Atari STe video issues (might also apply to other ST's with RF modulator)

[thgill]

Ok, so I posted this question over at Atari-Forum 2 years ago and got many replies, but never a cure. You can read the whole thread there for details.

 

http://www.atari-for...hp?f=15&t=19199

 

 

Question: Anyone with a 520 or 1040 STe machine have ghosted image problems? Usually looks like a halo/shadow effect to the right of graphics. Shows up mostly on light colored backgrounds.

 

Example:

 

 

 

 

 

This is from the Tempest 2000 Music Disk:

http://www.pouet.net...php?which=21030

 

 

You can see the shadowing off to the right of the big smiling face.

 

Anyone with a STe machine please try this disk and see what your results are.

 

 

Quoting my last post on this from A-F:

 

Ok, so I have another STe in my hands and its doing the exact same thing!

 

So, 4 total STe machines have been in my possession and that all exhibit the same behavior.

 

2 NTSC machines and 2 PAL machines.

 

I have tested them with 2 different SC1224's, 2 different RGB broadcast monitors (one JVC and the other Sony PVM), built different RGB video cables using quality VGA screened cable, lived in 3 different apartments and used different power supplies. Both original PSUs and retrofitted PicoPSUs and even an ATX unit. I have even built an inline LM1881 sync stripper to clean up the composite video as Sync. Instead of using RGB output I have also just built a composite video cable.

 

Always the same thing.

 

Either you guys simply don't notice this issue, or I am going crazy.

 

I have thought of disabling or full out remove the RF modulator to see if that has any effect. I am assuming the composite video that drives pin 2 on the 13 pin din is generated before the RF modulator. So removing it shouldn't knock out the composite sync. Thoughts on that?

[Fox-1 / mnx]

It looks like another tube is too close and interferes but I assume this is not the case?

 

 

edit: also, lift the monitor from the bench while it's running and check if the ghosting is changing/moving.

[thgill]

It's the only CRT in my house in use. I am currently using a Sony PVM 20 inch RGB monitor as my display so lift it up off the desk while the machine is running is kinda hard. It weighs 70 pounds!

 

None of my other devices have this kind of odd "ringing". Plus every STe I have used exhibited this same behavior.

 

 

Would be nice if other forum members can try that demo I pointed to and let me know their results. Perhaps this is a design flaw in the 520/1040 STe hardware?

[Christos]

I'd say that the video cable isn't shielded very well.

[+DarkLord]

Possibility there, any chance you could swap out cables and see if it made a difference?

[Charlie_]

Hi Thgill. I see some of what your saying. Maybe it is just my eyes....

However I see nothing like what I see in your picture.

Here is my STe and Mega STe.

 

*edit: the more I look at your picture it reminds me of what I see on my Mega STe with the 2.06 Atari logo when I 1st turn it on.

I have noticed that the STe and Mega STe have a much "weaker" display than my 1040STfm.

The 1040 STfm has more vibrant colors and is brighter.

Edited May 26, 2012 by Official Ninja

[thgill]

Damn. Thanks for the pictures Official Ninja. Its pretty noticeable if its present and I only see a bit in your 1st picture. 2nd picture I don't see any.

 

I will put together another cable tonight and test it again.

 

Weird thing is that it happens on 2 different SC1224 with their built in video cables.

 

Also happens with my DIY cable running to my 20 inch PVM monitor.

Edited May 26, 2012 by thgill

[+DarkLord]

Hmm, can't remember all the details but Atari used to include a small clip-on (demagnitizer/degausser?)

on SC1224 cables.

 

I know the cable on my Mega ST has one. It was supposed to have something to do with video.

 

Do you have one of those, or could get one and try it?

 

Just a thought...

[Charlie_]

It may be the environment. I know my basement is famous for causing tubes to look like they need a good degaussing.

I was trying a VGA upscaler , a home brew model, and it had wavy noise scrolling on the screen with my ST's and TRS-80 coco's.

The builder of the unit swears it does not do that for anyone else. And he sent me two of them and 2 different cables.

Edited May 26, 2012 by Official Ninja

[+DarkLord]

It may be the environment. I know my basement is famous for causing tubes to look like they need a good degaussing.

I was trying a VGA upscaler , a home brew model, and it had wavy noise scrolling on the screen with my ST's and TRS-80 coco's.

The builder of the unit swears it does not do that for anyone else. And he sent me two of them and 2 different cables.

 

Wouldn't be living anywhere near Area 51 would ya?

[thgill]

*edit: the more I look at your picture it reminds me of what I see on my Mega STe with the 2.06 Atari logo when I 1st turn it on.

I have noticed that the STe and Mega STe have a much "weaker" display than my 1040STfm.

The 1040 STfm has more vibrant colors and is brighter.

 

I think the display brightness may have to do with the capacitors on the motherboard and/or power supply being aged.

 

I know the video output on my UK 520STe (with PicoPSU) is crazy bright. Even with 150 ohm resistors on the RGB lines, I still have to dial down the brightness and contrast on my PVM monitor. I recently sold a 520ST that had far dimmer output than the STe. Since it was an original model, I suppose it probably could use a recapping.

Edited May 26, 2012 by thgill

[+DarkLord]

I have had a similar experience - when I replaced the P/S on my Mega ST4, everything was much crisper on the

display...

[+Stephen]

I only have a 520STFM, and the 1st I have ever used it was a few weeks ago. I built a custom monitor cable that lets it plug right into the DIN-6 (RGB) of my 1084S. I also used 150Ohm resistors on the RGB lines. The picture is incredible. I need to find a 19" RGB CRT though - the little 1084 is just too small.

[OBO]

Hi all,

 

I had various Atari St computers and had this kind of experience :

 

1040STF (NOT M, French version) : No ghost image, it was crisp.

MEGA STE (without RF) : Very light ghost image, almost invisible, but interference from the floppy disk activity & PSU could be "seen" on the screen, like diagonal lines moving across the screen

520STE W/4mo RAM, UK one with RF output : Ghost image quite visible with certain colors shown on screen, and a little bit of interference from floppy on screen.

 

All of them, connected using a SCART cable...

 

(Sorry for Bad English, I'm French )

[thgill]

Hi all,

 

I had various Atari St computers and had this kind of experience :

 

1040STF (NOT M, French version) : No ghost image, it was crisp.

MEGA STE (without RF) : Very light ghost image, almost invisible, but interference from the floppy disk activity & PSU could be "seen" on the screen, like diagonal lines moving across the screen

520STE W/4mo RAM, UK one with RF output : Ghost image quite visible with certain colors shown on screen, and a little bit of interference from floppy on screen.

 

All of them, connected using a SCART cable...

 

(Sorry for Bad English, I'm French )

 

This is very similar to my experience. I had a 1040STf with a sharp picture and no ghosting. When accessing the floppy I would see some lines on the screen, but most likely the PSU needed to be replaced.

 

I have owned multiple 520/1040 STe (NTSC and PAL) machines over the last couple years, and all of them suffer from this ghosted image issue. If you keep your contrast and brightness controls adjusted correctly, 90% of the time its not noticeable.

 

 

Seems the video quality in these machines are kinda on the poor side. Would love to find a proper solution to this. Sometimes I wonder if the RF modulator is causing this. I would remove it, but I fear I would lose the composite video from the 13 pin din and I use that as sync for my RGB monitor.

Edited June 1, 2012 by thgill