CurtPalme.com Home Theater Forum

tse · Joined: 03 May 2006 Posts: 1005 Location: Sweatbucket, Fl.

Posted: Thu Nov 13, 2008 3:49 pm Post subject:

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"Hey Scott is possible to make one of those? it looks like a transformer coil powered by a variable transformer?

Athanasios
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Crt's rule! I love this new Obsession!

Marquee Modifications and Performance Enhancement

Marquee Stuff"

I started a new thread with this.

If you can get a torroid transformer/coil big enough it wouldn't be too hard to do. A variac connected to the coil will produce an AC magnetic field which will lower the gauss. To increase gauss one must produce a high current DC pulse through the coil. It is easy enough to charge some large caps (a few 1000uF) to 200-300V and discharge through the coil. A gauss probe is very helpful when doing this.

Scott

Nashou66 · Posted: Fri Nov 14, 2008 1:06 am Post subject:

Ok I see so you would need a DC variable power supply to get up to 200-300 VDC or could it be a fixed rate one?
Then you would put a few high voltage and high uf caps in series or parallel ?
These would be charged up and then released in pulses through the coil?
How long and how do you create the pulses, and for what duration should the focus magnet be in the coil for?
And finally how are the caps connected to, i guess, the pulse generator and then to the coil?

Very Happy

Athanasios

**Curt Palme** · Posted: Fri Nov 14, 2008 1:18 am Post subject:

THat picture is truly of the bench of a mad scientist! Very Happy

Nashou66 · Posted: Thu Feb 04, 2010 1:58 am Post subject:

This is Bumped for Chris Johnson to see, he wants to build a gauss rig for the marquee magnets.

Athanasios

cmjohnson · Joined: 03 Apr 2006 Posts: 1677

I've seen that rig before. At VDC. Scott showed it to me. He adjusted a few coils and I observed the process.

I'm building my own version of this. It's a bit smaller but will take a K-D focus magnet system with the shell removed. It's too small for
a Thomson yoke, unfortunately.

I also have obtained some of the specs for the pictured magnetizing rig so I know what inductance values to shoot for.

This is in support of my effort to create optimized K-D yokes for Marquees, which shall be called Advanced FrankenYokes.

CJ

Nashou66 · Posted: Thu Feb 04, 2010 3:54 am Post subject:

I was going to make one of these too to bring up the gauss to the same as the barco 1208 coils which are the same stregnth as the stock Marquee's. the Sony 1292 coils are not as strong I found from my testing. I have one wound to marquee specs but I want to try a slightly thicker wire for the dynamic coils where it matters more to have less resistance which will allow the Dynamic focus amps to run cooler.

Athanasios

Nashou66 · Posted: Fri Feb 05, 2010 2:50 am Post subject:

Hi Guy's I wish I had one of these now. I just finished the HV lead repair and found the boot had a hole in it causing the HV to arc out. A few wraps of rubber tape cured that for my test tube. Now back to the magnetizing rig, the first Thompson Coil I hooked up was not focusing in the corners or for that matter over all with no electronics. Sure enough a weak magnet, i tried another one and much better static focus. I need to either buy a large coil and make my own rig or rush Chris into finishing his.

My Barkenstien coil I also tested and it works pretty good, but i still think I might have a bad focus board. the edges dont work as well , but it might be a backwards wired dynamic or static coil. More testing needed.

Chris let me know when you have your rig ready to go i can send you some 1292 coils and some barcos. I think if we go just a few gauss stronger it might work better.

I think you'd need a gauss meter , then test some thompson coils on the tube and find the one with the best static focus, measure that and set up the rig to increase the gauss just till you get perfect focus with no electronics.

Athanasios

cmjohnson · Joined: 03 Apr 2006 Posts: 1677

One thing I'd like to lay my hands on is a Marquee test chassis. I've got a worn green 9" tube I can use for testing, in the LC housing,
but I don't have a spare chassis.

All I need is the lower deck assembly, focus and deflection boards, and rear heat sink assembly. It's easily shippable via UPS,
especially if you ship the heat sink assembly separately.

If anyone has an 8500 chassis that they're not going to retube, that'd be perfect.

With a test chassis, I'd be able to get rolling on testing and adjusting new yokes pretty quickly.

If I had THREE total LC assemblies, I could actually do a full setup that takes the magnetic interaction between focus coils into account.

I don't even need tubes. I have enough 9" tubes lying around that'll light up and could be used for testing, and I can install them in the
LC assemblies easily enough.

Or, heck, just use 8" tubes. It's even easier.

CJ

CJ

Nashou66 · Posted: Sat Feb 06, 2010 4:35 am Post subject:

CJ thinking out loud Wink

I ordered that 16 gauge magnet wire for the dynamic coil Chris, I think it will work out well, one more thng i noticed in my test Chassis, it has a 34KV HVPS. I think that might be part of my focus issue with the Barkenstien Coils along with the excessive DCR of the dynamic coil.

I have spare Chassis (8000) with only the rear heat sink, not the other boards.

Athanasios

cmjohnson · Joined: 03 Apr 2006 Posts: 1677

I think I have a usable HDM and I certainly have a usable focus board. If the chassis is the hinged rear heat sink variety,
this will probably work well for me. PM me and let's see if we can make a deal.

CJ

Nashou66 · Posted: Sat Feb 06, 2010 4:44 am Post subject:

cmjohnson · Joined: 03 Apr 2006 Posts: 1677

I have an LVPS that's good but no HVPS. But I can score one.

Expect a PM tomorrow.