CurtPalme.com Home Theater Forum

madpoet · Joined: 30 Mar 2006 Posts: 851

Ok Lyckman, now you have me interested from your AVS post. Can you give more details on the custom wiring harnass? I hope your magnet experiments are still going well!

Lyckman · Joined: 09 Nov 2006 Posts: 66 Location: Gothenburg, Sweden

Ok, Harness details..

The harness is 8 wires total. 4 goes to the focus board and the other 4 to the stigmator board. I bought connectors from molex for this. 6 circuits for the harness going to the focus board (but only 4 is used). 4 circuits for the one going to the stigmator board:

http://www.elfa.se/pdf/43/04381299.pdf
I bought them from the swedish retailer Elfa (www.elfa.se), order number:
43-813-64 (6 circuits) (x3)
43-813-15 (4 circuits) (x3)
43-814-97 (Contact elements) (x24)

The contact element is of crimp-type, and I had the tool for that allready. If you aint got the tool available, you =can= use a small plier and trust in your patience... Wink

I have not found a "perfect" connector for the yoke, but I found one that works pretty well:

http://www.elfa.se/pdf/43/04386017.pdf
Elfa order no: 43-841-60

The yoke has 9 pins. Only 8 are used though, and the store was out of 9-pins so I got the 8-pin. It fits quite good and stays in place.

I had to buy the tool for wire attachement to this connector. It's a pretty simple tool, and you could manufacture one if you have a dremeltool or similar available. I bought: 43-851-67 (Elfa order no)

My pictures earlier in this thred shows the harness installed.

Best of luck! Smile

// Lyckman

Joust · Posted: Thu Mar 29, 2007 6:58 pm Post subject:

**AnalogRocks** · Posted: Fri Mar 30, 2007 12:22 am Post subject:

Ohhh the toys.

madpoet · Joined: 30 Mar 2006 Posts: 851

We just need a soluton for the magnets issue so we can get centering...

Joust · Posted: Fri Mar 30, 2007 1:09 am Post subject:

does it fit so tight that shims won't do anything?

So looking back in the post we need 750 turns on one winding measring ~30mH
how many turns on the other one to gove ~5mH? math makes it about 125 turns. is that what they are in practice?

nuttall_chris · Posted: Fri Mar 30, 2007 11:46 am Post subject:

Joust · Posted: Fri Mar 30, 2007 1:52 pm Post subject:

Lyckman says the Barco yoke does not ahve enough gauss to static focus the beam at all.
So it looks like i won't even be able to rewind these to be useful.

So in sumary on the Barco yokes.

UPDATE:
Barco yokes KF-3203G KOH16 and from 808 have inductance readings of 290uH and 41uH
KF-3205 KPK14 from 808s have inductance readings of 252uH and 53uH
These readings are 100 times less inductance than required and teh Gauss is too low to make the magnetics usefull.

Lyckman · Joined: 09 Nov 2006 Posts: 66 Location: Gothenburg, Sweden

I don't know about the gauss of the "KF-3205 KPK14" yokes. Have not tried them. May or may not work. Still, if the windings are to small, the dynamic focus wont work properly... If you want to know if it's usable. Try em on and determine if you can get static focus. If that's the case, it might be worth the trouble to rewind the coils.

The 3203 yokes showed them self unsufficient to give static focus. My impression was that the gauss was to low, but thinking about it... might it be the other way around, eg to much gauss? My knowledge in CRT is not enough to determine which, and unfortunately I have no instrument to measure gauss...

Joust · Posted: Fri Mar 30, 2007 5:14 pm Post subject:

OK Chris Nuttal and I just spent an hour in the lab and measured several focus yokes. We found some interesting data.

Coil readings (all measurements made @ 1khz):

Thompson from an 8500
Static Black – Red 29.9mH 58.5 ohms
Dynamic Yellow – Org 45.6uH 0.38ohms
Astig White – Violet 156uH 6.2ohms
Astig Grey – Blue 156uH 6.2ohms

Thompson from an 8000
Static Black – Red 28.7mH 58.5 ohms
Dynamic Yellow – Org 45.6uH 0.38ohms

Sony KEO23 sony # 1-452-811-11 (K22-22 ??) Tested in marquee as a Frankenyoke
Pin #
2-4 Astig Winding 52.6uH 3.494ohms
3-5 Static Focus 14.9mH 56ohm
6-8 Astig Winding 52.4uH 3.5ohms
7-9 Dynamic Focus 40uH 0.29ohms

Got a new set of yokes. they have slightly different marking but are essentially the same. confirmed with test equipment.
Sony KQE26 sony # 1-452-811-11 From a 1292 (22-22 ??) Tested in marquee as a Frankenyoke
Pin #
2-4 Astig Winding 53.8uH 3.46ohms
3-5 Static Focus 14.75mH 56.4ohm
6-8 Astig Winding 53.6uH 3.45ohms
7-9 Dynamic Focus 41uH 0.38ohms

Sony K2211 from ??
Pin #
1-2 Static Focus 25mH 69ohms
3-4 Dynamic Focus 51uH 0.22ohms

Barco 808s KF-3205 KPK14 (barco#1103910 pj serial number?? )
Pin #
2-4 53.6uH 3.3ohms
3-5 294u H 0.95ohm
6-8 53.6uH 3.3ohms
7-9 294u H 0.95ohm

Its curious that the Barco has like coils for the static focus and it seems both Sony and Electrohome use dissimilar coils. One very high inductance and one low. The Astig windings always seem the same.
So, presumably i can simply rewind the one coil with CJ's recommended 740 turns of 34ga wire and get up in the mH range. Would having the lower static coil with 5 times higher inducatance cause a problem? Probably easy to pull off windings.

nuttall_chris · Posted: Fri Mar 30, 2007 5:23 pm Post subject:

Barry, I have updated your info with Static/Dynamic/Astig info for all except your Barco KF-3205 KPK14

Thompson from an 8500
Black – Red Static Focus 29.9mH 58.5 ohms
Yellow – Org Dynamic Focus 45.6uH 0.38ohms
White – Violet Astig Winding 156uH 6.2ohms
Grey – Blue Astig Winding 156uH 6.2ohms

Thompson from an 8000
Black – Red Static Focus 28.7mH 58.5 ohms
Yellow – Org Dynamic Focus 45.6uH 0.38ohms

Sony KEO23 sony # 1-452-811-11 From a 1292 (22-22 ??) Tested as a Frankenyoke
Pin #
2-4 Astig Winding 52.6uH 3.494ohms
3-5 Static Focus 14.9mH 56ohm
6-8 Astig Winding 52.4uH 3.5ohms
7-9 Dynamic Focus 40uH 0.29ohms

Sony K2211 from ??
Pin #
1-2 Static Focus 25mH 69ohms
3-4 Dynamic Focus 51uH 0.22ohms

Barco KF-3205 KPK14 From a Barco 808s
Pin #
2-4 53.6uH 3.3ohms
3-5 294u H 0.95ohm
6-8 53.6uH 3.3ohms
7-9 294u H 0.95ohm

Chris.

dc_pilgrim · Joined: 31 Oct 2006 Posts: 225 Location: PA

The barco were from a barco graphics 808S.

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

The static coil's inductance is considerably less important than that of the dynamic windings. It's the dynamic focus system on the Marquee that works in resonance, to keep the power requirements down. If the dynamic coils are too far out of spec, the
focus amps may overheat and die.

There's a wide range of usable values for the static focus yoke but it is best to have an approximate match to the values found in a Thomson yoke from a Marquee.

Magnetic field strength is also important. Ideally, you want focus to be perfect with both the user and service focus at 50. If you have some decent ability to adjust focus, your inductance values are workable. If the range of focus is centered
around 50, your magnetic strength is about right. If the focus range is pushed well
toward one end of the range or the other, then odds are that the magnets are not
close enough to the right strength. They can be adjusted with the right equipment.
PM me for details if this is necessary. I can't just tell you that I can do it for you,
as it requires help and cooperation from someone else...someone who has not as
of this time agreed to regauss focus coils for everyone.

CJ

CJ

Joust · Posted: Sat Mar 31, 2007 3:54 am Post subject:

Not sure i follow you CJ.
would you try to rewind a coil on that Barco yoke? or are you saying the magnetics are out of whack?

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Both are important. If the focus doesn't work properly, it's a question of not being able to change the focus by large enough amounts, or it's a question of WHERE on the numerical scale it focuses.

Magnetic field strength specs for a Marquee (depending on the model) are roughly in the 275 to 294 gauss in the central coil. I've had good Frankenyokes (mark I) work well with 253 gauss measured but a higher
field strength would have moved the point of optimal focus closer to 50.

You may not be able to measure or adjust the magnetic strength of your
focus magnetics, but you CAN control some aspects regarding the field
coils themselves. And 750 turns of no. 34 wire seemed to put the STATIC
coil's inductance value right where I wanted it in a test case FY II.

CJ

Joust · Posted: Sat Mar 31, 2007 5:52 pm Post subject:

CJ,
how do you get the magnetics appart. do you use some kind of solvent?

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

A gentle tap with a wooden mallet works. GENTLY. Tap SIDEWAYS across the stack of
magnet parts to shear the glue.

Before you do this, take a permanent marker and make a V across ALL the magnetic
components so that you can reassemble them in the correct order.

CJ

Joust · Posted: Sun Apr 01, 2007 12:16 am Post subject:

ok.
I've broken Ferrite before. Embarassed

I'll be careful

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Give it a twist by hand, first. Or insert a razor blade between the pieces and tap gently
with a small hammer. The razor blade method is probably the safest, that is, if you don't cut yourself. And be careful not to cut any wires.

CJ

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central

So, how many people would be upset that I just threw away a 1292 tube with mags last week? Smile