Uploaded February 2016 | Updated September 2026, 3 weeks ago
When cathode rays tubes age one reason for poor performance is caused by the cathode’s diminishing ability to produce electrons. Attempting to “Rejuvenate” a CRT tries to correct this problem. In some cases it should be possible to image the cathode surface on the screen to see what is going on. I guess, a bit like an electron microscope. The video shows that electron emission can be improved by increasing anode voltage. This has limitations for x-ray free operation, so the preferred method is to increase the heater temperature. I heard of this technique used on black & white CRTs and have, so far, perhaps to do with the shadow mask or gun geometry, not managed this convincingly on a colour CRT.
When cathode rays tubes age one reason for poor performance is caused by the cathode’s diminishing ability to produce electrons. Attempting to “Rejuvenate” a CRT tries to correct this problem. In some cases it should be possible to image the cathode surface on the screen to see what is going on. I guess, a bit like an electron microscope. The video shows that electron emission can be improved by increasing anode voltage. This has limitations for x-ray free operation, so the preferred method is to increase the heater temperature. I heard of this technique used on black & white CRTs and have, so far, perhaps to do with the shadow mask or gun geometry, not managed this convincingly on a colour CRT.
