22-01-2016, 05:57 PM
Mark, thanks for your thoughts.
I extracted the bad cap and it's not as bad as I expected. 130uF on my Peak LCR meter which was measuring at DC. I don't have an ESR meter so used an audio generator at 10kHz with a 10R series resistor. Used a DVM to measure across the R and C. X at 10kHz is about 0.1R, total Z was about 0.4R which is nothing like as bad as I expected.
The 68K resistors are in series, one end to the mains input. They measure OK. The 75Ks are in parallel and measure OK. Most of the other caps are 2200u, either 10V or 16V. There's a 1000u near the output conenctors (I suppose I could use a 2200u) and a few smaller caps. Any indication as to which need to be HF rated low ESR parts? Or just assume they all need to be? Probably got the small caps around in low ESR versions. I'd need to order the 2200u to be sure of getting good small parts. Do these look about right: http://uk.rs-online.com/web/p/aluminium-...s/7395260/
I extracted the bad cap and it's not as bad as I expected. 130uF on my Peak LCR meter which was measuring at DC. I don't have an ESR meter so used an audio generator at 10kHz with a 10R series resistor. Used a DVM to measure across the R and C. X at 10kHz is about 0.1R, total Z was about 0.4R which is nothing like as bad as I expected.
The 68K resistors are in series, one end to the mains input. They measure OK. The 75Ks are in parallel and measure OK. Most of the other caps are 2200u, either 10V or 16V. There's a 1000u near the output conenctors (I suppose I could use a 2200u) and a few smaller caps. Any indication as to which need to be HF rated low ESR parts? Or just assume they all need to be? Probably got the small caps around in low ESR versions. I'd need to order the 2200u to be sure of getting good small parts. Do these look about right: http://uk.rs-online.com/web/p/aluminium-...s/7395260/
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
