AVS Forum banner
Status
Not open for further replies.
1 - 5 of 5 Posts

· Registered
Joined
·
178 Posts
Discussion Starter · #1 ·
Hello,


I have a 7 years old Seleco video projector (SVT 120) that I drive using S-video cable from a Pioneer laserdick (?1950) and Sony DVD (7700) players.


The projected image when using NTSC material is flickering. It affect all 3 tubes, not the CRT generated characters. It does not seem to affect PAL material, or not as much.


I used to be routing the video signal through my Onkyo receiver, but that makes matter worse. Going direct improves the image but never eliminates the flickering. I have tried fiddling with the connections, making sure they're tight, to no avail. I also tried to switch/plug things on and off around to try to detect an interference source.


Basically I think this is just the refresh rate being visible. Could this be caused by old tubes?


I know Seleco is not the most known/liked brand around here, but I was wondering if someone had an idea as to what could cause such problems in a "generic" CRT video chain.


Many thanks for your help.
 

· Registered
Joined
·
670 Posts
I'm sorry I am not familiar with your projector.


It sounds like something has gone awry in your projector, since the effect happens on both sources. I assume you have changed the cable out to be sure it is not some sort of interference.


Either the refresh rate is too low or it is failing to resolve both of the interlaced fields....


NTSC is "interlaced", meaning only each frame is made up of two fields. Maybe somehow the projector is not displaying one of the two fields?? You might try using a line doubler (progressive scan) so that each frame displays both fields (all scan lines) at the same time.


Sorry I can't be of more help.


Paul
 

· Registered
Joined
·
251 Posts
It's an odd one, since the normal explanation - flicker due to a low field rate - is ruled out because you say PAL is less problematic than NTSC, and PAL is 50Hz and NTSC is 60Hz....


Could it be macrovision? Does it affect LDs too (in which case it probably isn't macrovision)?


- David Eddy
 

· Registered
Joined
·
178 Posts
Discussion Starter · #5 ·
Thanks for the answers.


It is probably not macrovision since it happens on LD and since my code-free DVD player disables Macrovision...


Might the higher frequency of NTSC be pushing the pj too hard?
 
1 - 5 of 5 Posts
Status
Not open for further replies.
Top