C. 50 + 50 uF in B6CA38A (Techniek Radio/TV)

door Pandu Rajan , 28.04.2015, 10:55 (3501 dagen geleden)

Dear Forum members

I have a radio gram which has the set B6CA38A made by Philips India. Recently it developed a hum problem. On investigation I found one of the 50ufd capacitor faulty. I measured the capacitance of both. The healthy one showed a value 47ufd whereas the faulty one showed a value 0.008ufd. So practically the value of the faulty part had nearly become zero. This resulted in increase of the AC reactance to a very high value causing the hum.I had a spare filter capacitor, though old one, but on measuring the capacitance I found the values as 67ufd/75ufd. If I use this capacitor what problem would it cause? I understand that if a higher value of the filter capacitor is used then the valve EZ80/EZ81 is more stressed. But a filter capacitor which is old and due to aging whose capacitance value has increased will also cause the same problem which a new capacitor of higher value would have caused? Is it possible to detect by performance vise whether the filter capacitor value has increased or not?

Regards

P.Rajan