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Discussion Starter · #1 ·
Some have asked about the performance of these new style neck boards for the Marquee, and i got quite a lot of them.

I did put a set into my projector to do a fast test the other day.

They do a pretty decent bandwidth performance, and looks quite sharp, but they behave very nonlinear to gain, so when i run a contrast above 60 they start to track very badly.

When i was in Texas to pick up the projectors, the guy running the planetarium there told me they had been running the projectors at a contrast at max 50 to be able to get a decent gamma tracking.

So until someone comes up with a way to modify these boards ill not recommend them for HT use.
 

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Discussion Starter · #4 ·
Just did some more testing on another set of these neck boards, and they seems to have a unstable black level, flashing like a unstable dc level, i did notice it before but was not 100% sure it was a neck board issue, as i tested it in a modified projector.

I now have a 2nd 2004 Marquee setup in 100% original condition, as they had been running in the planetarium in Texas where i picked them up.

So from here it looks like the later Marquee, 2004 and forward with the 02VIM with peaking trimpots and factory installed vertical line mod + a set of these new style neck boards is some of the worse performance in the history of the 9500/ 8500 Marquee.
 

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this doesn't surprise me really. By the time VDC got the rights ot the chassis it was overdue for a complete re-design of many of the boards. The video menu's overlay-circuit in the VIM, those stupid coils and relays for switching to standard def. video on the HDM (and VIM too), the noisy stig amp, on and on. For goodness sake they were still making VIM's with 2 dozen useless Tantalum caps for the audio circuit well into the 2000's, although they did remove the RCA jacks eventually:rolleyes:

Scott told us they just weren't willing ot invest the engineering time to do a fresh ground-up board design, and from a business perspective this was justified. The people who kept buying the machines didn't really care about the things HT enthusiasts care about. The one exception is those neck-boards and that was only done because they had to when the Motorola transistors became un-available.

The band-aid fixes they did were just half-measures and as a result your better off with some of the older stuff IMO.
 

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Discussion Starter · #6 ·
this doesn't surprise me really. By the time VDC got the rights ot the chassis it was overdue for a complete re-design of many of the boards. The video menu's overlay-circuit in the VIM, those stupid coils and relays for switching to standard def. video on the HDM (and VIM too), the noisy stig amp, on and on. For goodness sake they were still making VIM's with 2 dozen useless Tantalum caps for the audio circuit well into the 2000's, although they did remove the RCA jacks eventually:rolleyes:

Scott told us they just weren't willing ot invest the engineering time to do a fresh ground-up board design, and from a business perspective this was justified. The people who kept buying the machines didn't really care about the things HT enthusiasts care about. The one exception is those neck-boards and that was only done because they had to when the Motorola transistors became un-available.

The band-aid fixes they did were just half-measures and as a result your better off with some of the older stuff IMO.
The old style neck boards are made up to 2008 i guess, so there is plenty of those.

The 2004 and forward 02VIM just need the 3 vertical line mod resistors removed, and the peaking trimpots, and it will perform the same as they did before.

Mike Parker have been able to mod the 02VIM to a very very low noise and clean 200Mhz bandwidth.
 

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@Stridsvognen:


Hi,


Yes, I'm the same guy that You know from the other forum...


Would You consider selling one (3 boards) or two sets (6 boards) to me?
I'd like to play around with them and maybe I'll find some ways for improvement...


PM me if interested.


Regards,
barclay66
 

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Discussion Starter · #8 ·
@Stridsvognen:


Hi,


Yes, I'm the same guy that You know from the other forum...


Would You consider selling one (3 boards) or two sets (6 boards) to me?
I'd like to play around with them and maybe I'll find some ways for improvement...


PM me if interested.


Regards,
barclay66
Hey barclay.

This is the only CRT forum :)

Pm me your address. And ill find a set you can play with.

Would be interesting if you share your experience in this thread, and i might be able to duplicate or confirm it here.
 

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I am about to put LCP tubes in one of the new simulator VDC machines and have been talking with Barclay about this.
Conclusion is that the jumper in position "A" must be moved to position "B" and the black wire that connects pin 1&2 to ground must be removed and replaced by a wire going from pin 2 to WH2 located on the PCB just under where the black wire connects to ground and besides R57.
Barklay is planning a change from version 81771 to 02-270340-01.
I asked:

Why do you think 02-270340-01 is much different from 81771?
As I see it the main difference is not in the i-sense over-i circuit. Both are almost indentical to the old VNB. Perhaps a matter of different settings of the over-i but the way it works is the same, as far as I can see.
There are much bigger differences in the brightness control circuit between the new and old VNB. The new VNB´s are identical (save for the spotkill transistor) here but there are lots of differences in the old VNB. Could that make a difference?

Barclay:
Hi,

You might want to look up this thread: http://www.avsforum.com/t/1127826/vdc-8-highres-projector#post_16022468

Here Scott explains the following:
"The schematic. 81771-01 is part number. This card is not compatible with original Electrohome style cards. P/N 02-270340-01 is new version but can be mixed with E-home cards."

And later:
"The 81771 cards won't work with the originals because when spotkill is enabled the transistors on the original cards will not allow the voltage to go higher than about +0.7 or 0.8V. That will not go high enough to kick in spotkill on the 81771 cards.
Spotkill has been a problem with different configurations because of the small difference between enabled and not. The 81771 takes more than +1V to kick in spotkill which allows more noise and crap without false enabling.
The 02-270340-01 card has the same thresholds as original Electrohome cards so spotkill works."

This is where my idea of functional similarity between an old style card and a 02-270340-01 comes from...

My comments:
I remember now that I actually read that thread.
But if I read Scott correct he is saying that with the new VNB the spotkill will no have so many false trigering as the old, so if you have the new versions in the rest of the PJ, you will only benefit from this.
Problem is with older PJ´s that the spotkill will not work at all...!
But I cannot see it would have any influence on brightnes and contrast???

Koldby
 

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By the way have you noticed that VDC placed a footprint for a better connection to VIM?
About time... Mini jacks for HighEnd Video signals is not a good idea IMHO!
 

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Discussion Starter · #12 ·
Go download the neck board diagram here.

http://repairalmostanything.com/board/93/marquee

Its made very clear how to change between LCP and LUG.

I have seen the footprint, but as it looks now those new neck boards have so many issues that i cant see any idea wasting time playing with cables and connectors.

If you can remove all the peaking and make them handle a 200Mhz bandwidth, where all 3 colors track together up to around 10fl on a 110" neutral gain screen, i would love to see what difference connectors and cables do.

Someone need to do some serious work on those to make a linear gain and bandwidth performance, and remove the harsh noise. If thats done im quite sure they will beat up the old style neck boards in most ways.
 

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Go download the neck board diagram here.

http://repairalmostanything.com/board/93/marquee

Its made very clear how to change between LCP and LUG.

I have seen the footprint, but as it looks now those new neck boards have so many issues that i cant see any idea wasting time playing with cables and connectors.

If you can remove all the peaking and make them handle a 200Mhz bandwidth, where all 3 colors track together up to around 10fl on a 110" neutral gain screen, i would love to see what difference connectors and cables do.

Someone need to do some serious work on those to make a linear gain and bandwidth performance, and remove the harsh noise. If thats done im quite sure they will beat up the old style neck boards in most ways.
I already have the schematic and seen what to do.
Yes the issues should be taken care of if they are so severe as you say. The connector/ cabel is possible on the old type VNB even if the footprint is missing. The connectors should have been changed long tim ago though!
 

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Discussion Starter · #14 ·
I already have the schematic and seen what to do.
Yes the issues should be taken care of if they are so severe as you say. The connector/ cabel is possible on the old type VNB even if the footprint is missing. The connectors should have been changed long tim ago though!
Try play a bit with the pattern we got made to test how the gain and bandwidth respond from 1:1 to 3:3 and gain from black to full pop.

You will notice that the 1:1 100% IRE will start change color as you turn up contrast, go back to where its linear, and put up a 100% IRE window and measure the output.

If your testing with a standard 02 VIM you should see to that the peaking trim pots and vertical line mod is removed.

The screenshot i addet is from a MP moddet video chain running 178Mhz 12fl on a 90" screen with neutral gain.

The new neck boards trows a very sharp pattern as long they are operated with a low drive, when the contrast passes 50-60 they start to behave quite strange.

The old style neck boards have quite a lot off issues to, but ill pick that one if i had to run with standard boards.

You might want to start looking at the input ( Moome/ VIM ) first, so you have a video chain that will pass a normal 1080P 60hz signal with a decent black pedestal, and noise level.
 

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Try play a bit with the pattern we got made to test how the gain and bandwidth respond from 1:1 to 3:3 and gain from black to full pop.

You will notice that the 1:1 100% IRE will start change color as you turn up contrast, go back to where its linear, and put up a 100% IRE window and measure the output.

If your testing with a standard 02 VIM you should see to that the peaking trim pots and vertical line mod is removed.

The screenshot i addet is from a MP moddet video chain running 178Mhz 12fl on a 90" screen with neutral gain.

The new neck boards trows a very sharp pattern as long they are operated with a low drive, when the contrast passes 50-60 they start to behave quite strange.

The old style neck boards have quite a lot off issues to, but ill pick that one if i had to run with standard boards.

You might want to start looking at the input ( Moome/ VIM ) first, so you have a video chain that will pass a normal 1080P 60hz signal with a decent black pedestal, and noise level.
So it is the linearity of the VNB when asked to output high power that is the issue here.
Is it the same if you set the brigthnes high , but the contrast still @ 50?
Pls explain what the two screen shots shows
Both new VNB?
First with contrast
 

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I cannot post any pictures as I havent yet had time to put the new tubes in.
In another forum member gjaky suggests it could be because the clamping circuit has been taken away in the new boards. This could be why the black level is unstable.
The question is also why did they use a hfa1100 with an emmitterfollower stage after instead of the original clc449 opamp?
 

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Discussion Starter · #18 ·
I cannot post any pictures as I havent yet had time to put the new tubes in.
In another forum member gjaky suggests it could be because the clamping circuit has been taken away in the new boards. This could be why the black level is unstable.
The question is also why did they use a hfa1100 with an emmitterfollower stage after instead of the original clc449 opamp?
There is just 1 way to find out. But ill suggest that you try run the Marquee for some time with a standard setup and old style neck boards, get the best result you possible can.

You should try test it the way i described above, do a gray scale where you document the performance, so you can see what gets better and what gets worse when you start changing components in your video chain. There is quite a lot of parameters who have to add up.
 

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The old neckboards and at least on set of new neckboards will stay unchanged as you need a reference.
The same is true for the rest of the boards in th PJ..
By the way, the factory line mod. can it be reversed?
 

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Discussion Starter · #20 ·
The old neckboards and at least on set of new neckboards will stay unchanged as you need a reference.
The same is true for the rest of the boards in th PJ..
By the way, the factory line mod. can it be reversed?
Yes just remove the 3 resisters who is soldered onto the board, if you have a pic of your 02VIM i can mark them for you.
 
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