UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Regentone A133 HT smoothing capacitors, V4 cathode resistor

Herald1360 · 20th Sep 2019, 9:15 pm

Sounds like the EL41 is getting tired. Another possibility (thinking UL41 DAC90A problems here)- have any of the unused pins on the valveholder (3,4,6) been used as tie points for wiring? If so, there may be some mileage in "floating" any such connections.

You can try reducing the grid resistor from 680k to ~330k to see if this helps a bit and just increase the cathode resistor to get the total current down to around 35mA. This will allow the valve to soldier on a while longer- probably for ever if the set is not used much!

20th Sep 2019, 9:15 pm	#20
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Regentone A133 HT smoothing capacitors, V4 cathode resistor Sounds like the EL41 is getting tired. Another possibility (thinking UL41 DAC90A problems here)- have any of the unused pins on the valveholder (3,4,6) been used as tie points for wiring? If so, there may be some mileage in "floating" any such connections. You can try reducing the grid resistor from 680k to ~330k to see if this helps a bit and just increase the cathode resistor to get the total current down to around 35mA. This will allow the valve to soldier on a while longer- probably for ever if the set is not used much! __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O