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"Mike Coslo" wrote in message
t... Cecil Moore wrote: The scan rate of most computer monitors is closely related to multiples of the scan rate of a NTSC television signal scan rate. How do you work that out? NTSC is 60Hz (30Hz Interlaced) So Most CRT monitors run at 70Hz, 75Hz, 85Hz and maybe 100Hz for a high end monitor at 1024*768 Where is the link between the vertical refresh rates? Have a google search for Vesa refresh rates for more info. Robin.. ( I used to work for NEC building computer monitors before NEC pulled out of manufacturing them in the UK) |
Robin,
I *haven't* worked in this area, but I still knew this comment was misplaced since I've seen all kinds of scan freqs over the years. -- Steve N, K,9;d, c. i My email has no u's. "Robin" wrote in message ... "Mike Coslo" wrote in message t... Cecil Moore wrote: The scan rate of most computer monitors is closely related to multiples of the scan rate of a NTSC television signal scan rate. How do you work that out? NTSC is 60Hz (30Hz Interlaced) So Most CRT monitors run at 70Hz, 75Hz, 85Hz and maybe 100Hz for a high end monitor at 1024*768 Where is the link between the vertical refresh rates? Have a google search for Vesa refresh rates for more info. Robin.. ( I used to work for NEC building computer monitors before NEC pulled out of manufacturing them in the UK) |
"Bill Turner" wrote in message ... Keep in mind the difference in phosphor persistence. TV CRTs are designed with enough persistence to make 60 Hz flicker invisible. Computer CRTs have no such limitation. -- Bill, W6WRT Computer CRT's also have phosphor persistence, this is also defined by the physical size and depth of each layer of phosphor as in a TV CRT, the difference is that the phosphor pixels are smaller, so can convert less electron beam energy to light, and for a shorter period of time. Robin |
Robin wrote: "Bill Turner" wrote in message ... Keep in mind the difference in phosphor persistence. TV CRTs are designed with enough persistence to make 60 Hz flicker invisible. Computer CRTs have no such limitation. -- Bill, W6WRT Computer CRT's also have phosphor persistence, this is also defined by the physical size and depth of each layer of phosphor as in a TV CRT, the difference is that the phosphor pixels are smaller, so can convert less electron beam energy to light, and for a shorter period of time. Robin Hey Robin! *You* tell us why computer screens flicker on television. Then explain why many of them have horizontal bars running vertically through the pictures. Then explain why the bars are of different sizes and timing from appearance from top to bottom of the screen. Then explain why some don't. - Mike KB3EIA - |
w4jle wrote:
If you go to Europe, you go nuts for the first few days getting used to the flicker as they use a 50Hz refresh rate. If a european ever goes to the US or far east he'll posibly go nuts over one of the main features of the NTSC color system, AKA as "Not Twice Same Colors" ;-) 73, Volker |
In message , Volker Kerkhoff
writes w4jle wrote: If you go to Europe, you go nuts for the first few days getting used to the flicker as they use a 50Hz refresh rate. If a european ever goes to the US or far east he'll posibly go nuts over one of the main features of the NTSC color system, AKA as "Not Twice Same Colors" ;-) 73, Volker Not really true, surely? There is 'something' about NTSC compared with PAL. However, I've never seen bad colo(u)r on NTSC sets which was not mainly due to poor signal quality anyway, and where PAL would probably been the same. These days, don't they transmit the correct colours as a reference in the vertical interval, and the set uses (or can use) this to correct the phase errors? Ian. -- |
Ian Jackson wrote: In message , Volker Kerkhoff writes w4jle wrote: If you go to Europe, you go nuts for the first few days getting used to the flicker as they use a 50Hz refresh rate. If a european ever goes to the US or far east he'll posibly go nuts over one of the main features of the NTSC color system, AKA as "Not Twice Same Colors" ;-) 73, Volker Not really true, surely? There is 'something' about NTSC compared with PAL. However, I've never seen bad colo(u)r on NTSC sets which was not mainly due to poor signal quality anyway, and where PAL would probably been the same. These days, don't they transmit the correct colours as a reference in the vertical interval, and the set uses (or can use) this to correct the phase errors? It is a source of great amusement to listen to people dissing one or the other - NTSC or PAL, or even SECAM. They all suck very much. Trying to decide which one sucks the most is a waste of time. - Mike KB3EIA - |
I would agree with that. Once I am use to the flicker, I marvel at the
cnsistancy of color from camera to camera. "Volker Kerkhoff" wrote in message ... w4jle wrote: If you go to Europe, you go nuts for the first few days getting used to the flicker as they use a 50Hz refresh rate. If a european ever goes to the US or far east he'll posibly go nuts over one of the main features of the NTSC color system, AKA as "Not Twice Same Colors" ;-) 73, Volker |
rite this down, "sync rate/refresh rate/scan rate/any other combinations
of words that means the same thing". Now stop this nonscense. Lets start a new thread, "did I spell non-scense rite ?" New thread idea, " do the quote marks come inside or outside the question mark"?" Butch KF5DE Bill Turner wrote: On Sat, 17 Jan 2004 19:47:49 -0000, "Robin" wrote: Computer CRT's also have phosphor persistence __________________________________________________ _______ I never said computer CRT's don't *have* persistence, I said that they are not limited by the 60Hz requirement of TVs. All CRT phosphors, whether for TV, computer or oscilloscope, have *some* degree of persistence. Hopefully the manufacturer has matched the persistence to the use. -- Bill, W6WRT |
On Mon, 19 Jan 2004 03:37:46 GMT, Mike Coslo
wrote: It is a source of great amusement to listen to people dissing one or the other - NTSC or PAL, or even SECAM. They all suck very much. Trying to decide which one sucks the most is a waste of time. Most probably correct. And what disturbs me most is that nobody has come up with something better available to the consumer "in general" I mean, maybe I'm expecting too much from an industry that has not been able to control "ghosting" effects in the end credits (white lettering on black background) on a reasonably new TV set when fed with S-Video from a digital source. OTOH, SECAM is a bit more complex than NTSC or PAL. To the best of my understanding, they actually send the chroma portion of the signal *after* the luminance, so sets that are fit for SECAM gotta have a delay line somewhere to brinc Chroma and Luminance back together, IIRC? And what about and adaption of "our" SSTV standards to "Fast Scan" television? Would that work within reasonable parameters? Volker |
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