Philips India set 15RB697/00S (Algemeen)

door Pandu Rajan @, 13.05.2018, 16:01 (2165 dagen geleden)

Dear forum members

While restoring this this set I have noticed a peculiar phenomenon. As per the schematic with an input voltage of 230V a.c. the anode voltage of valve EL84 is 234V d.c. and the screen grid voltage g2 is 220V. I get these voltages when the set is in radio mode. When the set is put to P.U. mode the HT supply to ECH81 and EF89 is disconnected thereby reducing the current through the main resistance R6 which results in the screen grid voltage of EL84 becoming more than the anode voltage by 15 Volt. Will this not effect the performance of the valve EL84?

Regards

P.Rajan

Philips India set 15RB697/00S

door Piet van der Pol @, Alblasserdam, 17.05.2018, 09:22 (2161 dagen geleden) @ Pandu Rajan

Hello,

This is not a problem. Only when the anodevoltage is very low, for example below 100V, the screengrid current will increase.

Piet

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