Return to the CurtPalme.com main site CurtPalme.com Home Theater Forum
A forum with a sense of fun and community for Home Theater enthusiasts!
Products for Sale ] [ FAQ: Hooking it all up ] [ CRT Primer/FAQ ] [ Best/Worst CRT Projectors List ] [ Setup Tips & Manuals ] [ Advanced Procedures ] [ Newsletters ]

 
Forum FAQForum FAQ   SearchSearch   MemberlistMemberlist  Photo AlbumsPhoto Albums  RegisterRegister 
 MembershipClub Membership   ProfileProfile   Private MessagesPrivate Messages   Log inLog in 
Blu-ray disc release list and must-have titles. Buy the latest and best Blu-ray titles to show off in your home theater!

THE MOD
Goto page 1, 2, 3, 4, 5, 6, 7  Next
 
Post new topic   Reply to topic   Printer-friendly view    CurtPalme.com Forum Index -> CRT Projectors
View previous topic :: View next topic  
Author Message
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Tue Aug 09, 2016 9:38 pm    Post subject: THE MOD Reply with quote


        Register to remove this ad. It's free!
After finishing the XG-VNB project I wanted to utilize the experience I gained with that, in a way that is more usable to the community...
So I made what I already said once:
A daughter board for the Electrohome VNB that completely bypasses the VIM's high frequency part. This alone would not worth to make it, the mod cures the VIM's weakest link: how the OSD signal is injected.

Unlike the original design this board does not use any series switching element in the signal path, still OSD injection and input blanking is carried out, with the least intervention to the input signal, all this with the best possible decoupling between the input signal and the OSD source. No needless amplifiers, and switchers in the signal path, the shortest, cleanest signal path possible.

Each board has an own local +/-5V supply that feeds the whole neckboard too. The most sensitive circuits on the VNB are fed from these supply lines.

For the blue tube a new experimental gamma circuit was also developed, again without adding a series element to the signal path (unlike to the original VIM design), so the signal path is equally "long" on all colours while the blue has gamma correction.

Interesting days are coming...



Mod_complete_1_rs.jpg
 Description:
 Filesize:  324.67 KB
 Viewed:  4764 Time(s)

Mod_complete_1_rs.jpg



_________________
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


Last edited by gjaky on Fri Jul 06, 2018 6:41 pm; edited 2 times in total
Back to top
View user's photo album (1 photos)
greg9518lc



Joined: 19 Apr 2016
Posts: 360



PostLink    Posted: Wed Aug 17, 2016 3:06 pm    Post subject: Reply with quote

Nice to see these are moving forward and the testing phase will soon
begin. Gjaky it will be interesting to see as this project moves forward
and a new line of mods is made available for Marquee and Barco owners.
What do think the biggest challenges will be moving forward?

_________________
VDC 9518LC modded: I do not sell or promote mods only interested in the best PQ possible......
Back to top
htguy1



Joined: 30 Jul 2008
Posts: 99



PostLink    Posted: Fri Oct 28, 2016 3:09 am    Post subject: Reply with quote

I look forward to seeing how this works out!
Back to top
greg9518lc



Joined: 19 Apr 2016
Posts: 360



PostLink    Posted: Sun Nov 06, 2016 5:24 am    Post subject: Reply with quote

Nice to hear your work is moving forward. I hear your direct gain solution has tons of potential and will further advance the Marquee to another level previous never seen before. Please update on your progress.
_________________
VDC 9518LC modded: I do not sell or promote mods only interested in the best PQ possible......
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Sat Nov 19, 2016 8:23 am    Post subject: Reply with quote

I now decided to let you know more about the details of the design. I share now the principle of operation along with the schematic drawings, although I won't share the PCB design.

So this design still uses the good old AD835, but in an unusual application. The whole thing is centralized around the fact that the AD835 has an output function of W=X*Y+Z (the AD834 don't have the "+Z" input).
The video input is directly tied to the input Y, the contrast signal is fed to input X, at input X there is an analog switch, that can toggle between the contrast voltage (normal operation) and the ground (blanking the input). Then there is the Z input where again there is an analog switch, that is toggled between the OSD/testpattern signal source and the ground.

-During normal video, the contrast voltage is fed to X and Z is grounded. so the OSD/testpattern is bypassed. The analog switch might have a crosstalk, but even then it is conducted down to the ground through its Rds(on), so in fact a quite good rejection is achieved this way. The output therefore is: W=Y*X+0
-When OSD/test pattern mode is on the X input is grounded (aka. muted video input) but the Z (OSD) signal is let through ie. W=Y*0+Z.
-During blanking the Marquee switches back to OSD source and injects blacker than black level through the Z input (OSD)

The AD835 when properly used has about -60dB rejection to the input signal when it is multiplied with 0, on the other hand the dynamic range of each color is only 48dB (as it has 8bit resolution)

However in this way the OSD/test pattern is not affected by the contrast setting, and makes the built in stair step pattern meaningless, but I don't think this would be a real problem.

So all needed feature was done only by playing around the AD835, but nothing was put in the video path, only the AD835, but you can't omit that, since some sort of contrast controlling is needed anyway...

The AD835 is slew rate limited by the first hand, that means high output voltage cost a lot of bandwidth, on the original 02p VIM therefore the output was not even properly terminated for the 75Ohm transmission line, still about 25% signal loss occuring on the coax cable through the VNB. By putting this small board right at the VNB you gain this 25% signal level (that translates to bandwidth overhead), and the input level requirement is still the same.

With this circuit I measured around 1,5ns rise/fall times at 0.7V output (1 pixel at 1080p 72Hz is 5ns wide) which is still plenty fast.

There is a separate low noise +/-5V power supply for each board that also feed the adjacent VNB's +/-5V line too.

The gamma correction is also "interesting" for the blue. With these multipliers used in CRT applications it is often overlooked that all inputs are actually high bandwidth capable, So unlike to the VIM the gamma is not added to the output signal as a serial element.
The input signal is monitored (before contrast control) and is fed to a high speed difference amplifier whether the input is higher or lower than the threshold and this simply modulates the contrast voltage, even if it is only one pixel wide. Again, the AD835's all input is high speed capable.
This gamma circuit is a so called ECL inverter with emitter degeneration. It is tuned such way that if the input voltage is larger that the threshold level it produces a (linearly) proportional output voltage, depending how much the difference is between the input and the threshold. This voltage modulates the actual contrast voltage and yield a square-like mathematical function (see simulations) -gamma curve.


This thing is basically working, let's talk about the problems then: The Marquee is a damn huge noise generator. Putting the VNB-DB on a VNB in a bare stock machine will make a lot of running "sparks" appear on the screen. A noise that is picked up by the daughterboard (interestingly in the NEC XG I had no such problem with a similar setup). Better grounding / shielding does not help. The noise is coming from two sources as it turned out, once it comes from the HDM's scan regulator supply (later ULTRA HDMs came with proper filtering for that rev. 8 or newer I think). The other source is the LVPS, especially the standby section (that generates the filament voltage as well). I could lower the LVPS noise wit hadding LC filtering, but the noise is still not completely gone, and I am currently working on the ultimate solution here.

The main reason why I revealed these things is to help others (who are technical minded enough) to mate this design with other top projectors like Barco 909, or Sony G90 -as I don't have any of these machines. A marquee VNB paired with my daughterboard result in a complete video block, only the interfacing have to be solved for other machines (and the power requirements of course).

Is it now OK to build a board for personal use (not for resale), also as I said I won't give away PCB designs, so either you have to invest your time in the PCB design, or buy a set of blank PCB from me at 30USD. I'll still undertake making complete board / modsets, once the power supply issue is fully sorted out.

Later I'll share what modifications are needed on the VIM, HDM (and LVPS once finalized).



gamma_sym.jpg
 Description:
Gamma simulation. Note the curves are largely exaggerated, but they show the actual behavior
 Filesize:  39.51 KB
 Viewed:  12385 Time(s)

gamma_sym.jpg



VNB_DB_V3a.pdf
 Description:
VNB-DB schematics

Download
 Filename:  VNB_DB_V3a.pdf
 Filesize:  27.41 KB
 Downloaded:  260 Time(s)


_________________
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
Back to top
View user's photo album (1 photos)
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Sun Dec 04, 2016 10:19 pm    Post subject: Reply with quote

The first preproduction boards (those are not considered as prototype) are already heading to their new owner, I am curious to hear some feedback Smile
_________________
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
Back to top
View user's photo album (1 photos)
racerxnet



Joined: 20 Jun 2007
Posts: 362
Location: Illinois


PostLink    Posted: Mon Dec 05, 2016 4:50 pm    Post subject: Reply with quote

gjaky wrote:
The first preproduction boards (those are not considered as prototype) are already heading to their new owner, I am curious to hear some feedback Smile


Who is the new owner? It sounded like the rights to the mod were sold to someone who is not allowed on this forum? How many projectors are these installed on? Also to note is the animosity of a couple people, who continue to post inflammatory statements on another web site. Do you really think that those statements will help sell your mods? I'd swear they are really foolish to think others will follow their path. Just saying!

I hope the mods work really well and benefit others. You would be better off keeping the troublesome couple from selling your upgrade.

MAK
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Mon Dec 05, 2016 6:12 pm    Post subject: Reply with quote

A little background story: I had the basic concept of this mod in my head for a while, but I am mainly a NEC guy, and don't use a Marquee for main projector anymore. I even revealed my idea coarsly here quite while ago, and got an offer from cmjohnson so we could work together: I design the board, and he would arrange the manufacturing and share the money somehow -I rejected this offer. Then I told the idea to that someone who is not allowed to post on this forum, and he encouraged me to bring this thing alive, in fact he made me find an alternative solution for the blue gamma correction -but we didn't agree anything financially. He has a set of boards (as a gift), but those are of a prototype version, and not everything is perfect on them as of yet, I don't think he is using them at the moment...

The second set was supposed to be sold someone else here on this forum, but because of various reasons this did not work out. In the meantime I think more than 90% of the problems got worked out, so I literally gave away this second set of boards to Barclay66, who actually helped me with chasing down the needed HDM modifications. Barclay also has a good understanding to electronics, so I guess if he finds some more problems we can work out those effectively...

So far I did not make a single penny with these mods.

I did not ask anyone to form opinion on my work, nor to form opinion on Mike's mods -I already was queried regarding this...


I try to stand on my own legs. I made the boards in a way so they could find their way (theoretically) to any high end CRT projector (like Sony G90 or Barco 909). I understand that not many people are planning to spend money on CRT projection, and for Marquee MP has already well established name, that's why I wanted to make something that is "universal".

I am sort of playing with open cards as I already shared the schematic diagrams and full theory behind my mods (Nor MP, nor Greg Eisemann does this). As I compete with their mods (mostly with MP's at the moment) it also means this is an alternative for those who estranged by their mods for some reason, but I can't control (either way) what others say...

_________________
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
Back to top
View user's photo album (1 photos)
racerxnet



Joined: 20 Jun 2007
Posts: 362
Location: Illinois


PostLink    Posted: Mon Dec 05, 2016 6:19 pm    Post subject: Reply with quote

Thank You for the kind and considerate reply. I hope to see the results soon.

MAK
Back to top
jbmeyer13



Joined: 03 Dec 2010
Posts: 1131



PostLink    Posted: Tue Dec 06, 2016 9:00 pm    Post subject: Reply with quote

gjaky wrote:
A little background story: I had the basic concept of this mod in my head for a while, but I am mainly a NEC guy, and don't use a Marquee for main projector anymore. I even revealed my idea coarsly here quite while ago, and got an offer from cmjohnson so we could work together: I design the board, and he would arrange the manufacturing and share the money somehow -I rejected this offer. Then I told the idea to that someone who is not allowed to post on this forum, and he encouraged me to bring this thing alive, in fact he made me find an alternative solution for the blue gamma correction -but we didn't agree anything financially. He has a set of boards (as a gift), but those are of a prototype version, and not everything is perfect on them as of yet, I don't think he is using them at the moment...

The second set was supposed to be sold someone else here on this forum, but because of various reasons this did not work out. In the meantime I think more than 90% of the problems got worked out, so I literally gave away this second set of boards to Barclay66, who actually helped me with chasing down the needed HDM modifications. Barclay also has a good understanding to electronics, so I guess if he finds some more problems we can work out those effectively...

So far I did not make a single penny with these mods.

I did not ask anyone to form opinion on my work, nor to form opinion on Mike's mods -I already was queried regarding this...


I try to stand on my own legs. I made the boards in a way so they could find their way (theoretically) to any high end CRT projector (like Sony G90 or Barco 909). I understand that not many people are planning to spend money on CRT projection, and for Marquee MP has already well established name, that's why I wanted to make something that is "universal".

I am sort of playing with open cards as I already shared the schematic diagrams and full theory behind my mods (Nor MP, nor Greg Eisemann does this). As I compete with their mods (mostly with MP's at the moment) it also means this is an alternative for those who estranged by their mods for some reason, but I can't control (either way) what others say...


Gabor- this has been great work thus far; don't listen to anyone who says otherwise. Its this type of thinking (and efforts) that keeps innovation alive in a very small hobby. Keep up the promising work Thumbs Up

_________________
Projector: Modded 9501LC ULtra- MP VIM, Vold VNB, ETECH LVPS, Silver VIM Cables, HD10F's & a V1 case!
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Wed Dec 07, 2016 8:07 pm    Post subject: Reply with quote

Thank you guys for the kind words! Thumbs Up
_________________
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
Back to top
View user's photo album (1 photos)
draganm



Joined: 08 Mar 2006
Posts: 8761
Location: Colorado


PostLink    Posted: Thu Dec 15, 2016 6:15 pm    Post subject: Reply with quote

congrats on the brilliant circuit design.

One question, if this is a daughter board for the VNB, how are you getting the video signal to the board (I don't see a coaxial jack on your PCB)

or, are you adding these onto the VIM actually? It seems more likely they go on the VIM since that is where you need ot remove the OSD problem right?

if it's on the VIM, then where is the ribbon cable coming from for J2?

Sorry for all the questions, but the pic of the boards doesn't tell the whole story Smile if it's proprietary, that's ok too

_________________
MARQUEE HD MODS: Bring your Marquee CRT projector (or clone) back up to spec and offer even greater performance!
Back to top
View user's photo album (2 photos)
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Fri Dec 16, 2016 5:43 pm    Post subject: Reply with quote

The boards are daughterboards for (each) VNB actually. The pictured boards were not fully finished when they were photographed. The input is J4 which is indeed not a coaxial connector, I considered using 75Ohm MCX connectors as well, but they pump up the cost, and I don't feel they give much in return. I know the simple pin headed connector is not the Holy-Grail for video signals but it just simply works.
For that matter the Moome card on the VIM also using commercial multipin connector, furthermore the standard 02p VIM does not even back terminate properly the coax cable between the VIM and VNB.
The input of this daughterboard is connected to either the input BNC connector directly or the the Moome card's output directly with a coaxial cable (so the video signal actually jumps through the VIM entirely), this can be done without penalty since the input is already properly double terminated, so in fact it does not matter if it is only 2cm PCB trace or 30cm coaxial cable.

For J2 a "new" cable comes from the VIM, on the VIM a passive PCB is added that collects all the needed signals (contrast voltage, the OSD signal, OSD/source control signal).

I rather decided to give a long run for the OSD signal (which is not critical) rather than slicing up the video stage as it is with the conventional VIM-VNB setups (which includes the MP mods as well).
Slicing up the video stage means you need a terminated coax cable inbetween that cuts you gain half (if it is terminated properly) As I said the VIM is not terminated properly, so the gain loss is only ~25% but in return there are reflections. With my solution this step is completely omitted, which pays back as bandwidth overhead, as the AD835 looses its bandwidth the most with high output voltage.
I hope my answer was well detailed Smile

_________________
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
Back to top
View user's photo album (1 photos)
mp20748



Joined: 12 Sep 2006
Posts: 5358
Location: Maryland

TV/Projector: 9500LC Ultra / Super 02 and 03 VIM


PostLink    Posted: Sat Dec 17, 2016 1:07 am    Post subject: Reply with quote

gjaky wrote:


I rather decided to give a long run for the OSD signal (which is not critical) rather than slicing up the video stage as it is with the conventional VIM-VNB setups (which includes the MP mods as well).
Slicing up the video stage means you need a terminated coax cable inbetween that cuts you gain half (if it is terminated properly) As I said the VIM is not terminated properly, so the gain loss is only ~25% but in return there are reflections. With my solution this step is completely omitted.....


First let me say to you again, that you should use a little Professional Courtesy, and STOP bringing up my name and referring to anything I'm doing as to say you are doing something better. Not sure why every now and then you jump out there with slight insults and subtle slanderous remarks. And from the different times I've challenged you on this, one would think you would cut this out...tactics, that I myself as has so many others have never done.

So once more, I'll ask if you could just make whatever you are trying to do happen. And when that happens, then you can boast about your work and your work alone. And present yourself as someone with dignity, because you would not have to belittle or degrade someone else work to make your work appear what you claim it is.

When that day comes when your work exceeds or is better than anything I'm doing, be the bigger person and let someone else make that claim.

Btw, there are reasons everyone who has been designing these video circuits have been using that same model you're speaking against for their video design. And with your discovery, no one is doubting that you'll make it happen, only wish you just make it happen and stop talking about a space ship that has not got off the ground yet..............
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Sat Dec 17, 2016 7:04 am    Post subject: Reply with quote

mp20748 wrote:
gjaky wrote:


I rather decided to give a long run for the OSD signal (which is not critical) rather than slicing up the video stage as it is with the conventional VIM-VNB setups (which includes the MP mods as well).
Slicing up the video stage means you need a terminated coax cable inbetween that cuts you gain half (if it is terminated properly) As I said the VIM is not terminated properly, so the gain loss is only ~25% but in return there are reflections. With my solution this step is completely omitted.....


First let me say to you again, that you should use a little Professional Courtesy, and STOP bringing up my name and referring to anything I'm doing as to say you are doing something better. Not sure why every now and then you jump out there with slight insults and subtle slanderous remarks. And from the different times I've challenged you on this, one would think you would cut this out...tactics, that I myself as has so many others have never done.

So once more, I'll ask if you could just make whatever you are trying to do happen. And when that happens, then you can boast about your work and your work alone. And present yourself as someone with dignity, because you would not have to belittle or degrade someone else work to make your work appear what you claim it is.

When that day comes when your work exceeds or is better than anything I'm doing, be the bigger person and let someone else make that claim.

Btw, there are reasons everyone who has been designing these video circuits have been using that same model you're speaking against for their video design. And with your discovery, no one is doubting that you'll make it happen, only wish you just make it happen and stop talking about a space ship that has not got off the ground yet..............


Mike, and you should stop behaving like a child when your name gets mentioned...
Where I actually mentioned your name was atually a simple fact, that does not degrade nor glorify your work.

Quote:
Btw, there are reasons everyone who has been designing these video circuits have been using that same model you're speaking against for their video design.


These are just empty words, please explain those reasons "you should use a little Professional Courtesy". I already explained my reasons which I -by accident- could support with facts.
Now you came in that your work was slandered by me, but feel free to speak what is the concept of your work and what advantages could it offer (even over my design).

People are asking questions about this modification to get a better understanding to it, so I try to explain the idea and concept behind it.

_________________
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
Back to top
View user's photo album (1 photos)
mp20748



Joined: 12 Sep 2006
Posts: 5358
Location: Maryland

TV/Projector: 9500LC Ultra / Super 02 and 03 VIM


PostLink    Posted: Sun Dec 18, 2016 12:08 pm    Post subject: Reply with quote

[quote="gjaky"]
Quote:
Btw, there are reasons everyone who has been designing these video circuits have been using that same model you're speaking against for their video design......

These are just empty words, please explain those reasons "you should use a little Professional Courtesy". I already explained my reasons which I -by accident- could support with facts



Let's see... your design was announced earlier this year, and one of your cohorts opened about 4 different threads talking about an Innovative New Marquee Mod that would be the cats meow and would blow my mods away... and the threads were loaded with insults, slander and claims of a product that originally started out using the AD834 because of it's higher bandwidth rating. With also indicating the weakness of the AD835 and why you could never use it... the design went on to someone for testing, with you later posting that there was a noise problem... the noise problem was later solved, but then you would have to post of how to fix a problem in both LVPS and HDM because the noise was coming form those two sources... to later you present the same Mod with it now using the AD835 instead of the AD834 you praised so much... and this design has been sent off for testing, but yet no one has said one thing about it... but before I go on, you had also posted about the original design still having a noise problem, that maybe someone else might even be able to solve, so you would provide some drawings with it.

And with all that, a few days ago you posted this (below) where you mention me three times in this post. And in this last post, you spell it out as its been for the longest... Nothing worth really talking about, or nothing anyone has come forth to say it's working. In fact, you even include that several people have a set of them but still no one indicating that design concept you had in your mind to be a viable product. And at this point, I'm still baffled as to why you keep bringing me and my Mods up in your post..Rolling Eyes

gjaky wrote:
A little background story: I had the basic concept of this mod in my head for a while, but I am mainly a NEC guy, and don't use a Marquee for main projector anymore. I even revealed my idea coarsly here quite while ago, and got an offer from cmjohnson so we could work together: I design the board, and he would arrange the manufacturing and share the money somehow -I rejected this offer. Then I told the idea to that someone who is not allowed to post on this forum, and he encouraged me to bring this thing alive, in fact he made me find an alternative solution for the blue gamma correction -but we didn't agree anything financially. He has a set of boards (as a gift), but those are of a prototype version, and not everything is perfect on them as of yet, I don't think he is using them at the moment...

The second set was supposed to be sold someone else here on this forum, but because of various reasons this did not work out. In the meantime I think more than 90% of the problems got worked out, so I literally gave away this second set of boards to Barclay66, who actually helped me with chasing down the needed HDM modifications. Barclay also has a good understanding to electronics, so I guess if he finds some more problems we can work out those effectively...

So far I did not make a single penny with these mods.

I did not ask anyone to form opinion on my work, nor to form opinion on Mike's mods -I already was queried regarding this...


I try to stand on my own legs. I made the boards in a way so they could find their way (theoretically) to any high end CRT projector (like Sony G90 or Barco 909). I understand that not many people are planning to spend money on CRT projection, and for Marquee MP has already well established name, that's why I wanted to make something that is "universal".

I am sort of playing with open cards as I already shared the schematic diagrams and full theory behind my mods (Nor MP, nor Greg Eisemann does this). As I compete with their mods (mostly with MP's at the moment) it also means this is an alternative for those who estranged by their mods for some reason, but I can't control (either way) what others say...





So with your last comments on this, you then post this:


Quote:
feel free to speak what is the concept of your work and what advantages could it offer (even over my design)


I'll rather not get into a pissing contest here, especially with a product that's not finished...

The answer to this is simple. No one really cares about designs and concepts, when you have yourself said that there is NO finished product. And when the finished product arrives, that is when I think it would make sense to discuss your product in light to what else may be out there, but again, have a little dignity about yourself and let someone else toot the horn for you.



Quote:
People are asking questions about this modification to get a better understanding to it, so I try to explain the idea and concept behind it.


Your cohorts for the most part are trying to keep your efforts alive. There have been and I'm sure there are people interested. But until you post clear results of a finished product, you're only doing yourself more harm, because you're showing that you're not able to make what you have in your mind a reality.... and if all that I've done so far was present concepts and opinions, then you would be right to challenge me. But of course, that's not the case with what I have been doing. When you present something, you have the responsibility to make it happen. And after a good period of time you're not able to make it happen, why would anyone really be interested in the concept of a product you could not pull out of your mind, with you now saying that you've involved others in solving the final 10% of the bugs.

I'm only on this thread, because you have indirectly invited me here. I'm not hear to speak against you or anything that you're doing. Just can't understand why you keep mentioning something I'm actually doing in comparison to something you've yet to make happen. I also believe it's inappropriate to speak negative about a potential competitors work. I think you should have the same right I have to bring forth a Mod, with my wish only being that you do so using some professional courtesy. And in no way would I not want to see your efforts rewarded when the product is finally finished.

Simply make it happen, if it's better so be it. If not, so be it. But either way you or I should not get caught in any discussions of which is better.
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Sun Dec 18, 2016 1:49 pm    Post subject: Reply with quote

You always mention my "cohorts", and it is not the first time I say that I never asked anyone to form opinion neither on my work neither on yours. So if you have any evidence of the opposite please speak up, but until then this is just plain simple accusation. Meanwhile you are also welcome any posts where I said anything wrong of your work...
It is not my responsibility if there are people whom you have a problem, so don't blame me for that.

You are mixing things with my daughterboard adventures as well, history again:
In 2014 I found some major faults with my -then new to me- NEC XG 135LC's video path. After initial trials I could not solve the bandwidth issue of the neckboards, so I thought I try to mate the Marquee VNB with the NEC XG 135LC. For that an iportant step was to add contrast setting feature to the VNB, and this is where the VNB daughterboard came into the view. I was aware of that it will be difficult to do that, so I though why not do the best possible bandwidth if I do something? So I indeed went with the AD834 on a daughterboard attached to the VNB. With two year's hard work I managed to finish that project and I was happy with the end result, and this projector is working fine eversince. It was hard to do but it was fun as well, I gained a lot experience with it. But no one (except me Smile) wants to modify an NEC XG.
So I thought I should reuse all the gained experience in an other project that may actually bring some money to the kitchen. And this was when the Marquee daughter board's idea born. With konwing that the VIM input is 0.7V and the VIM output is also 0.7V I though too much things happening there for too little, so the daughterboard idea came in again.

As for how my Mod is at now... Just because I don't post 10+ blurry, out of convergence screenshots a day my modification may work, and in fact it is indeed working. Myself only have a Marquee 6500 so I didn't want to bother with screenshots with using suboptimal machine, I simply verified and measured that the concepts are working. Instead I gave mods to others who have the right machine to properly present it.
The only thing on which I still want to improve further is the gamma correction... (but that can be disabled anyway)

As I see forum member Wolfman will be getting the latest and best of your mods. I'd be happy to offer a set of my boards to Wolfman for a mod contest in January, if you agree.
So he not just could compare with your work but he could report if the "space ship is able to take off".

_________________
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
Back to top
View user's photo album (1 photos)
redfox001



Joined: 16 Mar 2009
Posts: 2240
Location: The Netherlands


PostLink    Posted: Sun Dec 18, 2016 3:26 pm    Post subject: Reply with quote

Thanks Gjaky for a brilliant and simple idea. So simple anyone could have thought of it but they didn't Wink
_________________
701s->runco933->8500ultra->hd1->hd350->vw100->cinemax+919sp+3x919+9500mp->cinemax+919sp(modded)+kuro600a
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2641
Location: Budapest, Hungary


PostLink    Posted: Sun Dec 18, 2016 5:33 pm    Post subject: Reply with quote

Here is a youtube video for the unbelievers:
VNB-DB Video
Thumbs Up

_________________
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
Back to top
View user's photo album (1 photos)
mp20748



Joined: 12 Sep 2006
Posts: 5358
Location: Maryland

TV/Projector: 9500LC Ultra / Super 02 and 03 VIM


PostLink    Posted: Sun Dec 18, 2016 7:17 pm    Post subject: Reply with quote

redfox001 wrote:
Thanks Gjaky for a brilliant and simple idea. So simple anyone could have thought of it but they didn't Wink


Not sure why this concept is being seen as a brilliant idea, when it goes completely against video circuit design for CRY technology. It's not that no one thought of it, it was done on the Dwin projector. It was safe there, but putting three video drive boards/circuits complete with input stage at each CRT socket. And considering, you're also putting three high bandwidth circuits right near and close to both deflection modules.... and let us not forget the that the input of these three separate stages goes to the VIM module to get its feed from the Moome. With this design, the noise problems that were mentioned made perfect sense.

Also and as some already know, some years back I had to attend an FCC Compliance seminar. In that seminar. Myself and other circuit designers were required to get that certification to assure you did not design a circuit that would be in violation of the FCC interference rules. That is when you really learn why some of the circuits all share the same concept, especially the higher bandwidth amplifier stages. So the concept is not new. There are several reasons why an input stage is not placed near the CRT sockets and away from the deflection stages. On the Marquee, the Canadian Rule requirement is stricter than the US. In both Interference and Radiation. That explains why the stick neck boards had the covers and the covers had two ground wires. To include why the Matquee uses Lead Shieding and no other manufacturer used the shieding. Also, it would help to know the noise issues on that chassis and why they were not a problem at the scan rates the were using during the original design concept.

So I would agree that this is a good design concept. I've said a many time, the Marquee chassis is a noise bed.
Back to top
Display posts from previous:   
Post new topic   Reply to topic   Printer-friendly view    CurtPalme.com Forum Index -> CRT Projectors All times are GMT
Goto page 1, 2, 3, 4, 5, 6, 7  Next
Page 1 of 7
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum