ATV DIGITAL LINE SYNC TOOL FOR PAL 625 DESIGN BY G3SXC
This is a really interesting Tool for anyone wanting to look at certain lines of a TV picture on an Oscilloscope. The principle is simple but very effective lets say you wanted to display line 14 only on your Oscilloscope from a PAL 625 picture I think you would find it difficult...First you need a Reference point and that is a LM1881 sync separator commonly used. That will give you ODD and EVEN frames...Next you need to Count all the lines from 1 to 625....In this clever design by G3SXC Lancs he used a PIC16C84 u/P....He used the PIC to do all the counting and gating of signals and also it feeds the LED Serial 4 Digit Display of which the MSD was read out as the letter "L" meaning line followed by the 3 digit number 001 to 625....On the front panel was a knob that sent the number required up or down and this was the optics removed from a mouse. However you could use up/down buttons if you changed the software....The Input to the unit just requires Video at the Standard level or a X10 Amplifier can be switched in at an higher impedance...There is a Video out socket that displays on the picture you fed in a bright up line that is the number displayed on the LED Display....Also a Sync pulse to trigger your Oscilloscope so you can just see that line only... This Tool really is useful when dealing with Video in a serious mode and wanting to look at certain lines only without keep playing around with the level and filters etc.... Both of us two guys have been playing around with ATV for over 37 years from flying spot scanners to home brew 405 camera's even walking portable on 70c/m Live 30 years Ago to the present days Technology. ............. G3SXC and G3RFL ....
