08-04-2024, 08:10 PM
There has always been plenty to both think about and practice in standards conversion, from cameras looking at monitors, discreet analogue, discrete digital, dual ported RAM, FPGAs, computer graphics cards, HackTV, and now single board computers not converting but generating video as a gui. No doubt this won’t be the end of the story, but perhaps represents the most cost effective yet though the RP1 hardware on a Pi5 zero if it appears will be lower cost too.
I’ve followed the attempts at rebuilding the 15GP22 over the years and it looked promising for quite a while but eventually the optimism seemed to die away. I guess there are a fair number of working CT-100s out there, around 40 or 50 I think , so the rebuilding of the 15GP22 is perhaps not worth the very large costs that would be involved. However what you allude to is intriguing in terms of doing the whole rebuild ‘cold’. Do you think that a sustainable degree of vacuum could be achieved cold , or would outgasing from the glass and metallic components simply lead to the vacuum softening over time? Or would the strategy involve re-pumping the envelope periodically? I suppose thatin theory the gun assembly could be taken off the base and the cathode and heater replaced, and then the assembly re-mounted on an a base that could be cold sealed onto the neck. If the stem could be valves then re-pumping would be possible. Has your 15GP22 gone soft, is emission the issue or have the heaters opened up? I did once manage to ‘weld’ a colour CRT heater using the high voltage arc method, I was 13 years old and used a monochrome set as the HV source!
I’ve followed the attempts at rebuilding the 15GP22 over the years and it looked promising for quite a while but eventually the optimism seemed to die away. I guess there are a fair number of working CT-100s out there, around 40 or 50 I think , so the rebuilding of the 15GP22 is perhaps not worth the very large costs that would be involved. However what you allude to is intriguing in terms of doing the whole rebuild ‘cold’. Do you think that a sustainable degree of vacuum could be achieved cold , or would outgasing from the glass and metallic components simply lead to the vacuum softening over time? Or would the strategy involve re-pumping the envelope periodically? I suppose thatin theory the gun assembly could be taken off the base and the cathode and heater replaced, and then the assembly re-mounted on an a base that could be cold sealed onto the neck. If the stem could be valves then re-pumping would be possible. Has your 15GP22 gone soft, is emission the issue or have the heaters opened up? I did once manage to ‘weld’ a colour CRT heater using the high voltage arc method, I was 13 years old and used a monochrome set as the HV source!
