"Richard Knoppow" wrote in message
m...

"MoiInAust" wrote in message
...
Thanks again Piero.

Interleaved as before

"Piero Soldi" wrote in message
...
OK, make some measures.

With a VTVM or other *high* impedance voltmeter, make a reading at
juncton between R43 and C97 ( 4uF ) and chassis ground.

Must be approximately *minus* 3-4 volt.

That's the foot of the AVC chain and surely 3-4 Volts is *much* too low.
I get 27-30, which would be expected with a total current of 110 mA and a
total AVC chain of 275 Ohms.

Again, make a measure at junction between pot R46 pin 3 with R55 and
chassis.

Must be approximately *minus* 0,3-0,4 volt.

There is no pot R46. Do you mean RV3. Which do you mean by 'pin 3'

Cheers
Alan

The designations are different on the US and UK versions of the
schematic. RV-3 and R-46 are the same, i.e., the RF gain pot. The voltage
table specifies measuring to the pot but fails to say which contact. Since
the pot is variable (doh) that makes a difference. There is a US version
of the schematic at BAMA which will show the differences in component
lables. I still can't see how the AVC bus could become positive unless
there is something shorting it to the B+ (HT) or else you are measuring to
the wrong reference.


No, the AVC is definitely is NOT negative with reference to the chassis, but
the EMER773 states reference must be to the slider of RV3, where is should
be -1.2v. That is the reading that used to be OK and now is not. And I've
checked and rechecked aagain all the changes I made.