Sampling H-sync pulse

[Blue Dog]

Trying to think up a way to 'log' an NTSC video signal- just the horizontal sync pulse from front to back porch (don't need the rest of the sig for analysis). I'd like to be able to buffer 2 or 3 samples, dump and compare (I know they should be the same....).

Any help/schem/component suggestions would be appreciated.

thanks

 

[Roff]

Trying to think up a way to 'log' an NTSC video signal- just the horizontal sync pulse from front to back porch (don't need the rest of the sig for analysis). I'd like to be able to buffer 2 or 3 samples, dump and compare (I know they should be the same....).

Any help/schem/component suggestions would be appreciated.

thanks

Could you elaborate on this? What are you trying to do?

 

[Blue Dog]

got a couple surveil cams (9) around the house and barn that mess up (ya I got 'em free), traced prob to a bad caps on 2- I borrowed a scope and noticed that when the cap was going the pulse shape changed- want to record the snyc pulse data (weekly) and compare to a good one to monitor the condition of the cams and repair before failures and it gives me an opportunity to get back in to the hobby- last thing I built was a COSMAC ELF

 

[Brevor]

Since April 1st is two weeks away maybe you're serious.
I suppose you could use an A/D converter to measure the pulse width and amplitude and then record the data on the COSMAC ELF for analysis.
Or it may be easier to just replace the caps in all the cameras and be done with it.

 

[Blue Dog]

The ELF is long gone (have upgraded several times since high school in the '70s). I know the cap replacement would be the easier but I really want to learn more about sampling, adc's and 'smart' waveform analysis.

So if I was to sample, perhaps I would need to be in the 10+mhz range to get decent resolution- any thought to an appropriate adc?

The easy way would be to by new cams.