Anyone modify a B&W TV to become a B&W HDTV monitor?

[wa2ise]

Anyone do that? Take a B&W TV and convert it to a B&W HDTV monitor. Two areas that would require a lot of effort would be to modify the horizontal deflection circuits, and also improve the bandwidth of the video amplifiers. To do 720p you'd need the horizontal to do 43KHz, a big jump from 15750Kz for old fashioned NTSC. Long ago I worked for a medical equipment company where we modified B&W 525i monitors to 525p. The horizontal retrace time stayed about the same even when we got the horiz osc to run at 31KHz. IIRC it was about 10usec, out of 63usec for NTSC, 31usec at 525p and 23usec for 720p, Which would eat up half of the image at that point. Removing the very high voltage winding off the flyback cut the flyback time about half. And then you'd need another source of very high voltage.

As for the video amp bandwidth, it would need to be 4 times better than that in an NTSC set, around 15MHz for 525p. Or about 9 times better for 720p. These numbers needed to make the horiz resolution match that of the new vertical resolution (assuming the CRT's spot size isn't too big).

Looking at this, it looks like an undoable project...