Originally posted by: ripa
I'm sorry, but the search function seems to be a bit limited (only searches thread titles).
Anyway, I thought that the rotational speed difference would only yield a different frame rate but otherwise compliant PAL signal. I didn't think of the effects on the modulated signal. Since both PAL and NTSC video signals are FM modulated onto a 7,1MHz carrier, playing that back at a wrong speed would shift the carrier frequency, probably causing demodulating to fail. Also, I just noticed the technical discussion forum, where I should have posted this instead. I guess I got too excited about the prospect of playing back PAL discs on the X0. Sorry about that.
Originally posted by: Laserman
I thought I covered most of this before?
I thought I covered most of this before?
I'm sorry, but the search function seems to be a bit limited (only searches thread titles).
Anyway, I thought that the rotational speed difference would only yield a different frame rate but otherwise compliant PAL signal. I didn't think of the effects on the modulated signal. Since both PAL and NTSC video signals are FM modulated onto a 7,1MHz carrier, playing that back at a wrong speed would shift the carrier frequency, probably causing demodulating to fail. Also, I just noticed the technical discussion forum, where I should have posted this instead. I guess I got too excited about the prospect of playing back PAL discs on the X0. Sorry about that.
I don't think you should worry about it, finding or making a X0 equivalent PAL player has been a reoccuring topic since the beginning of the presevation efforts.
You can find detailed information of the NTSC and PAL laserdisc formats here:
The LaserDisc Technical Page
As you can see the NTSC carrier is 8.1Mhz and the PAL is 7.1Mhz, also the BW and sound carriers are different so very likely also the filters before the demodulation stage need to be changed.