Post by Richard on Apr 11, 2024 17:16:28 GMT 12
I've completed this project which had brittle and missing veneer, a finish that was beyond waxing to restore, a rusty speaker with an open circuit field coil, faulty valves and capacitors and resistors requiring replacement in the chassis.
i removed most of the rust from the speaker and used rust convertor (the one with phosphoric acid), then painted and replaced the field coil, lucky I had a spare. I cleaned the pole piece with steel wool, whilst it was apart, a lot of dust buildup over the years, so the voice coil now moves freely. I replaced most of the capacitors and some of the resistors that were out of spec.
The Garrard record deck motor was not rotating, nor would it rotate if i gave it a push, its a shaded pole induction motor with a speed governor, very similar to windup gramophones. The fault with the motor was shorts between the bars on the squirrel cage rotor, caused by years of wear and tear, mainly metal filings worn from the motor. I cleaned between the bars, assembled and the motor started rotating by itself. The pickup wasn't outputting Audio, the rubber parts around the armature had dried up and gone hard. I had some silicon tubing that was the right size and fitted that to the pickup armature, reassembled now outputs audio again.
i removed most of the rust from the speaker and used rust convertor (the one with phosphoric acid), then painted and replaced the field coil, lucky I had a spare. I cleaned the pole piece with steel wool, whilst it was apart, a lot of dust buildup over the years, so the voice coil now moves freely. I replaced most of the capacitors and some of the resistors that were out of spec.
The Garrard record deck motor was not rotating, nor would it rotate if i gave it a push, its a shaded pole induction motor with a speed governor, very similar to windup gramophones. The fault with the motor was shorts between the bars on the squirrel cage rotor, caused by years of wear and tear, mainly metal filings worn from the motor. I cleaned between the bars, assembled and the motor started rotating by itself. The pickup wasn't outputting Audio, the rubber parts around the armature had dried up and gone hard. I had some silicon tubing that was the right size and fitted that to the pickup armature, reassembled now outputs audio again.
