CurtPalme.com Home Theater Forum

stridsvognen · Guest

In some ways i think your both right, and i'm sure if everybody meeting looking the same thing everyone will agree.

i'm sure its possible to get black using lumagen, even with the mod, but like mike say, its not the absolute best black.

As i seen it with the mod, when coming out of black will be a low gamma, without the mod a high gamma, Installing the mod means adjusting the brightness -30... thats a lot, and also the reason the big confusion whats good G2 and Drive, don't seems like anyone knows for sure. So it will depend if the mod is installed, or not.

Without the mod some say my green tube is almost gone, with the mod its almost new. from the G2 and drive settings.

I'm not old in this CRT stuff, so ill not make any claim of knowing anything for sure, but like to share my experience.
If anyone think I'm just making nonsense please ignore, if it rings a bell anywhere, feel free to try the same stunt, and see what you think yourself.

I would love meeting some of you hardcore CRT guys. Like my time in hifi, there is to much talk and to little action.

I would pick up my bag, and get over the big water if anyone open the door.

I'm a person who say what i think and without hiding my opinion, so I'm no good for very sensitive people, but love if someone is up for a good argue.. finishing with convincing one or another.

I make mistakes, plenty of them, think its the only way to get wiser on anything.

Whos up for a VIM mod shootout.. Wink

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

I think your right Kurt on many points. I guess I just have not seen the elevated issue on any of my Vims. Some with the mod too. I have
one vim that has the line issue, I should do the mod and see what happens. But for the most part I just put that line, when I used that Vim, onto the black border of the Screen. You do not see it there so it was never a big issue.

I do what to try Mikes and you idea of putting an external switch for the Internal video to shut it off and on.

Also with regards to what I see using the VP to get Black, or Blacker than Black. Black is a voltage of 0, so would a negative voltage at that point lower the voltage seen in the vim so that the elevated voltage the marquee's video chain creates would be nulled by the Assumed negative voltage of the input signal?

Athanasios

mp20748 · Posted: Tue May 01, 2012 7:37 pm Post subject:

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

I was looking at the SM and think it be more elegant if we some how use an 3 channel RGB op amp that has a selectable power option that will only turn off when triggered. We can use the INT/EXT signal that switches to external video from the Vim to turn off the Op Amp( unity gain). This will take the internal video out of the path on its way to U110.

What do you think?

We could do this on the VIM or on the CLM after U110 now that I looked at the Schematics again.

Not sure about the other associated signals. it might be possible to maybe do the same idea with a on/off switch for the power to the pixel generator if it doesnt affect any other signals. No we can't it creates the same INT/EXT signal wee need . Maybe we can use it to turn of the quad op amp used for the internal video( U110)?

Athanasios

mp20748 · Posted: Tue May 01, 2012 8:47 pm Post subject:

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stridsvognen · Guest

Mike... Can you explain to us mortals, whats going on there.. and whats the result.? Very Happy

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Looks like he put a switch to turn off and on U106. he tied into the power supply pins which are lifted. At least thats what it looks like to me.
Basically the idea I posted above, but Mike doesnt it affect the Vims ability to keep external video on? Wouldn't the Pixel generator turned off disable the INT/EXT signal as well?

mp20748 · Posted: Tue May 01, 2012 10:25 pm Post subject:

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Now mike could we not add a Transistor switch that would switch the power on when we find a signal source to activate it when any menu
button is pressed?

maybe the Vishay DG417?

Athanasios

mp20748 · Posted: Tue May 01, 2012 10:33 pm Post subject:

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

You have the same pic on the screen shot war, is that before this mod? It does seem like you did get a bit more sharpness in the text but my Monitor is not the best here at work so I really can't tell too well .

Nashou

mp20748 · Posted: Tue May 01, 2012 10:45 pm Post subject:

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

I have been looking for a trigger to switch off U106 and con not find a way, I think it might be better to somehow modify your approach? Can you try to keep the power to U106 and instead cut it to op amp U110 and see if the same results are there? This way we can use the INT/EXT signal to power the switch on and off.

Athanasios

mp20748 · Posted: Tue May 01, 2012 10:54 pm Post subject:

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Maybe something from U88 CD0-15?

Those go into U106, maybe they are activated when an internal pattern or menu item is needed?

Athanasios

stridsvognen · Guest

Look like some have been busy while i was sleeping.. Thumbs Up

If possible ill prefer no programing, like that will complicate things a bit here in my end.

But ill ill love to know what pins to lift on U106, to test this, and whats the capacitor for.? how big is it.?

I'm so exited to try this. Smile

stridsvognen · Guest

My CLB looks like this.. 50-2036-03P

Not so easy to lift the pins on that one.

barclay66 · Posted: Wed May 02, 2012 9:45 am Post subject:

Hi,

I've been reading this thread with growing interest. I don't have the line fix installed and even though I don't experience a visible line (VIM: 50-2035-03P / 03-270335-03P). Nevertheless I'm always interested in upgrades which will improve picture quality. So I did some research:

I have some other idea for You guys. Instead of disabling U106 You could cut off the generator's output. For this I'd insert some high-bandwith video driver (one for each color, gain=1) with enabling/disabling capability after the outputs of U110. Knowing U110's gain setting (gain=2) it even could be possible to replace U110 with these video drivers. When disabled, their outputs will go into a high impedance state, thus removing any adverse effects to the video chain.

I think that the MAX4223 could be suitable: http://datasheets.maxim-ic.com/en/ds/MAX4223-MAX4228.pdf

Now for the complicated part: For enabling/disabling at the right time we need a suitable signal. It is obvious that we can't use the "INT/EXT" signal because it is switched on a pixel by pixel basis (see CLM Specification excerpt below). What I could imagine is that the signal called "TEXT" (see output pin 19 of U94 and input pin 25 of U106) could be used for this as it seems like a general command for either menus and/or test patterns. I will have to check this with my oscilloscope.
Maybe I'll have some time for this in the evening and will come back with additional information tomorrow.
Fortunately the extender boards I finished yesterday allow me to take measurements...

Regards,
barclay66

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

That is what I suggested in an earlier Post Barclay. But you do not need a high bandwidth RGB driver. Just a simple switch to either cut off or pass the outs from the CL415. You could put the switch on the inputs to the CL415 or the outs, and use the INT/EXT to cut the switch, hence the DG417 or something similar. A simple transistor would work Source drain and Gate( triggered by the INT/EXT). we just need to know how much voltage that INT/EXT is and find an appropriate switch.

Athanasios