Richard Knoppow ha scritto:
"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.
--
Richard Knoppow
Los Angeles
WB6KBL
Hello Alan, Richard and Colin.
Alan, yes, i've done a tenfold error !
Take in good advice what Richard say, about the AVC bus,
he's absolutely correct, *if you are shure of wiring redone*.
The Richard's subsequent reply is *perfect* to pin down the
error(s) or defective component(s), and also the Colin's
reply is of great help.
I can't add anything to those replies.
Good debugging,
cheers, Piero.