| Interested in purchasing upgrade? |
| Yes |
|
79% |
[ 39 ] |
| No |
|
20% |
[ 10 ] |
|
| Total Votes : 49 |
|
| Author |
Message |
RogueChili
Joined: 31 Mar 2008
Posts: 162
Location: Westfield, MA
|
| Posted: Sun Jul 19, 2009 3:17 pm Post subject: |
|
|
| overclkr wrote: | | HV-MAN wrote: | | If it all works out, and it looks like it is, count me in. |
Wanna do the same for my G90's? :D |
It’s possible, what aspect of the design are you interested in?
|
|
| Back to top |
|
 |
overclkr
Joined: 08 Mar 2006
Posts: 4227
|
| Posted: Sun Jul 19, 2009 6:05 pm Post subject: |
|
|
| RogueChili wrote: | | overclkr wrote: | | HV-MAN wrote: | | If it all works out, and it looks like it is, count me in. |
Wanna do the same for my G90's?  |
It’s possible, what aspect of the design are you interested in? |
No more streaking!
G90's streak as well........
Cliff
|
|
| Back to top |
|
|
ecrabb
Forum Moderator
Joined: 13 Mar 2006
Posts: 15909
Location: Utah
TV/Projector: JVC RS40, Epson 5010
|
| Posted: Sun Jul 19, 2009 6:12 pm Post subject: |
|
|
| overclkr wrote: | | G90's streak as well........ |
No sh*t, Cliffy? Interesting!
I have some streaking with my G70, too... Is it the same problem on all three machines? Do NECs and Ehomes do it, too?
SC
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
speedyandre
Joined: 18 Dec 2006
Posts: 291
Location: Netherlands
|
| Posted: Sun Jul 19, 2009 7:29 pm Post subject: |
|
|
Hi guys 
Because I'll move to another home within 2 weeks testing has to wait until my new setup is running.
As far as I can see the red wire of the blue modded neck board seems to be loose compared to other boards.
I like to know how this wire is mounted on the neck board, maybe I can reconnect or fix it.
The picture fades away slowly.
My old blue neck board works fine all the time so there is no problem with the tube or the HV.
When I have moved I can replace the other neck boards easily because the 1292 will not be ceiling mounted yet.
I'm a little bit surprised about the other Sony crt's streaking too, this is not discussed as much as the 1292 
André
_________________
I'll be broke
|
|
| Back to top |
|
|
RogueChili
Joined: 31 Mar 2008
Posts: 162
Location: Westfield, MA
|
| Posted: Sun Jul 19, 2009 8:51 pm Post subject: |
|
|
I suspected all along the G90 had the streaking problem because the driver circuitry is almost identical to that of the 1292. I was surprised there were no inquires during my 1292 posts.
The original design will work very well on the G90 eliminating 98 percent of the streaking. I say 98 percent because analyzing the signal with the scope shows a slight amount of ringing still present in the signal with my mod installed. It follows that there is some amount of streaking present in the light output of the crt however the visual effect is almost nonexistent.
The goal for version two is to completely eliminate the distortion and make it be both electrically and mechanically compatible with the 1292, G90 and the 808. I have the schematics for each of these and neck boards for all but G90. One encouraging note, with some modification the original mod was installed on an 808 with the same positive results.
When it will be available? I can’t say at this point only that it is in progress. Attempting to design the hybrid with a integrated streaking mod is proving to be extremely challenging.
|
|
| Back to top |
|
|
deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
|
| Posted: Sun Jul 19, 2009 9:08 pm Post subject: |
|
|
| ecrabb wrote: | | overclkr wrote: | | G90's streak as well........ |
No sh*t, Cliffy? Interesting!
I have some streaking with my G70, too... Is it the same problem on all three machines? Do NECs and Ehomes do it, too?
SC |
Depends.
My 10PG was streaking a little, but when I changed out my video out board, most of it was gone. Not sure if it was the way I ran the wires when I reassembled it or that the new board was in better shape. Apparently the way the wires are run throughout the PJ are important, the NEC PG's do not have the RGB amps on the neck board, so I'm thinking that section is critical on having the wires run just right so they do not cause problems.
Deron.
|
|
| Back to top |
|
|
deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
|
| Posted: Sun Jul 19, 2009 9:11 pm Post subject: |
|
|
Do CRT monitors streak? I do not remember seeing any streaking on any CRT monitor I ever had.
I though these PJ's were state of the art, did they not design so as not to streak, or was that something they did not care about?
Deron.
|
|
| Back to top |
|
|
speedyandre
Joined: 18 Dec 2006
Posts: 291
Location: Netherlands
|
| Posted: Sun Jul 19, 2009 10:43 pm Post subject: |
|
|
Sony was aware of the streaking and placed extra fans behind the neck boards in the 1292.
This didn't eliminate the streaking but made it more acceptable.
I like the idea that the modded neck boards need less cooling, I soon can get the fan noise lower 
André
_________________
I'll be broke
|
|
| Back to top |
|
|
RogueChili
Joined: 31 Mar 2008
Posts: 162
Location: Westfield, MA
|
| Posted: Sun Jul 19, 2009 11:07 pm Post subject: |
|
|
| deronmoped wrote: | Do CRT monitors streak? I do not remember seeing any streaking on any CRT monitor I ever had.
I though these PJ's were state of the art, did they not design so as not to streak, or was that something they did not care about?
Deron. |
I second that thought! The more I studied the circuit the more I wondered what they were thinking! It doesn’t seem possible they were not aware of the potential problems. My conclusion was it was considered acceptable for the content they expected to be displayed at the time. Not to mention a much simpler and less expensive design.
|
|
| Back to top |
|
|
RogueChili
Joined: 31 Mar 2008
Posts: 162
Location: Westfield, MA
|
| Posted: Sun Jul 19, 2009 11:10 pm Post subject: |
|
|
| ecrabb wrote: | | overclkr wrote: | | G90's streak as well........ |
No sh*t, Cliffy? Interesting!
I have some streaking with my G70, too... Is it the same problem on all three machines? Do NECs and Ehomes do it, too?
SC |
My 1042q and 1252 don't streak!
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Sun Jul 19, 2009 11:59 pm Post subject: |
|
|
| RogueChili wrote: | | deronmoped wrote: | Do CRT monitors streak? I do not remember seeing any streaking on any CRT monitor I ever had.
I though these PJ's were state of the art, did they not design so as not to streak, or was that something they did not care about?
Deron. |
I second that thought! The more I studied the circuit the more I wondered what they were thinking! It doesn’t seem possible they were not aware of the potential problems. My conclusion was it was considered acceptable for the content they expected to be displayed at the time. Not to mention a much simpler and less expensive design. |
I checked out the schematics today and the circuits are very complex. There are several DC restore circuits through the chain. It seems that things could have been more simple. The cathode and G-1 drivers are the same part. A part that was designed to drive the cathode with its inverted video (lower output voltage makes brighter output). The G-1 driver puts out the opposite polarity of video and has to cook with max power dissipation at dark video content and less as the content gets brighter. Its output has to be AC coupled ad DC restored to a negative voltage signal to bias the CRT correctly. Alot of projectors used the Sanyo video packs this same way. The video output amplifiers are difficult to design when the only parts available are for monitors with their relatively low voltage drive needs. Even those transistors are getting hard to find.
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
Mark_A_W
Joined: 15 Mar 2006
Posts: 3068
Location: Sunny Melbourne Australia
|
| Posted: Mon Jul 20, 2009 12:02 am Post subject: |
|
|
| ecrabb wrote: | | overclkr wrote: | | G90's streak as well........ |
No sh*t, Cliffy? Interesting!
I have some streaking with my G70, too... Is it the same problem on all three machines? Do NECs and Ehomes do it, too?
SC |
Yes, I have seen streaking on a early XG, but it's not very bad.
My later XG with the high bandwidth neckboards will streak if I use a gamma curve with a bump. With a linear tweaked gamma curve streaking is minimal, but not completely unheard of. Nothing like a bad 1292 however.
My various PG Xtras NEVER streaked.
My feeling is "normal" streaking is a side effect of chasing higher bandwidth. It seems to be a fine line they danced around chasing bandwidth.
So I'm not surprised that lower end projectors don't streak.
|
|
| Back to top |
|
|
Mark_A_W
Joined: 15 Mar 2006
Posts: 3068
Location: Sunny Melbourne Australia
|
| Posted: Mon Jul 20, 2009 12:09 am Post subject: |
|
|
| tse wrote: |
I checked out the schematics today and the circuits are very complex. There are several DC restore circuits through the chain. It seems that things could have been more simple. The cathode and G-1 drivers are the same part. A part that was designed to drive the cathode with its inverted video (lower output voltage makes brighter output). The G-1 driver puts out the opposite polarity of video and has to cook with max power dissipation at dark video content and less as the content gets brighter. Its output has to be AC coupled ad DC restored to a negative voltage signal to bias the CRT correctly. Alot of projectors used the Sanyo video packs this same way. The video output amplifiers are difficult to design when the only parts available are for monitors with their relatively low voltage drive needs. Even those transistors are getting hard to find.
Scott |
Scott, if I read correctly, you are saying that in all push-pull neckboard designs (Sony, NEC for instance) using a pair of output amps, the G-1 driver has to "push" up to Zero to do Black?
So a black image stresses the G1 driver as much as full white stress the Cathode driver?
Is this because the video packs can't amplify a "negative" signal - you'd need the mirror image amp, like voltage regulators (say 7815 and 7915)?
Is that it?
|
|
| Back to top |
|
|
tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
|
| Posted: Mon Jul 20, 2009 12:22 am Post subject: |
|
|
| Mark_A_W wrote: | | tse wrote: |
I checked out the schematics today and the circuits are very complex. There are several DC restore circuits through the chain. It seems that things could have been more simple. The cathode and G-1 drivers are the same part. A part that was designed to drive the cathode with its inverted video (lower output voltage makes brighter output). The G-1 driver puts out the opposite polarity of video and has to cook with max power dissipation at dark video content and less as the content gets brighter. Its output has to be AC coupled ad DC restored to a negative voltage signal to bias the CRT correctly. Alot of projectors used the Sanyo video packs this same way. The video output amplifiers are difficult to design when the only parts available are for monitors with their relatively low voltage drive needs. Even those transistors are getting hard to find.
Scott |
Scott, if I read correctly, you are saying that in all push-pull neckboard designs (Sony, NEC for instance) using a pair of output amps, the G-1 driver has to "push" up to Zero to do Black?
So a black image stresses the G1 driver as much as full white stress the Cathode driver?
Is this because the video packs can't amplify a "negative" signal - you'd need the mirror image amp, like voltage regulators (say 7815 and 7915)?
Is that it? |
The G-1 driver has to be biased somewhere near the middle of its output range for black. The cathode driver is biased near the positive rail for black. Power dissipation is minimum with the output near the positive rail.
The G-1 output video pack is about max dissipation situation with black input. So yes, black G-1 is almost as bad as white cathode.
A mirror of the cathode circuit would be best for the G-1 driver. These parts were designed for monitors and one doesn't have the drive needed for the projection tube.
Scott
_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
|
|
| Back to top |
|
|
RogueChili
Joined: 31 Mar 2008
Posts: 162
Location: Westfield, MA
|
| Posted: Mon Jul 20, 2009 12:50 am Post subject: |
|
|
| speedyandre wrote: | Sony was aware of the streaking and placed extra fans behind the neck boards in the 1292.
This didn't eliminate the streaking but made it more acceptable.
I like the idea that the modded neck boards need less cooling, I soon can get the fan noise lower :thumbsup:
André |
Those dam fans! Check this out, my baby is running quiet and cool purring like a kitten
| Description: |
|
| Filesize: |
53.65 KB |
| Viewed: |
12145 Time(s) |
|
| Description: |
|
| Filesize: |
56.73 KB |
| Viewed: |
12145 Time(s) |
|
| Description: |
|
| Filesize: |
38.26 KB |
| Viewed: |
12145 Time(s) |
|
|
|
| Back to top |
|
|
speedyandre
Joined: 18 Dec 2006
Posts: 291
Location: Netherlands
|
| Posted: Mon Jul 20, 2009 10:02 pm Post subject: |
|
|
Did you change anything to the PS fans?
How many fans do you have in total now?
I have used the same material for the exhaust fans on top, but laminated to bend the air in one direction
André
_________________
I'll be broke
|
|
| Back to top |
|
|
RogueChili
Joined: 31 Mar 2008
Posts: 162
Location: Westfield, MA
|
| Posted: Tue Jul 21, 2009 1:45 am Post subject: |
|
|
The method to the madness is to minimize recirculation of hot air and bring in more volume of ambient (cool) air; together this allows lower circulation rates (lower fan speeds) with similar heat transfer rates.
The number of fans remains the same(that has a ring to it) however they are all running at a lower RPM determined by different value zener diodes. Two of the neck board fans are repositioned to the modified side panels with the air flow inwards (cool air blowing onto the neck board heat sinks). The top mounted fans are reversed so the air flows inwards (keeping steady flow of cool over crt’s and boards). The power supply fans are reversed so the air flows outwards (no hot air from the power supply into the main cabinet). One of the two rear fans is reversed so one flows inwards the other outwards (cool air in hot air out). The plastic grills are cut out and replaced with free flowing screens reducing the restriction to air flow and reducing noise. There are various air dams to control the flow within the cabinet. The ones in the pic are made with cardboard and duct insulation and will be replaced with sheet metal fabrications. The main air exhaust points are the underside vents, the power supply, the original rear top cover vents and the opening around the lenses.
Use this information at your own risk: There is no warranty neither expressed nor implied and I am not liable for any of your past, present, nor future actions. Even should these modifications be preformed to the letter you could still damage any number of components in your projector causing it to no longer function. Even if it appears to function properly your actions may cause it to self destruct with collateral damage to everything. Oh, and your carbon footprint may increase!
|
|
| Back to top |
|
|
overclkr
Joined: 08 Mar 2006
Posts: 4227
|
| Posted: Tue Jul 21, 2009 2:12 am Post subject: |
|
|
| ecrabb wrote: | | overclkr wrote: | | G90's streak as well........ |
No sh*t, Cliffy? Interesting!
I have some streaking with my G70, too... Is it the same problem on all three machines? Do NECs and Ehomes do it, too?
SC |
It's pretty rare when it happens but it does happen. Mostly with certain text. If this guy can do this mod for the G90, I'm damn near tempted to retube......... 
Cliffy
|
|
| Back to top |
|
|
asubert
Joined: 01 May 2008
Posts: 26
Location: FRANCE
|
| Posted: Fri Jul 24, 2009 12:42 pm Post subject: |
|
|
Dear all,
I see you did a great job on this topic.
Streaking problem is also my concern. I have drastically reduce it by lowering contrast and brightness, but it is still there.
I'm interesting in this mod, but there is some issue that make me hesitating:
1) I'm living in France, and I don't think about sending my parts oversea, that can take several weeks without my CRT
2) I have no technical knowledge. When I read the notice to demount board on the neck, it look a little hard for me. I've already use a welder, but i'm not sure if I would like to take the risk of burning the board, making my CRT dead.
But I'm very interesting if there is an easier way to do it. I will post a topic on french forum, to invite other sony's owner to visit this topic.
I think about one french guy that is very active in electronics mod for SOny (he did a and supply a sony IFB-DVI card for the community). He may be helpful.
THe noise reduction is also an interesting part of this work...
|
|
| Back to top |
|
|
|
|
