The line oscillator has to run close to the line frequency and is then
phase-locked to it by the horizontal hold mechanism. If the oscillator is
tuned for 19kHz it's a big stretch to get it to sync to a 15kHz input
signal.
Yes, you might be able to modify some components to slow it down, or even
Oh, yes, the entire discussion is about monochrome video. Sorry, should
have mentioned it in the follow up email as well.
On 2021-04-11 9:26 p.m., gregebert wrote:
At least it's just monochrome. NTSC composite video with color is
rather complex, though I must say it is also ingenious in that
Still new to the whole composite video thing---could you clarify what is
the stretch? Do you think the driving electronics might not work at the
lower NTSC frequency? Or is there a mechanical impediment, like the
windings of the CRT's yoke? Thank you!
Jens
On 2021-04-11 7:19 p.m., Adrian
At least it's just monochrome. NTSC composite video with color is rather
complex, though I must say it is also ingenious in that it is
backward-compatible to monochrome and packs so much video information into
a 3.58Mhz bandwidth. Similar for PAL, though higher bandwidth.
On Sunday, April 11,
It sounds a bit of a stretch - 15kHz to 19kHz. You could try running the
monitor without an input signal and adjusting horizontal frequency (if
there is one) to see what range it can manage.
Another possibility is to fix it in software by creating a custom monitor
signal. Some information is at
Thank you! I think it should be possible to modify the horizontal and
vertical deflection circuitry on the board to make it a proper NTSC
frequency, yes?
Jens
On 2021-04-10 10:52 p.m., 5-ht wrote:
Jens,
The horizontal sync requirement of this monitor (52 uS / 19.2Khz) is
somewhat higher
