BX695A/BX704A O/P transformer (Algemeen)
door Pandu Rajan 
, 30.03.2021, 09:46 (1334 dagen geleden)
Dear Friends
In the service manual of BX695A the D.C resistance of the O/P transformer primary winding indicates 3200 ohms of each half. Whereas in the service manual of BX704A it shows 330 Ohms of each half. Is there some mistake in the resistance shown in the service manual because normally the resistance of the primary winding is around 300 ohms each half for the sets with EL41 in Push Pull.
Best Regards
P.Rajan
BX695A/BX704A O/P transformer
Hello Pandu,
I think that the 3200 Ohm of the BX695A is not the dc-resistance but the load resistance (for ac signal). The total primary load resistance would than be 6400, which is pretty close to the 7000 Ohm in the datasheet for the EL41. On top of that: If the 3200 Ohm would be the dc-resistance, than the voltage loss in the primary would be way too high (about 35 mA x 3200 Ohm = 112 Volt !).
The 330 Ohm for the BX704A probably is the dc-resitance, because as a load 660 Ohm is way too low.
Edit: The 3200 could also be a typo, maybe it should say 320 as dc-resistance.
Greetings,
Robert
BX695A/BX704A O/P transformer
door Pandu Rajan , 30.03.2021, 16:24 (1334 dagen geleden) @ Robert Gribnau
Dear mr. Robert
Thanks for the reply.
Regards
P.Rajan