OK the scope has been a great help, using close to the book values I found the Thyratron firing typically in the 500Hz range, once every 2 mS to give the best voltage output, but with a lot faster ringing going on in the coil.
So a change to the C value from 10 to 1 nF and a play with the pot and the best I get now is at 50KHz frequency, the peak voltage into 200 Meg is now 4,200 Volts, 21 uA (microAmp) and with the 10 Meg load of the DVM the output drops to 1500 Volts at 1.5 mA, so considerably better performance.
I have not finished yet will see how shifting the rods helps, but guess this is close to the limit
I am certainly going to have to encase this unit with the RF properties it has.
Trevor OK on the ECL80, I will see how the EL91 survives the ordeal over a couple of hours, I like using the 7 pin valves as that is what I have most of from military gear. It is all powered up from a 12 Volt to HT buck PSU at present, so little damage can happen if things go pop.
Frank, With these changes to the frequency it is certainly better for the CRT's I think the max some can use is 6KV but doubt I will ever get to work at that voltage more like 4KV max.
Adrian
So a change to the C value from 10 to 1 nF and a play with the pot and the best I get now is at 50KHz frequency, the peak voltage into 200 Meg is now 4,200 Volts, 21 uA (microAmp) and with the 10 Meg load of the DVM the output drops to 1500 Volts at 1.5 mA, so considerably better performance.
I have not finished yet will see how shifting the rods helps, but guess this is close to the limit
I am certainly going to have to encase this unit with the RF properties it has.
Trevor OK on the ECL80, I will see how the EL91 survives the ordeal over a couple of hours, I like using the 7 pin valves as that is what I have most of from military gear. It is all powered up from a 12 Volt to HT buck PSU at present, so little damage can happen if things go pop.
Frank, With these changes to the frequency it is certainly better for the CRT's I think the max some can use is 6KV but doubt I will ever get to work at that voltage more like 4KV max.
Adrian
Learning as I go!
Youtube EF91 Valve
Youtube EF91 Valve
