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gary wrote:That looks fine harry, but I have just thought of something. Is your sync detector in the right position? Obviously, as the first (or last) aperture is passing the light source THAT is when the detector should be pointed at that missing sync segment. In this case it would be right next to your light source but from memory I think you have it mounted elsewhere - the answer to that is just move that bit of white paper to whatever segment is in front of the detector as the end of the last line passes the light source. Ideally the front edge of the missing sync (that is where the leading edge would be if it wasn't missing (gawd)) is where the detector should be. (This is ridiculously difficult to describe).
OH !!!!!! Yes move the missing sync i can do that i understand now that makes sense ,i will work it out today ..have to go out later might have time to work it outOne way I can think of setting that up is to just have your light source on and a white piece of paper in the "focus" spot. turn the disk until the first raster line just comes on to (or the last goes off) the white paper. Hold the disk at that location and replace the corresponding encoder segment with that bit of paper.
Yes thats a good procedure ,i can see what you mean now by have the encoder on something to rotate some that needs adjusting at least once .
Sheesh - if you can follow that you're a better man than I Gunga Din...
gary wrote:Yes, Harry that's fixed it, well done.
That worked so well I think it is showing that one (at least) of your apertures is obstructed, possibly by dirt etc. It might be worth passing a needle through them to clean them up a little.
gary wrote:There is a one good argument for getting the monitor part of this project going Harry, in that it will be DC coupled so you won't get the unavoidable sag associated with the AC coupling of PC recording.
I will look into trying to improve the video signal part next ,todays a big day and will improve the video in another way i have now got it on crystal motor control !
And it gets to correct speed very fast no over hunting for correct speed its pretty good..have not used the 4046 pll in many years nice to have a switch on and work right off the bat .
The 400 hz is off the lm311 encoder circuit now thats what i like to see!
I put in a switch so i can switch between PWM manual and crystal controlit was there so why not .I notice on the your last offering there is quite a bit of sag causing picture-on-sync syndrome.
Lets see what happens on the next test ..i hope with the speed no longer an adjustment it will be better ..
edit: you could, of course, pipe it into one of your previously constructed monitors too.
gary wrote:Just to be clear Harry, the sag in the video is due solely to the AC coupling with the PC sound card and has nothing to do with your circuitry - you have widened the sync pulses which helps but that is about as much as you can do.
Oh theres another thing when i view and record both programs slow down the 300mhz pentium there a few second delay in what is filmed to what is viewed perhaps this is a record thing to if i use both programs at the same time .
Well i am glad i am doing the sync pulse part right .Of course, good speed control has advantages in other areas.
I suppose I have add that the sag leading to picture-on-sync is the main reason I use and promote sync on the right channel.
I suppose theres no reason i could not do that to as well just connect the unsynced video to a plug out and sync just it does the mix as well via another plug....i just wanted to do the mix as a challenge you got me interested .None-the-less what you are doing is perfectly viable - just keep in mind that there will be some picture content where the sag is so bad it may lead to loss of sync or poor greyscale no matter what you do.
Oh theres another thing when i view and record both programs slow down the 300mhz pentium there a few second delay in what is filmed to what is viewed perhaps this is a record thing to if i use both programs at the same time .
tell you it will be so much easier not having to worry about that motor speed..
Hmmm, there must needs be some delay but not of the order of seconds - very strange.
Harry I always meant to add recording to TBP - as you can see there is a disabled "NBTV wave file" option in "destination" menu " for TBP, and that would have eliminated any delay between what-you-see and what-you-get. Alas, as I have lost my source code for alpha TBP it will now never eventuate.
[/quote]tell you it will be so much easier not having to worry about that motor speed..
Indeed!
harry dalek wrote:Gary looking at a bit of the missing picture when viewing on big screen do you think that is due to the width of the sync pulse still being to narrow ?
gary wrote:harry dalek wrote:Gary looking at a bit of the missing picture when viewing on big screen do you think that is due to the width of the sync pulse still being to narrow ?
No, your sync is fine - if anything a little too wide (.29 mS). No, any picture problems will be related to the fact that your speed is still varying quite wildly from -12% to +7%
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