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Hello, I am rebuilding and older duel 811 tube coil to a dual 572B coil. The coil is actually in good working condition but I am changing out the weaker parts to best of bread ones. The older 811 Svetlana tubes have gotten holes burned through the plates and stuff. ;) I am not very knowledgeable about tube coil things so I have run into some questions. Here are the pictures, schematic and parts list. https://imgbox.com/2b6HInfN https://imgbox.com/3WydJGVU https://imgbox.com/t77lsj9u https://imgbox.com/PFLbaBgP https://imgbox.com/JRwxfEns Questions: 1. The original microwave caps out of the microwave transformer were 1.786uF (C1) but I am changing them to two new caps I had to 2.381uF at 2500VAC total. I am thinking the exact value of these caps is not critical at all? 2. There is that C2 cap at 10kV 1nF. Does it really do anything useful at all or is it just eyewash and can be removed? 3. The plate transformer (T3) has two ~2nF caps across the heater winding. Do they really do anything at all either? If such parts really are useless I will remove them. 4. The grid leak thing has a 8.1 kOhm 30 watt resistor in parallel with a 2.2nF 2kV ceramic cap (C6 R1). This was original to the dual 811's. Should it be changed for dual 562Bs? Any other suggests are welcome and thank you for your consideration! Terry _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxxxxxx https://www.pupman.com/mailman/listinfo/tesla