rca_14pd8053 Strange noise

[Notimetolooz]

Is the sound coming from the speaker? With that loud of sound you probably can feel the cone of the speaker vibrate. It could be that the vertical sweep signal is getting into the sound amplifier. Re-check your work. Some set use the audio amplifier to reduce the power supply voltage to other parts of the set. The electrolytic caps around the audio amplifier are very important. What you are hearing may be the result of changing a few caps at a time.
If you are unsure of where the sound is coming from, disconnect the speaker and substitute a 4 to 10 ohm resistor of a couple of watts size. It could be something else vibrating like the yoke or transformer.

[dieseljeep]

Originally Posted by Notimetolooz

Is the sound coming from the speaker? With that loud of sound you probably can feel the cone of the speaker vibrate. It could be that the vertical sweep signal is getting into the sound amplifier. Re-check your work. Some set use the audio amplifier to reduce the power supply voltage to other parts of the set. The electrolytic caps around the audio amplifier are very important. What you are hearing may be the result of changing a few caps at a time.
If you are unsure of where the sound is coming from, disconnect the speaker and substitute a 4 to 10 ohm resistor of a couple of watts size. It could be something else vibrating like the yoke or transformer.

That's one of those RCA's that use a dual purpose tube, 6CU8 for the IF and vert osc. Maybe there's something wrong with the tube.

[jr_tech]

Does the pitch of the sound change when you change the vertical hold knob?
I’m thinking that vertical pulses are getting into the audio output stage (since you indicate that the volume control has no effect)... likely bad filter caps in the 275 volt supply.

jr

[Jon1967us]

Originally Posted by jr_tech

Does the pitch of the sound change when you change the vertical hold knob?
I’m thinking that vertical pulses are getting into the audio output stage (since you indicate that the volume control has no effect)... likely bad filter caps in the 275 volt supply.

jr

Yes, in fact the sound changes as I adjust the vertical hold on on the back.
Good call. Most likely the remaining multi section filter cap and or the wax papers on the PCB, which still have to be done.

That sound is a bit intimidating. It sounds like the set is about to self destruct!

Will keep you guys posted and thanks for the help!

[old_coot88]

Bad filter caps in the power suppy are the most obvious problem. What caps have you replaced so far?