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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Tue Oct 26, 2010 8:42 pm Post subject: |
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| vinm wrote: | Ok, now it's clear, i remember of an old post that said about the use of not exact values from Electrohome to use what they already had in store.
Athanasios, only to raise the confusion  , do you mean 47nF ?
Vincenzo |
LOL, hahahah.
No use wima 4.7 nf's or vishay brand of Polypropylene . both are better than mylar.
Right, i am doing a board right now with 22uf 50v caps for the entire CVA. I also am changing the diodes to the Soft recovery types. I'll use this in my test bed since its not an Ultra board and can not be used in my Longbows.
Athanasios
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vinm
Joined: 06 Oct 2010
Posts: 18
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| Posted: Thu Oct 28, 2010 10:13 am Post subject: |
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| Quote: | | Right, i am doing a board right now with 22uf 50v caps for the entire CVA. I also am changing the diodes to the Soft recovery types. I'll use this in my test bed since its not an Ultra board and can not be used in my Longbows. |
Athanasios are you replacing diodes with same values or you found a new type with better specs ? (I'm not started resoldering yet )
Vincenzo
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dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
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dvh99
Joined: 25 Dec 2009
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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vinm
Joined: 06 Oct 2010
Posts: 18
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| Posted: Thu Oct 28, 2010 7:45 pm Post subject: |
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dvh99 it seems that you already done all nashou mods. 
If I understand well, the diodes are D103 and D104 (and similar) that forms the "Baker clamp" as described in service manual.
If those are the replacement parts I don't understand if they are faster than original
On data sheets the sbvy27 has Maximum reverse recovery time of 15ns instead of original 1n914 that has 4ns
....probably I'm looking at wrong parts 
Vincenzo
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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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| Posted: Sun Oct 31, 2010 5:03 am Post subject: |
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Hi Guys, I had an extra rear heat sink lying around and decided to see how those diodes work. I have wanted to replace the caps on it as well so I did that as well as remove all the 1N4003 diodes and put in the SVBY27-200 ones.
Before on a the CVA/VDM where I changed the resistors and Caps the grid still moved just a little bit up and down.
TSE mentioned to me that you can see that it comes from the CVA if you remove the cables from the connector on the board you will see the grid stop moving. He told me there is lots to do there to stabilize it, but never went in to detail.
I never got around to doing any more testing there but have always wanted to revisit this. I also wanted to try using the 22uf 50v caps in place of the 10uf 250v stock caps that Chris Stevens from Accurate Imaging used.
I finished up the boards tonight and now with both these changes the grids do not move at all from the short 10 minutes i looked at it on my Test Bed marquee 8xxx.
there ares o many of these diodes all over the place in the Marquee chassis. I plan to replace all now and will study the LVPS and find Soft recovery replacements for that as well.
I think this will be a very good up P.O.O.G.E up Grade.
Drags I hope you give these a try and also try the 22uf 50 volt caps. they are soooo much smaller in physical side but looks like they work really well. Id like to get some one else's observation here as well.
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
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dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
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| Posted: Sun Oct 31, 2010 11:24 am Post subject: |
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counted 24 1n4003 diodes on the cva is that correct?
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
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Nashou66
Joined: 12 Jan 2007
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Location: West Seneca NY
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vinm
Joined: 06 Oct 2010
Posts: 18
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| Posted: Sun Oct 31, 2010 2:08 pm Post subject: |
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I'm interested in this new upgrade for CVA, I'll add diodes to my next order, meanwhile i can test my fixed CVA with 'old' mods , so i can tell the differences before/after.
Strange caps substitution from 10/250 to 22/50, another case of use of common stocked components ?
Yestereday i finished to resolder my CVA so it's waiting me to fire up (not literally I hope  ) my marquee!!
dvh99 I counted 12 1N4003 on the schematic, Have you counted directly on board ?
Vincenzo
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draganm
Joined: 08 Mar 2006
Posts: 8990
Location: Colorado
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| Posted: Sun Oct 31, 2010 3:08 pm Post subject: |
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| Nashou66 wrote: | Drags I hope you give these a try and also try the 22uf 50 volt caps. they are soooo much smaller in physical side but looks like they work really well. Id like to get some one else's observation here as well.
Athanasios |
I plan to Nash, with warm cycling weather about to disappear the new diodes are some of the stuff I'll be testing in my mule-chassis. I don't think I'll be substituting 50v caps in that circuit though, possibly try the higher 22uf but as large of a V rating as I can reasonably fit onto the board. I just can't risk having dozens of these out there that start acting up 6 months to a year down the road. Your results sound very good though, any stabilization to conv. is always welcomed.
| vinm wrote: | On data sheets the sbvy27 has Maximum reverse recovery time of 15ns instead of original 1n914 that has 4ns
Vincenzo |
this a big concern for me as well. This is obviously not a problem on the CVA and will also probably be fine on the Focus circuit, but, AFA noise suppression is concerned the biggest possible benefit could be in using these in the direct video path on the neck-boards? However At 1080P 72Hz (70+Khz H sweep?) would the 75% slower recovery time create a problem?
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vinm
Joined: 06 Oct 2010
Posts: 18
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| Posted: Sun Oct 31, 2010 3:38 pm Post subject: |
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Oops , Nashou answer first, I can beat you on writing speed (I have to translate to write something with meaning  )
| draganm wrote: | | this a big concern for me as well. This is obviously not a problem on the CVA and will also probably be fine on the Focus circuit, but, AFA noise suppression is concerned the biggest possible benefit could be in using these in the direct video path on the neck-boards? However At 1080P 72Hz (70+Khz H sweep?) would the 75% slower recovery time create a problem? |
On neck boards there are 1n4003s between Q1-Q22 and Q13-Q14, do you want to replace them with sby's ?
For CVA, I think that would be good summarize component list of current upgrades:
R117, R217, R317, R417, R517, R617, R118, R218, R318, R418, R518, R618 : 0,47ohm 1/2w fuse resistor
c108 C109 C208 C209 C308 C309 C408 C409 C508 C509 C608 C609: 10uF 350V NOW 22uF 50V
C102 C106 C127 C202 C206 C227 C302 C306 C327 C402 C406 C427 C502 C506 C527 C602 C627: 22uF 100V
C121 C221 C321 C421 C521 C621: 4,7nF 100V Wima
R168 R169 R170 R171 R268 R269 R270 R271 R368 R369 R370 R371 R468 R469 R470 R471 R568 R569 R570 R571 R668 R669 R670 R671 : 1,2ohm 1/2W
I forgot something else ?
Vincenzo
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dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
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| Posted: Sun Oct 31, 2010 4:11 pm Post subject: |
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| vinm wrote: | I'm interested in this new upgrade for CVA, I'll add diodes to my next order, meanwhile i can test my fixed CVA with 'old' mods , so i can tell the differences before/after.
Strange caps substitution from 10/250 to 22/50, another case of use of common stocked components ?
Yestereday i finished to resolder my CVA so it's waiting me to fire up (not literally I hope ) my marquee!!
dvh99 I counted 12 1N4003 on the schematic, Have you counted directly on board ?
Vincenzo |
no from the parts list.
24 diodes
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vinm
Joined: 06 Oct 2010
Posts: 18
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| Posted: Sun Oct 31, 2010 4:33 pm Post subject: |
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My part list is different , it is for board version 03-2623330-01P
It's the board with the pin connector P2 ,
not the version with white connector
Vincenzo
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dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
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| Posted: Sun Oct 31, 2010 4:34 pm Post subject: |
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vnb met smb connector.
no bolt or nut or ring required
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Sun Oct 31, 2010 6:08 pm Post subject: |
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Guys, your getting the diode specs wrong. The 914's are the small signal ones, those are small red ones with glass casings.
The 1N4003's do not even list reverse recovery time on most spec sheets I looked at.
http://www.fairchildsemi.com/ds/1N/1N4003.pdf
The SBVy27's are "soft" recovery. Its that feature which is important in noise reduction. I did see the recovery time listed some where
it might have been in my pooge articles but the SVB's are faster.
Dragan, Trust me on the 50 volt caps. That rail does not ever get that high of voltage spikes, I have never seen it go higher than 23.7v volts. Remember the Marquees are one of the few PJ's that have very few on board voltage regulators. Most of the voltage is right from the LVPS. only where there are a few 9 volt and 12 volt and 2.5 volt uses is there an onboard regulator. I Wish there where then I could replace them all with high end built Voltage regulator from Burson, belleson, or Dexa . Scott also said that Electrohome probably had thousands of the 10uf 250 volt cap in stock and used those to save on inventory stocking costs. Mike parker is using a 50 to 63 volt cap there as well.
Dennis, your part list is for the older CVA/VDM in the M8000. I can tell from the bad Copy Quality. I have three sets of schematics in my link. Also that link will not work after Nov 8th i think.
vinm, I plan to change every single 1N4003 Diode in the Marquee as well as the other large signal types. for the small signal types i have not seen soft recovery types and I do not thing they would be worht changing any how.
Hope this clears up some things.
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!!!
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Marquee Modifications and Performance Enhancement
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vinm
Joined: 06 Oct 2010
Posts: 18
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| Posted: Sun Oct 31, 2010 6:39 pm Post subject: |
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Athanasios
The new cap mod seems in contraddiction with old mod that raised max voltage from 250V to 350V
Btw reasoning about it it's seems more "logical" to raise capacitance if, as you indicated, the voltage supply is sufficiently clean, in this way it should help to mantain stable voltage.
My reference to recovery time was for 1n914's , actually it's not indicated recovery time for 1n4003's
Vincenzo
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Sun Oct 31, 2010 6:52 pm Post subject: |
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Right Vincent, I have learned a lot since i started this thread after spending more time reading other electronic forums I came across while researching
for this thread. The POOGE Chronicles are really excellent resource with many different ideas and explanations on why they do them.
Back when I used upping the voltage idea it was following an upgrade thread of another AVS member's ideas. It still doesn't hurt but some high voltage caps in higher uf values are costlier than lower voltage parts. Also I look at ripple current , some caps had better ripple current as voltage went up in the caps value.
I like the Panasonic FM and FC series caps for excellent ESR values and a pretty good reputation for longevity. They do not come in High voltage applications and
that was another reason for my choice, but Chris Stevens notes were really why i tried the 22uf 50 volt ones, he actually used BC philips 35 volt 22uf caps. He also loved Wet Tantalums like the Ones in Dragans pics earlier in this thread.
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
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vinm
Joined: 06 Oct 2010
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