CurtPalme.com Home Theater Forum

barco_75 · Joined: 14 Jan 2009 Posts: 171 Location: Chicago

Hi, can some one tell me what the correct wiring is for the Red, Green, and Blue focus voltage wires which are hooked up to the focus block. Does the wiring match the order of the trim pots behind the focus block? I've taken a couple of photos of possible options. The wires are color coded.

Option 1 matches the order of the trimpots
Option 2 matches the photo of the board shown on Curts 808s layout page (under setup tips & manuals).

I'm thinking it is option 1 but Curt's photo shows differently. It could be the wires in his photo are not properly color coded.

If I get it wrong will I blow anything up?

km987654 · Posted: Wed Nov 12, 2014 6:50 am Post subject:

I believe you don't need to connect those so if you want to connect them it shouldn't matter which order.

barclay66 · Posted: Wed Nov 12, 2014 7:50 am Post subject:

Decibel · Joined: 31 May 2007 Posts: 904 Location: Roma - Italia

km987654 · Posted: Wed Nov 12, 2014 8:05 am Post subject:

Decibel · Joined: 31 May 2007 Posts: 904 Location: Roma - Italia

cosaw · Posted: Wed Nov 12, 2014 10:19 am Post subject:

I think I've misunderstood all this. All machines with Panasonic tubes don't have the focus voltage wires - I'm correct on that, yes? barco_75 you've put Sony tubes in your 808?

So are people saying that even the Graphics 808s with the Sony tubes and the focus wires doesn't need the wires connecting to the focus block in order for the projector to work?

redfox001 · Joined: 16 Mar 2009 Posts: 2257 Location: The Netherlands

Do connect the wire from the quadrupler if you let that one hang it will spark. Doesn't matter to what pin. I worked with a quadrupler from a 808 in a cine 9 and let that wire in a piece of wood but later I also connected this block and the whole starting noise is less and seems faster. And I had sparks once without. Oh and it that case also let the black ruber on the pins if you open the crt while operating you don't want 1000V.
I think the order is completely irrelevant as it only splits a voltage.

barco_75 · Joined: 14 Jan 2009 Posts: 171 Location: Chicago

I converted my BG808 to a BG808S. I now have sony tubes and the 120 mhz amps. Each RGB amp has a red wire which is to be hooked up to the focus block. Per Curts 808 description:

"In BG 808s sets that use Sony tubes, this block also feeds the 5Kv focus voltage to the tubes (not used in the other 808 models.)"

One wire does go to the quadrupler and that is not in question (it's the wire on the left in my photos).

I think it is important to have the wire hooked up...the order I'm not sure. Why would Barco add the wire if it had no reason to?. Also, I think the order is important otherwise they would not have color coded the wires.

Here are a few references I found:

http://www.curtpalme.com/Barco808_Layout1.shtm

http://www.curtpalme.com/Barco808_Layout7.shtm

I would go by Curt photo is layout 1, but I can't be certain he hasn't switched the RGB amps (for instance from Blue to Red). I know in mine, I actually have the color coded RGB amps switched. Does anyone have a 808s that they can check?

cosaw · Posted: Wed Nov 12, 2014 3:40 pm Post subject:

I agree with everything you said.

Don't want to confuse the matter so feel free to ignore this: I have a Barco Data 500 and the Blue wire is at the back of the focus block while the red wire is at the front of the focus block.

I'm sure Curt will know the answer to this when he sees the thread.

barco_75 · Joined: 14 Jan 2009 Posts: 171 Location: Chicago

If I understand correctly it matches my option 1 photo (see titles, its the second photo)? Is the focus block the same part #? I don't know if the data 500 is the same.... Anyone with an 808s?

cosaw · Posted: Wed Nov 12, 2014 7:22 pm Post subject:

redfox001 · Joined: 16 Mar 2009 Posts: 2257 Location: The Netherlands

The splitter that is in the CRT part also has three wires going out and it does not matter what order you use as the splitter does nothing with the voltage but make three connections.

The splitter in the back you are talking about can not split different voltages for different tubes. There is nothing in it but a lot of siliconkit to not get sparks.

km987654 · Posted: Wed Nov 12, 2014 11:17 pm Post subject:

cosaw · Posted: Thu Nov 13, 2014 10:48 am Post subject:

barco_75 · Joined: 14 Jan 2009 Posts: 171 Location: Chicago

So I'm a bit confused. It seems the consensus with those responding to this post state the wire has no use. However, Curt states it

"In "BG 808s sets that use Sony tubes, this block also feeds the 5Kv focus voltage to the tubes (not used in the other 808 models.)"

The above thoughts seem to contradict each other. Regardless it seems that it can't hurt to hook the wires up but I'm not sure why the order would be important for the ES set and not the EM set if the focus block has the same function. Does anyone have a Barco reference (schematic or the like) they could share which confirms some of the conflicting information.

cosaw · Posted: Thu Nov 13, 2014 3:56 pm Post subject:

I can't argue with your logic at all barco_75, that's why I agreed with you further up in the post.

If I knew the focus block was just a voltage divider then I'd say the order didn't matter anyway - but I don't know that.

I think Curt is holding out on us just to see where this thread goes. Smile

Come on Curt you've had your fun - what's the definitive answer. Wink

km987654 · Posted: Thu Nov 13, 2014 10:04 pm Post subject:

cosaw · Posted: Fri Nov 14, 2014 10:20 am Post subject:

Thanks for elucidating km987654. It makes sense now - each wire must correspond to each potentiometer on the other side of the block.

km987654 · Posted: Fri Nov 14, 2014 10:36 am Post subject:

Electrostatic focus is carried out by a grid inside the tube. On the focus block of an ES set there is a potentiometer for each color and you adjust those making it a mechanical adjustment. ES tubes loose there ability to focus as hours go up. EM tubes are less likely to loose focus.