Re: WANTED: Good Source of Electronics Theory

EADGBE wrote:

> Eeyore <rabbitsfriendsandrelati...@[EMAIL PROTECTED]
> wrote:
> >
> > There's something amiss with the biasing of the output
emitter-follower
> > stage. The voltage on the base of Q208 should be about 1.2V less (not
0.2V
> > less I think that 6.8V should be 5.8V) than the voltage on the base of
> > Q207. That suggests possibly zero or very low current in Q205's
collector
> > circuit. Suggest you measure the voltage across the 12k connected to
> > Q205's base-emitter.
>
> You are ABSOLUTELY CORRECT.  I took another good, hard look at the
> service manual schematic (very fuzzy), and the base voltage of Q208 is
> indeed +5.8V.
>
> How did you deduce this?

Because there should be 2 Vbe's difference betwen those 2 points (to turn
on the
complementary emitter follower stage).


> I'm not sure about the 12K resistor across Q205's base-emitter.  I
> will take a voltage measurement across that resistor and post it here.

That will be helpful.

Graham