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PostPosted: Fri Oct 19, 2012 10:44 pm
by AncientBrit
Hi Harry,

Please find attached some further pix.

The head amp is built on stripboard and housed in the space where the original electronics were housed so it's fully screened.

Also v3 of the cct showing where I had to use screened cable for interconnection.

Cheers,

Graham

PostPosted: Thu Oct 25, 2012 2:48 pm
by Harry Dalek
AncientBrit wrote:Hi Harry,

Please find attached some further pix.

The head amp is built on stripboard and housed in the space where the original electronics were housed so it's fully screened.

Also v3 of the cct showing where I had to use screened cable for interconnection.

Cheers,

Graham


HI Graham

Sorry about the late reply ..thanks for the extra pictures of the head amp i can see mechanical cameras and electronic scanning cameras are pretty much the same for this ...this information will make that part easier since i know which way to go .

I had trouble when i got to the saw tooth part it worked but i was not happy not getting the same results as your circuit perhaps because of my parts substitutions...so still working on changing that i am on version 3 and this one seems good last worked but i was getting the pulse mixed in the sawtooth didn't look clean enough for me ...so i will copy the one that is working and adjust it for the 12.5 hz and both see if i can now amplify them with the ic amps i have .
So looking to be a mix and match see what works .

Thanks also for the version 3 schematic ! i will have a good look at the extra information .

PostPosted: Sun Oct 28, 2012 8:50 pm
by Harry Dalek
Hi have not posted much on my project as i think its a bit different to a mechanical camera and don't want to bore any one :wink:
I finished the working deflection amps i think i have more than enough power to to drive the saticons yoke coils the Lm1875 amp is 20 watts and can drive it with 50 volts if i had to but i am just using 12volts so far no need for a heat sink at those low volts might be different when it drives the yoke.

I would like to know that the v and h scanning is correct i am thinking of just hooking it up to a crt scope and see what the scan looks like ,i have a fair amount of adjustment over the sawtooth so i hope the linearity of the sawtooth is good enough in these adjusted circuits .

Any case soon time to move onto the next 2 sections .

PostPosted: Thu Nov 01, 2012 11:22 am
by Harry Dalek
Well i am just about finished in doing all the sections to the camera i just haven't done the blanking transistor to the cathode part .
It just needs each section to be connected to each other hooking up the power supply and such so a bit more soldering .
I hope it works but expect more fault finding and changing as per normal least i have made head amps and video sync mixers before if they give me any grief.

So the boring part is over and the headache part starts i expect :shock:

PostPosted: Sun Nov 04, 2012 7:07 pm
by Harry Dalek
The wiring of the boards is talking a while the saticon tube is powered up now ...a few pictures of it today of my little friend is getting a smoke free test. :wink:

PostPosted: Fri Nov 09, 2012 2:00 pm
by Harry Dalek
This where i am up today all the high and low voltages to the saticon are hooked up now and the deflection circuits are powering the yoke all this part looks good the thing could very well be seeing every time i power it up ,i have still the head amp and video sync mixer power up and test .
Still no smoke this must be a good sign :wink:

PostPosted: Sat Nov 17, 2012 9:05 pm
by Harry Dalek
Well last few days i have been doing light tests with the camera without results ...i even swapped the image tube with a Newvicon after speaking with Graham my mistake was the Target signal is very weak ..

So after checking the head amp and testing after that i had light detection with the Newvicon ..So today i went back to the Saticon and repeated this test and it now works as well so i am back to the old tube and will progress with it now .

I also had trouble with its old lens the shutter opening kept closeing so thats been fixed also something i don't understand it a Transparent star thats on the middle of the lens even the Newvicons lens has this as well i have no idea what its use is and will it effect the image.

I will post pictures on a scrapped one.

PostPosted: Sun Nov 18, 2012 12:06 pm
by Harry Dalek
Looking at my images i noticed i have skipped the Newvicon part so i will post those give you an idea of size difference between the image tubes ...

I think the Newvicon was the last of the home video camera image tubes its sort of sad as i wonder how small they could of went with these things it would of been interesting.

If all gos well with the rest of the saticon build might make a smaller compact camera using this tube ...any case its all a nice try .

PostPosted: Wed Nov 21, 2012 11:39 pm
by AncientBrit
Hi Harry,
re the star in the centre of the lens the zoom lens that formed part of the colour camera I took apart to make my NBTV saticon had a form of auto-iris.

With power off the iris was pulled closed by means of a small spring.

The iris was mechanically connected to a solenoid and when power was appled to this solenoid the iris fully opened.

Looking in the handbook I bought it appeared that the solenoid was fed with some form of PWM signal so its effective power could be modulated thereby opening or closing the iris a measured amount.

In my camera I applied the full voltage so on power up it fully opens the iris, so I have to drive the camera on Target volts alone.

Could the star be an iris which is fully closed so it cuts off most light??
Are you getting light through the lens??

Cheers,

Graham

PostPosted: Thu Nov 22, 2012 1:52 pm
by Harry Dalek
AncientBrit wrote:Hi Harry,
re the star in the centre of the lens the zoom lens that formed part of the colour camera I took apart to make my NBTV saticon had a form of auto-iris.


Sorry Graham should of checked for some reason my reply didn't post !
So Its not the iris Graham..in the photos it looks like it is just the photo angle off the black part of the iris the Star is a transparent .

With power off the iris was pulled closed by means of a small spring.


Yes i worked that out now have it just wired open fully .

The iris was mechanically connected to a solenoid and when power was appled to this solenoid the iris fully opened.


I didn't try to power it open there were a few wires reminded me of a stepper motor so i just took the easy way out .

Looking in the handbook I bought it appeared that the solenoid was fed with some form of PWM signal so its effective power could be modulated thereby opening or closing the iris a measured amount.


Yes looked a little to much work to bother with when just wireng it open so it doesn't spring back any more i just wanted all the light and not bother with that part .

The Star is a transparent sticker i think i took the 3rd lens i had apart and its between the first 2 lens thats closest to the target apart of the image tube .
I would need to cut it open to see for sure ..i can only think its used when the camera is fully in sun light and the iris is shut a fair amount do that part is used perhaps as a filter of some sort ..i still don't understand why its not seen in the image if the iris is fully open unless the size of light to the target is always around under the size of that transparent star.

Its used in 3 different brands of camera i scrapped..
In my camera I applied the full voltage so on power up it fully opens the iris, so I have to drive the camera on Target volts alone.


Thats what i was thinking its no use for what we want so just open it fully.

Could the star be an iris which is fully closed so it cuts off most light??
Are you getting light through the lens??
[/quote]

Yes i am getting light past the lens i made sure before i put it back on the image tube and with a light test seems to work also i can tell with focus the light level changes so i again hope this is a good sign .

Sorry the muck up in replying !

PostPosted: Thu Nov 22, 2012 6:24 pm
by AncientBrit
Hi Harry,

Not sure why you are having problems syncing a monitor.

Are you not blanking the signal and adding syncs as per my original circuit?

Cheers,

Graham

PostPosted: Thu Nov 22, 2012 9:06 pm
by Harry Dalek
AncientBrit wrote:Hi Harry,

Not sure why you are having problems syncing a monitor.

Are you not blanking the signal and adding syncs as per my original circuit?

Cheers,

Graham


I have had to change it a bit Graham due to swapping parts like the deflection circuits didn't work correctly for me ..so thats different to yours i just got it going with the parts i had.

I am getting a very nosiy signal ...so i am just looking at having a correct 400 hz sync pulse at the right pulse width could be the voltages to the circuits need dropping i noticed on the mechanical one i was working on they were a bit fussy on that side of things ...then i will ad the video signal again to the mixing circuit ...
To me the video signal is noisy as in the deflection frequencies can be heard but it should be expected since thats whats moving the electrons..i suppose in mechanical cameras only dealing in a line frequency as well.

I still have the cathode to ground i haven't changed that back yet .

PostPosted: Thu Nov 22, 2012 9:45 pm
by AncientBrit
Hi Harry,

With grounded cathode there'll be no camera blanking.

All that will happen is that any signal produced will have black flyback lines where the beam discharges the target during flyback.

Also see my PM re system blanking

Cheers,

Graham