11-09-2019, 08:14 AM
Getting bogged down in boaty stuff this week, not getting much time in the workshop.
I have restuffed the wet electrolytics though.
Its the first time I have done any of these and I was fascinated by the construction.
Basically an aluminium can with a vent on a top cap under a tin cover, red rubber cap on top. Plastic thread on the bottom with a brass fixing nut.
But inside 2 sets of concentric aluminium rings with slots in them,one above the other. immersed originally in an electrolyte which is probably not very nice.
The reservoir capacitor was almost totally dried out but the smoother had not leaked and was still full.
I cut the tops off with a hacksaw and released the riveted bottom connection, pulled all the guts out, washed the tubes and fitted 47uf 450v capacitors.
I poked the + lead through the bottom as the connection and connected the - lead to a folded piece of tinplate that was a tight springy fit inside the tube to make the negative connection.
With the tin cap and rubber refitted they look original.
I also replaced the -HT smoothing capacitor, C3 on the Philips sheet, 100uf @12v with a new 25v item, it was no longer a capacitor, reading very high on the Chinese magic box due to leakage.
Powering up I have good HT but no sound. Injecting a tone into the G1 of the EL41 V4 gets a good output but nothing if injected into the slider of the volume control or the phono socket. The EBC41 seems to be OK so I will have to trace back and find why, the combined tone and phono switch is in this circuit but it looks OK. I am suspicious of the tapped volume control, they are known to be unreliable and its a special item difficult to find a replacement for.
I have restuffed the wet electrolytics though.
Its the first time I have done any of these and I was fascinated by the construction.
Basically an aluminium can with a vent on a top cap under a tin cover, red rubber cap on top. Plastic thread on the bottom with a brass fixing nut.
But inside 2 sets of concentric aluminium rings with slots in them,one above the other. immersed originally in an electrolyte which is probably not very nice.
The reservoir capacitor was almost totally dried out but the smoother had not leaked and was still full.
I cut the tops off with a hacksaw and released the riveted bottom connection, pulled all the guts out, washed the tubes and fitted 47uf 450v capacitors.
I poked the + lead through the bottom as the connection and connected the - lead to a folded piece of tinplate that was a tight springy fit inside the tube to make the negative connection.
With the tin cap and rubber refitted they look original.
I also replaced the -HT smoothing capacitor, C3 on the Philips sheet, 100uf @12v with a new 25v item, it was no longer a capacitor, reading very high on the Chinese magic box due to leakage.
Powering up I have good HT but no sound. Injecting a tone into the G1 of the EL41 V4 gets a good output but nothing if injected into the slider of the volume control or the phono socket. The EBC41 seems to be OK so I will have to trace back and find why, the combined tone and phono switch is in this circuit but it looks OK. I am suspicious of the tapped volume control, they are known to be unreliable and its a special item difficult to find a replacement for.
Boater Sam.
