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deltec
26-10-23, 16:49
mark dashed flickering line for this service could some boday explain how this works regards deltec
Huevos
30-10-23, 23:33
VBI line.

You can stop this in ChannelSelection.
deltec
31-10-23, 16:12
Could u explain I’m lost what do ido in the Chanel slection
Joe_90
31-10-23, 17:11
It's only of use if you can see a flickering dashed line at the top of the screen on some channels. If you set the option it overwrites the line with a solid one which is less obtrusive. You wouldn't even see the line if you have left your TV with the default overscan setting. Any of us who disable overscan (in order to see the complete borders of the transmitted image (or on-screen menu) will occasionally see this VBI line on certain channels. Google VBI for more info.
adm
31-10-23, 18:03
It's only of use if you can see a flickering dashed line at the top of the screen on some channels. If you set the option it overwrites the line with a solid one which is less obtrusive. You wouldn't even see the line if you have left your TV with the default overscan setting. Any of us who disable overscan (in order to see the complete borders of the transmitted image (or on-screen menu) will occasionally see this VBI line on certain channels. Google VBI for more info.

In the good old days of analogue TV they used a few lines of the vertical blanking to insert the teletext/ceefax information. On some monitors you could see this information as white horizontal crawling dots on the very top of the screen. This is digital information on an analogue signal , Black =0, White = 1. Occasionally when one of the lesser channels shows a old TV program that has been rescued and/or restored you will see the dashed flickering line.

This youtube video shows this information (about 5 seconds worth onwards from the link)
https://youtu.be/duRKoWyfTWs?t=395

The whole video explains the technology but you may find the presenter rather dry/boring
Joe_90
31-10-23, 18:13
I'm of an age to know all that @adm, having been brought up on 405/625 line B&W TV :) - The Irish terrestrial provider finally turned off its teletext service (overlaid on the digital signal) just last week, as they have been unable to source replacement equipment to continue. I was trying to encourage @deltec to do his own research!