Philips radio B4X65A (Techniek Radio/TV)
door Pandu Rajan 
, 02.03.2018, 14:47 (2463 dagen geleden)
Dear members
In the above set one end of the capacitor C 41 15K is connected the transformer winding S25 which goes to the anode of EL84. The other end of this capacitor is grounded.
An identical set was made by Philips India no B4CA65A where this capacitor is connected across the winding S25 instead of the other end to ground.
What is the advantage / disadvantage of both methods?
Regards
P.Rajan
Philips radio B4X65A
door rene , Castricum, 02.03.2018, 20:29 (2462 dagen geleden) @ Pandu Rajan
Dear Pandu.
What you describe is the Boucherot capacitor.
Named by a French scientist.
This capacitor must be replaced preventive
While restoration.
The target of a Boucherot capacitor is to avoid oscillation at high frequency.
Philips radio B4X65A
door John Hupse † 
, Schoonhoven, 02.03.2018, 21:18 (2462 dagen geleden) @ Pandu Rajan
What is the advantage / disadvantage of both methods?
A shorted capacitor often destroys the primary winding of the output transformer.
Advantage of the B4CA65A design is that a shorted capacitor will only stop the music. The transformer is saved.
The design of the B4X65A gives more stability to the LF amplifier, as the phase shift of the amplifier is better controlled by the LC-network this way.
Philips radio B4X65A
door Pandu Rajan , 03.03.2018, 15:18 (2462 dagen geleden) @ John Hupse †
Dear friends
Thank you very much for the explanation.
Regards
P.Rajan