When TV first appeared it was a 30 line mechanical system pioneered by John Logie Baird. These days there are still 30 line TV enthusiasts, although now PCs can be used to do line conversion and reception.
See https://www.taswegian.com/NBTV/forum/
See also http://www.tvdawn.com/background/
Showing posts with label nbtv. Show all posts
Showing posts with label nbtv. Show all posts
13 Oct 2019
10 Feb 2015
Narrow Band TV (NBTV)
Partly because bandwidths are very low, there has been a revival of interest in NBTV systems similar to the early TV transmissions by Baird in the 1920s and 1930s.
There is even a Televisor kit available for about £40 delivered (in the UK) with a CD with some still and moving images and its own test card generator. I am quite tempted!
The televisor kit is available for £35.94 + shipping from http://www.mindsetsonline.co.uk/Site/Home (search for televisor). This is compatible with the 32 line standard of the NBTV Association. The NBTV Association home page is at http://www.nbtv.wyenet.co.uk/index.htm .
Bandwidths are audio only, so a tape recorder or CD are fine. Over the air transmissions only require audio bandwidths too. Of course, with just 32 lines don't expect brilliant images! The narrow bandwidth should make it possible to transit moving images over a standard FM or AM link.
I think the very first transatlantic DX tests were done using the Baird system in the late 1920s or early 1930s.
There is even a Televisor kit available for about £40 delivered (in the UK) with a CD with some still and moving images and its own test card generator. I am quite tempted!
The televisor kit is available for £35.94 + shipping from http://www.mindsetsonline.co.uk/Site/Home (search for televisor). This is compatible with the 32 line standard of the NBTV Association. The NBTV Association home page is at http://www.nbtv.wyenet.co.uk/index.htm .
Bandwidths are audio only, so a tape recorder or CD are fine. Over the air transmissions only require audio bandwidths too. Of course, with just 32 lines don't expect brilliant images! The narrow bandwidth should make it possible to transit moving images over a standard FM or AM link.
I think the very first transatlantic DX tests were done using the Baird system in the late 1920s or early 1930s.
4 Jul 2013
30 line TV
It is a long time since the Baird 30 line TV system was replaced by 405 line and then 625 line TV here in the UK. However, there are still enthusiasts building mechanical 30 line TV systems and getting respectable results. At one time I joined the NBTV group (does it still exist?) who promote(d) hobby activity with 30 line TVs, particularly mechanical versions with scanning discs etc. Bandwidths needed for such systems are very narrow (audio) so the signal can be transmitted using a standard voice transmitter. These days it is possible to produce 30 line TV using a PC, but this not quite the idea: one can after all communicate worldwide by Skype video or FaceTime.
This video (linked from its original location on You Tube) gives some idea of what is possible.
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