View Full Version : Ion trap adjustment and placement


Madeline12
04-21-2024, 12:53 AM
Still working on my first tube tv restoration. Next up is working on the picture tube assembly itself… to note, this entire tv and cabinet was FILTHY. I have yet to clean the assembly in question, so please ignore that portion…

I’m not seeing anywhere in the schematics for this model (Stewart Warner 9121A) listing the exact position of the ion trap for this model. Upon opening it up, I noticed someone in the past did some work on this, as there were some wrong tubes in the wrong sockets, and a few newer capacitors with the wrong specs. Which leads me to wonder if the ion trap is also incorrectly placed, as the picture tube itself is functional yet I am getting no picture.

Attached is a photo: although not pictured, I see it was previously glued to the tube itself. Also, from what I understand, the arrow is pointing in the opposite direction of the screen, which is incorrect. Can anyone confirm if this is true? And does anyone know if the position is correct if it is sitting at around 2 o’clock viewing from the back?

Thanks for any help in advance!

vortalexfan
04-21-2024, 01:41 AM
Usually with the ion traps (in my experience anyways) are to be adjusted by first rotating it left or right for the brightest picture and then moving it back and forth along the length of the neck of the tube for proper centering of the image. I'm assuming this is a round picture tube like the 12BP4?

Madeline12
04-21-2024, 01:45 AM
Usually with the ion traps (in my experience anyways) are to be adjusted by first rotating it left or right for the brightest picture and then moving it back and forth along the length of the neck of the tube for proper centering of the image. I'm assuming this is a round picture tube like the 12BP4?

It’s a 16RP4 :) and sounds good, this is helpful. Any word about the arrow? I saw somewhere mentioning that if an ion trap possesses an arrow indicates it should face the screen, although they were discussing a different brand and model…

vortalexfan
04-21-2024, 01:48 AM
It’s a 16RP4 :)

OK, its a much bigger tube than the one that's in my Meck TV that I restored a few years back but still considered a round picture tube and the adjustment steps I mentioned would still apply to yours.

bandersen
04-21-2024, 03:06 AM
Here's a video I made about adjusting the ion trap magnet and focus coil
https://youtu.be/3ChX_HjJ0xM?si=SCN1styHe2e-OqdC

vortalexfan
04-21-2024, 11:41 AM
It’s a 16RP4 :) and sounds good, this is helpful. Any word about the arrow? I saw somewhere mentioning that if an ion trap possesses an arrow indicates it should face the screen, although they were discussing a different brand and model…

The Arrow I believe is supposed to face forward. my TV's ion trap magnet also had an arrow on it and mine had to face forward in order for it to function properly. Also banderson's video will be helpful as well.

Madeline12
04-21-2024, 11:51 AM
The Arrow I believe is supposed to face forward. my TV's ion trap magnet also had an arrow on it and mine had to face forward in order for it to function properly. Also banderson's video will be helpful as well.

Ok, sounds good. So it seems mine was installed backwards in this case, as the arrow is pointing towards the base of the tube away from the assembly. Thank you kindly!

kvflyer
04-21-2024, 11:52 AM
The arrow should face forward (toward the phosphor).

Madeline12
04-21-2024, 11:54 AM
The arrow should face forward (toward the phosphor).

Haha just responded to another comment a moment before yours, but highly appreciated.

Thank you everyone!

kvflyer
04-21-2024, 11:54 AM
Haha just responded to another comment a moment before yours, but highly appreciated.

Thank you everyone!

:thmbsp: