SSTV NBTV ?
Posted: Sun Sep 30, 2018 12:19 am
I came across this a posting from chris long on facebook a tv system bit like slow scan tv and a bit like NBTV \
For those without face book heres what i found
https://www.facebook.com/groups/1522320 ... 778730135/
https://www.facebook.com/search/str/ZL2 ... ded_videos
ANOTHER TEST of high-speed SSTV using ZL2AFP software, in the lead up to tests of MOVING picture narrow-bandwidth TV. Vic Brown G3SDQ transmitted 72-line images of his London (UK) shack briefly on 3712.5kHz (80 metres), which I received and recorded via the Hack Green online web-SDR, about 200km to the North-West of Vic in Cheshire. He transmitted one picture every three seconds. I decoded the pictures from the Hack Green audio stream, here at VK3AML in Melbourne, Australia. Each Saturday morning between 07:30 and 08:00 UTC, the narrow band TV net in UK experiments with new methods of NBTV on 3712.5kHz plus or minus QRM. Please, if you're within range in Europe, do join us!
Chris Long Last week, we tried the 48-line version of the ZL2AFP software, transmitting one picture per second:
In the WATERFALL DISPLAY of the audio stream produced by the ZL2AFP software, you can see the 96 subcarriers, one per picture scan line, each modulated by very narrow bandwidth FM - in fact if you look hard you can almost see a negative image of me in the waterfall. This is an entirely analog process, though it uses multiple subcarriers similar to OFDM technique:WATERFALL DISPLAY of the narrow band video signal used for this test. Each of the 72 lines of the image are simultaneously scanned, and each line is allocated a separate NBTV audio tone, spaced about 30 Hz apart, frequency modulated by the greyscale values, and occupying a band of frequencies from about 300 Hz to 2600 Hz:
As below he says you will not find the software on the net well that was 2016 ? fft-tv.zip any case very interesting may be its there now ....i found one link to download the file but it was dead link sadly.
Chris Long By the way, the software that was used for those tests was not on the page for which you gave the url. It is a development from it, also by Con Wassilieff ZL2AFP, and as far as I know it's unpublished, but I can give you the zip files if you message me.
For those without face book heres what i found
https://www.facebook.com/groups/1522320 ... 778730135/
https://www.facebook.com/search/str/ZL2 ... ded_videos
ANOTHER TEST of high-speed SSTV using ZL2AFP software, in the lead up to tests of MOVING picture narrow-bandwidth TV. Vic Brown G3SDQ transmitted 72-line images of his London (UK) shack briefly on 3712.5kHz (80 metres), which I received and recorded via the Hack Green online web-SDR, about 200km to the North-West of Vic in Cheshire. He transmitted one picture every three seconds. I decoded the pictures from the Hack Green audio stream, here at VK3AML in Melbourne, Australia. Each Saturday morning between 07:30 and 08:00 UTC, the narrow band TV net in UK experiments with new methods of NBTV on 3712.5kHz plus or minus QRM. Please, if you're within range in Europe, do join us!
Chris Long Last week, we tried the 48-line version of the ZL2AFP software, transmitting one picture per second:
In the WATERFALL DISPLAY of the audio stream produced by the ZL2AFP software, you can see the 96 subcarriers, one per picture scan line, each modulated by very narrow bandwidth FM - in fact if you look hard you can almost see a negative image of me in the waterfall. This is an entirely analog process, though it uses multiple subcarriers similar to OFDM technique:WATERFALL DISPLAY of the narrow band video signal used for this test. Each of the 72 lines of the image are simultaneously scanned, and each line is allocated a separate NBTV audio tone, spaced about 30 Hz apart, frequency modulated by the greyscale values, and occupying a band of frequencies from about 300 Hz to 2600 Hz:
As below he says you will not find the software on the net well that was 2016 ? fft-tv.zip any case very interesting may be its there now ....i found one link to download the file but it was dead link sadly.
Chris Long By the way, the software that was used for those tests was not on the page for which you gave the url. It is a development from it, also by Con Wassilieff ZL2AFP, and as far as I know it's unpublished, but I can give you the zip files if you message me.