, taking several minutes to transfer...

Although conceptually slowing things down to fit in the same bandwidth as CW (say 200Hz) might be interesting, again I'm not going there...the Cop McDonald monochrome standard would require an estimated minute and a half of time per frame!

It's a shame that MSTV (Medium Scan TeleVision) never really got a foothold. Although many consider the Apollo TV system to be SSTV, I tend to think of it as MSTV (Medium Scan TeleVision), 10 frames/sec., 320 lines, 500kHz bandwidth. At least the early ones, how the colour system in later missions/versions was done I'm not sure other than they used a RGB colour-wheel arrangement in the camera...partly mechanical...which means the single camera tube used needed a panchromatic response...and/or the pre-amp gain was switched depending on the current colour filter...quite a task considering the variable illumination levels encountered and temperature excursions...and working in a vacuum...and the remote controlled pan/tilt control from Earth during departure...

https://www.youtube.com/watch?v=9HQfauGJaTs

Steve A.
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Re: VSSTV

Postby Harry Dalek » Tue Apr 20, 2021 5:27 pm

I have seen Vsstv a while back it painfully slow for me ! i would loose interest !
Towards the end of the Devil Build i tried this frame on 2hz and 240 lines not really SSTV but slowed down NBTV i call it SNBTV :wink:
Movement would be seen every frame little bit faster by 3 than fastest SSTV 7 sec
Not bad on This Tiny VCR139 and of cause using your circuits ! i just slowed it down ..Using FreeNBTV to make the video format .
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