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1031
Joined: 22 Mar 2006
Posts: 657
Location: Finland
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| Posted: Fri Oct 16, 2009 2:13 pm Post subject: |
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| mp20748 wrote: |
Hey, I expect better from you..
I've found several ways to clean up the G2 to the CRT's. I use several HVPS for the R@D. I've already confirmed the benefits of making these changes, and that's why I've put so much into it. It's been on the shelf for awhile with intent to get back to it later. It's one of those things that works very well, BUT, you first would have to clean up the rest of the video chain before you can really see a difference.
As you know, I don't tweak around adding anything unless I know there's a benefit for adding it. Other than the tants and a very few other capacitors, I love using cheap caps. In fact, most of the electrolytics i use are cheap caps. I use them because I've never seen any benefit in using more expensive caps. I've only been able to see the use for more expensive caps in audio tube amps. So, when I'm adding something, believe me that there's a reason for it.
So if i say as i said so many times before that the biggest source for the noise in a marquee is NOT the LVPS. And that's why I only replace the caps on the 85 volts rails (as Scott eluded to previously). And that's why use up to 24 inductors (beads and coils) on my VIM alone. I also add several on the neck boards.
The problem with inductors is finding the right inductor for the frequency (noise) you want to deal with. This is not easy, mainly because when you deal with inductors, they can also create more noise if not within the right range.
Anyway... you're one of the few people I would love to spend a day with here at the MOD factory. So if you're ever here in the states let me know. plus, we have a joint project we need to get back to (what you sent me). I have one more project to wrap up here in the shop, then I'll get back to you and open a thread on my forum, and we'll go from there.. |
Mike. Thing is, that maybe there is language barrier (mostly from my poor english skills) My point was to say that if using inductor place where is no load behind (resistance or capasitance) Like putting inductor to G-2 wire that connects from VNB to tube is not effective way to kill noise, capacitor in same place (between voltage and GND) work then better.
Then what i meant "finding right size cap.." was that if you put too large cap to G-2 line that can lead to situation that when there is need to shut down G-2 line , that cap can made that shut down time too long.
Hmm. Tempting, i have to ask to my girlfriend what she thinks if we change our Italy trip plans to States / MP-Mod factory 
No seriosly. If i have plans to travell to America, of course! But in near future that is not going to happen, but who knows maybe later..
That "project" what i sendet to you is something that has no hurry at all. I dont have any extra time to do modīs right now (too much work to do) I have one idea that is related to that project, but i havent got time to test/develope that more.
_________________
Marquee 9500LC (Frankenyokes / Thomas electric tubes / HD-10L / +many modīs)
DVDO VP-50
New hobby, Rally
http://www.youtube.com/watch?v=vX2Rtpr1njs
http://www.youtube.com/watch?v=6ZP9FEFXV5c
http://www.youtube.com/watch?v=j065vei6j6s
http://www.facebook.com/pages/JTS-Racing-team/204443719572685
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1031
Joined: 22 Mar 2006
Posts: 657
Location: Finland
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Sun Oct 25, 2009 5:41 pm Post subject: |
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| 1031 wrote: | | HK-Steve wrote: |
I have some EMI tape in the mail, will let you know how it goes for shielding.
Cheers
Steve |
Any news ? |
Is this what your looking for?
| HK-Steve wrote: | Athanasios,
You really don't want to know what I have in there, or do you??
Everything has been replaced, the pic is before the last set of mods done on the same day
after it was up and running, the evening and today has been lots of changes.
Like this
dturco,
The HVPS is pretty good for parts not failing, it is more the potted section which give all the trouble.
Having said that, there are certainly many parts which can be upgraded to improve the stability and quality of the output voltages.
Cheers
Steve |
But one thing Jarmo, Steve told me via video chat that the tape began to curl up on some edges so he has to add a layer of some non conductive adhesive sheets or tape over the copper tape. I haven't seen him online to ask if any changes were made. But it couldn't hurt except for maybe the pocket book But this hobby will do that no matter what you do 
Nashou
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Oct 25, 2009 6:44 pm Post subject: |
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| Nashou66 wrote: | | 1031 wrote: | | Current is so minimal there, tube takes only few micro amps . So inductors rating is not critical. |
Drags I confirmed it with HK-Steve last night, it is in the micro amp range. the heater actually uses more.
Athanasios |
oops, you guys have been talking about G2 voltage for 2 pages now and I'm still thinking about the heater voltage, my brain is fried.  I've got a little too much work in October and need a vacation away from circuit boards.
Anyway, here's my little inductor on the heater voltage lines. These fit perfectly and are quick for me with minimal time added since I'm already moving the jumper wires when I replace the caps. Be sure to use the bead only on the right side and form the wire tightly so that the bead doesn't move around and bridge or short some of the solder points to the bead.
For the final filtering, I'm using MP's cap layout but I put in the some dipped Tant's. A ceramic might work better here depending of the frequency of the noise not captured by the bead. I'll have to scope a stock board vs. Tant vs. and Ceramic and post some pics of that. If you use the Tants watch for Polarity, this is where the Ceramic would be nice and one less thing to think about
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Oct 25, 2009 7:53 pm Post subject: |
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| Nashou66 wrote: | | Drags I think a COG ceramic would be the best choice, but make sure COG not X7R those i have read are a bit noisier. Nashou |
I don't see any of the COG's in the compact multi-layered types?
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Sun Oct 25, 2009 8:31 pm Post subject: |
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Finding a 1uf of that type is hard to do so a film type could work too but finding one small enough to fit is the hard part, kemet makes a nice COG type ceramic radial type in a 5% tolerance but they are expensive and I only found the 100nf(.1uf) type for just over 6 bucks each at newark. Data sheet Gold Max
http://www.newark.com/kemet/c350c104j1g5ta/ceramic-multilayer-capacitor/dp/70K9967
And I found a novacap 1uf COG radial but at over 16 bucks i would not try it. I am sure there can be some out there but i never really looked hard for them at that value.
http://www.novacap.com/pdfs/DSCC.pdf
http://www.mouser.com/ProductDetail/Novacap/87106-059/?qs=sGAEpiMZZMuAYrNc52CMZKDVpEeAy%252bs01SVH4yZHg6k%3d
But the COG values from my readings have lower distortion values than X7R types. in SMD styles they are easier to find in the higher vales but in radial at those 1uf and up values they are cost prohibitive , unless you want to use them in your own machine. And the better COG,s would work better on the VNB that gets a bit hotter than other boards. Less drift in value is what you want as temp and frequency rise. I too am still learning a lot about components and there is soo much info and miss information its hard to sift through it all. I guess Scott's comment of "you never know till you try it yourself" is all we can go by some times. Now that I got the Blend set up and all I need to do is tweak it i will start up with experimenting.
Steve and Walter have given me lots of ideas ,info and sparked some of my own theories i'd like to give a shot at.
But i need to set up a test PJ also before i can "play" again. Damn these Marquees and all the fun you can have with them!!!
I should have got an Ampro like Mcgyver and Chip
NOT!!!!!
Athanasios
_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher
"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
One Smart Dog!!!
Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Oct 25, 2009 9:08 pm Post subject: |
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that's expensive, at over $6. each it would add $36. to the cost of one set of VNB's. There's no way my pricing structure will support that. Also, I'm not sure a high end cap is needed here. We're not actually putting the cap into a circuit, simply using it as a filter to pull HF noise to ground right?
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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HK-Steve
Joined: 15 Jul 2006
Posts: 849
Location: Switzerland
TV/Projector: Marquee 9500, Epson 8100
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| Posted: Thu Oct 29, 2009 10:35 am Post subject: |
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Sorry Guy's,
I have had a really busy week.
I will upload some pics, and let you know how the EMI tape is going.
If I can get my scope going again, I will also test how well it shields.
Jarmo, I could send you a roll of EMI tape if you want to play with some.
Cheers
Steve
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HK-Steve
Joined: 15 Jul 2006
Posts: 849
Location: Switzerland
TV/Projector: Marquee 9500, Epson 8100
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| Posted: Thu Oct 29, 2009 11:54 am Post subject: |
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Here are some pics of the tape peeling off.
This would easily short the circuit board once the tape touches it.
So I installed some sound absorbtion over the EMI tape.
Enjoy
Cheers
Steve
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HK-Steve
Joined: 15 Jul 2006
Posts: 849
Location: Switzerland
TV/Projector: Marquee 9500, Epson 8100
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| Posted: Thu Oct 29, 2009 12:02 pm Post subject: |
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All finished.
Cheers
Steve
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1031
Joined: 22 Mar 2006
Posts: 657
Location: Finland
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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GeorgeSong
Joined: 31 Oct 2008
Posts: 74
Location: Canton,China
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| Posted: Thu Oct 29, 2009 1:50 pm Post subject: |
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it's me
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Thu Oct 29, 2009 5:57 pm Post subject: |
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| Nashou66 wrote: | | ,Dragan always said he loved the G70 LC chambers over the Marquee's. Athanasios |
it's the only good part of a G70
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Thu Oct 29, 2009 6:20 pm Post subject: |
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Yea, and those marquee's need all the help they can get.....
Sorry, I had to. You guys opened yourselves up for that one...... 
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HK-Steve
Joined: 15 Jul 2006
Posts: 849
Location: Switzerland
TV/Projector: Marquee 9500, Epson 8100
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| Posted: Thu Oct 29, 2009 8:43 pm Post subject: |
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macgyver655
Don't go there Girlfriend, Hmm Hmmmmmmmmm
Cheers
Steve
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