Hey, didn't we meet at Art's?

We sure did! Hope you get your problem fixed dude.

Cliff

bump (again):

Quick q for tse above or at : http://www.avsforum.com/avs-vb/show...6&&#post7001246

Update:
I am not giving up on this PJ {I guess I am a sucker for punishment or what?}
WHY you ask, right?

Well, when it IS working (converged and stable after 15 minutes) it does throw a very nice picture! :D :D

Hey Clarence (if you are reading this) remember I commented the other day that that Barco you were selling (to Dave?) had a VERY nice picture? This Ampro is already putting out a similar picture. AND...the focus board is totally dead AND the glycol is murky AND has not been set up 100% right! So I guess it sure does have potential!

Progress:
(1.) I ordered a Red C-element from Brenda at VDC, she says that the $100 does not include shipping and that "includes shipping" thing is a rumor on the internet!

(2.) Then I ordered a set of 2,4,6 pole CPC magnet assemblies from VDC, hoping to get rid of the triangular dots.
Funny that the Tech there (Nathan Thom) said that the Ampro 4200's Focus board has a bad reputation for reliability! Ya, tell ME about that! :eek:

(3.) I bought an Oscilloscope, a Powersupply, a function generator and a Sony 1271 Switcher on e-bay! I'm hoping to get that focus board repaired and look into why this @#$% convergence drifts. :cool:

Using the scope...I hope to get the sub-brite/contrast/gain adjustment done properly. I think a PC's software test pattern generator can be used as a direct replacement for a Video test pattern generator, right? :confused:

The PJ is still up there, I'm building a workbench and storage shelving in the basement first. No space to work plus I end up spending an hour to find some tool before using it!! HA HA


Lastly, I'm still waiting for tse to shed some light on the current ratings of that convergence board. Complete details are above.

-Rajiv

Raj, you are a trooper ;). I pray I NEVER have to go through what you are with my Ampro!

Finally had a chance to check the current limit circuit on the 3/4600 registration amplifier. It will limit at a nominal 1.9257576 amps. Had to recalculate that one.

Whenever the amplifiers tried to draw more current than that the limit circuit would essentially regulate the current to that value by turning down the conduction of the power transistors on the little aluminum plate. That would cause the plate to get hot and if it got hot enough the thermostat would trip which turned off the 25VDC that went to the output amps.

This all limited the maximum power draw from the LVPS to less than 100W for the registration amps. If you were using 100W for registration you were doing something wrong.

Finally had a chance to check the current limit circuit on the 3/4600 registration amplifier. It will limit at a nominal 1.9257576 amps. Had to recalculate that one.

Whenever the amplifiers tried to draw more current than that the limit circuit would essentially regulate the current to that value by turning down the conduction of the power transistors on the little aluminum plate. That would cause the plate to get hot and if it got hot enough the thermostat would trip which turned off the 25VDC that went to the output amps.

This all limited the maximum power draw from the LVPS to less than 100W for the registration amps. If you were using 100W for registration you were doing something wrong.


WOW, tse, you are my HERO ! :D :D :D

This will enable me to verify what is happening in that circuit once and for all !
Thanks a million!

I'll keep you posted on the progress.

Thanks again! :)

Ok, I finally got a chance to work on the focus board.

As others predicted the MOSFET on the power supply board is shorted out. The power diode is also shorted out. I found the Diode [FES16JT ] on Mouser, but no-one has the MOSFET. I called Mouser and they say their techs will look for an equivalent part.


The schematic specifies IXTH5N100 but my board has APT1002R4BN
It is a N-channel High Voltage Power MOSFET with these characteristics:

1000 volts, 5 Amp, 2.4 Ohm Rds

If anyone has an semiconductor equivalent book and can look up this information, I'll really appreciate it.

I did a google search but could not find anything online.

TIA!

-Rajiv

I just ordered a Mouser Equivalent for the MOSFET - STP5NB100
TO-220AB 1000 volts 5.0 amp 2.4 ohms
It's specs are the same as IXTH5N100.

Wish me luck !

Oops. The STP part is TO-220 package. Your original part is TO-247. The closest sub that Mouser stocks is STW9NK90Z. It is 900V but that will work ok. Peak voltage is less than 700V.

Be sure to check the 22 ohm resistor that is between the PWM chip and the mosfet. If it is gonzo the PWM chip is probably fried, too.

Oops. The STP part is TO-220 package. Your original part is TO-247. The closest sub that Mouser stocks is STW9NK90Z. It is 900V but that will work ok. Peak voltage is less than 700V.

Be sure to check the 22 ohm resistor that is between the PWM chip and the mosfet. If it is gonzo the PWM chip is probably fried, too.

You are right, tse, the TO220 package is a little smaller and the pin spacing is different, but I thought I could just spread the legs a bit...

The main reason why I chose the other one was because all specs including the Rds was matching with the originally spec --- 2.4 ohms.

The one you suggest has a Rds of 1.1 Ohms. I wonder if that makes a difference.??? :confused: :confused:

I do like the 8 amp rating though! Much better than 5 amp.


Thanks for the tip about the chip. :) I will check it out tonight.

-Rajiv

One more thing, tse,
What is the voltage INPUT to this power supply circuit?

Also, I am wondering why bother making a SMPS for just a simple 40 v DC. Maybe there is a lot of current involved???

The main input to the supply is about 300VDC. The output power is 80 or 100W (2 to 2.5A @ +40V). Something like that. The reason for the supply, in the first place, is to allow use of the model 2000/4000 SMPS while implementing magnetic focus. The electrostatic focus units did focus without needing that 80-100W.

Oh, yeah. It is usually better to have lower resistance in your mosfets. Just like have more current capability.

Rajdude,

I'm pretty sure the IXYS part can also be found on the HOT board in the 2000/4000. If the part you ordered does not work you might try to locate a spare HOT board. I have A 2000 HOT board that I have cannabalized some parts from. If you want, I can remove one of the IXTH5N100 mosfets from it.

HI Thurman ,
Sorry for the delay in my response and thanks for the offer.
I'll let you know soon if I need them.

-Rajiv

So I finally got some time to work on the PJ. I totally disassembled it and did the following mods:


Enlarged holes for all three fans
Changed Glycol
Installed red C element
Installed new CPC magnets (astigmator magnets) which have all three poles (2,4 AND 6)
Painted it black


After reassembly I carefully switched it on. No errors on the LCD. The new FM board's PSU is supplying +40V to the focus power amps. [THANKS a MILLION TO SCOTT!]

But soon… I smelt burning plastic. :eek: :eek: After sniffing around, I found out that some resistors on the registration amp board are overheating now.

Specifically, R69, R49 are heating up like crazy! :( Please note that I have the 3600/4600 reggie amp board {81010A) in my 4200. It was working just fine for a few months now. I checked the connector on the cable going to the yoke boards, I see two pins are nearly shorted out on all three tubes. I guess it is because of the windings, right?

I have connected the yoke interface plugs for front table config as per the Ampro 2000’s manual. Looks like something is not configured right

Apart from checking for shorts, I am stumped. PLEASE HELP!

-Rajiv

I think I know what the problem is here.

I just need to rotate the horizontal & vertical registration plugs on the yokes. :D


I remembered this after I looked at the circuit diagrams of the old and new reg boards. The new registration amp board (transplanted into my 4200) was taken from a 3600/4600. Those power amps invert the signals. Hence I had to rotate the connectors on the registration board to make it all work properly.

When I reassembled the PJ, I just connected them as per the old board. Hence the reg board is not working properly. I will test out my theory tonight (after I get back home from work)

I just hope I did not damage anything :(

-Rajiv

Guys,
Has anyone tried to reinforce Ampro PJs' case hinges?

Mine are broken (as most I've seen).

-Rajiv

How long before they will archive a old thread ?

A while... it only happens periodically.

You may want to loose the hinges along with the hood...

On my second 4600 I have set up in the garage I did an ON-OFF-BACK on again temperature check with a Fluke temperature gauge

I let it run for about 1 1/2 hours at each check point at an ambient temp of 23C constant

The hood alone adds 5 to 6C under the best thermal conditons...

This is set on saw horses about 3 feet off the ground. I can imagine in a small room the trapped ceiling heat and it's recycled trapped heat is going to make it even worse. I hate to do it ,but in this interest of my 1st 4600 already mounted on the ceiling downstairs, I might stick the hood on it (insert arrgh) and report back with any negatives

I haven't been following your thread as I don't have a 4200 and can add nothing other than a quick glance thru it, but chip and tse are dead on with the height/screen dim's

The Ampro's run cooler when their locations are level and slightly inside the screen height, or at least half the body splits the top image resulting in better focusing at the furthest distances ie. bottom.

Love those Magneplanar's!! All you need is some big and nasty Krell's to make them sing!

Regards
David

It has been a while since I visited this thread and noticed David's reply.


...I can imagine in a small room the trapped ceiling heat and it's recycled trapped heat is going to make it even worse.


Well, the HT room is getting ready and I am planning to counter this problem with a 6" cooling duct for the PJ. I plan to connect it to the two belly fan opening and sucking air out of the PJ using a quiet inline fan mounted remotely. (no belly fans in the PJ!)

How about that ?

So I finally got the PJ working again. It is hanging from the ceiling.

The dark paint on the room's walls REALLY helps!


Is there anything I can do further which can improve this PJ's focus?
Also, how to improve convergence? I run out of range in some settings.

Now that dreaded convergence drift is not there anymore (YAHOO!!) :D I still have to let it warm up ......but after that the convergence is stable.

The focus is still not what it should be. Also, running the HTPC at 1024x768 is relatively sharp. But if I increase the rez. to 1280x720 (720p) the image gets soft. :(

I can see scanlines at 1080i (via the cable box).
At 720p via cable box, the scan lines are still there but pretty faint.

The focus is not very sharp in the corners.

Apart from upgrading to a different PJ, what can I do?

Wow!
That sure is an overkill ( the dedicated AC)

If it was overheating, there has got to be something else wrong!

Exactly which board was overheating?

Rajdude,

Thanks for clarifying the BMP image thing.

Yes I we Ampro'ers need to help out each other as Dion would say!
I'm sure you must have seen his site.

I will post some stuff on your other thread about cooling.
I went overkill really...I have an air-conditioning (spot air conditioner -- located on the second floor ) which has a 120pi duct specifically dedicated for the projector --
try overheating on me now(!).......actually to be honest it never did...
but I just wanted to keep it fairly cool with the extreme humid summers we
have over here....summer were a bit tough....

It took me a few months to do it cos I had to re-enforce my ceiling with additional
Ipe beams.

Will get some more pics and info for you on your other thread which is probably more appropriate.

Wow!
That sure is an overkill ( the dedicated AC)

If it was overheating, there has got to be something else wrong!

Exactly which board was overheating?

Rajdude,

Normally nothing overheats, or gave me any problems. But when I had it floor mounted I found that it ran a lot better with the cover off and the lid open (where the registration board is located). When
I decided to mount in on the ceiling I got a dedicated Air-Conditoning unit just to use mainly in the summer (I haven't finished it all yet, but it's almost there, basically I'll be able to control the amount of cool air that flows in also).....due to my room layout my normal air conditioning unit is situated at the far end of the room near the screen and was not really powerful enough to keep the room cool in the summer.

And another reason was that eventually I may take out all the fans....I say I may cos not sure at this stage unless I've tested it a bit more to see how it performs. Or I might just get lower noise fans for the LVPS and the two 80cm fans above the RGB board/Horizontal board etc.... At the moment the belly fans are gone for good. I think on the 4300 the LVPS fan is also 80cm as standard, but would have to measure it to check.


I'll send you some pics in the next few days once I can get hold of my digital camera!

H,mmmm.
that 4300 has 5 fans , eh?

the 4200 has only three, two 80mm belly fans and one 60 mm in the LVPS.

Pics man ! We need to see the pics! :D

Rajdude,

Normally nothing overheats, or gave me any problems. But when I had it floor mounted I found that it ran a lot better with the cover off and the lid open (where the registration board is located). When
I decided to mount in on the ceiling I got a dedicated Air-Conditoning unit just to use mainly in the summer (I haven't finished it all yet, but it's almost there, basically I'll be able to control the amount of cool air that flows in also).....due to my room layout my normal air conditioning unit is situated at the far end of the room near the screen and was not really powerful enough to keep the room cool in the summer.

And another reason was that eventually I may take out all the fans....I say I may cos not sure at this stage unless I've tested it a bit more to see how it performs. Or I might just get lower noise fans for the LVPS and the two 80cm fans above the RGB board/Horizontal board etc.... At the moment the belly fans are gone for good. I think on the 4300 the LVPS fan is also 80cm as standard, but would have to measure it to check.


I'll send you some pics in the next few days once I can get hold of my digital camera!

Yes 5 in the 4300, 2 120mm belly fans and 3 80mm....shall get pics soon!

H,mmmm.
that 4300 has 5 fans , eh?

the 4200 has only three, two 80mm belly fans and one 60 mm in the LVPS.

Pics man ! We need to see the pics! :D

Calling all Ampro experts!

I have noticed a couple of new issues other than what I am discussing in the “dots” thread. So I want to move the ampro related issues to this thread since that dots thread is getting a lot of posts regarding the original topic (which is good!)

Most of the convergence controls are reversed.
For example, if I want to move the lines to the left, I have to press the right cursor button (on the wired remote). Same for vertical controls.

I wonder is this why I run out of convergence range. :confused:

Curved top and bottom

I also have the horizontal (top and bottom) keystone maxed out when the memory is nulled. But even after that the picture has curved top and bottom.


The screen is 86" wide and the PJ is around 120 inches from the screen. For stock HD10 lenses, I guess this is OK.

Ok Chip,
I will try that out tonight.
Thanks!


This is the test pattern I want you to use while playing with the blanking system. See the three vertical lines that look out of place? This is usually caused by the blanking system. This has been discussed here many times in the past. It shows up most on internal test patterns but can cause problems in the projected image.

Chip

Chip is referring to this image:
http://funkyhuman.com/hosted_images/IMG_5131.JPG

I also measured the screen. The screen is actually 86inches wide (NOT the 76 inches I have been posting) I wonder where I got that 76 number. Diagonally (for a 16:9 Image) the image measures around 98”.

So I guess this means that I really don’t need the HD10L lenses.


Over the weekend, I also moved the PJ a little further back. This filled out the whole screen with 1080i sources. The raster is also maxed out but there is something like 5 mm unused raster on the sides. That should be fine.

I also tilted the PJ back a little bit down. This helps in the convergence. It has raised the image to the top of the “painted wall” screen.

Chip,
I tried that out yesterday night, and you were right !
By adjusting the left blanking I am able to get rid of the three weird lines (shown in the shot below)

But quite frankly, I did not see an improvement anywhere else. The externally fed test patterns were fine earlier. I did not get a chance to look at them (the wife just does not appreciate the entertainment value of test patterns ! ;) )


Ok Chip,
I will try that out tonight.
Thanks!




Chip is referring to this image:
http://funkyhuman.com/hosted_images/IMG_5131.JPG

Hey Scott! :D
Where are you these days ???

That new toy is keeping you busy?


Calling all Ampro experts!

I have noticed a couple of new issues other than what I am discussing in the “dots” thread. So I want to move the ampro related issues to this thread since that dots thread is getting a lot of posts regarding the original topic (which is good!)

Most of the convergence controls are reversed.
For example, if I want to move the lines to the left, I have to press the right cursor button (on the wired remote). Same for vertical controls.

I wonder is this why I run out of convergence range. :confused:

Curved top and bottom

I also have the horizontal (top and bottom) keystone maxed out when the memory is nulled. But even after that the picture has curved top and bottom.


The screen is 86" wide and the PJ is around 120 inches from the screen. For stock HD10 lenses, I guess this is OK.

Hi Rajiv,

Here are some pics of the vents that I've used.

#Pic 1 PJ with two outgoing vents and 1 incoming cold air (air-conditioned)


#Pic 2 Closeup of outgoing vents, these are 100mm pi ducts.


#Pic 3 Vents inside PJ

#Pic 4 Another pic of PJ this time I'm using two cold vents, one for the PSupply.


#Pic 5 I am using this type of AC fan, but the one I'm using has a 100mm pi vent connected to it, this is an old type I used for another projector. The current one is inside the ceiling in another room and difficult to take pics!

I will probably go for the configuration shown in #Pic 4, though all this will be boxed in at the back, so most of the vents won't be visible. I'm still experimenting! Today I spent 3 hours converging this @1080p coming out from a Faroudja DVP 3000 (SD DVD), it looked very nice! But still have to do grayscale and G2 settings. I haven't even touched astigmation yet. Anyway running it for 6 hours today, the system temperature was almost constant around 23 degrees and PS temperature was again almost constant around 21/22 degrees centigrade....I checked evey half an hour....and it just didn't shift...and the picture did look pretty amazing. I still have to do some more work on it though, need to move my screen a bit forward, get the rear hushbox done, and hopefully get HD-DVD fed into it!

Shaz

Remaining pics,

Excellent work Shaz ! I must say it looks like an octopus now!

I guess after being boxed it it wont look so ....ummm.... shall I call it ..."strange" ?

I like how you raised the horizontal supports off the PJ's belly by using the bolts. (seen in Pic 2) I will have to do something like that since the front support partially covers the fan openings.

I bought 4" start collars / flanges for providing a secure transition to the ducts to the PJ. I still have not done anything to my PJ. Maybe tonight I will get some time to work on it. The wife is not home tonight ! ;) :D :D

Hey Scott! :D
Where are you these days ???

That new toy is keeping you busy?

I've been working on this. The simulations show about flat response to 80MHz. No promises. If it makes it then 1080p will work alot better than with standard 4200 CRT cards. Maybe the RGB board won't take too much work. This is kinda a long shot but worth a little time and effort.

Scott

Hi Scott, while I have your attention, do you have any idea on solving this problem:

http://www.avsforum.com/avs-vb/showthread.php?p=8560304&&#post8560304

Basically,
I run out of convergence range in width linearity and top/bottom keystone.
and my convergence controls work in reverse

Hi Scott, while I have your attention, do you have any idea on solving this problem:

http://www.avsforum.com/avs-vb/showthread.php?p=8560304&&#post8560304

Basically,
I run out of convergence range in width linearity and top/bottom keystone.
and my convergence controls work in reverse

Not sure if this works with a 4200 but press 33[code] and read the results on the remotes LCD display. It sounds as if it's set up for rear projection or some other projection format. If you have a owners manual double check all your sweep connections.

Chip

Calling all Ampro experts!

I have noticed a couple of new issues other than what I am discussing in the “dots” thread. So I want to move the ampro related issues to this thread since that dots thread is getting a lot of posts regarding the original topic (which is good!)

Most of the convergence controls are reversed.
For example, if I want to move the lines to the left, I have to press the right cursor button (on the wired remote). Same for vertical controls.

I wonder is this why I run out of convergence range. :confused:

Curved top and bottom

I also have the horizontal (top and bottom) keystone maxed out when the memory is nulled. But even after that the picture has curved top and bottom.


The screen is 86" wide and the PJ is around 120 inches from the screen. For stock HD10 lenses, I guess this is OK.

On the 4200 projectors, when you change the configuration of the projector (table/ceiling and front/rear) with the deflection connectors on the yoke bds you have to also change the registration connectors. If you look at the pic you can see two connectors with two wires each. The board is labled horiz and vert. Those are the registration connectors. It sounds like you need to unplug them, turn 180 degrees, and plug back in. Then left will be left and vert will be vert. That might be why you run out of range. Also, pay attention to the highlighted areas on the internal test patterns. Use "4" "test" with your video source connected to register. When you adjust SIZE only converge the area between the middle and half way to the edge of the screen. Use the LIN adjustments to do between the middle and edge of the screen.

Scott

33 code gives me this:

Ceiling mounted
Front Projection

This is correct. I have all manuals Ampro made :) I use the 4000's manual for the sweep connector settings. They checkout fine. :confused:
Running out of ideas now :mad:

Not sure if this works with a 4200 but press 33[code] and read the results on the remotes LCD display. It sounds as if it's set up for rear projection or some other projection format. If you have a owners manual double check all your sweep connections.

Chip

Hi Scott,
Yes, I did change the deflection AND the registration connectors.

Strangely...The image shift and phase controls do work correctly. :eek:

Only the registration controls dont work as they are supposed to. :confused:

But note that I swapped out the reg amp board with the one on the 4600? That board's circuit is slightly different. The op-amps are fed with the inverting input instead of the regular input in the older boards. (Remember we discussed this quite some time back.... it is somewhere up in this thread)? Hence the output is inverted.

To counter that, I just inverted the connectors going to the convergence yokes.


I remember another thing:
When I had totally dismantled this PJ and then re-assembled it, I forgot that I had to invert the connectors on the reg amp board. As a result the resistors were overheating! I turned those connectors around and things became normal.

I am willing to try anything. if I rotate the reg. connectors on the yoke board...will it hurt anything? (of course I will shut down the PJ first!)

Maybe that will make the registration controls work properly?

But doesn't this do the same thing as rotating the same cable's end on the reg amp board (as above)...and hence overheating resistors.


On the 4200 projectors, when you change the configuration of the projector (table/ceiling and front/rear) with the deflection connectors on the yoke bds you have to also change the registration connectors. If you look at the pic you can see two connectors with two wires each. The board is labled horiz and vert. Those are the registration connectors. It sounds like you need to unplug them, turn 180 degrees, and plug back in. Then left will be left and vert will be vert. That might be why you run out of range. Also, pay attention to the highlighted areas on the internal test patterns. Use "4" "test" with your video source connected to register. When you adjust SIZE only converge the area between the middle and half way to the edge of the screen. Use the LIN adjustments to do between the middle and edge of the screen.

Scott

The orientation of the convergence coil connectors will not change the power level of anything. It just causes the opposite thing to happen as far as convergence is concerned. I suggest that you plug the two position connectors in the direction that gives proper movement on the screen. Just reverse them and turn on the projector. Don't make adjustments, just let it run and satisfy yourself that all is well. You will have to completely redo registration. Everything will be opposite of what it should be.

Scott

Yes, the vents do look a bit "octopus like", once the box goes up it will all dissapear.....and so should the octopus!

Raising the horizontol supports was handy for the ducts, and also for tightening the bolts above from the mount -- makes it a lot easier to work with.

Well, post some pics when u've done your ducts!

Shaz


Excellent work Shaz ! I must say it looks like an octopus now!

I guess after being boxed it it wont look so ....ummm.... shall I call it ..."strange" ?

I like how you raised the horizontal supports off the PJ's belly by using the bolts. (seen in Pic 2) I will have to do something like that since the front support partially covers the fan openings.

I bought 4" start collars / flanges for providing a secure transition to the ducts to the PJ. I still have not done anything to my PJ. Maybe tonight I will get some time to work on it. The wife is not home tonight ! ;) :D :D

The orientation of the convergence coil connectors will not change the power level of anything. It just causes the opposite thing to happen as far as convergence is concerned. I suggest that you plug the two position connectors in the direction that gives proper movement on the screen. Just reverse them and turn on the projector. Don't make adjustments, just let it run and satisfy yourself that all is well. You will have to completely redo registration. Everything will be opposite of what it should be.

Scott


hey Scott and Chip!

A BIG THANKS (again!)

Your hint was absolutely right. I reversed the convergence connectors on the yoke board and both issues got solved in a jiffy ! No overheating resistors too !:D :D

I no longer have curved top and bottoms, I have plenty of range in all controls. The convergence is spot on ! I pic never looked better. I will post some screenshots soon. :D :D

I just cant thank you enough! :D

Now, only if we can get rid of the lines caused by SMPS and I am a happy camper!

Rajiv,

That's great news! Glad to hear u got the convergence thing sorted at last. Must feel really nice hey?!

Shaz

hey Scott and Chip!

A BIG THANKS (again!)

Your hint was absolutely right. I reversed the convergence connectors on the yoke board and both issues got solved in a jiffy ! No overheating resistors too !:D :D

I no longer have curved top and bottoms, I have plenty of range in all controls. The convergence is spot on ! I pic never looked better. I will post some screenshots soon. :D :D

I just cant thank you enough! :D

Now, only if we can get rid of the lines caused by SMPS and I am a happy camper!

"Scott and Chip"? Don't you mean Wayne and Garth?
We're not worthy, We're not worthy... :D

Hey Scott!
I was just wondering if you got some time this long weekend to work out those SMPS lines on your 4200? :)

Finally dived in. I moved the 2000 out of the way and set the 4200 in place. That took alot of ambition 'cuz I was wanting to work on something else and didn't really feel like working on projectors all weekend. My projector is my television. I haven't owned a direct view TV for more than 20 years. The 2000 was looking so good. So it's pretty much set-up. It does look a little better than the 2000 but not as good as it should. I'm thinking the coolant fluid in this thirteen year old projector is a little cloudy. The sharpness just isn't there.

The projector has been on continuously for eight hours. Guess it isn't going to blow-up right away.

The extra "lines" are there whenever the registration is turned on. It looks like SMPS noise but might be something else. I'll tackle it once the focus is like it should be.

Scott

Scott, when I first got this 4200, I felt the same way.
The coolant was very murky and the image was not clear. Once I changed the coolant, the image improved dramatically.

You gotta change the glycol, extremely easy on these Ampros....but of course you dont need me to tell you that ;)

As for improving the focus and the lines....I am waiting with bated breath.... :D

I highly recommend swapping the Reg amp board with one from a 3/4600. It is a direct swap. MUCH better convergence! You may have one lying around.

Just one look at that heatsink on the stock 4200's reg amp and you know it all ! :(

The extra "lines" are there whenever the registration is turned on. It looks like SMPS noise but might be something else. I'll tackle it once the focus is like it should be.

Scott

Scott,

I'm another guy who has the same "line" problem on my 4200 (for the last 6 years). You're right - I never noticed, but it goes away when the registration is turned off. The first thing I did was to re-cap the SMPS. It improved the image quite a bit, but the extra line mess didn't go away.

It must be a common 4200 problem. I too will be very gratefull if you can find the problem.

Interestingly enough, my 4200 uses exactly the same P/N reg amp board as my 4600 (which hasn't replaced the 4200 yet).

Ray

My 2000 didn't have this problem and I'm pretty sure that it has the same registration board. The difference being the 4200 has the green convergence option. The output amps might be different, too. Do you guys have the green option with your sets?

Scott

Scott,

My 4200 doesn't have the green convergance option. That's great that you found one with the option.

I probably told you before, but I had a pair of zero hour NOS 2000G that I recently sold to friends. I once tried to stack them, and I remember checking with Elite Video about cost to upgrade to the COG option. When I found out I'd have to take out a second mortgage to modify them, I gave up on the idea. They told me that I'd also have to swap out the CPU modules to get the software upgrade to control the registration board.

When I set up the first 2000 at my friend's house using a good screen, I could have kicked myself for selling them. The picture was drop dead beautiful, and rock solid stable. It had that elusive 3-D picture quality about it. Really a great little projector.

Ray

Hello

I am looking for a Ampro 4600 motherboard.I will upgrade my 4300 to a 4600.I have all other
parts from two 3600 but the moterboard is different. I change the focusboard and the focuscoils from the 3600 to the 4300 and the focus becomes mutch better.I also change the
neckboards.

Regards
Piet

Scott,
How do I find out if my PJ has this convergence on green option?
Also, what is this option and what does it do?

-Rajiv

My 2000 didn't have this problem and I'm pretty sure that it has the same registration board. The difference being the 4200 has the green convergence option. The output amps might be different, too. Do you guys have the green option with your sets?

Scott

There are a bunch of little daughter boards attached to the registration board for the green convergence option. Some of them are for contrast modulation.

I took them off and though it might have reduced the noise there was still some there. There was also an I2C bus error diplayed on the remote control.

The 2000 has a later right hand section than the 4200. That might be the difference. I'll try to find out if they can be swapped and compare the noise level.

Both have center section with p/n 80892. Right hand section of 4200 is 80893. The 2000 has 81289.

Scott

Scott,

My 4200 doesn't have the green convergance option. That's great that you found one with the option.

I probably told you before, but I had a pair of zero hour NOS 2000G that I recently sold to friends. I once tried to stack them, and I remember checking with Elite Video about cost to upgrade to the COG option. When I found out I'd have to take out a second mortgage to modify them, I gave up on the idea. They told me that I'd also have to swap out the CPU modules to get the software upgrade to control the registration board.

When I set up the first 2000 at my friend's house using a good screen, I could have kicked myself for selling them. The picture was drop dead beautiful, and rock solid stable. It had that elusive 3-D picture quality about it. Really a great little projector.

Ray

Yeah, the 2000s were nice little projectors. The 4200 has all the same bds except for the mother bd and focus modulator. There were several revision levels, though. My 4200 is a 1993 model. My 2000 was built several years later, very near the end of Ampro.

EV was jiving you about the CPU exchange. This 4200, with the options, has the older, long CPU card. Probably just an EEprom change needed to install the options.

Scott

Hello

I am looking for a Ampro 4600 motherboard.I will upgrade my 4300 to a 4600.I have all other
parts from two 3600 but the moterboard is different. I change the focusboard and the focuscoils from the 3600 to the 4300 and the focus becomes mutch better.I also change the
neckboards.

Regards
Piet

The main difference between the two mother boards is the 4600 was built to meet UL (the US version of VDE) specs. There were some spacing changes made between connectors with higher voltages. I don't remember any big differences other than that. I'll try to find more details but I think it wouldn't take too much work to adapt a 4300 mother bd to a 4600.

Scott

Hello
Yes it is hard to find the difference because it is 3 layer motherbord .Therefor i am looking
for a 4600 motherboard.

Piet

Is there that much of a difference between a 4300 and 4600?......My understanding was that they are pretty much the same machine. With only slight improvements on focus (stronger magnets on 4600) and a brighter image (36Kv HVPS vs. 34Kv on the 4300).

Shaz

Hello
Yes it is hard to find the difference because it is 3 layer motherbord .Therefor i am looking
for a 4600 motherboard.

Piet

Send me the part number for the 4600 MB, I may have one... stacks and stacks of parts ;)

hello
The part number is 65434 RV A

Piet

Rajiv, did you ever post any pics of your 4200? Or, better yet, is the 4200 working well?

Don

Hi Don,
I thought I did :) didn't I?
They should be earlier in this thread. :confused: If not I can post them together somewhere here.

....and YES! the 4200 works very nicely. Due to the help of everyong at AVS especially Scott and Chip and a couple of others, I ahve got it to a point where it is satisfying. It's convergence is stable and does not overheat at all (never did anyway)

Of course the tweaker inside me wants more from it ! :p HA HA.

So you got one too? :confused:

Rajiv, did you ever post any pics of your 4200? Or, better yet, is the 4200 working well?

Don

I haven't yet read through all of this thread, so sorry if this question has already been asked/answered.

With all of these modifications/tweaks, what is the max resolution that you have been able to display with the 4200? I seem to recall Ray mentioning in the past that the 4200 seems to throw a fit if you increase the resolution much over 720P, and therefore 960P/1080P was not a realistic option. Just wondering if this is still the case or whether I'm mistaken.

I have a 4200, basically sitting idle in the corner of my garage, that I may finally give another go after making my way through the posts in this thread. Looks like a lot of useful information posted here and it's much appreciated.

Thanks,

Dan

Hi Dan,
I am not sure what it means by "throwing a fit" but I have fed my 4200 resolutions all the way up to 1920 x 1440p (a 4:3 version of 1080p) It never has given be any error.

Now whether it is able to resolve those resolutions is another question!

The best it can do (with my setup) is 720p and 1080i. Both these rezs are resolved very nicely and I view these rezes daily.

I have tried feeding 1080p to it but the image becomes soft. This PJ does not have the bandwidth for 1080p. I have also tried 960p but it also is too soft.

Frankly where will you get 1080p content these days anyway?

One thing I must point out....the 4200 has an issue with "phantom scan lines", Scott may be able to solve it.

Further details on resolution and this issue can be seen in another thread I started:
http://www.avsforum.com/avs-vb/showthread.php?t=726083



I'd say fire it up ! You wont regret it!
Good luck!



I haven't yet read through all of this thread, so sorry if this question has already been asked/answered.

With all of these modifications/tweaks, what is the max resolution that you have been able to display with the 4200? I seem to recall Ray mentioning in the past that the 4200 seems to throw a fit if you increase the resolution much over 720P, and therefore 960P/1080P was not a realistic option. Just wondering if this is still the case or whether I'm mistaken.

I have a 4200, basically sitting idle in the corner of my garage, that I may finally give another go after making my way through the posts in this thread. Looks like a lot of useful information posted here and it's much appreciated.

Thanks,

Dan

The 4200 is perfectly capable of scanning at 1080p. The video bandwidth is not quite up to what it needs to be, though. I'm not trying to get any hopes up but I'm working on a bandwidth upgrade. I just bought a 4200 and with the Sony tubes it will never be quite as sharp as a projector with Panasonic tubes. But, it should still be capable of a good picture. First thing is the neck cards have to have a fairly flat responce out to 80MHz. My spice simulations show that this is possible but the simulations are usually a bit optimistic. I've started on building the neck card but probably won't get the parts that I ordered until next week. If it works good enough then the RGB board's BW will be checked. With some luck the 4200 will be in 1080p territory.

Scott

Scott,

This might be a good time to mention another issue.

In addition to the "phantom scan line" issue with my 4200, the other problem I've always had is related to the scan frequency of the source. There is a relay circuit on the HOT board that switches in any of three possibe "compensation(?)" circuits based on the frequency of the source material (lo, medium, and hi freq).

If memory serves me right, the vertical board has the frequency sensor circuit composed of some op amps that drive the relays on the HOT board.

My problem is that around 38khz the board switches from the mid freq range to the hi freq relay circuit on the HOT board. The net effect is that 1080I material (32khz) there is no switching, and I am ok. However, for 720P and above (1080P) material, the hi freq circuit switches in, and it severly cuts down the max width of my rasters.

I put a jumper on the freq detection circuit so I always stay in the mid freq range. That at least gets me up thru 720P with max width rasters available. For anything above 720P such as 1080P, I can't get the registration to correct the convergance.

If I remove the jumper, I can run at 1080P, but my raster width shrinks by about 1/3.

Just curious if you guys have the same problem?

Sorry to keep dumping these problems on you. I'm not sure where all the 4200's are coming from lately. For years, there was only 2 or 3 of us with 4200's here at the forum.

Thanks,
Ray

Something is wrong. The HOT bd regulates the deflection current so the raster should stay fairly constant in width. 1080p is around 68KHz which shouldn't be a problem for the 4200.

Scott

OHHHH LA LA !!! Sounds SHWEEEEET !!! :D :D :D

Scott, I am getting goosebumps ! sitting here and reading this. :eek:
Hey how come you get these neck boards made so quickly? You etch them yourselves?

But frankly, if you find a way to get rid of the phantom scanlines, that will be even nicer. With the lack of 1080p content, I really dont worry about that too much.


Now now.... I am asking to too much too soon !
Scott, keep up the good work ! Let us know if you need any help or test guinea pigs or something.

The 4200 is perfectly capable of scanning at 1080p. The video bandwidth is not quite up to what it needs to be, though. I'm not trying to get any hopes up but I'm working on a bandwidth upgrade. I just bought a 4200 and with the Sony tubes it will never be quite as sharp as a projector with Panasonic tubes. But, it should still be capable of a good picture. First thing is the neck cards have to have a fairly flat responce out to 80MHz. My spice simulations show that this is possible but the simulations are usually a bit optimistic. I've started on building the neck card but probably won't get the parts that I ordered until next week. If it works good enough then the RGB board's BW will be checked. With some luck the 4200 will be in 1080p territory.

Scott

My problem is that around 38khz the board switches from the mid freq range to the hi freq relay circuit on the HOT board. The net effect is that 1080I material (32khz) there is no switching, and I am ok. However, for 720P and above (1080P) material, the hi freq circuit switches in, and it severly cuts down the max width of my rasters.



Ray,
My PJ does the same thing, anything above 1080i like 720p and above, the raster ends up with around an inch blank on both sides. :mad: (well, let me be accurate…..maybe a quarter of an inch for 720p, more for 1080p) I was thinking of playing with the width pot a little, but have not done that yet.

By the way, what does that compensation circuit do? I wonder if that makes the image soft :confused:



I put a jumper on the freq detection circuit so I always stay in the mid freq range. That at least gets me up thru 720P with max width rasters available. For anything above 720P such as 1080P, I can't get the registration to correct the convergence.

If I remove the jumper, I can run at 1080P, but my raster width shrinks by about 1/3.

Just curious if you guys have the same problem?


I don’t have an issue with convergence at 1080p, but then my convergence amp board is from a 4600. When I first swapped it…I noticed it does have higher gain than the older one, and oh yes! MUCH more stable.



As for the raster shrinking to 1/3….I don’t think my rasters go that small at 1080p…..they are just slightly smaller than 720p.

So basically it means that your PJ is unusable at 1080p because of the 1/3 raster ? :eek:
(unless, of course, that jumper thing)

Something is wrong. The HOT bd regulates the deflection current so the raster should stay fairly constant in width. 1080p is around 68KHz which shouldn't be a problem for the 4200.

Scott

Scott,

I tried swapping both the HOT board and vertical board in the 4200 with all the boards in the 2000G models and didn't see any difference with the 1080P width problem. I didn't know what else to try or look at.

My "max width" pot is maxed out to get the raster as large as possible. I'm driving a rather large screen, and I need all the phosphor I can get. I suspect it could be tied in to the width problem. It's borderline stable at 1080P.

By the way, my favorite "feature" for the 4200 is the swapability of spare parts with all the 2000's out there. Also, no surface mount components, just plug in IC's.

-Rajiv

My 4200 already had the same convergance amp board as the 4600. I don't know if the Panasonic tubes have something to do with it. I had sort of given up on 1080P because of the phantom scan lines, and the overall soft image. I don't really have a 1080P source other than the computer which I don't like to use. I was playing with PowerStrip once, and it sent out a super high scan rate that fried some components on the HOT board. No more.

Ray

My "max width" pot is maxed out to get the raster as large as possible. I'm driving a rather large screen, and I need all the phosphor I can get. I suspect it could be tied in to the width problem. It's borderline stable at 1080P.


Ray,
after you changed the width pot, did you have:
1. heat issues? [Overheating etc]
2. unstability at 1080p?

Mine is stable at 1080p and I wonder if increasing the width caused your unstabillity

-Rajiv



My 4200 already had the same convergance amp board as the 4600. I don't know if the Panasonic tubes have something to do with it. I had sort of given up on 1080P because of the phantom scan lines, and the overall soft image. I don't really have a 1080P source other than the computer which I don't like to use. I was playing with PowerStrip once, and it sent out a super high scan rate that fried some components on the HOT board. No more.

Ray

Yes, agree with you Ray, but with Scott's upgrades we may be able to tackle that issue.

The bigger issue (IMHO) is the focus and the phantom scan lines. Of course having Sony 09MI tubes does not help either.


Hey, do your phantom scan lines change at all , if you run different resolutions or different refresh rates? Mine dont....unless I am doing 1080p and then the whole picture softens...softening those" "phanton scan lines" too...but not by a whole lot.

Lastly I too am really afraid with powerstrip. I once fed my PJ some high refresh rate but luckily I had my hand on the power switch! :eek: I was saved that day but will never try that trick again. :o

I see Ray has given a pretty thorough description of what I had recalled reading in some old posts that I referred to in this thread as 'throwing a fit.' I'm sure Scott will be able to provide some insights as to the cause and solution and it will be interesting to see what he comes up with.

Thanks for the link to your other thread Rajiv. I had completely missed it. Looks to be exactly the type of info I was looking for and I will spend some time reading it all the way through.

Still not sure if I'll give the 4200 another go or not. Mainly due to convenience issues and lack of technician skills on my part, though, and certainly not anything to do with a lack of capabilities on the part of the projector. I'll keep reading this thread all the way through first before throwing in the towel completely and just selling it off.

Thanks again for the replies and info,

Dan

Scott,

This might be a good time to mention another issue.

In addition to the "phantom scan line" issue with my 4200, the other problem I've always had is related to the scan frequency of the source. There is a relay circuit on the HOT board that switches in any of three possibe "compensation(?)" circuits based on the frequency of the source material (lo, medium, and hi freq).

The relays short across the linearity coils as you go up in frequency. At 15KHz all three are in connected in series as lower frequencies need more linearity correction. Above 48KHz all should be shorted across.

If memory serves me right, the vertical board has the frequency sensor circuit composed of some op amps that drive the relays on the HOT board.

My problem is that around 38khz the board switches from the mid freq range to the hi freq relay circuit on the HOT board. The net effect is that 1080I material (32khz) there is no switching, and I am ok. However, for 720P and above (1080P) material, the hi freq circuit switches in, and it severly cuts down the max width of my rasters.

When the raster size is in the reduced state does the static keystone still work? I'm not asking you to blow-up your projector. Don't mess with this if you don't feel comfortable. At the factory we would pull the two position connector that goes from the Spellman to the mother bd. The HV wouldn't come up so the tubes wouldn't be damaged if something went wrong.

I put a jumper on the freq detection circuit so I always stay in the mid freq range. That at least gets me up thru 720P with max width rasters available. For anything above 720P such as 1080P, I can't get the registration to correct the convergance.

If I remove the jumper, I can run at 1080P, but my raster width shrinks by about 1/3.

You sound like you have some technical knowledge. Can you use a scope? Do you have access to one?

Just curious if you guys have the same problem?

Nope.

Sorry to keep dumping these problems on you. I'm not sure where all the 4200's are coming from lately. For years, there was only 2 or 3 of us with 4200's here at the forum.

Thanks,
Ray

Scott

OHHHH LA LA !!! Sounds SHWEEEEET !!! :D :D :D

Scott, I am getting goosebumps ! sitting here and reading this. :eek:
Hey how come you get these neck boards made so quickly? You etch them yourselves?

They came from www.apcircuits.com . Email your board files and two days later you have your boards. I got four of the neck cards (they only make them in pairs) for $120 including shipping.

But frankly, if you find a way to get rid of the phantom scanlines, that will be even nicer. With the lack of 1080p content, I really dont worry about that too much.

I know I said it looks like power supply noise but when the registration is off and the noise goes away it points more in the registration board's direction. My 2000 without the noise has a different section of reggie bd. That might be it. Still trying to find out if the firmware needs to be different to use it in the 4200.


Now now.... I am asking to too much too soon !
Scott, keep up the good work ! Let us know if you need any help or test guinea pigs or something.

Guinea pigs may be needed later.

Scott

I see Ray has given a pretty thorough description of what I had recalled reading in some old posts that I referred to in this thread as 'throwing a fit.' I'm sure Scott will be able to provide some insights as to the cause and solution and it will be interesting to see what he comes up with.

I think that I know what you are talking about. If you increase the width pot you reach a point where the picture starts scrambling like it's loosing sync? That is the overwidth protection circuit kicking in. It usually makes you back off on the width pot pretty quickly, doesn't it? It looks bad but doesn't hurt anything as long as you don't leave it like that. If you do something is apt to blow-up.

Thanks for the link to your other thread Rajiv. I had completely missed it. Looks to be exactly the type of info I was looking for and I will spend some time reading it all the way through.

Still not sure if I'll give the 4200 another go or not. Mainly due to convenience issues and lack of technician skills on my part, though, and certainly not anything to do with a lack of capabilities on the part of the projector. I'll keep reading this thread all the way through first before throwing in the towel completely and just selling it off.

Oh, dust it off and play with it some more. If you think you might want to sell, do it soon. The prices aren't likely to be going up.

Thanks again for the replies and info,

Dan

Scott

They should be earlier in this thread. If not I can post them together somewhere here. I didn't them as I was looking for pics of the way it is working now.

So you got one too? Not yet, but am thinking about a 4200 on Curt Plame's site.

Anyway, this was/is a very good and informative thread! If Steve does come up with new neck cards, that will make me even more interested..... :cool:

don

I didn't them as I was looking for pics of the way it is working now.

Not yet, but am thinking about a 4200 on Curt Plame's site.

Anyway, this was/is a very good and informative thread! If Steve does come up with new neck cards, that will make me even more interested..... :cool:

don


Hi Don,

You can see some of my 4200's recent pics on this thread:
http://www.avsforum.com/avs-vb/showthread.php?t=726083

After that I have improved the convergence and geomtery so it looks even better. If I get some time tonight.... I will post new pics here.

As for getting a Stock 4200 now....may I suggest getting Sony G70 instead. Not that there is anything wrong with a Stock 4200 as such but I see so many things that must be tweaked in a stock 4200 to make it look nice!!

So unless you are a tweaker OR find a 4200 which already has been tweaked...I think you will end up spending a lot of time with your 4200! :eek:

That said...it is a very satisfying PJ for a tweaker type guy.



BTW...by Steve...you really mean Scott right? ;)

Yes, we too are waiting for his neck board mods...maybe they will elevate the status of this PJ !



By the way, did I ever post a list of all the mods/tweaks I have done to my 4200 here?

Oooppsss Yea, I meant Scott. And no, I don't think I ever saw a complete list. It would be great if you have time to post them.

Don

Thanks Scott -

The relays short across the linearity coils as you go up in frequency. At 15KHz all three are in connected in series as lower frequencies need more linearity correction. Above 48KHz all should be shorted across.

That makes a lot of sense. I've always been frustrated with the Ampro schematics. There's always a minimum of information about waveforms, voltages, and functionality.

When the raster size is in the reduced state does the static keystone still work? I'm not asking you to blow-up your projector. Don't mess with this if you don't feel comfortable. At the factory we would pull the two position connector that goes from the Spellman to the mother bd. The HV wouldn't come up so the tubes wouldn't be damaged if something went wrong.

Wow-sounds like I should be careful! I remember when I first got the 4200 and I called Ampro just before they went under. I talked to a guy (Bill Fowler I think - did you know him?) and he warned me about running the projector with the width pot set too low. At the time I was clueless. Does that sound like the same issue?

You sound like you have some technical knowledge. Can you use a scope? Do you have access to one?

I was an electronic technician in the Army for 4 years, then went on to get my EE. I designed a crude oscilloscope for my senior thesis project (mostly borrowed some Heathkit schematics). I'm a Sr. Control Systems eng at Rockwell now. I don't have a scope, but have often wished I did. I would only need it for the 4200, and just couldn't justify it. I'll have to see if I can borrow one somewhere.


I think that I know what you are talking about. If you increase the width pot you reach a point where the picture starts scrambling like it's loosing sync? That is the overwidth protection circuit kicking in. It usually makes you back off on the width pot pretty quickly, doesn't it? It looks bad but doesn't hurt anything as long as you don't leave it like that. If you do something is apt to blow-up.

That's exactly what happens. Is there any other way to get full size raster's other than the width pot?



Ray

Ray,

It's good to see a fellow EE in this thread. Watch out, we'll put you to work! :p I think Rajiv has technical training, too.

There is a reason your projector isn't scanning right at 1080p. It sounds like the width regulator circuit doesn't have enough voltage coming in. That's why I asked about the static keystone. The keystone is produced when the width circuit modulates the voltage going to the yokes with a vertical frequency ramp. If there isn't enough headroom the width will be low and the modulation won't work. I'll bet your pj is ceiling mounted? Could you try this in your spare 2000? I can try to guide you through fixing it if you like or if you want to send me one of your HOT bds I'll check it out for you.

Do you work with or know someone that does RF design with bipolar transistors? I'd sure like to ask that person a couple of questions concerning this CRT card that I'm working on. I took a microwave class back in '76 but most of it has rubbed off now. I've tried to study up on it but nothing puts me to sleep quicker than reading about a Smith chart. :confused:

Scott

Ray,

It's good to see a fellow EE in this thread. Watch out, we'll put you to work! :p I think Rajiv has technical training, too.



:) So you guessed it, eh? Yes, I too have gone to electrical engineering college.... but I gotta admit that my knowledge is REALLY rusty now! HA HA.

I was a very active hobbyist until a few years back, when I was in India. But mostly used to tinker with audio related stuff.... amps, eqs etc etc. but no video :( . Audio is my first love. Oh how much I used to wish I had a oscilloscope then!

But when I moved to USA, this hobby has taken a backseat. So much stuff is available which is so much more affordable PLUS getting married, baby and everything does not leave much time for my personal hobbies!

The good thing about moving to USA is stuff like O'scope, function generators powersupplies etc etc is MUCH more affordable. I have all of these now (mostly collecting dust :o ).

Actually I had to build myself a regulated PSU in India due to high cost!

I am still reading up on video these days. Gotta try to hook up a O'scope to a pattern generator and se what is looks like. You guys have a link / info on some site or book to learn basic video waveforms and innards of a CRT TV like stuff?

Hey Scott!
Any update ?

I am still reading up on video these days. Gotta try to hook up a O'scope to a pattern generator and se what is looks like. You guys have a link / info on some site or book to learn basic video waveforms and innards of a CRT TV like stuff?

Two links that have alot of info regarding CRT displays.

http://www.national.com/an/AN/AN-656.pdf#page=1

http://www.*********/eviltwin/forum_posts.asp?TID=297&PN=1

4000d.pk goes where the asterisks are???? It won't let me put them in?

Check the .pdf by US Precision Lens. It is everything you need to know about CRT video projectors.

http://dion.swamp.dk/ampro4200g.html

Interesting site regarding the 4200.

Scott

Hey Scott!
Any update ?

Well, I've got one of the neck cards partially stuffed and have applied power. Good thing is it didn't catch on fire!

First snag. I believed Panasonic's spec sheet that stated that no capacitors were required on the outputs of their voltage regulators. Yeah, right. My -4V for the video preamp stage was a ramp waveform about 2Vpp at 200KHz. Things settled down after I put a 22uF cap on the output of the regulator.

Next snag was a little oopsy on my part. When the blanking signal is applied the output goes to about mid-point insted of to black like it should. Had to add a resistor to the solder side of the board and change another resistor value to fix that.

At this point the card is working but the bandwidth is low. At least it isn't oscillating. Remember Murphy's law "oscillators won't, but amplifiers will".

That's where I'm at. Hope to get some more work done this weekend.

I've been playing around with the projector some, too. I tried a Marquee focus magnet on the green. The dynamic windings are too much different to work right but the magnet can work for the center of the screen. The center did focus somewhat sharper than with the original magnet. I had another magnet to try but it was too long to get on the neck without pulling the tube out of the chassis. I'm using the 4200 as my television and couldn't go too far without running out of time to get it back together. I'm thinking about setting up another area for working on projectors without using my TV projector.

Scott

While digging through some old junk I found this little gem. This is usually the first thing that gets lost with the Ampro/Esprit projectors. How many of you have ever seen one?

Scott

Scott,
I have exactly the same remote. Although the bottom cover is not there.

I guess without this these Ampros are a dud, unless you do the PC remote thingy.

-Rajiv



While digging through some old junk I found this little gem. This is usually the first thing that gets lost with the Ampro/Esprit projectors. How many of you have ever seen one?

Scott

I have two new issues: :(

1. The blue registration gets all whacked out. I have to twist a daughter board on the big registration board to get it back to normal. Every time I start the PJ....the blue is slightly off. Just a twist of that board...it gets back to normal.

The twist has to be done away from the connector end of the board; if I move the connector end of the board…nothing happens. I guess the connector is OK....maybe some track or solder has loosened? :(
Any ideas?

2. HV Arc.
This has happened only once but has got me worried. Yesterday while watching a movie, a loud snapping sound was heard and the PJ went blank for just half a second. :eek: After that the PJ was fine until we switched it off. The “snapping sound” sounded like a loud static discharge, I hear it is an arc. :confused:

Why does that happen and does it mean the PJ is dying? :confused:
What is the solution?

Thanks Scott !
Good info there.

By the way the link to evil twin has to be massaged to really work. The correct replacement for the **** is 4000p "dot" dk

Two links that have alot of info regarding CRT displays.

http://www.national.com/an/AN/AN-656.pdf#page=1

http://www.*********/eviltwin/forum_posts.asp?TID=297&PN=1

4000d.pk goes where the asterisks are???? It won't let me put them in?

Check the .pdf by US Precision Lens. It is everything you need to know about CRT video projectors.

http://dion.swamp.dk/ampro4200g.html

Interesting site regarding the 4200.

Scott

While digging through some old junk I found this little gem. This is usually the first thing that gets lost with the Ampro/Esprit projectors. How many of you have ever seen one?

Scott

I was willing to bet that you were refering to the little cover door.

The two new Ampro 2000's I had both had brand remotes in the boxes. They even still had the protective plastic film over the displays. Even new out of the box from the factory, one of them had already lost the cover.

I sure hated to part with those remotes.

My old beater does, however, have a cover.

Ray

I have one right here in front of me. But as stated, the cover is missing. I've never seen a cover.

Chip

Another bit of Esprit trivia. The focus circuit of the 4200 didn't have enough range to easily set the CPC (flair and stig) magnets. This tool let you extend the vertical deflection board for access to the 20V rail. One switch position would let you see what you needed to set the flair, the other position was for the stig adjustment. This was what we used at the factory to set-up the projector.

Scott

Wow - that's amazing timing. I decided to redo the stig and flair a couple of days ago on the 4200 after reading the threads about moving the magnet assembly as far forward as possible. I was thinking to myself that there wasn't a lot of focus range. I did the best I could, and the results seem a little better with the magnets in the full forward position, but it wasn't dramatic like I hoped.

Lacking adequate remote adjustment, could a guy slide the focus yoke fwd/rev to make the stig / flare more obvious?

Ray,

It's good to see a fellow EE in this thread. Watch out, we'll put you to work! :p I think Rajiv has technical training, too.

There is a reason your projector isn't scanning right at 1080p. It sounds like the width regulator circuit doesn't have enough voltage coming in. That's why I asked about the static keystone. The keystone is produced when the width circuit modulates the voltage going to the yokes with a vertical frequency ramp. If there isn't enough headroom the width will be low and the modulation won't work. I'll bet your pj is ceiling mounted? Could you try this in your spare 2000? I can try to guide you through fixing it if you like or if you want to send me one of your HOT bds I'll check it out for you.

Do you work with or know someone that does RF design with bipolar transistors? I'd sure like to ask that person a couple of questions concerning this CRT card that I'm working on. I took a microwave class back in '76 but most of it has rubbed off now. I've tried to study up on it but nothing puts me to sleep quicker than reading about a Smith chart. :confused:

Scott

Thanks for the offers to help with the HOT board. It's strange because Ampro checked the HOT and Vertical board when I first got it. Swapping the 2000 boards didn't show any difference. I've got the 4200 in a rear screen setup with no keystone at all (picture below).

I'm with Rajiv at this point - if I can't get the Phantom lines to go away, I'm not going to expend any more energy on 1080P (or anything else). I'll never be happy with it now that I've seen how much cleaner the picture looks with the registration turned off.

If you're looking for some transistor help, post a thread something like "Looking for Transistor Expert". I did it with a neckboard transistor problem a few years ago, and got a Silicon Valley expert to help out. Your microwave class was about the same time that I graduated ('74).

Ray

Wow - that's amazing timing. I decided to redo the stig and flair a couple of days ago on the 4200 after reading the threads about moving the magnet assembly as far forward as possible. I was thinking to myself that there wasn't a lot of focus range. I did the best I could, and the results seem a little better with the magnets in the full forward position, but it wasn't dramatic like I hoped.



Here is how I do it and I get plenty of static focus range this way. Dynamic is another story...for (IIRC - blue mostly and to some extent - Red too) some tubes.....dynamic does not seem to function/or have very little range.

I DO NOT slide the focus magnets all the way forward. I think that is wrong anyway. Only the deflection yokes/coil has to be slid all the way forward. Anyway... back to what I was saying.

I set the static and dynamic focus settings to the center (50/77). I then loosen the focus magnet and slide it fore and aft along the tube neck. At one point I get the best focus…I tighten it there.

That’s it !

The good thing is for the green and red, the best focus I get is when the Electronic focus is at 50 ! The blue still has to be tweaked.



Lacking adequate remote adjustment, could a guy slide the focus yoke fwd/rev to make the stig / flare more obvious?


Not sure about that, but my stig and flare is VERY obvious. I did notice that my magnets function differently than what Guy Kuo’s document says ….but they sure do work……and I am able to tweak the dots to almost perfect rounds.

But then…I do have the full 2/4/6 pole CPC magnets from VDC




I'm with Rajiv at this point - if I can't get the Phantom lines to go away, I'm not going to expend any more energy on 1080P (or anything else). I'll never be happy with it now that I've seen how much cleaner the picture looks with the registration turned off.



I second (or first???) this too. !

But this PJ does not focus as sharp as it should, I remember Scott noticed that when he first got the 4200. I think something should be done about that.

Rajiv,

Your description is exactly the way my focus magnets are set up also.

Some time ago my HVPS failed, and all I could find was a 3300/4300 replacement. I took a chance on it without knowing if the pinouts and voltages would be the same, and it worked out ok. I sure held my breath the first time I hit the power on button.

To get it back into focus I had to slide the focus yokes forward about an inch. I did like you mentioned, and preset the remote to 50% before positioning. The newer supply has a higher anode voltage, by a couple of thousand volts if I remember correctly.

Ray

Ray and Rajiv,

If you look at the right hand section (standing behind the projector) of the registration board is yours surface mount parts or through hole? The surface mount one is 81289. My 4200 has the through hole part, my 2000, the SMD. I'm wondering if the through hole board is the noise maker. My 2000 does not have the noise.

Scott

Scott,

My 4200 has an 80893 main board and two daughter 80894 boards - all thru hole, not SMD.

That must be because you have a very new generation 2000.

The thing is, the two new in box 2000's I had were very early models with thru holes, and they were flawless. That's the big thing I really liked about them. The image was rock solid on both.

I might go see one of them tomorrow night, and I'll double check it.

Ray

I just tried putting the SMD function summer section in my 4200. That generated a bunch of I2C errors. Man, I hate firmware and programmable logic chips. I don't know if there is a firmware version for the older, long, through hole CPU bd that is compatible with the SMD fsummer. My 2000 has the shorter, SMD CPU.

Anyway, if you set the number 2 dipswitch on the CPU to "on" the errors don't show and you have control of the unit.

None of the registration functions worked. The picture was contorted in some wild bends and after a couple of minutes the thermal switch on the reg amp would trip which shuts off the amps.

So after this experiment I replaced the original fsummer bd., attached the red and blue daughter bds (they do the corner pin and key functions). I left off the green daughter bd and the daughter bd that covers the center section.

Everything looks great. I'm not seeing the noise, the picture looks clean????

I am watching a kinda "dark" movie. Gonad the Barbarian. I can't believe that I've never watched this before. It's new to me.

Scott

That's great Scott! I'm kind of bummed though.

I saw your note this morning, and remembered I had a spare 2000 convergance board that I could play with. First I re-seated all the 4200 convergance boards and connectors with no luck on the phantom lines.

Next I started swapping 2000 boards with the 4200. I really like a 9" EM projector that uses readily available parts from probably the most available projector out there. The obvious board I wanted to swap was the 80887 power supply which could be putting noise out maybe due to a bad filter cap.

A long story short - I swapped any and all boards and didn't see any difference at all. The one board I couldn't swap was the 80945 PLL (Phase Locked Loop?) board (under metal enclosure). The 2000 uses an 80886 PLL board that doesn't have the two cables plugged in.

The thing I didn't realize was that the old spare 2000 convergance board also had the two "Converge on Green" option boards which my 4200 doesn't have. I plugged in the larger 80895 COG center board and it really warped the display all over the place. The smaller 80894 green daughter board didn't make any difference.

Even with the two COG cards I would probably still need a different EEPROM for the CPU board, right?

Gonad the Barbarian?

Thanks,
Ray

Ok - it's later in the day and I tried a couple more things. I took the registration power supply board out of my 4600 and tried it. It didn't help - but it did work ok.

I also swapped the Registration amp board assembly from the 4600 (same p/n) and that didn't help either. The Phantom lines are still present. I'm running out of things to try.

OK guys, the wife is not home. I will try to see if I can take some quick photos to describe which board I have.

I am pretty sure nothing in my PJ is SMD....all boards are through-hole.


Scott.....Gonad the barbarian.....eh??
Some one is h**ny tonight ;) ;)
:D

I've just got a feeling that the through hole fsummer bds are to blaim. They are covered with AD633 analog multipliers which are pretty noisey. The SMD version uses multiplying DACs. There is some type of programmable part on the SMD bd. I don't know why it wasn't set up to interface the different serial busses. That would have made alot of sense.

Scott

Here is the pic of my reggie board as promised. Sorry could not post it yesterday, as soon as I took the pic, the wife was back :eek:

http://funkyhuman.com/hosted_images/IMG_5236.jpg

as you can see...it is full of through hole components.

The board on the upper left side is giving me grief these days. I have to twist it to get the blue convergence back on the mark. looks like a loose / bad solder or something.

Ok Scott,
I am afraid to ask but I gotta ask this question :

Judging from all this....do you think there is anything we can do to get rid of the phantom scan-lines?

If not, how to minimize them?

-Rajiv


I've just got a feeling that the through hole fsummer bds are to blaim. They are covered with AD633 analog multipliers which are pretty noisey. The SMD version uses multiplying DACs. There is some type of programmable part on the SMD bd. I don't know why it wasn't set up to interface the different serial busses. That would have made alot of sense.

Scott

So I found a solution to the problem I mentioned inthe post above (re-posted below)

I just re-seated the board and things look like normal ! :D

Of course I know that is the first thing one should do to boards which pop-out, but somehow I never got around to doing it! :o

Here is the pic of my reggie board as promised. Sorry could not post it yesterday, as soon as I took the pic, the wife was back :eek:

http://funkyhuman.com/hosted_images/IMG_5236.jpg

as you can see...it is full of through hole components.

The board on the upper left side is giving me grief these days. I have to twist it to get the blue convergence back on the mark. looks like a loose / bad solder or something.

Hey Scott,
Any progress on the phantom scan-lines issue?

I know you were working on improving the bandwidth, so I also wonder what ins the progress on that front. Or did you start a thread of your own ? (maybe I missed it?)

When I first got this 4200 it had some noise in the picture. Probably what you refer to as the phantom lines. I did some board unpluggin' and pluggin' back in with the registration boards and it is now so faint that it only shows sometimes, a little bit. Magic, I guess. Haven't worked much on anything else. The projector looks really good with 1080i so there hasn't been too much reason to mess with it.

Two 3600 chassis were heading for the dumpster during the warehouse clean-up at VDC so I re-directed them to my car and they have found their way to my house. I'm itching to get one working. Hard to come up with the time, though. Too many projectors, too many projects.

Scott

I did some board unpluggin' and pluggin' back in with the registration boards and it is now so faint that it only shows sometimes, a little bit. Magic, I guess.


Hmmm, that is interesting. :)
Maybe I can try that out tonight. I will zap all those connectors with a gold contact cleaner too, lets see what happens.

Just to be sure:
You are refering to the daughter boards on the big registration control board (shown above in the pic I posted), right ?

I had already cleaned all other connectors (motherboard - cards and cables) earlier when dissasembling the PJ for glycol and fan upgrades.

Yep, the daughter bds on the registration bd. I did remove the green convergence daughter bd and the contrast mod bd, too. That gave I2C errors but switch 2 on the CPU card disables them. The daughter bds do the corner adjustments. The registration will work without them, though the corner functions are not there.

Scott

Oh well, I need help (again). After working just fine for the past few months my Ampro 4200 is having issues.

Yesterday night, I turned it on to watch a movie, nothing showed up on the screen. Then I looked down into the tubes….nothing!

I checked the keypad, did a status check, everything checks out fine…it says “system ok”. All functions work just fine, it detects the signal input, I can only go through the test patterns and the help....but nothing appears on the screen. No test patterns, no help, zilch, nada!

From the keypad, absolutely everything seems to be OK. I can hear the relays clicking when I change the frequency (input or test patterns). The frequency counter works fine.

Just…there is no image! The tubes don’t light up!

How can I troubleshoot this? Please help me.

Did you toggle the RGB CUT OFF settings on the remote?

Nevermind... if it was a simple cut off, I don't think your test patterns would display.

Check brightness and contrast settings (via the remote) for the screen program that you are trying to display.

The help and test screens use different memory locations and may work ok, while the regular screen doesn't if it lost it's presets (defaults to zero I think).

The screen blanking settings can also cause it to not to display an image.

Ray

Did you toggle the RGB CUT OFF settings on the remote?

Nevermind... if it was a simple cut off, I don't think your test patterns would display.


yes yes !
I have already tried that .

Nothign displays....not even the test patterns. It just says (on the keypad/remote) that it is displaying xyz pattern...but the tubes dont light up at all :confused:

Check brightness and contrast settings (via the remote) for the screen program that you are trying to display.

The help and test screens use different memory locations and may work ok, while the regular screen doesn't if it lost it's presets (defaults to zero I think).

The screen blanking settings can also cause it to not to display an image.

Ray


I have tried the brightness settings,

BTW, did I write that the test patterns are working?
No no....sorry to be confusiing....nothing displays on the screen no matter what I do !

Not even the test patterns. :mad:

If the 30 code returns "system ok" and it's not lying to you then most likely there is no video driving the tubes. Break out your DVM and measure the end of the big brown power resistor, on the green CRT card, that is nearest the bottom of the card. Should be either +180V or +190V. Now measure the end nearest the middle of the card. If it measures the same then the video is not there and the tube(s) will be cutoff. If it measures 10 or move volts less than the other end then there is probably video present and something else is causing the problem. The tube heaters are lit? Do you hear the cackle of the HV coming up? While you have the DVM near the CRT card measure the G-2 pot pins. There should be +400 to +850V there. Don't worry, we'll get you through this.

Scott

It's past midnight and I just took a peek at this thread before going to sleep.


Don't worry, we'll get you through this.

Scott

I know, I know ! :D :D :D
First, let me thank all you guys, (and especially Scott!) for helping me out here with this PJ.

So lets get to business,
[1] I do hear the crackle of HV at startup.
[2] The CRT's heaters are NOT lit
[3] It surely detects a video input because if I turn off the 1271 switcher , it says NO INPUT
[4] All the Spellman's lights are lit (as usual)

As for taking out the DMM, I surely can, but I am flying out to India this saturday morning. I was packing like crazy and just finished last minute shopping. Strangely, the wife never likes my wardrobe :o :o Oh ya, I just bought a 220 to 110 voltage converter from Radioshack. My wife & sis-in-law have already burnt TWO vonage routers in a row before reliasing that the cheapo "adapter" she was using does NOT convert the voltage ! :mad: :eek: :eek:
GRRRRRR ! Women!

The third router is flying out with me !


Anyway, I will try measuring the voltages tomorrow evening, if I finish this packing!

I just hope this is not a spellman problem. Looks like the heaters are not getting any voltage


If the 30 code returns "system ok" and it's not lying to you then most likely there is no video driving the tubes. Break out your DVM and measure the end of the big brown power resistor, on the green CRT card, that is nearest the bottom of the card. Should be either +180V or +190V. Now measure the end nearest the middle of the card. If it measures the same then the video is not there and the tube(s) will be cutoff. If it measures 10 or move volts less than the other end then there is probably video present and something else is causing the problem. The tube heaters are lit? Do you hear the cackle of the HV coming up? While you have the DVM near the CRT card measure the G-2 pot pins. There should be +400 to +850V there. Don't worry, we'll get you through this.

Scott

Did you toggle the RGB CUT OFF settings on the remote?

Nevermind... if it was a simple cut off, I don't think your test patterns would display.


Hey Clarence,
After I came back home after meeting you that day (THANKS! :D ) I did some tweaking. I moved it back a little and re-did the convergence. I was amazed at the results! :eek:
By just moving it a bit backwards the image is now fully filling in the screen and 99% of my corner convergence problems went away ! Now I have almost perfect convergence all around. :D The image has dramatically improved! I can now easily see pores on people's faces on HD signals (on close ups).

Now I’d say in terms of clarity and sharpness, this PJ may be at least 90% of what I saw at your place. I am soooo excited about this. I just cannot believe my eyes!

I really want you to come visit me and see this for yourself. I would love to hear what you’d say about this. I am sure another set of eyes would be very nice to further improve this PJ. Please do come by sometime.

Sure, the grey-scale SUCKS big time! In dark scenes a while shirt is very bluish! In bright scenes a white shirt is totally white!
I got to work on this after I come back from India

But Hey, Thanks a TON for the inspiration! :D


Oh ya….All this improvement has made regular DVDs look far more fuzzy (by comparison) and slightly unwatchable. I guess NOW I want to buy a HD-DVD player.


Now, only if I can get it up and running again! :mad:

If the heaters are not lit then the tubes no workey. That should be an easy fix as the circuit is pretty simple.

Scott

If the heaters are not lit then the tubes no workey. That should be an easy fix as the circuit is pretty simple.

Scott


Having not looked at the schematics yet, do all the 3 tubes get their heating voltage from one circuit? Must be like that and maybe that ckt is on the motherboard...no wait...maybe one of those cards right? The neckboards wont have that, or do they?

But it was working soooooo nicely for so many days.. :mad: How could this happen all of a sudden?



Oh well , as they say in Hindi .... "Nazar lag gayee" which means something like if you talk good about something it goes bad! ?

Same thing as we say "touch wood or knock on wood here" :D

Ok guys, I am back from India and ready to take up this "troubleshooting project".

So where do I start?

I just re-read Scott's instructions about measuring voltage; will do that ASAP

Hi Scott,
I measured the things you told me to, here are the results:

About the two ends of the brown power resistor, on the green CRT card:

Situation: No input:
Both ends = +179 V DC

Situation: Internal Test pattern on:

>> V at pin that is nearest the bottom of the card = 179 V

>> V at the end nearest the middle of the card = around +250V (but my DMM beeps, indicating some error or something.)


The V at the G-2 pot pins is around 850V at the right side and around 250V at the left side.

The tube heaters are not lit.
I hear the crackle of HV while starting the PJ.

Any tips / instructions on what can I do?

Meanwhile I will also look into the circuit diagram of the CRT boards.

Thanks again!


If the 30 code returns "system ok" and it's not lying to you then most likely there is no video driving the tubes. Break out your DVM and measure the end of the big brown power resistor, on the green CRT card, that is nearest the bottom of the card. Should be either +180V or +190V. Now measure the end nearest the middle of the card. If it measures the same then the video is not there and the tube(s) will be cutoff. If it measures 10 or move volts less than the other end then there is probably video present and something else is causing the problem. The tube heaters are lit? Do you hear the cackle of the HV coming up? While you have the DVM near the CRT card measure the G-2 pot pins. There should be +400 to +850V there. Don't worry, we'll get you through this.

Scott

The heaters not being lit is probably the biggest reason for no picture. The heater regulator is a TO3 package device that is located on the right side of the SMPS box. The regulator is plugged into a brown plastic socket that is very cheap. There were often problems with the regulator pins not making good contact with the socket. Many times they were just soldered together at the factory. Check this first.

Scott

Scott,
I removed the regulator from the TO3 socket. It's pins were pretty tight, I could feel a lot of resistance while pulling it out from the socket. I zapped the pins with some deoxit and installed it again.

No improvement. :o PJ still behaves the same.

Any Other tips?

Thanks
Rajiv

The heaters not being lit is probably the biggest reason for no picture. The heater regulator is a TO3 package device that is located on the right side of the SMPS box. The regulator is plugged into a brown plastic socket that is very cheap. There were often problems with the regulator pins not making good contact with the socket. Many times they were just soldered together at the factory. Check this first.

Scott

Looking at the schematic of the motherboard, the CRT's heaters are supplied straight by a "Filament Regulator". That 4 pin connector is labelled J41. But I cannot find any reference to the actual IC - LM384 (correct?) on the motherboard schematic.
[edit: found it on the SMPS schematic]

I also cant find the circuit diagram (if there is one). At least there should be some diagram which depicts what is being fed to the regulator.
[edit: found it on the SMPS schematic]


Maybe the regulator is bad?
Maybe there is a fuse in the circuit somewhere ?
[edit: found a fuse in the ckt too, on the SMPS schematic]

I have a very bad (almost unreadable) service manual of the 2000. I can see the regulator on the SMPS board in that (80725C Block diagram) But the associated schematic has no reference to it (strange!)


Looks like the regulator circuit was improved after the 2000 model. The x600 manual shows the regulator has changed to a LT1083CP and moved to a seperate board - 81256

Ok ,
it seems to me that the regulator must have gone bad.

The regulator ckt is being fed from the SMPS via the fuse board. The fuse board has a tell-tale LED. [edit: wrong!] On my PJ that LED is lit, so the fuse must be intact.

Maybe the regulator burnt out or something.

I should be able to prod the case of the regulator IC (the output) with my DMM and check the voltage, right ?
Anyone knows how much is the output of the regulator??

Attached is part of the SMPS schematic. It looks like the filament rail doesn't have an LED on it so best to check right on F1. It should have about +10V on BOTH ends. The regulator output should be +6.3V.

Scott

You are right Scott! The LED is really not there. I must need more coffee!

I tried to check the output voltage on the regulator but it is dificult to do so with the insulated cover on. There is a hole for the test prod, but that is too small, I shall have to improvise! Maybe I will drill another hole at the side.

Oh yes, I tried to run the PJ without the adjacent board, but it gave me some "interlock error". Understandably, that board must be required before the PJ will fire up.

I will try out these things and report back, seems to me that it is either the fuse or the regulator IC.

Thanks again!

Attached is part of the SMPS schematic. It looks like the filament rail doesn't have an LED on it so best to check right on F1. It should have about +10V on BOTH ends. The regulator output should be +6.3V.

Scott

I just tested the fuse, sure enough it was blown. I replaced it and it blew up again! :mad: :mad:

So maybe the IC is burnt out. Is there something else I can check before ordering a new IC ? :confused:

Oh yes, I can take out the IC from the socket and check if the output pin is shorted to GND. :)

Thanks
Rajiv

Hopefully it is something other than the regulator. Those might be expensive and hard to find, these days.

Scott

Scott,
I took out the LM338K (the regulator) none of the pins are shorted out.

Then I checked the filament to GND resistance, they are not shorted out either (all three tubes measure around 4.2 ohms)

Looks like the three tubes' heaters/filaments are connected in parallel since the resistance drops as I connect the headers one by one.

I dont see the LM338 depicted in any circuit diagram. The block diagram shows it but does not show its circuit. This IC must have the associated circuitery like the 2 resistors and some caps somewhere! I wonder where they are. :confused: :confused:
They do not show up on the SMPS' schematic. If I can find them, I can check for a bad resistor/capacitor.

You have any idea where to find them?


By the way, Mouser has this IC for $7.28 ....not bad at all :D
http://www.mouser.com/search/refine.aspx?Ntt=511-LM338K

Do you think it is worth ordering / giving a try. Or do you think I should look somewhere else in the PJ for faults first?


Hopefully it is something other than the regulator. Those might be expensive and hard to find, these days.

Scott

Hey Rajiv,

The regulator circuit is in the upper right corner of the pdf. Try removing the regulator from it's socket and see if the fuse blows then. It's possible that C9 has gotten old and dried out. The rectifier, CR10, could have shorted. Not too much else there. The filaments are connected in parallel. When warm they draw about 1/4A each.

Scott

Good morning Scott!
Strangely I dont see the LM338 regulator anywhere in that circuit!
Maybe since it is off board, they did not depict it ? But that would be strange.
They also dont show the small 3 pin connector on this schematic. But that connector is shown on the motherboard's diagram.

Anyway, I will check out those components and report back tonight.

Thanks!

Hey Rajiv,

The regulator circuit is in the upper right corner of the pdf. Try removing the regulator from it's socket and see if the fuse blows then. It's possible that C9 has gotten old and dried out. The rectifier, CR10, could have shorted. Not too much else there. The filaments are connected in parallel. When warm they draw about 1/4A each.

Scott

:eek: Scott,
I am really stumped on this one!

I checked each and every component in that ckt. Everything is fine !
I even tested the regulator IC in a typical application circuit, it is really working as intended, even with a load !

So there has to be something wrong elsewhere.

One thing.....when the fuse blows, it blows very slowly. ....takes approx two seconds to glow red and then blow up. It does not blow instantly like what would happen if there was a short-circuit somewhere.

You got any more tips ?

Next thing to try would be to pull the regulator from the socket and run with a new fuse. Without a load the filter cap (C9) will charge to +10 to +20V and the fuse shouldn't blow. Try connecting a power resistor (10 to 100 ohm) from the fuse to ground (chassis). The output should then be near +10V. At least try with IC removed if you don't have a power resistor handy and see what happens. Connect your DVM to the fuse and ground and monitor the voltage as you turn on set.

Scott

Before I read this post, I was in the basement doing exactly what you told me here ! :D

Yes, without a load, the voltage is 20.57 volts DC. Sorry, cant find a power resistor....will go to the 'shack tomorrow morning to get one.

Next I put in a new fuse and also the IC . I also noticed that the fuse blew instantly this time. I had my DMM on the fuse but the fuse blew too fast for the DMM to register anything.

Now with the fuse blown, one end of the fuse is at zero volts but the other is at 2. (something) volts. Does this give a clue ?

-Rajiv


Next thing to try would be to pull the regulator from the socket and run with a new fuse. Without a load the filter cap (C9) will charge to +10 to +20V and the fuse shouldn't blow. Try connecting a power resistor (10 to 100 ohm) from the fuse to ground (chassis). The output should then be near +10V. At least try with IC removed if you don't have a power resistor handy and see what happens. Connect your DVM to the fuse and ground and monitor the voltage as you turn on set.

Scott

Hmmm. With fuse and without regulator you get about +21V on the fuse and it doesn't blow?

Connect regulator and fuse blows?

Sounds like the overload is on the output side of the regulator. It is a 5A part so will not current limit until well after the fuse is blown.

Did you try unplugging all the CRT cards from the mother bd and run with regulator in place?

You must be getting a pretty good size pile of dead fuses. Yikes!

The insulator under the regulator is in good shape? No metal burrs poking through?

Scott

Hmmm. With fuse and without regulator you get about +21V on the fuse and it doesn't blow?

Connect regulator and fuse blows?


Yes ! :( :mad:


Sounds like the overload is on the output side of the regulator. It is a 5A part so will not current limit until well after the fuse is blown.

Did you try unplugging all the CRT cards from the mother bd and run with regulator in place?



Not yet, although I did think about it. :o

I did not do it because I thought maybe I would damage something OR maybe the PJ wont even switch on. But now that you recommend that, I will do that tomorrow night. I'm not home today.

Do you think there is a possibility that a tube's heater is shorted out or something?



You must be getting a pretty good size pile of dead fuses. Yikes!

The insulator under the regulator is in good shape? No metal burrs poking through?

Scott

Yes, I did check that but will re-check it.

Thanks for helping me on this, Scott ! I hope we solve this mystery soon, my wife is like…..”How come you bought this pile of junk! “

HA HA !

Hi Scott,
I did some tests and seems like it boils down to one thing. The fuse in the filament heater circuit cant take the load of all 3 (RGB) heaters simultaneously! :confused:

I know it is rather strange but here are my findings:

Situation : All CRT cards disconnected:
V at o/p of reg IC = +6.96 VDC
V at fuse = +16.9 VDC

Situation: Fuse taken out and All CRT cards disconnected:
V at fuse = +10 VAC

Situation: Only RED CRT connected
V at o/p of reg IC = +6.94 VDC
Filament = ON
Test pattern = OK :D

Situation: Only RED + GREEN CRT connected
V at o/p of reg IC = +6.91 VDC
Filament = ON
Test pattern = OK :D

Situation: Only BLUE CRT connected
V at o/p of reg IC = +6.94 VDC
Filament = ON
Test pattern = OK :D

Situation: All CRT connected
Fuse blows :mad: :mad:

Note that the input of that IC is almost 17 volts and it is taking it down to 7 volts.....dropping 10 volts. That may be excessive or is that how it is supposed to be??
Let me check the datasheet of that IC to see what they recommend.

Meanwhile, do you think I should try it out with a 3 or a 4 AMP fuse ? I hope I wont blow out anything.

Scott,
From what I see in the datasheet, around 3 volts drop at the regulator IC is a good figure for max current o/p.

Also since you mentioned earlier that the input should be around 10 volts (measured at the fuse) but my Voltage at the fuse measures 17 volts, maybe that is the problem!! ?? :confused:

YAHOO !

I got the PJ up and running again !

I fed the heater ckt with an external supply to find out what was going on. Started with a current limited setting at 1 amp and found out that the ckt is actually drawing around 2 amp at startup and soon settles to around 1 amp. Check out my setup in the attachment.

So I changed the fuse to a slow blow version of 2 Amps. And now the PJ is back to normal !

Nice!

Thanks a ton Scott for helping me out here.
More later. Wife is asking for a treat !

Good man! So it was only fuse fatigue? That circuit does put the filter cap charge current through the fuse. The high frequency AC current tends to heat the fuse element more than the DC current. Way to go!

Scott

A treat? You mean she wants you to put the Ampro up for sale now that you got it working? ;)

Congrats man. Way to hang in there. This thread is destined to be the longest "It's not working... it's working... it's not working... it's working" thread ever.

Now go enjoy some movies!

-Mark


YAHOO !

I got the PJ up and running again !

I fed the heater ckt with an external supply to find out what was going on. Started with a current limited setting at 1 amp and found out that the ckt is actually drawing around 2 amp at startup and soon settles to around 1 amp. Check out my setup in the attachment.

So I changed the fuse to a slow blow version of 2 Amps. And now the PJ is back to normal !

Nice!

Thanks a ton Scott for helping me out here.
More later. Wife is asking for a treat !

Thanks Scott! :D :D
It was just a simple fuse thing. But I wonder why it was working for so long and all of a sudden the ckt started drawing more at startup? :confused: But Hey ! I finally got some use out of that nice PSU!

Now I wanted to ask you one more thing. Since the PJ is down on the floor, is there anything I could do to improve it while I am at it?

Here is a little list of what I was thinking about:

1. Set the gray-scale.
My PJ’s grayscale tracking is pretty bad. Whites are white at high IRE but very bluish at low IRE.

There is a procedure described in the 2000’s service manual (page 3-7, title – Analog RGB1 replacement procedure). It talks about setting up the grayscale using an oscilloscope. Do you think it is worth it?
If so please guide me in this:
1. It talks about giving an input of 1 v p-p color bars with IWQ, burst and chroma off. I don’t have a NTSC color bar generator. Can I use a HTPC with a test pattern generator instead? If yes which test pattern should I use?

2. It also talks about a 1 in 3 out distribution amp. I don’t have it. Can I just do all three colors one by one instead?


2. Do the optimization for 1080i procedure you mentioned sometime back in another thread.
http://www.avsforum.com/avs-vb/showthread.php?p=8537631&&#post8537631

I will need to borrow a riser card from Mike, if he still has one I can borrow :)

Thanks Mark!
Well... she has not mentioned that (yet).

But I dont want to give it up yet. I think there is some more performance to be extracted out of this thing!

About movies......sure ! But I will set it up on the floor/coffee table for now. Give me more access to tweak that thing :D
Bring them on !

A treat? You mean she wants you to put the Ampro up for sale now that you got it working? ;)

Congrats man. Way to hang in there. This thread is destined to be the longest "It's not working... it's working... it's not working... it's working" thread ever.

Now go enjoy some movies!

-Mark

Thanks Scott! :D :D
It was just a simple fuse thing. But I wonder why it was working for so long and all of a sudden the ckt started drawing more at startup? :confused: But Hey ! I finally got some use out of that nice PSU!

Now I wanted to ask you one more thing. Since the PJ is down on the floor, is there anything I could do to improve it while I am at it?

Here is a little list of what I was thinking about:

1. Set the gray-scale.
My PJ’s grayscale tracking is pretty bad. Whites are white at high IRE but very bluish at low IRE.

There is a procedure described in the 2000’s service manual (page 3-7, title – Analog RGB1 replacement procedure). It talks about setting up the grayscale using an oscilloscope. Do you think it is worth it?

If you have a scope it would be worth checking the sub-brite settings.

If so please guide me in this:
1. It talks about giving an input of 1 v p-p color bars with IWQ, burst and chroma off. I don’t have a NTSC color bar generator. Can I use a HTPC with a test pattern generator instead? If yes which test pattern should I use?

A gray stairstep pattern would be best. Use whatever format/resolution that you normally watch.

2. It also talks about a 1 in 3 out distribution amp. I don’t have it. Can I just do all three colors one by one instead?

Actually, yes. Just as easy to use graybars if you have it. The important thing is to verify or set the black bar, of each color, to the same DC level.


2. Do the optimization for 1080i procedure you mentioned sometime back in another thread.
http://www.avsforum.com/avs-vb/showthread.php?p=8537631&&#post8537631

I will need to borrow a riser card from Mike, if he still has one I can borrow :)

You can do the greyscale adjustments with the RGB board in place.

Scott

Guys,
What was the code to display an test pattern which is synced to the input being fed to the PJ?

I forgot it and cant seem to find it.

68-CODE?

Press "4" then "test". The "step" button selects different patterns.

Scott

Thanks Scott,
here is a version of a cheat-sheet I use sometimes. Not 100% accurate but getting there.
I updated it with this info:

So I finally got some time today O hook up the o'scope to the HTPC and , for the first time in my life, view video patterns!

Before I play with my PJ, I thought I should look at what the TPs look straight from the video card's output.

Here is a test pattern I am using (1280x720p):

http://funkyhuman.com/hosted_images/grayscale1.jpg

Here is a scoped image of this test pattern taken from a nVidia Qudro FX500:

http://funkyhuman.com/hosted_images/oscope1.jpg

Notice all the stair-steps are of equal height. :)

Now check out the same TP outputted from an exact same PC but with the on-board intel video chipset's output:

http://funkyhuman.com/hosted_images/oscope2.jpg

I notice that the stairs are a little curved to the right an the steps at the top are shorter in height.


Does it signify black crush?

One more question about the TPs:

while taking the above shots the scope is at 0.2v/div (vertical). Hence you can see that the output of the Quadro video card is 1.25 volts p-p

The instructions in the Ampro 2000 manual state that I should input a 1 volt p-p.

Does the difference matter? :confused:



Interestingly the other card's output is lower.

Ok something weird is happening in my PJ (or maybe I connnected something wrongly)

Following the directions of the service manual, I connected the probe to TP2. (actually I am not sure if I really connected it to TP2 since that test point is missing. The manual shows it to be right behind the big heatsink. There is another TP which is in the center of the board , which is where I connected the probe)

Anyway, I get a pattern which is (sort of) reverse of what I should be getting. See it here:

http://funkyhuman.com/hosted_images/oscope3.jpg

I can set the peak white to be +40V. But there is no way I can adjust the black level to be +170v.

In fact it is around -80v (MINUS! :eek: ) It is adjustable between 0 and -80v

What's wrong?

So I finally got some time today O hook up the o'scope to the HTPC and , for the first time in my life, view video patterns!

Before I play with my PJ, I thought I should look at what the TPs look straight from the video card's output.

Here is a test pattern I am using (1280x720p):

http://funkyhuman.com/hosted_images/grayscale1.jpg

Here is a scoped image of this test pattern taken from a nVidia Qudro FX500:

http://funkyhuman.com/hosted_images/oscope1.jpg

Notice all the stair-steps are of equal height. :)

Now check out the same TP outputted from an exact same PC but with the on-board intel video chipset's output:

http://funkyhuman.com/hosted_images/oscope2.jpg

I notice that the stairs are a little curved to the right an the steps at the top are shorter in height.


Does it signify black crush?

Now you're gonna have some fun! Sticking a scope in there. The stairstep pattern with the shorter steps is actually showing a little white crush. Like the picture on the monitor the steps get brighter as you move from left to right.

Scott

One more question about the TPs:

while taking the above shots the scope is at 0.2v/div (vertical). Hence you can see that the output of the Quadro video card is 1.25 volts p-p

The instructions in the Ampro 2000 manual state that I should input a 1 volt p-p.

Does the difference matter? :confused:



Interestingly the other card's output is lower.

The video signal is not terminated with 75 ohms when connected to the scope (1 Meg Ohm input). When connected to the RGB card (75 Ohm input) it will be half the unterminated amplitude. For RGB the signals should be 0.7Vpp when terminated. Both of your signals are low in amplitude.

Scott

Ok something weird is happening in my PJ (or maybe I connnected something wrongly)

Following the directions of the service manual, I connected the probe to TP2. (actually I am not sure if I really connected it to TP2 since that test point is missing. The manual shows it to be right behind the big heatsink. There is another TP which is in the center of the board , which is where I connected the probe)

Anyway, I get a pattern which is (sort of) reverse of what I should be getting. See it here:

http://funkyhuman.com/hosted_images/oscope3.jpg

I can set the peak white to be +40V. But there is no way I can adjust the black level to be +170v.

In fact it is around -80v (MINUS! :eek: ) It is adjustable between 0 and -80v

What's wrong?

The CRT card drives the tube cathode with an inverted signal. Black will be around +175V (Brightness and sub-brite settings control exactly where). The brighter parts of the signal will be lower voltage. Set to +40V with contrast and sub-contrast controls.

Scott

Scott, Thanks!
Just clarifying...
Are you saying that I should have the left end of the pattern at +170v and the right side at +40v?
Dont you think those voltages be negative instead?

Pl see this image:
Is my understanding correct ?

http://funkyhuman.com/hosted_images/oscope4.JPG

I also have a "invert" switch on the scope. I can use it to make the pattern look like as shown in the manual.

The CRT card drives the tube cathode with an inverted signal. Black will be around +175V (Brightness and sub-brite settings control exactly where). The brighter parts of the signal will be lower voltage. Set to +40V with contrast and sub-contrast controls.

Scott

Your illustration is correct. Black is indeed +175V (G-2 effects that but the video amplifier is happiest there). As the cathode voltage decreases the tube conducts more. G-1 is normally at zero volts. A tube has to be turned off by reverse biasing (G-1 negative relative to K). The closer to the same voltage these two are the higher the tube conducts. Seems backwards but that is how it works.

Scott

Thanks for all the tips Scott.

I have successfully done the procedure. All three tubes' are at 170 volts (the manual says 170) I could NOT get the bright end to be at 40v. The most I could get it was at 42.5v

I guess this is because the signal from the VGA card is less than .7 v p-p, right?

Anyway, after doing that I see that the pic shows not much improvement. The whole pic was a little reddish (it always was like that unless I adjust the signal pots) Hence I adjusted the pots and now it is pretty white at high IREs.

The low IREs are another story. The image is greenish-bluish in dark scenes.

I guess i will have to do the 2-point calibration by the eye now, right? (no colorimeter, sorry !)

One thing did change a bit. The pic bloomed at around 32 brightness. Now I can raise the brightness to around 45 before it starts blooming.

Thanks for all the tips Scott.

I have successfully done the procedure. All three tubes' are at 170 volts (the manual says 170) I could NOT get the bright end to be at 40v. The most I could get it was at 42.5v

This whole exercise is to get the video amplifiers into a good operating region without black or white crush.

I guess this is because the signal from the VGA card is less than .7 v p-p, right?

Yeah, the circuits are designed for nominal input = 0.7Vpp. Your input is close enough. It will work ok.

Anyway, after doing that I see that the pic shows not much improvement. The whole pic was a little reddish (it always was like that unless I adjust the signal pots) Hence I adjusted the pots and now it is pretty white at high IREs.

The low IREs are another story. The image is greenish-bluish in dark scenes.

Set your contrast for a dim picture. Set blue cut-off so only red and green are showing. Adjust red and green G-2 so picture is yellow and darkest bar of stairstep pattern is not visible. Sit in the dark for a while so your eyes are used to it. Now turn on the blue and adjust blue G-2 for gray.

I guess i will have to do the 2-point calibration by the eye now, right? (no colorimeter, sorry !)

One thing did change a bit. The pic bloomed at around 32 brightness. Now I can raise the brightness to around 45 before it starts blooming.

You did set the cathode levels to +175V with brite at 80%?

Once the dim picture is right set contrast to 90% and once again cut-off the blue. Adjust the red and green pot near the input connector for yellow. Then turn on blue and adjust for gray.

I don't know what the manual says to do but you want to set the levels with the scope with the remote brite at 80% and contrast at 80%. Pots at the RGB board input connectors max CW.

Scott

You did set the cathode levels to +175V with brite at 80%?

Nope, I set the cathode levels to +170v with the brite and contrast set to 95. (this is as per the service manual of 2000. Were the 4200’s levels different? :confused:


Set your contrast for a dim picture. Set blue cut-off so only red and green are showing. Adjust red and green G-2 so picture is yellow and darkest bar of stairstep pattern is not visible. Sit in the dark for a while so your eyes are used to it. Now turn on the blue and adjust blue G-2 for gray.

Once the dim picture is right set contrast to 90% and once again cut-off the blue. Adjust the red and green pot near the input connector for yellow. Then turn on blue and adjust for gray.



This procedure is very interesting. I will try it out soon.

You mention that “adjust blue G-2 for gray” Was that a typo? :confused:
I thought G2 had nothing to do with the grayscale adjustment. :o

My PJ blooms big time if I turn the contrast controls over 50 or so. :eek:
Is it safe for it to be at 90 for a short time when I am adjusting something?

Also is this premature blooming (at 50 contrast) normal? :confused:
Shouldn’t it bloom over 95 or something?



I don't know what the manual says to do but you want to set the levels with the scope with the remote brite at 80% and contrast at 80%. Pots at the RGB board input connectors max CW.

Scott


The manual says keep brite and contrast at 95/95. Maybe 4200 was different?

Here are the two pages from the Ampro 2000’s manual which I was following:

Page1

http://funkyhuman.com/hosted_images/RGB_board_adj1.gif

Page2

http://funkyhuman.com/hosted_images/RGB_board_adj2.gif

Thanks again !

Nope, I set the cathode levels to +170v with the brite and contrast set to 95. (this is as per the service manual of 2000. Were the 4200’s levels different? :confused:

No. That was right. I forgot the exact number.

This procedure is very interesting. I will try it out soon.

You mention that “adjust blue G-2 for gray” Was that a typo? :confused:
I thought G2 had nothing to do with the grayscale adjustment. :o

Not a typo. Tiny little turns of G-2 will set the bars to gray in the darker areas. This should be set before the brighter areas.

My PJ blooms big time if I turn the contrast controls over 50 or so. :eek:
Is it safe for it to be at 90 for a short time when I am adjusting something?

What do you mean by blooming?

Also is this premature blooming (at 50 contrast) normal? :confused:
Shouldn’t it bloom over 95 or something?

Nothing bad should be happening with contrast at 50. It is normal to run brightness and contrast at 80 or higher.


The manual says keep brite and contrast at 95/95. Maybe 4200 was different?

Nope. That's the same.

Here are the two pages from the Ampro 2000’s manual which I was following:

Page1

http://funkyhuman.com/hosted_images/RGB_board_adj1.gif

Page2

http://funkyhuman.com/hosted_images/RGB_board_adj2.gif

Thanks again !

's alright, 's ok.

Hi Scott,
by "blooming" I am refering to the phenomenon of:
Spread of spot on cathode-ray tube phosphor due to excessive beam current.

At very high brightness the beam loses its focus. This usually happens at very high levels of contrast and brightness, but in my PJ this starts happening at around 45 contrast.

The image loses focus....the scan lines dissapear into a fat blob.....it looks pretty bad. But by that time the image is extremely bright.

I think my brightness controls are off.

Thanks for the other tips, I will try them out shortly.

WOW !

I CANNOT BELIEVE MY EYES !

Scott your procedure made a difference of night and day on my PJ.

I just can’t describe how good it looks after doing that procedure. I have proper color balance now. Whites are white no matter it is dark or light. I have shadow detail like I have never seen on ANY PJ! I swear I can see seams on People's black jackets! AND blacks are still black, not gray!
Caucasian skin tones are just about right on......well maybe a little pinkish. The excessive red is gone now!

The image simply looks awesome! I wish I could post a picture (can’t…no camera…..got stolen in India!........but I am getting another one….soon)

So , Exactly what did I do? Looks like some sort of grayscale calibration but done without a colorimeter. Frankly, at first, it sounded like snake-oil to me !! (not really HA HA ! I am exaggerating)

Hey ! This procedure should be a sticky here!

Who-ever has NOT tried this on their CRT PJ (and has not got a professional calibration done) is missing out BIG TIME!
I took like 15 minutes to do it and it made a HUGE HUGE difference!


Scott, Dude, thanks a million!

Just in case someone wonders what I am talking about, here is what Scott told me to do:


Set your contrast for a dim picture. Set blue cut-off so only red and green are showing. Adjust red and green G-2 so picture is yellow and darkest bar of stairstep pattern is not visible. Sit in the dark for a while so your eyes are used to it. Now turn on the blue and adjust blue G-2 for gray.

Once the dim picture is right set contrast to 90% and once again cut-off the blue. Adjust the red and green pot near the input connector for yellow. Then turn on blue and adjust for gray.



Man! after this I was awake until after midnight...could not get my eyes off the screen!

Hey Rajiv,

That procedure was the official Ampro color balance technique. They were too cheap to buy a color meter so it was all done by eye. The yellow then gray method works pretty good. I'm glad it worked out for you. The 4200 isn't a bad projector. It should do a smokin' 1080i and 720p.

Scott

Oh Yeah !
NOW it sure does a "smoking 1080i"! :D :D

I notice 1080i actually has slightly more detail on this PJ than 720p. But then I have not dialed in the focus and schempflug 100% yet (it is still on the table). Once I get to hang it again I will do all those things and post some screenshots. Got to still buy the digi-cam. :(

Last night I showed it to the wife, she was mighty impressed. (she is especially hard to impress) :cool: She kept pointing out the detail in people's faces and how accurate the colors were now. :D


Hey... got to ask you two things.

[1] About the maximizing of rasters.

Is it OK to mess around with the width pot? :confused:

The thing is ...even with the width control maxed out the tube faces have quite a bit of unused real-estate at the sides. (especially at 720p, at 1080i it is much smaller) The unused space may be half an inch at both sides at 720p.

I understand there is a width pot on one of the cards which maximises tube usage. But then I read something about overheating neck cards if you increase the width.

What is your advise on this?

[2] How to center the raster?

On the red tube the raster is not centered. :( I know this PJ does not have raster centering rings, so I used to move the focus magnet and the CPC magnets around to center the raster.

But what is the right way?

Hey Rajiv,

That procedure was the official Ampro color balance technique. They were too cheap to buy a color meter so it was all done by eye. The yellow then gray method works pretty good. I'm glad it worked out for you. The 4200 isn't a bad projector. It should do a smokin' 1080i and 720p.

Scott

Oh Yeah !
NOW it sure does a "smoking 1080i"! :D :D

I notice 1080i actually has slightly more detail on this PJ than 720p. But then I have not dialed in the focus and schempflug 100% yet (it is still on the table). Once I get to hang it again I will do all those things and post some screenshots. Got to still buy the digi-cam. :(

Last night I showed it to the wife, she was mighty impressed. (she is especially hard to impress) :cool: She kept pointing out the detail in people's faces and how accurate the colors were now. :D


Hey... got to ask you two things.

[1] About the maximizing of rasters.

Is it OK to mess around with the width pot? :confused:

The thing is ...even with the width control maxed out the tube faces have quite a bit of unused real-estate at the sides. (especially at 720p, at 1080i it is much smaller) The unused space may be half an inch at both sides at 720p.

I understand there is a width pot on one of the cards which maximises tube usage. But then I read something about overheating neck cards if you increase the width.

What is your advise on this?

[2] How to center the raster?

On the red tube the raster is not centered. :( I know this PJ does not have raster centering rings, so I used to move the focus magnet and the CPC magnets around to center the raster.

But what is the right way?

If your horizontal frequency is below 48KHz you can set the width as wide as you want. 720P is about 45KHz so should be no problem. You can check by entering 36 then press "code". It is the pot on the HOT bd that is an inch or so in front of the fuse. The HOT bd switches the retrace time to 3uS once the horizontal freq passes 48KHz. The short retrace time places a higher voltage on the output mosfets and can become too high with wide raster/high sweep freq.

You have a very unique 4200 if there are no centering rings. We only made a few before we realised they would be a good addition. If you are up to installing them I can send you three sets. There really isn't a good solution to positioning the rasters without them. You can rotate the focus mags and get some movement. A little convergance shift is ok. The CPC mags should be used for getting best focus.

Scott

Scott

As usual that's really great info about width and centering.

My 4200 is one of the later models that uses the P19 style tubes, and it doesn't have any centering rings either. I was able to get the blue centered by rotating the focus ring assembly. It took me two years to figure that one out.

Do you know if the centering rings would work on a 4600 model? Is there anything mechanically different about the mounting against the deflection yoke?

I recently replaced the 4200 with the 4600 in my rear screen setup, and I am totally blown away with the performance of this thing. I had to replace the tubes because the chassis had over 30K hours on it. I used 3 new P19LUG's with a red "C" element upgrade. The electrical focus is razor sharp on all three tubes. The 1080I scan lines are hurting my eyes at 12 feet. I need a 1080P solution at this point.

Anyway - the red and blue rasters are off center on the 4600. I can max out the shift adjustments to get them to where they need to be, but a static solution would be so much more elegant.

We're all much appreciative of your support.

Ray

Ray,

I'll make you the same offer to send centering rings. They will work with the 4600 but you will have to figure a way to mount them. There isn't an easy way to attach them like on the 4200. To get static shift without rings only requires a DC current through the deflection yokes or the registration coils. An isolated DC DC converter, an inductor to isolate the AC signal, and a resistor to set the current. One amp through the reg coil will shift the image about 1/2" on tube face. Parts for one reg coil would be about $20.

Scott

Scott-

Why on earth are there no centering rings on the 4600? I might be interested in adding some to mine. Do you have enough to go around?

Also, thanks for all of the great information you have shared in this thread.

Rajiv-

Looking forward to seeing some screenshots!

-Mark

Two reasons:

1. No easy (cheap) way to do it.

2. It was becoming more and more obvious that things like centering rings took more technical ability, to set correctly, than most sellers, buyers, owners had or wanted to learn.

The unfortunate thing is by then all the engineering resources were going into light valve and DLP projectors. Management looked into the crystal ball and made their decision. They were partially right.

Scott

Scott-

Could you explain to me why the centering rings are easy to add to the 4200 but not the 4600? What am I missing?
Thanks.

-Mark

Different yokes. The 4200 uses Sony yokes, the 36/4600 uses Thomson. You just had to glue a couple of small cable clamps on the back of the Sony yokes and instant centering ring mounts. The Thomson yokes had less astigmatism distortion in the corners. So the Sonys and centering rings went away.

Scott

I see. Thanks Scott. This is what Chip has been working on, I think. I'll wait until he comes up with a solution :)

-Mark

I see. Thanks Scott. This is what Chip has been working on, I think. I'll wait until he comes up with a solution :)

-Mark

It's done but un-tested :D I probably won't get a chance to pull my tubes and install the modded covergence yoke until later in the week. E-mail me and I'll fill you in. stefuel@aol.com

Chip

Ray,

I'll make you the same offer to send centering rings. They will work with the 4600 but you will have to figure a way to mount them. There isn't an easy way to attach them like on the 4200. To get static shift without rings only requires a DC current through the deflection yokes or the registration coils. An isolated DC DC converter, an inductor to isolate the AC signal, and a resistor to set the current. One amp through the reg coil will shift the image about 1/2" on tube face. Parts for one reg coil would be about $20.

Scott

Thanks Scott - I'll send you a follow up PM about the rings. Looks like it's worth a shot.

The electronic centering circuit also doesn't look as bad as I thought it would be. Looks like since it's in parallel to the existing wiring, there might not be as much risk in getting a deflection burn from loss of sweep.

Ray

Interesting things are happening in this thread !

Scott, the freq. counter shows 44xxx for 720p. At 1080i it is much smaller (I forget). Hence I am going to try out the width pot soon.

As for the centering rings, this PJ may already have them (if I recall correctly). I kinda remember they were extremely hard to rotate.
Thanks for your generous offer, but I will check first (ASAP).

If your horizontal frequency is below 48KHz you can set the width as wide as you want. 720P is about 45KHz so should be no problem. You can check by entering 36 then press "code". It is the pot on the HOT bd that is an inch or so in front of the fuse. The HOT bd switches the retrace time to 3uS once the horizontal freq passes 48KHz. The short retrace time places a higher voltage on the output mosfets and can become too high with wide raster/high sweep freq.

You have a very unique 4200 if there are no centering rings. We only made a few before we realised they would be a good addition. If you are up to installing them I can send you three sets. There really isn't a good solution to positioning the rasters without them. You can rotate the focus mags and get some movement. A little convergance shift is ok. The CPC mags should be used for getting best focus.

Scott

Ray,
your comments about the 4600 are tempting, to say the least. :D
But I got scanlines at 1080i too...... BIG ones..... and my tubes are the older Sonys 09MIs!

At 720p they start filling in. Last I checked 1080p was pretty soft. I wish this PJ has better EM focus.

Does the 4600 have enough bandwidth to do 1080p? I heard they dont.


Scott

As usual that's really great info about width and centering.

My 4200 is one of the later models that uses the P19 style tubes, and it doesn't have any centering rings either. I was able to get the blue centered by rotating the focus ring assembly. It took me two years to figure that one out.

Do you know if the centering rings would work on a 4600 model? Is there anything mechanically different about the mounting against the deflection yoke?

I recently replaced the 4200 with the 4600 in my rear screen setup, and I am totally blown away with the performance of this thing. I had to replace the tubes because the chassis had over 30K hours on it. I used 3 new P19LUG's with a red "C" element upgrade. The electrical focus is razor sharp on all three tubes. The 1080I scan lines are hurting my eyes at 12 feet. I need a 1080P solution at this point.

Anyway - the red and blue rasters are off center on the 4600. I can max out the shift adjustments to get them to where they need to be, but a static solution would be so much more elegant.

We're all much appreciative of your support.

Ray

Does the 4600 have enough bandwidth to do 1080p? I heard they dont.

Apparently not, or perhaps just barely. This is why Scott was working on a solution using Marquee neck cards in the Ampro. The Marquee neck cards have much higher bandwidth I guess.

I think he eventually decided it wasn't practical... or something. I'd still love to see it happen.

-Mark

Mark,

If you have the source try setting it up at 1080p, maximise the raster usuage. Your setup has to be good. But I'm running 1080p on a 4300 and the picture is pretty darn good. The colors, are as always with Ampro stunning. I have Green and Red C-Element (color corrected) on mine. More bandwith, raster centring and the optic mods (Chip is working on that) would be great though.

Shaz

Hi Scott,
I peeped into my PJ last night. It sure does have those rings. :)

Now I remember adjusting them when I was doing the full astig/focus/centering (while the PJ was hanging) I remember centering the rasters then, but now when I moved the PJ to the table, the red and blue rasters are shifted to the left.

Maybe I should worry about raster centering only after I hang the PJ again.

Those look like 2 brown plastic rings with tabs. Are they moving some magnets or are they magnetized themselves? :confused:


You have a very unique 4200 if there are no centering rings. We only made a few before we realised they would be a good addition. If you are up to installing them I can send you three sets. There really isn't a good solution to positioning the rasters without them. You can rotate the focus mags and get some movement. A little convergance shift is ok. The CPC mags should be used for getting best focus.

Scott

Shaz,
How did you maximize the raster usage? Using the width pot?
Any negative effects like unstability / overheating after that?


Also, have you tried 1080i ? My PJ does 1080i the best (as of now) and does not need width adjustment for that rez. At 720p the raster starts getting smaller.

What is the disadvantage of doing a interlaced 1080 instead of progressive?

Does 720p actually have more pixels than 1080i?

Mark,

If you have the source try setting it up at 1080p, maximise the raster usuage. Your setup has to be good. But I'm running 1080p on a 4300 and the picture is pretty darn good. The colors, are as always with Ampro stunning. I have Green and Red C-Element (color corrected) on mine. More bandwith, raster centring and the optic mods (Chip is working on that) would be great though.

Shaz

Hi Scott,
I peeped into my PJ last night. It sure does have those rings. :)

Now I remember adjusting them when I was doing the full astig/focus/centering (while the PJ was hanging) I remember centering the rasters then, but now when I moved the PJ to the table, the red and blue rasters are shifted to the left.

Maybe I should worry about raster centering only after I hang the PJ again.

Those look like 2 brown plastic rings with tabs. Are they moving some magnets or are they magnetized themselves? :confused:

The centering rings are magnets. Very weak, though. When the tabs are overlapped they have the most strength. If you overlap them (the two fields add) and then rotate them together the raster will move in a circular pattern at max excursion. The raster can be placed anywhere in the circle by adjusting the rings. Place the tabs on opposite sides (the fields cancel) and spin them together the raster should move very little.

Before moving from table to ceiling I like to set sweep for ceiling and set raster position (tube face) on the table. Picture is up side down but it is easier to deal with the rings on the table. It helps alot to pick all the silicon or whatever off the rings before adjusting.

Scott

Does 720p actually have more pixels than 1080i?

CRT's don't have pixels buddy :)

Honestly I'm not qualified to answer this question from a technical standpoint. But what I can tall you is that some people seem to prefer 720p, and others prefer 1080i. I think it varries from person to person and you have to consider the variables like the projector, sources, screen size, etc. To say that one is always better than the other is probably not fair.

I'd say try them both and see which one looks better to you. That's what matters most.

-Mark

Dude!
I know that by now! HA HA :D

I was refering to the resolution (hence the number of pixels) input signal.....the number of pixels you feed your PJ as an input.


CRT's don't have pixels buddy :)

Honestly I'm not qualified to answer this question from a technical standpoint. But what I can tall you is that some people seem to prefer 720p, and others prefer 1080i. I think it varries from person to person and you have to consider the variables like the projector, sources, screen size, etc. To say that one is always better than the other is probably not fair.

I'd say try them both and see which one looks better to you. That's what matters most.

-Mark

Hey Rajiv,


How did you maximize the raster usage? Using the width pot?
Any negative effects like unstability / overheating after that?


Just using Image Size, I get almost full raster (very close to edge of tube face), I don't seem to have the raster shrinkage problem that u get on your 4200.

No negative effects. I haven't touched any of the pots on the HOT board.



Also, have you tried 1080i ? My PJ does 1080i the best (as of now) and does not need width adjustment for that rez. At 720p the raster starts getting smaller.

What is the disadvantage of doing a interlaced 1080 instead of progressive?

Does 720p actually have more pixels than 1080i?

I have tried 1080i and 720p, preferred 1080p, and to be honest it didn't look soft to me.....but I'm no expert(!) and not seen a G90 in action either!

Shaz

Hmmmm....
That is very interesting! 1080p and no raster shrinking!
You must have a good 4300.

I wonder how much the 4300 is different from the 4200. :confused:

I know that the 4600 is substantially different than the 4200.

Hey Rajiv,



Just using Image Size, I get almost full raster (very close to edge of tube face), I don't seem to have the raster shrinkage problem that u get on your 4200.

No negative effects. I haven't touched any of the pots on the HOT board.




I have tried 1080i and 720p, preferred 1080p, and to be honest it didn't look soft to me.....but I'm no expert(!) and not seen a G90 in action either!

Shaz

Ray,
Tse sent me some rings last year and this thread got me motivated to try them on my 3600. I mounted them just forward of the focus yoke. I do not know if these should be in front of the convergence coil or behind so I took the easier route and mounted them behind it. It seems to work.

I took a centering bushing from an old focus yoke to use in mounting them as the hole in the rings are much too large for the 8" tube neck. I used a wire tie (white in photo) to secure the rings close to the convergence yoke. One of the yoke clamps would probably be tighter.

My blue would not center completely even after rotating the focus yoke 180°, With the rings, I reset the blue shift from 77 back to 50 and centered the raster completely. I had to keep the yoke rotated, but it is centered.

Ray,
Tse sent me some rings last year and this thread got me motivated to try them on my 3600. I mounted them just forward of the focus yoke. I do not know if these should be in front of the convergence coil or behind so I took the easier route and mounted them behind it. It seems to work.



Hi Allen,

Thanks for the heads up. Looks like you might have saved me a lot of work. I've got some old yokes, and was hoping to salvage something from them that might fit the rings. Hope to get the rings toward the end of the week.

Ray

Hmmmm....
That is very interesting! 1080p and no raster shrinking!
You must have a good 4300.

I wonder how much the 4300 is different from the 4200. :confused:

I know that the 4600 is substantially different than the 4200.

Rajiv,

The 33/43 and 36/4600 horizontal deflection circuits are very similar. One of the differences between them and the 4200 is the circuit that senses the horizontal deflection current. The 33/43/36/4600 circuit has compensation for frequency response that maintains raster width as frequency increases. The 4200 will allow the raster width to decrease as the freq goes up. There is a test point on the HOT bd that can be monitored that lets you adjust the width to maximum safe level. Yell if you want to mess with it.

Scott

Hey, at least u have centring rings!
I don't think I have any on mine....when I run it at 1080p, it would be very useful to have centring rings, I have to move the raster using static shift (I think it was), almost max to the right -- to get it fairly centred.

Not sure if my 4300, is a good one...I think most of them are pretty good. If setup properly....and cooled!

Shaz

Hmmmm....
That is very interesting! 1080p and no raster shrinking!
You must have a good 4300.

I wonder how much the 4300 is different from the 4200. :confused:

I know that the 4600 is substantially different than the 4200.

You sure you are using the static shift to move it sideways?
On my PJ the static shift only moves the raster up or down!


I have to move the raster using static shift (I think it was), almost max to the right -- to get it fairly centred.


Shaz

So in the past few days, I adjusted the width pot and hung the PJ. :D

The width pot really works :D (DUH! :o ) and now I am able to get 720p all the way to the ends of the tube. I set the width pot so that I have around 2 mm on the sides at 720p.

When I was converging the PJ yesterday night I noticed two strange things:

1. If I have the image width maxed at 720p the static keystone and pin cushion controls have no effect!
To make them work I have to reduce the width so that I have around 10mm unused space (or more) on the sides. Strange!

2. If I increase the brightness above 75 or so, the top 10% of the screen widens and starts flickering. The quick fix is to reduce the width a bit more.

Does that mean that I simply can’t use the full tube width for 720p?


By the way, 1080i is fine.

Hey Rajiv-

I noticed similar issues when I tried to adjust the width pot on my 4600. I got some more width out of it but it didn't really seem to be useable. If I increased the width past a certain point it would flicker and shake or something. I don't quite remember.

Incidentially, how did you go about adjusting that pot? I found that there was a board in the way that I had to remove just to get to it. Looking at Curt's diagram I guess it was the Vertical Deflection board that was in the way. Were you able to adjust the pot without removing that board?

-Mark

Mark,
on my 4200 this HOT board is the board on the extreme right side (with PJ on the floor and you behind the PJ).

That pot is very easily accessible, heck it is even turned upwards to enable the tech to just use a screwdriver vertically. It does not need a stubby screwdriver or anything.

On my board it is very clearly labelled on big letters - WIDTH.

At this point, I do agree that that width pot is unusable. Now all that has happened is that instead of the width maxed out via the keypad I have it maxed out at the pot and the keypad is around 80 or something.

Either way I have to leave around 10 to 15 mm unused on the sides of the tubes.

I just hope Scott has a solution to this.

Hey Rajiv-

I noticed similar issues when I tried to adjust the width pot on my 4600. I got some more width out of it but it didn't really seem to be useable. If I increased the width past a certain point it would flicker and shake or something. I don't quite remember.

Incidentially, how did you go about adjusting that pot? I found that there was a board in the way that I had to remove just to get to it. Looking at Curt's diagram I guess it was the Vertical Deflection board that was in the way. Were you able to adjust the pot without removing that board?

-Mark

So in the past few days, I adjusted the width pot and hung the PJ. :D

The width pot really works :D (DUH! :o ) and now I am able to get 720p all the way to the ends of the tube. I set the width pot so that I have around 2 mm on the sides at 720p.

When I was converging the PJ yesterday night I noticed two strange things:

1. If I have the image width maxed at 720p the static keystone and pin cushion controls have no effect!
To make them work I have to reduce the width so that I have around 10mm unused space (or more) on the sides. Strange!

There is a linear pass transistor (Q6 on heatsink) that controls width. Static key and pin essentially modulate the width. When the width is increased enough there is no longer any voltage across the pass. The voltage going to the pass can be increased by adjusting R3. I recommend first measuring the voltage on the center pin (Q6) at a specific frequency (like 1080i) and note it so you can reset to factory if you need to later.

2. If I increase the brightness above 75 or so, the top 10% of the screen widens and starts flickering. The quick fix is to reduce the width a bit more.

Does that mean that I simply can’t use the full tube width for 720p?

See if the above helps.


By the way, 1080i is fine.

By increasing the voltage to the width control circuit you are reducing the maximum usable horizontal freq. Not a problem if you aren't ever going to use anything over about 75KHz. Increase this voltage just enough to get the width and keystone range that you need. Too much will make Q6 work harder than it needs to.

Scott

I recommend first measuring the voltage on the center pin (Q6) at a specific frequency (like 1080i) and note it so you can reset to factory if you need to later.


Un-Oh….Too late . I have already messed up with that pot. :mad:

Anyway I had to reduce the width pot to back to what it was (approximately). The image just was not stable!


By increasing the voltage to the width control circuit you are reducing the maximum usable horizontal freq. Not a problem if you aren't ever going to use anything over about 75KHz. Increase this voltage just enough to get the width and keystone range that you need. Too much will make Q6 work harder than it needs to.

Scott


Yup that is what I ended up doing. I think the image is slightly wider now (than what it was before I tweaked the width pot)

So I guess full width rasters are not for this PJ.
Frankly it is not too bad now, but I'd be happier with a little more !

Thanks! :)

Ok here is one more thing I noticed when I hung the PJ.

The image is now softer than what it was when it was on the table. The image has gone down from a “smoking hot, tack sharp” one to a slightly soft image where I can’t see the depth of field differences in things like “House” in 720p

Earlier I was easily able to figure out where the camera was focusing while watching “House”. For example, I could easily see whether Dr. Cameron’s nose was in focus or her eyes! :eek:
Yup! It was that sharp! :D


The only difference I can see is I moved the PJ around a foot (or maybe more) forward. I did this to make the image fit my screen properly. Earlier I was just putting the coffee table on the rear sofa riser , hence I had to keep it there (a foot back)

My screen is around 87 inches wide

I read somewhere that these HD-10 lenses don’t do screen this small very sharply. The screen has to be bigger for them to be able to project a sharp image.

Is this what I am hitting against? :confused:
Do I need HD-10L?

Anyone?

Looks almost like this PJ may not be suitable for my screen size, unless I change the lenses ??

Ok guys, I am posting some info about how to improve the convergence drift issues.

From what I understand this is valid for most other PJs too.

I was talking to Mark about this and here is what his comments were.


The mechanical set-up and the convergence settings have a large effect on how stable the image is. We both already know this, or at least we've been told this before. It's widely known that getting the mechanical adjustments nailed and minimizing all static adjustments will help increase the stability of the image. So, knowing this I can deduce that if I redo my whole set-up from scratch and the result gives me more convergence drift than before, then the mechanical set-up was probably better the first time. At least this is the assumption I've made. The more time you spend with a PJ the better you will be at understanding how it works and getting the mechanical set-up perfect.

Doesn't your 4200 have centering rings? If so, have you used them to center the raster on the tube face with the static shift neutralized? If you had to use static shift to center the rasters I'd expect that to be the #1 contributing factor to convergence drift.


Yes it does have the centering rings. But here is the problem………..it does not have enough range. I can only do one of these two things:

1. Center the raster horizontally, or
2. Center the raster vertically.

Cant do both. :mad:


I thought that it is the ‘dynamic adjustment’ which puts more stress on the circuits. Hence I centered the raster horizontally and used the Static adjustment to center the rasters vertically. (You can’t use Static adjustment to center the rasters horizontally on the 4200; that is a dynamic function)

Is this not the right thing to do?
What is the next best thing to do if the centering rings wont center the raster?

Centering horizontal with the rings and vertical with the static shift should be the best way to do it. Less power that way anyhow.

Scott

Thanks Scott! Good info.
That is what I am doing anyway.

By the way, what is your screen's size?
You have a 4200 now, right?

Centering horizontal with the rings and vertical with the static shift should be the best way to do it. Less power that way anyhow.

Scott

Rajiv,

My screen is 60 x 80" or 100" diagonal. All my video runs through my satellite receiver which outputs 1080i but cuts off some of the left and right sides to fit the 4 x 3 screen. I guess it's like 1440 x 1080i. The 4200 looks magnificient with HD video. Run that video through my gamma (shadow enhance) box and the blacks are black. Nice contrast ratio. The 4200 isn't a bad projector.

Scott

Of course it is not a bad PJ !!! :D :D

Scott, I moved my PJ a foot back. The image is sharper now. My screen is around 87" wide. The projected image is like 90 inches.

I suggest someday trying to pull back your PJ and see if the image becomes sharper.

Mine does. :confused:

Other people here have told me that the HD10 lenses do not throw a sharp picture on small screens.

Do you have HD10L lenses instead ?

Rajiv,

My screen is 60 x 80" or 100" diagonal. All my video runs through my satellite receiver which outputs 1080i but cuts off some of the left and right sides to fit the 4 x 3 screen. I guess it's like 1440 x 1080i. The 4200 looks magnificient with HD video. Run that video through my gamma (shadow enhance) box and the blacks are black. Nice contrast ratio. The 4200 isn't a bad projector.

Scott

Here are some pictures of my projector as it looks now.

These are thumbnails, click on them to see a bigger, high resolution photo.

http://www.funkyhuman.com/hosted_images/IMG_0277_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0277.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0278_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0278.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0279_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0279.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0280_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0280.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0069_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0069.JPG)

Here are the LONG promised screenshots of my 4200 :D

All are taken at 720p



http://www.funkyhuman.com/hosted_images/IMG_0286_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0286.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0285_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0285.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0283_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0283.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0284_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0284.JPG)

http://www.funkyhuman.com/hosted_images/IMG_0287_small.JPG (http://www.funkyhuman.com/hosted_images/IMG_0287.JPG)

I have used these rubber fan mounts and found them to be pretty nice.
You just pull them through the holes and they isolate the chasis from the fan a little bit.

IMHO it reduces the noise. :D

They were cheap, bought here:
http://www.jab-tech.com/4-Pack-Anti-Vibration-Fan-Mounts-Closed-Corners-pr-3269.html

These ones are meant for fans with closed corners....but when my fans arrived I discovered that they had open corners....nevertheless they work just fine.

The ones for closed corner fans are these ones:
http://www.jab-tech.com/4-Pack-Anti-Vibration-Fan-Mounts-Open-Corners-pr-3270.html


http://www.funkyhuman.com/hosted_images/IMG_0067.JPG

http://www.funkyhuman.com/hosted_images/IMG_0065.JPG

http://www.funkyhuman.com/hosted_images/IMG_0066.JPG

So Raj... what are you moving to?

Well this projector is so very nice but I eventually found out that it is not really suitable for my screen (only 87" wide) It performs its best at bigger image sizes like 100" or more. At those sizes it is extremely sharp and fully converged.

The small size of my room and huge door like speakers dont allow me to have a bigger screen :(

Maybe with HD10L lenses (instead of the stock HD10) it may perform better on such a small screen.

But I recently found a G70....

So what are you running these days?

I heard even people like Art moved on the digitals! :eek:

So Raj... what are you moving to?

A 9500 Ultra. Chip has all my old Ampro stuff.

Well this projector is so very nice but I eventually found out that it is not really suitable for my screen (only 87" wide) It performs its best at bigger image sizes like 100" or more. At those sizes it is extremely sharp and fully converged.

The small size of my room and huge door like speakers dont allow me to have a bigger screen :(

Maybe with HD10L lenses (instead of the stock HD10) it may perform better on such a small screen.

But I recently found a G70....

So what are you running these days?

I heard even people like Art moved on the digitals! :eek:

I told you a very long time ago to try a set of HD-10L's. You won't really see the straight 10's shine till you're up in the 120-140 inch range. You don't have to believe me. Just try this one time. set your green lens adjustments to dead center and slowly move the projector back until it focusses perfectly in the center. If your beam focus and astigmation are correct, you will see a ultra sharp image but will be way to big for your room. Before you waist all that time you have invested in this projector, find a set of 10L's and try it. It will be much cheaper than starting from scratch with a new projector.

Chip

Chip, is that 120-140 diagonal or 120-140 wide?

I have a 126" st130 that might look pretty good with that pj.

Chip, is that 120-140 diagonal or 120-140 wide?

I have a 126" st130 that might look pretty good with that pj.

I'm not 100% sure because it was 4 years ago that I did that test. But I'm pretty sure it was "WIDE". I tried it on a 120 diag 4:3 screen first then had to pull it back further. I was unable to do the test at my house as I had no room big enough to do the test. I had to use a barn wall that was sheetrocked and painted white.

Chip

Chip
You are 100% right !

I have tested this too and found your claims are absolutely right. I am not sure about the 120" thing but my PJ was extremely sharp and fully converged at around 100" . I had no room to go bigger.

But alas, I was never able to find a set of HD10L lenses for a reasonable price.

I told you a very long time ago to try a set of HD-10L's. You won't really see the straight 10's shine till you're up in the 120-140 inch range. You don't have to believe me. Just try this one time. set your green lens adjustments to dead center and slowly move the projector back until it focusses perfectly in the center. If your beam focus and astigmation are correct, you will see a ultra sharp image but will be way to big for your room. Before you waist all that time you have invested in this projector, find a set of 10L's and try it. It will be much cheaper than starting from scratch with a new projector.

Chip

Raj, wish I'd known you wanted a set. I've got one in my garage I'd sell ya for a good price, but I suppose you've moved on now.

Hey ! Where did my FS thread go?