Dim CRT on an R2001D
Posted: Fri Dec 15, 2023 3:29 am
As with many others, I had a dim CRT on my R2001D.
I have read many articles about using a Sencore CR-70 to 'rejuvenate' the CRT, but I lacked the CR-70. And, after spending a couple hundred dollars for a used CR-70, I replaced all of the electrolytic capacitors, as I found a few to be bad. The unit still would not pass the 'field test', so I opened it back up and found R-211, the Cutoff Set pot open. I ordered a new pot, and once the pot was modified to fit the CR-70, the unit now passes the field test!
I performed the test of the CRT, but it did not have any emission reading, nor could I set the cutoff level. As I had read others had had the same situation, I tried the CRT rejuvenate and Auto Restore functions of the tester, but still I had no emission or cutoff reading on the meter. But, I put the CRT socket back on and hooked up the high voltage board, and tried it our.
After getting the CRT all hooked up and power applied, it worked great! I could not believe the difference in intensity! The scope display was originally dim , but OK, to begin with, however, the text was very difficult to see. Afterwards, it was like a new CRT, the scope and text were the same intensity, and I could increase it to very bright afterwards!
I have heard this may only be a temporary fix, but it is still less expensive than a new CRT, and the R2001D isn't going to be turned on 8 hours a day/5 days a week in my home shop, unless I get a large increase in communications repairs, so I am not worried about it!
I have seen some people are working on LED displays that will operate in X/Y/Z mode, and they should come in different sizes for old CRT equipment, if that does come out being true, and at a reasonable cost, these old CRT display devices may have a new life!
I have read many articles about using a Sencore CR-70 to 'rejuvenate' the CRT, but I lacked the CR-70. And, after spending a couple hundred dollars for a used CR-70, I replaced all of the electrolytic capacitors, as I found a few to be bad. The unit still would not pass the 'field test', so I opened it back up and found R-211, the Cutoff Set pot open. I ordered a new pot, and once the pot was modified to fit the CR-70, the unit now passes the field test!
I performed the test of the CRT, but it did not have any emission reading, nor could I set the cutoff level. As I had read others had had the same situation, I tried the CRT rejuvenate and Auto Restore functions of the tester, but still I had no emission or cutoff reading on the meter. But, I put the CRT socket back on and hooked up the high voltage board, and tried it our.
After getting the CRT all hooked up and power applied, it worked great! I could not believe the difference in intensity! The scope display was originally dim , but OK, to begin with, however, the text was very difficult to see. Afterwards, it was like a new CRT, the scope and text were the same intensity, and I could increase it to very bright afterwards!
I have heard this may only be a temporary fix, but it is still less expensive than a new CRT, and the R2001D isn't going to be turned on 8 hours a day/5 days a week in my home shop, unless I get a large increase in communications repairs, so I am not worried about it!
I have seen some people are working on LED displays that will operate in X/Y/Z mode, and they should come in different sizes for old CRT equipment, if that does come out being true, and at a reasonable cost, these old CRT display devices may have a new life!