Uploaded January 2017 | Updated September 2026, 3 weeks ago
I recently found a very cheap Eimac 4CX1500 B in unknown condition, so we hooked up a few wires and power supplies to check it out.
I was not expecting much of it but it turned out to be far better than expected.
This setup can be used for most Power Tubes, it will give at least an indication if it would work or not at all. It also gives a rough classification about the overall condition, providing you do have the readings of a known good tube for comparison.
This is a quick and safe low voltage test which certainly cannot test the tube to full spec, so bear in mind that a good looking tube may still arc at full plate voltage.
For further info on this type of tubes, i highly recommend Eimac's book "Care and feeding of Power Grid Tubes" , don't know if it's still available new, i bought my copy sometimes back in the 80's.
(c) 2017
dynoguy.co.uk
I recently found a very cheap Eimac 4CX1500 B in unknown condition, so we hooked up a few wires and power supplies to check it out.
I was not expecting much of it but it turned out to be far better than expected.
This setup can be used for most Power Tubes, it will give at least an indication if it would work or not at all. It also gives a rough classification about the overall condition, providing you do have the readings of a known good tube for comparison.
This is a quick and safe low voltage test which certainly cannot test the tube to full spec, so bear in mind that a good looking tube may still arc at full plate voltage.
For further info on this type of tubes, i highly recommend Eimac's book "Care and feeding of Power Grid Tubes" , don't know if it's still available new, i bought my copy sometimes back in the 80's.
(c) 2017
dynoguy.co.uk
