I have the Niptix running now with NBTV signals.
Results so far........
1. With less than 15ma through the LEDs the picture can be watched in a room with the normal lights on.
2. One 4017 on the line clocking is not working so picture is only 25 pixels wide. ( it was working yesterday) so that has to be attended to.
4. The third column is on all the time......discovered that when I changed leads over I have shorted a transistor, so that will have to be sorted.
5. This is the most interesting. There is a 2 pixel constant vertical shift up and down on the picture at about 3 cycles per sec.
Thinking about this I believe that the 19.2kHz pixel clock osc is very very slightly off from the pixel rate from the CD.
So, when a new line starts sometimes the 19.2 first pixel clocking has not quite started and at other times it is one cycle too late, resulting in this slight cyclic vertical shift. I may change the CD to see if the cycle alters slightly to prove this.
I shall put a trimmer in the Xtal osc circuit to try and 'pull' its freq.
Or reset the osc at every line using the 32 line pulses.
Or more interestingly, put in a free running 19.2kHz osc pot control.....this will still give a good stable picture which can be either 'stretched' or 'compressed' vertically by slight pot twiddle.
I reckon that if, for example, the osc ran at half speed the picture would only be 24 pixels high and if twice the speed only half the picture would be shown over the 48 pixels.
One can do interesting things with a matrix that you can't do with a Nipkow disk.
Other than all the above I think that the picture is very impressive when viewed at about 8 ft away on the club's test CD.
I shall put my initial results up on my site soon, together, hopefully with the correctly running pictures.