CurtPalme.com Home Theater Forum

[Nashou66]

[mr_ro_co]

[andreas]

god morning! i have opened the housings and picked out the pairs. The color change is from orange/white to yellow/green. Acording to the scedual in the thread from mr steve that would be the static focus wires. Can i conect these to the static focus marquee wires and then do the same for the dynamic focus and so on. Do i even need to mesure the ohms? what i will do is to leave the 6pol wiring anone because the marquee doe not have them.

[andreas]

this must be it then. The ones that coming out of the coil in pairs are nor actually the right pairs then acording to your picture? the static focus must be the white/orange that turns to green/yellow. then there are opne more pair of green/yellow. Then there are two pairs of blue/red that is to be used as well. can i conect them and try if it works and then change if the wiribg is wrong? or would that destroy the PJ?

thanks again

[mr_ro_co]

[Nashou66]

you guys need a LCR meter to measure inductance. I found it invaluable for winding the Barkenstien Coils.

Andreas, doing a little coloring I see in that one pic

nashou

[dvh99]

mike mentioned once some components on the fgm needed another value for these yokes to work properly.
this won`t be necessary if you wind the yokes to get the same inductance as the marquee coils though i`m not 100% sure.

[andreas]

thanks again for the good picture. The red lines are great i can see what is what now. A friend will come later with a multimeter so i can messure that the conections are the right ones. I just bind them together and start to hook all up now.

[andreas]

hehehe, yeh the lion king is the best=) the cables that is left alone, can i just put some tejp over the naked part?

[andreas]

my wiring! i will plug it in and try if it works=) lets hope for a miracle

[andreas]

oh, the cpc magnets sits realy far back! should i cut of some of the plastic on the g-90 yoke to get the magnets more far upwards??

[Nashou66]

What would be ideal would be to find a way to use some Variable control voltage that the Sony's CPC magnets use. I believe the CPC magnets are built into the sony Focus Coil. In the G90 there are no manual adjustments for focus, it is all done via remote.
I Was thinking of some how using the un used portions of the marquee that have a variable remote function for the CPC but there are not enough of them to use, for example, tint,detail, volume etc. Unless a separate amp board with the correct voltages and some sort of remote code could be built to utilize the G90 CPC magnets in the focus coil assembly. Too costly and too much time to do i would think.

you could remove the plastic housing and wrap the magnet structure in Rubber tape. I did that for a barco coil set while i was making changes in the windings. it freed up space for the CPC's.

Athanasios

[andreas]

aha, so the sony yoke can be put on without its housing and just tejp=) i was thinking of cuting the edge of and glue them. like the picture below:

[Nashou66]

You can cut that section off but dont have to glue it. The CPC clamps will hold it in place. Also adding a strip of medical tape length wise on the tube will help hold it in place as you slide it over.

Athanasios

[andreas]

Hello! Ive turned the PJ on and it works, but it does not work that good yet.... one thing is that the picture is leaning. The other and probably more dificult to fix is that the focus is not that good, specially not in the center. The good thing is that i can adjust astig all over the zones as original on the marquee! I figure that the astig conection is the corect then.

if i turn the overall focus up 100 it is defocusing but when ramping under 50 nothing more hapens, its like its out of range for where it would be sharpest. Do you think it has to do with the conections ive made? AND corner focus does not seem to do much. the center focus afects the cornes greatly and the corners are actually the shapest. When doing the rgb focus the range rans out when going down to about 20(same for all colors). now its time to sleep

thanks again for all help ive got from you all!

sorry for posting this in the wrong thread before,its geting late. by the way i did cut that section of so i could get the yokes more close to the tupe face.

[mr_ro_co]

[mr_ro_co]

[Nashou66]

This thread is continued on the frankenyolk thread for topic consistency.

Here are the beginning posts where this one ends:

http://www.curtpalme.com/forum/viewtopic.php?p=340415#340415

Athanasios

[htguy1]

Hi,

So where are we on all this? have people gotten these to work pretty well or is this still a mod in need of reworking?

Thanks

GOd bless...
Mark

[cmjohnson]

Tag, to bring this topic back up to where I can find it easily!


To update this topic, I have decided that the best way to deal with "other" focus yokes in a Marquee is to attempt to
make them more electrically compatible with the Marquee's systems by modifying the electronics to drive them more as they were intended to be driven in their donor projectors.

In some cases this isn't going to be possible. The G90, for example, runs the focus yokes at about double the available voltage on the Marquee focus module. Boosting the supply voltage to the Marquee FGM from 24 to 50 volts would be a huge project.

The Marquee FGM's highest input voltages are +/- 24 volts while the G90 runs its focus boards at +/- 50 volts.

Interestingly, the Barco 909's focus board is fed by only 19 volts. I see not more than 12 volts in the focus generator circuit supplies.

The basic idea for adapting the drive electronics to work with the magnetics is simply this: The Marquee focus system works on a resonant LCR circuit, with the dynamic focus coil being the L in that circuit. Capacitors on the focus board are switched in combinations to provide resonance in the appropriate scan rate frequency range.

In order to use a focus yoke with a different inductance and have it work efficiently, it will be necessary to alter the values
of the switched resonance capacitors on the FGM. But only if the values of the focus yoke coil inductance varies by a significant amount. I'd say that you need a 10 percent difference in coil value in order to have a real need to alter capacitor values to
bring the system back into resonance.


I was glad to find this thread, for many reasons, one of which is that I don't have to open up the magnetic stack in a G90 focus coil to determine what's what. There is always a slight risk of breaking either a ferrite or alnico ring when you attempt to open one up, and I think that doing so can negatively affect the magnetic alignment as well, no matter how carefully you reassembly the parts and line up your witness lines that you (hopefully) applied with a permanent marker.

For connectors, I got the right ones from salvaged wiring harnesses out of a scrapped G90. Short of fabricating all new adapter cables, this is the best way I've come up with to cable up a G90 yoke to the Marquee chassis. Ask Curt or Craig, they might have some extras hanging around.

FYI, the connector type used on the G90 yokes is the JST SM series. I leave identifying the exact parts for you as an exercise for your creativity and resourcefulness. You will need both 5 and 8 contact versions.

The connectors used on all Marquee magnetics cables are Molex KK series. Available at Mouser Electronics.

As for the electronic CPC rings on a G90, those are only driven by DC voltages provided by the 12 channel DC supply on the G90 DF board. Rail voltages are only +/-6 volts.

Actually coming up with a system to drive the G90's electronic CPC rings would be the simplest of any possible project if
you wanted to add functional magnetics to a Marquee that were unique to a different projector. Not saying it would be an afternoon's work, but it's functionally only a dozen variable DC sources at low voltage. It could be done with a DC power supply and a handful of trim pots.

The G90 focus yokes also internally carry their own 4 and 6 pole electronic astigmators. But those require active drive signals.

We can use EITHER ONE with the Marquee, but we can't use both at once as we don't have enough astig outputs.

However, for test purposes, we COULD "borrow" the astig circuit from red or blue and use it to drive the 6 pole circuit, while using the astig from green to drive the 4 pole circuit, which would leave one CRT without astig control of any kind.

So think about that: Green has 4 pole astig, and uses blue's astig circuit to drive the 6 pole astig winding. Red uses its own 4 pole astig circuit, blue, which has the LEAST effect on picture sharpness, runs without electronic astig.

I'll be trying that.