UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

simpsons · 23rd Nov 2020, 11:13 am

Thank you Heatercathodeshort for introducing Bertha to the conversation.

I have B&K 470 which I have had variable results. Either it worked or ruined the cathode on Delta gun CRT's.

It is interesting how the different approach to cleaning the cathode has developed. The B&K raising the heater voltage and zapping the cathode with 450 volts whilst at the same time switching off the heater, Bertha, from my understanding using around 250 volts and raising the cathode temperature until no further improvement in emission and finally, in a "Trinitron only" design keeping the heater at 6.3 volts and applying 115 volts until again the emission has improved.

All of the designs requiring a high degree of trust and really user experience when, should the procedure result in the CRT being worse than when just the heater voltage is raised, all is lost.

This brings me to the question. Which is better. Leaving the CRT with a raised heater voltage or try rejuvenation?

23rd Nov 2020, 11:13 am	#8
simpsons Octode Join Date: Feb 2007 Location: Harrow, London, UK. Posts: 1,493	Re: CRT Rejuvenation orientation Thank you Heatercathodeshort for introducing Bertha to the conversation. I have B&K 470 which I have had variable results. Either it worked or ruined the cathode on Delta gun CRT's. It is interesting how the different approach to cleaning the cathode has developed. The B&K raising the heater voltage and zapping the cathode with 450 volts whilst at the same time switching off the heater, Bertha, from my understanding using around 250 volts and raising the cathode temperature until no further improvement in emission and finally, in a "Trinitron only" design keeping the heater at 6.3 volts and applying 115 volts until again the emission has improved. All of the designs requiring a high degree of trust and really user experience when, should the procedure result in the CRT being worse than when just the heater voltage is raised, all is lost. This brings me to the question. Which is better. Leaving the CRT with a raised heater voltage or try rejuvenation?