MoiInAust ha scritto:
Hi Piero

Many thnaks for your ongoing hep re this. I have interleaved comments in
your posting .

When you have restored the capacitors and resistors, substituted any
valve ? If so, check for a *slightly* gassy one !
( RF amplifiers, mixer, MF amplifiers )

*** Many new valves BUT I have disconnected the AVC line from V1,2,5,6 and
there is absolutely NO current flow across that gap or chnage in the wrond
voltage at V8, so I think we can rule out gassy valves?
Cleaned carefully where soldered new components ?

Capacitors are of the *best* type ? ( low loss types ).

*** They are a darned sight better than the leaky (in both ways!) tubs that
I removed.

Impedances are very high, a current of 3 *microAmp* is nothing with a
grid resistance of 100 KOhm, but with a 5 MOhm, became noticeable.

Wires are well insulated ? No cracks or degrading rubber ?

*** not to allow foreign contact
Cheers,
Piero.

*** still scratching skull (hair out!)



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.

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

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

After done, post readings.

HTH,
Piero.