CurtPalme.com Home Theater Forum

[Flash]

Been struggling to get my Barco setup for a couple of years now. Purchased it from a specialist who fully rebuilt and reconditioned it, this cost me a small fortune.

Had problems configuring it right from the start, but initially assumed that this was just because I’d never done the raster centring stage before. Started several threads around this over the past couple of years. Turns out that it’s not me being thick though. Have since figured out that the red, and in particular the blue have some sort of ‘issue’.

With the projector properly aligned to the screen, and the green set to the midpoint (49 on a Barco), and a small gap around the edge of the phosphor to take the forbidden zone into account, the image at its widest point almost touches the outside edges of the green raster. There’s a perfect gap around the edge as recommended in the manual and the setup guides on this website.

However, a coarse raster shift to 56 is then needed on the red in order to properly centre that. This is only a little way out, but I understand that having to correct this on a Barco is quite unusual. The blue though... it needs set to 26, which is a fairly extreme setting, and must be putting a lot of strain on the circuitry.

With those settings dialled in, all the rasters are centred and the widest part of the image uses as much of the phosphor as is recommended. I’m then able to do mechanical alignment on the crosshairs, go through the rest of the geometry, and iterate through the convergence, and electronic focusing etc. In the end I achieve a decent picture that fills the screen nicely.

So how do I correct the problem on the red and blue guns? Is there some part of the actual circuitry that I need to adjust manually? Potentiometers perhaps? If so where is this located, and how do I go about making the adjustment?

I can provide photos of the image in the tubes and on the screen if that helps?

[Curt Palme]

There are only V shift pots on the 909, on the vertical board. A lot of strain on the circuitry? Not really, just set it up and it will be fine. It wasn't uncommon on some Barcos for things like keystone or pin to be at close to max settings in some installations, and they worked fine.

[Curt Palme]

There are only V shift pots on the 909, on the vertical board. A lot of strain on the circuitry? Not really, just set it up and it will be fine. It wasn't uncommon on some Barcos for things like keystone or pin to be at close to max settings in some installations, and they worked fine.

[Flash]

Thanks - that’s a relief!