CurtPalme.com Home Theater Forum

[stefuel]

Scott, have you tried those yokes that I sent you yet?

[nomadII]

TSE,

Great to have your participation!!!

Now have have VDC crank up the assembly lines.

live long & phosphor.

G90 yokes actually sell for less than those of the 1292, but neither seem to be stocked parts.

[AnalogRocks]

[AnalogRocks]

[Nashou66]

I have been looking at some barco yokes but i think they need the static coil rewound. it shows only a value of 1 ohm. and the dynamic coil has the same value when read with a multimeter. here ares some pics and i have posted over on avs too.










Disassembled




these are the values i measured

KF-3203 KOK21
2-4 = 3.5 ohm, stig winding

3-5 = 1 ohm, static focus (whole raster and top/bottom)

6-8 = 3.5 ohm, stig winding

7-9 = 1 ohm, dynamic focus (left/right side)

\Athanasios

[Joust]

Yep. Chris and I tested a set of those on the LCR meter. The Static and dynamic windings are off from what they need to be to work on the Marquee.
Furthermore others have tested them and the magnetics do not have sufficient gauss to focus the beam. I have not tested this. It would be interesting to see if simply rewinding it works. It would also be good to get another independent tester to try those yokes.

[Nashou66]

But i beleive the ones tested had different second set of numbers and a g after the first set. do you think this might make a differance? did you document the measurments so we can compare? On the red winding its 1 ohm which is higher than the stock Thompson's dynamic reading of .5 this number should be enough right?
Also how would you get the magnets to have an increased gauss or is that not possible?

Athanasios

[Joust]

ah. Yeah, its in this thread dude.
but here it is again..
Barco 808s KF-3205 KPK14 (barco#1103910 pj serial number?? )
Pin #
2-4 53.6uH 3.3ohms
3-5 294u H 0.95ohm (750 turns of #34 wire on the static coil will give you good performance.)
6-8 53.6uH 3.3ohms
7-9 294u H 0.95ohm

[Nashou66]

so your saying after i rewind it should work? Or, did you try it and the magnetics were too weak? Also i should then leave the Dynamic coil alone. my readings are close but just a little higher on all. i'll have to wait till the morning to call the electric shop and see what they did or didnt do. maybe they'll sell me some magnet wire and i'll try to wind it myself, so i'll have to wind three layers at 250 winds per layer right?

EDIT: Also would it be possible to build your own magnet array using the existing atig coils, rewound static and dynamic coil and the metal spacers between the magnets with magnets of the proper gauss value? I found a magnet manufature http://www.tscinternational.com/mainferr.html . What are the values of the KF2211 and KF22 22 magnets individualuy if they are all different , I think we would also need to put them in the right order so not to possibley damage the tube as i think it was stated by CMJ somewhere in this thread.


Athanasios

[cmjohnson]

I'm not about to speak out of turn and tell anyone that anyone else WILL do a specific job for you, but TSE does
have access to a fixture that can change the strength of magnetization of those magnet assemblies.

Whether or not he can or will do it for you is entirely NOT my business. You might ask him directly.
But in principle, the concept behind changing the strength of the magnets is pretty simple.
The assembly is placed on a support fixture located at the center of a LARGE toroidal electromagnet,
and it's pulsed from a suitably charged large value capacitor and a switch to dump the charge through the coil.

If the magnet ends up being too strong, it can be weakened by placing it at the center of a large toroidal transformer
hooked to a Variac. Just a little current through the transformer (AC current) will take a little off the magnet's field
strength. Too much will weaken it too much and then it has to go back to the magnetization jig.

CJ

[Joust]

CJ, can you define LARGE?
can this be made? or are you talking specialized equipment similar to a MRI machine?

TSE, any coments? Would you be willing to give it a stab?

[Nashou66]

Joust or CJ is there any way to test each magnet in the franken yoke asembly so i can try to find a similar gauss valued magnet and make my own assembly as a test bed?. also i want to still try the magnet core with out the windings to see if the magnetic feild is strong enough, can this be done without the wireing harness's connected and juts the magnets over the tube neck?

Athanasios

[Joust]

[Nashou66]

[Joust]

Look to see that you can attain the same amount of focus with the KD yoke as you do with the Thompson both without coils plugged in.
Use a grid for that colour you are working with. You could probably get away with using the two yokes on two different colour tubes. this will save a lot of time and allow you to put them both up at the same time.
if you munged the order of the rings you may be pooched on those ones. Thats why CJ advised drawing a large V on them before you separate the rings.

Good luck with that project.
I'm anxious to see the results.

[Nashou66]

I put the v on them after but i think i had them put down on my counter in the right order i did it with in a minute of dismantaling. he test tube i have here looks fairly good so i might just keep the tube in the refrence 8 and test with that one less time removing that tube for this one...hmmm the refrence 8 has only 48 hours on it! not sure now. decisons desicions !

Athanasios

Just noticed your in ontario! how far from Buffalo? maybe we can colaborate onthis project some time in person.?

[Joust]

i'm near Ottawa. About 6 hours from buffalo

[Nashou66]

What type of magnetic material are the magnets made of. I would guess ceramic, but does anyone know what grade 1-8?

Athanasios

[CZ Eddie]

Gotta love that google ad sense.

[Nashou66]

LOL I didnt even notice that ! good one !

[nomadII]

I'm not smart enough to get the punch line. Are all magnets neodynium??