This is my latest standards converter. It is programmable so can generate a range of standards from a 625 line input. It also comes with a programmable modulator.
The converter can generate a standard with any number of lines from 16 to 830 and any number of active lines(lines with picture content) between 8 and 800.
It can generate field rates of 25, 30, 50 and 60 Hz. 50 and 60 Hz are interlaced. It has selectable sync height from 20 to 50% in 5% steps. The length of the front porch, horizontal sync pulse, back porch and broad pulse are all programmable. The number of broad pulses can be in the range of 1 to 50. The left and right of the picture can be cropped independently. There is also a method of moving the picture vertically.
The modulator uses two MC44BS373. It covers 30 to 900 MHz in 5 ranges. The frequency step size is dependant on range.
It can do negative video and FM sound or positive video and AM sound.
It can do video/ audio carrier separations of 4.5, 5.5, 6.0 and 6.5 MHz or if in positive video and AM sound mode the video and sound carriers can be set independently.
Both the converter and modulator can be easily programmed by using the two control knobs.
Some basic knowledge of the standard you want to generate is needed.
I have tested it myself and can confirm it is not idiot proof. It is possible to enter nonsensical settings in such a case it will just sit there not producing any output.
I have tested it on 405, 819, 625 and 525 lines. That's as far as my collection of TV's goes. Anything outside those have not been tested but should work.
All information needed to build one is on the
Hedghog PSC webpage or if you would like one built forum member Freya will supply them.
A link to a description of the menu is
here
Frank