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Do you have any other CRTs you can test with the CR70 ?
I just tested 2 - 10BP4's and on one the cutoff set would not budge the needle. The other I was able to set the needle in range with great difficulty. The needle wanted to jump higher or lower. Both of these test good on my Super Mack. Pulling a set with a known good tube is a little difficult at this time as my back is acting up and I don't want to move my 8TS30
I also recommend you run through the calibration instructions to make sure it's working properly.
Thank you for this information Bob.
Set the CR70 controls to the following, F1 to 1, F2 to 2, K to 3, G1 to 4, G2 to 5 ,gun select to R/B&W ,CRT select to Video, function to Remove G1 short.
Done
Hook a DC Voltmeter ground lead to G1 lead of universal adapter and the positive lead of the DVM to the K lead of universal adapter.
When the rejuv button is pressed the DVM should read greater then 350 volts DC.
It reads -430v
Set the function switch to the rejuv position and re-press the rejuv button and check again for greater than 350 volts DC.
It reads -425v
Set function to Auto Restore and set external DVM to DC current. Press the rejuv button and the CR70 should cycle three times. When on the current should read between 80 and 120 mA.
Reads 120 ma
Set function switch to manual 1 restore.Press the rejuv button and the external DVM should read between 80 and 120 mA with no cycling.
Works reading 120 ma
Set function switch to manual 2 restore. Press the rejuv button and the external DVM should read greater than 150 mA
Measures 180 ma
Set function switch to cutoff. Set external DVM to DC volts. You should be able to read the BIAS voltages.
They measured a few volts low for each.
Move the positive lead of the DVM to the G2 lead of the universal adapter. When the cutoff control is adjusted look for a voltage swing of 20 to 400 Volts DC.
Reads 62v low to 501v high. This is off.
Move the DVM ground lead to the F1 lead of the universal adapter and the positive lead of the DVM to the F2 lead . You should be able to read the filament voltage on the DVM. It will be dependent upon where the filament volts settings are set to.
Reads slightly higher than the CR70 meter reads. I guess this is to compensate for the voltage sag? maybe...
Note: if your CR70 has two power transformers on the bottom panel the filament voltages will be AC volts.
One transformer. Output is DCV.
I appreciate your help Bob. I just don't know if this is working correctly or not. Is my Super Mack telling me the wrong result or my CR70.....
Is there a CR70 service manual in electronic format for download? I only was able to find the user manual.
BTW, this universal adapter is ridiculous to use and I really need to make a proper adapter for the older CRT's.
Many thanks,
Scott
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