RGB mod of CRT Panasonic TC-14S20RDF on MX-3 chassis

[Kvazikvark]

So far, this will serve as a continuation of the discussion about the RGB modification of the Panasonic TC-14S20RDF CRT from the original thread.

Summary
I thought this RGB mod would be a cakewalk, so I copied a solution from one user on this forum. However… like another user, I also ended up with a dark picture. After reading the datasheet, I now realize that the OSD chip uses RGB signals at a much higher voltage level (around 0–3.2 Vp-p) compared to standard RGB (0–0.7 Vp-p). This explains why the image was too dark.

Now I need to adjust the RGB signal to achieve a proper picture.

In this thread, I’ll document my progress as I work through the project.

Currently, I am setting up a workspace for an oscilloscope and waiting for all the necessary parts to arrive. Among the items that haven’t even been ordered yet, the only thing left to source is an isolation transformer. I’m looking for a factory that can manufacture one for me.

PS
English isn’t my native language—though I understand everything written or spoken in it perfectly, I haven’t dedicated enough time to studying grammar yet, so my phrasing tends to be clumsy. I decided to try running my text through Deepseek, and… I loved the results! I’ll probably keep drafting messages this way from now on.

[ahkek89]

So far, this will serve as a continuation of the discussion about the RGB modification of the Panasonic TC-14S20RDF CRT from the original thread.

Summary
I thought this RGB mod would be a cakewalk, so I copied a solution from one user on this forum. However… like another user, I also ended up with a dark picture. After reading the datasheet, I now realize that the OSD chip uses RGB signals at a much higher voltage level (around 0–3.2 Vp-p) compared to standard RGB (0–0.7 Vp-p). This explains why the image was too dark.

Now I need to adjust the RGB signal to achieve a proper picture.

In this thread, I’ll document my progress as I work through the project.

Currently, I am setting up a workspace for an oscilloscope and waiting for all the necessary parts to arrive. Among the items that haven’t even been ordered yet, the only thing left to source is an isolation transformer. I’m looking for a factory that can manufacture one for me.

PS
English isn’t my native language—though I understand everything written or spoken in it perfectly, I haven’t dedicated enough time to studying grammar yet, so my phrasing tends to be clumsy. I decided to try running my text through Deepseek, and… I loved the results! I’ll probably keep drafting messages this way from now on.

Hello, were you able to address this? I also have the same issue on this chassis.

[Kvazikvark]

Hello, were you able to address this? I also have the same issue on this chassis.

Hello, unfortunately I haven't had time to continue the project practically, there are only theoretical outlines. I planned to make a simple op-amp amplifier for each of the RGB signals and adjust the Vp amplitude using trimmer potentiometers. That should work, and as for gamma, it's unlikely that I'll need to adjust it since the microcontroller should handle it itself, from what I've read.