vidor cn429

[tiv48]

this was bought to me to look at after some one else had had a go and given up.
the first thing i noticed was a wax cap c9 had been snipped at one end
3 other caps had been changed including that cap.
i conected it to my eliminator ,all i got was a loud squeeling noise that could be turned down by the volume control ,moving the dl96 put a stop to that so removed it cleaned the pins and sprayed cleaner into the base.
i was now left with a moterboating niose reconecting c9 stopped that.
no signals getting through but a crackle when the wave change swich was moved.
using a signal injector produced an output from almost every where.
out with the meater to check volts around v1 (osc) nothing far out.
as i was shure the problem was with the osc i got the scope out checking at the coil end of r3 the osc anode load the set bust into life
looking at the circuit surgested c8 osc decoupling must be open circuit
this turned out to be the case as it had been removed completly.
i did not have a 0.05mf cap so fitted a 0.02mf
the set now works well.
rob t