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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Mon Sep 19, 2016 5:37 am Post subject: |
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| Tim in Phoenix wrote: | Guys
Waveforms on test gear are not what matters. The image quality on the screen is what matters. Good luck in your endeavor. |
Yes, but without someone buying my board how could he decide if it looks good on screen or not? Is that enough if I tell it looks good?  It's like selling a sports car, but not telling anything about the engine or performance, only that "it goes fast!"
As for this particular design all efforts waere made in mind with the picture quality, ie. to minimalze the bandwidth loss, to minimalize the induced noise to the signal, to minimalize the induced distortions, etc. But to not just speak in the light air, what I can backup with measurements I do it and share.
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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barclay66
Joined: 27 Jun 2011
Posts: 1304
Location: Germany
TV/Projector: Marquee 9500 Ultra
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| Posted: Mon Sep 19, 2016 12:06 pm Post subject: |
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Come on guys,
Gabor is doing everything he can in order to produce an optimum result. After all, good results on the test bench are a much better basis for the overall success than bad ones, aren't they?
Instead of questioning everything (no improvement, no market, waveforms vs. image quality etc.) we should welcome his endeavor. At least I do...
Gabor: Count me in for at least one set!
Regards,
barclay66
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haireez
Joined: 14 Jun 2007
Posts: 207
Location: singapore
TV/Projector: Vidikron Vision 1 - Ultra
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| Posted: Mon Sep 19, 2016 12:28 pm Post subject: |
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Yes, me too if the results are positive. Looking forward to this and I'm monitoring closely now for any updates.
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2 White Vision 1
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greg9518lc
Joined: 19 Apr 2016
Posts: 360
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| Posted: Mon Sep 19, 2016 7:47 pm Post subject: |
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I will be in for these as well as it is a process
and testing is moving forward there seems
to be some kinks that need to be worked out but
So far these look promising but time will tell. Voldemort
is very picky so these have a ways to go yet to pass
Quality control but the bandwidth and sharpness is there
In spades.
_________________
VDC 9518LC modded: I do not sell or promote mods only interested in the best PQ possible......
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digitalayon
Joined: 02 Mar 2009
Posts: 921
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| Posted: Fri Sep 23, 2016 2:01 pm Post subject: |
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So would these go into general production for orders or would they just be customer mad?
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Fri Sep 23, 2016 5:35 pm Post subject: |
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| digitalayon wrote: | | So would these go into general production for orders or would they just be customer mad? |
Well, generally I aim production for orders, I seriously considered to make all documentation freely available, as I did with my previous XG-VNB project, but I think not many people here are comfortable of building boards with all SMD parts, so they might want to buy the ready-made borad anyway, then why bother with the free version?
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Francisco
Joined: 05 Apr 2007
Posts: 305
Location: The Netherlands
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| Posted: Fri Sep 23, 2016 7:15 pm Post subject: |
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Wow gjaky I admire your efforts. I still have a 909 test machine here which I be willing to try your modifications on like I did with the pre sample Barco HDMI port3 input board. I also can compare it with the Greg Eisemann videochain modifications.
Let me know in PM if you like to discuss.
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Philips vacuum cleaner | Trystar double toaster | Car radio with orange plastic memory arrows | Class A Fridge
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Fri Sep 23, 2016 7:20 pm Post subject: |
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| Francisco wrote: | Wow gjaky I admire your efforts. I still have a 909 test machine here which I be willing to try your modifications on like I did with the pre sample Barco HDMI port3 input board. I also can compare it with the Greg Eisemann videochain modifications.
Let me know in PM if you like to discuss. |
Sure thing, I'm interested in that, but first I want to see the first (presumably happy  ) Marquee-mod owner, then we can move on to the next stage
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Fri Sep 23, 2016 7:20 pm Post subject: |
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I may as well step up to the plate. I've got two closely matched 909s in a stack on my ceiling, so doing instantaneous A/B comparisons between boards is easier for me than anyone else out there. Let me know.
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thewolfman
Joined: 28 Mar 2011
Posts: 1311
Location: Sweden
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| Posted: Fri Sep 23, 2016 8:14 pm Post subject: |
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| cmjohnson wrote: | Some people don't mind if the audience is small, they just like to solve the challenge and create something that they themselves can use.
In what little spare time I have left I'm working on a circuit that allows a complete stack of G90 magnetics to be run in a Marquee.
Actually it's TWO circuits, one is basically a broadband impedance matching transformer between the deflection yoke and the HDM, and the other is a 12 channel control circuit so you can use G90 electronic CPC coils in a Marquee.
I won't make a penny off it. I'll still make at least one set of each. |
Oh, you will make money alright. Trust me on that! Funny thing.. I'm opening up my wallet as speak.
Seriously, I want that bad ass set up in my unit, so prepare to make me another! If, it means you lonaning my entire unit "to dial things in" that wont be a problem.
Talk to MP for details if you want in on this.
I have the 909 + Sony 1292 Frankenyokes.. now I want the Holy grail with the G90 stack.
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cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
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| Posted: Fri Sep 23, 2016 11:12 pm Post subject: |
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I'm waiting for a quote on prototype impedance matching transformers. The manufacturer has been given the specs and the application engineer understands the requirements. I'm just waiting for them right now.
Once I have that working then the CPC driver can get some attention.
Now, as for this gjaky mod, I'm VERY good at soldering surface mount components. The board doesn't have a lot of parts on it and I'm willing in principle to at least TRY building one and if it's not too difficult or time consuming to load the parts on it and solder them, then I would consider taking on the assembly task if it is worth my while.
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nidi
Joined: 17 Aug 2008
Posts: 305
Location: Switzerland
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| Posted: Sat Sep 24, 2016 12:04 am Post subject: count me in |
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I'm in on it as well, have another set ready !!
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cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
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| Posted: Sat Sep 24, 2016 12:38 am Post subject: |
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I suggest you talk to Craig Rounds (CIR Engineering) and reserve a complete set of G90 magnetics if you want a chance at this promising but not yet proven working modification.
I have only my own set.
Or you might get on a waiting list with Curt for when he gets in a parts G90, if he ever does.
Special note: Not only do you want to get the compete magnetics, you ALSO want to specify that you also get the cables that the G90 magnetic's cables attach to. Having that extra cable with the mating connector makes it MUCH easier to adapt the G90 magnetics into the Marquee.
What I do is I turn those extra cables into adapter cables. G90 connectors on one end, Marquee connectors on the other end.
I have the parts to handle the Marquee side, but you or I need to provide the G90 side connectors.
And, this is surprisingly important: In the G90 magnetics, there is a small plastic wedge ring that fits into the front of the focus
yoke. It is often ignored when pulling the magnetics off. You DO want to get those so the focus yoke centers properly without being canted on the tube neck.
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thewolfman
Joined: 28 Mar 2011
Posts: 1311
Location: Sweden
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| Posted: Sat Sep 24, 2016 6:17 am Post subject: |
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I'll ask CIR if he has any G90 when I get around to it.
Last edited by thewolfman on Sat Sep 24, 2016 4:57 pm; edited 1 time in total
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Sat Sep 24, 2016 8:52 am Post subject: |
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| cmjohnson wrote: | Some people don't mind if the audience is small, they just like to solve the challenge and create something that they themselves can use.
In what little spare time I have left I'm working on a circuit that allows a complete stack of G90 magnetics to be run in a Marquee.
Actually it's TWO circuits, one is basically a broadband impedance matching transformer between the deflection yoke and the HDM, and the other is a 12 channel control circuit so you can use G90 electronic CPC coils in a Marquee.
I won't make a penny off it. I'll still make at least one set of each. |
I was quiet on this topic, but in fact I also investigated some of the weaknesses of the HDM.
That impedance converter should have prefectly linear bandwidth in excess of 1MHz, while capable of handling currents up to 10A. This does not sound cheap to me. I think it would be cheaper to convert the HDM to match the G90 coils. It is possible to alter the current limit, or even the DC-DC converter for supply current much easier.
One should check the resonance frequency of the different deflection coils. I one checked a NEC PG xtra deflection coil, that showed resonance frequency over 1.5MHz, that seems to be plenty enough for producing even an 1us rertrace pulse (1us retrace pulse equals to 500kHz frequency). The resonance freqency could indicate if it is indeed the coil which introduces the ringing or not.
The ringing is the effect of the inadequate damping of the retrace pulse, which can be because of poor dampening, or the coil itself is operating near its resonant frequency and is not an ideal coil anymore rather than an LC network. Note, a coil over its resonance frequency become a "capacitor". To find the resonance frequency you need a function generator with 50 Ohm output and an oscilloscope: Put your coil on the output of the generator, feed the coil with sine signal at any convenient output voltage level, and watch the output signal with oscilloscope. The resonance frequency is where the impedance of the coil is the highest, ie, the output voltage is the highest after the 50 Ohm resistor. I never did this with a Marquee coil, but would be interesting to know.
My XG 135 has comparably low retrace times to the Marquee, and I was unable detect any apparent raster ringing with my XG so far, even in the shortest retrace times (1.4us advertised, but the actual blanking time is ~1.7us as I measured). The XG uses the same concept with the H-Deflection as the Marquee, so it has splitted deflection coils and are connected in series / parallel depending on the scan frequency. In the XG each H def coil is 80uH inductance is it act up as either 160uH or 40uH summed. While the Marquee coil is 270uH each(sum 135uH or 540uH). So on one hand interwinding stray capacitance can be an issue with the Marquee coil, that is inherent and can't do much about it.
However on the contrary the Barco 909 has some ugly high inductance deflection coil, that is not even splitted, about 1.5mH, still people not complain about raster ringing, and Barco claims 1.8us retrace time until 90kHz and 1.1us above that, which is actually sounds amazing.
So as I studied the top performer projector's deflection circuit approaches I noticed something which also worth a try.
Around the Horizontal output FETs there needs to be a damping diode to dampen the current spike during retrace (which might end up as raster ringing). In the FETs used for deflection circuits usualy already contain this diode built in the FET, yet every other make than Electrohome used extra external diodes for this damping, often not even one.
As you might know the Marquee HDM employs 3 FETs in series , so the 3 built in diodes are effectively in series as well. In the XG there are 10 FETs (2 parallel group (consisting of 5 FETs) in series) each having their own damper diode, yet 2 further external diodes are used. The G90 has only 2 transistors in parallel, and it uses 8 additional external diodes (!). Barco 909 has 9 FETs in 3x3 series/parallel configuration each having an internal diode but further 7 external diodes are also used. This could be a clue as well.
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
Last edited by gjaky on Sat Sep 24, 2016 10:44 am; edited 1 time in total
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Sat Sep 24, 2016 9:15 am Post subject: |
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| cmjohnson wrote: | | Now, as for this gjaky mod, I'm VERY good at soldering surface mount components. The board doesn't have a lot of parts on it and I'm willing in principle to at least TRY building one and if it's not too difficult or time consuming to load the parts on it and solder them, then I would consider taking on the assembly task if it is worth my while. |
I understand that but if I let away my idea for free, the others are "welcome" to copy it and make money of it instead me.
Otherwise Perhaps I can loan a board for you if you are that interested in testing.
My concern is that you are looking for repoduce my boards for your 6 Marquees, that you could sell easier then. So I give away my intellectual property for free and you gain on YOUR sellings, great, let's do this, this is what I always dreamt of! NO! 
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
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| Posted: Sat Sep 24, 2016 2:38 pm Post subject: |
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No, I'm suggesting that I might be able to be your HIRED ASSEMBLER. Nothing more.
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Sat Sep 24, 2016 3:11 pm Post subject: |
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| cmjohnson wrote: | | No, I'm suggesting that I might be able to be your HIRED ASSEMBLER. Nothing more. |
For 100USD you can have a set of blank PCBs and the parts list, and you source the parts for yourself, I think that's a fair offer.
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Sat Sep 24, 2016 3:23 pm Post subject: |
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Why not also consider selling a kit? I'd think that the labor is going to be as much, or more than the cost of the parts (depending on quantity of course). Those of us good at soldering would probably have fun assembling it.. HEATHKIT LIVES AGAIN!
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greg9518lc
Joined: 19 Apr 2016
Posts: 360
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| Posted: Sat Sep 24, 2016 3:38 pm Post subject: |
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| gjaky wrote: | | cmjohnson wrote: | | Now, as for this gjaky mod, I'm VERY good at soldering surface mount components. The board doesn't have a lot of parts on it and I'm willing in principle to at least TRY building one and if it's not too difficult or time consuming to load the parts on it and solder them, then I would consider taking on the assembly task if it is worth my while. |
I understand that but if I let away my idea for free, the others are "welcome" to copy it and make money of it instead me.
Otherwise Perhaps I can loan a board for you if you are that interested in testing.
My concern is that you are looking for repoduce my boards for your 6 Marquees, that you could sell easier then. So I give away my intellectual property for free and you gain on YOUR sellings, great, let's do this, this is what I always dreamt of! NO! |
Yes Gijaky you can have my money. The frankenyokes will not help with linearity and in fact the VDC neck boards focus
razor sharp so the reason for this project is? The new vim also improves on the focus and linearity.
The raster ringing can be pushed out according to Voldermort with a simple
mod so there is no reason to go down that path. This would be shared if he was
a member of the community as well as other developments that have come to light this past year for the Marquee.
These new mods will be installed in my 9500LC on October 15th-17th. We have decided to hold off on the meet until
the Gijaky mods are finalized so looks like spring next year best case scenario. I think Voldermort plans on stopping
at MP's the 12th to work out there differences so indeed the future looks promising............... 
_________________
VDC 9518LC modded: I do not sell or promote mods only interested in the best PQ possible......
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