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

cathoderay57 · 19th Sep 2019, 8:46 pm

Hi John, the key thing is not to exceed the max spec reservoir capacitance for the rectifier. EZ40 has a max spec cap of 50uF. However it also recommends surge limiting resistors in the anode circuits ranging from 125R for an HT of 250v to 300R for an HT of 350v. It would be interesting to know if your set has any anode series resistors fitted. Alternatively you might find a surge limiting resistor between cathode and the reservoir cap. Disadvantage of that location is it takes full HT current so needs to be higher wattage than those in the anode circuits. The higher the value of capacitor used, the more important is the need for surge limiters. Hope I'm not teaching granny to suck eggs
Cheers, Jerry

19th Sep 2019, 8:46 pm	#10
cathoderay57 Nonode Join Date: Oct 2017 Location: Bristol, UK. Posts: 2,387	Re: Regentone A133 HT smoothing capacitors, V4 cathode resistor Hi John, the key thing is not to exceed the max spec reservoir capacitance for the rectifier. EZ40 has a max spec cap of 50uF. However it also recommends surge limiting resistors in the anode circuits ranging from 125R for an HT of 250v to 300R for an HT of 350v. It would be interesting to know if your set has any anode series resistors fitted. Alternatively you might find a surge limiting resistor between cathode and the reservoir cap. Disadvantage of that location is it takes full HT current so needs to be higher wattage than those in the anode circuits. The higher the value of capacitor used, the more important is the need for surge limiters. Hope I'm not teaching granny to suck eggs Cheers, Jerry