This morning I dismantled the speaker and cleaned out the magnetic dust and debris from the speaker speech coil gap.
I had to be a bit brutal with the speaker by cutting 4 holes in the diaphragm to enable me to access the screws to release the magnet assembly.
There were some large lumps in and around the speech coil there was no wonder it was sounding poorly,
and you could see where the speech coil had been rubbing.
Some of the larger lumps I was able to flick out with a thin jewellers screwdriver, using a vacuum cleaner to suck them up.
But the smaller chips and dust were impossible to get out.
I had the idea to use a thin piece of plastic with medium hard wax rubbed into the tip. This worked well and eventually I could see no more bits in the gap.
There were 4 brass spacers to fit between the basket and the magnet, to help prevent them from moving I put a small drop of superglue on the edge of each.
Once I had got all 4 screws fitted, before tightening them, I fitted my trusty spider centering shims in the speech coil gap,
then tightened the 4 screws diagonally and then the centre screw in the spider.
At this point I made the repairs to the 4 flaps I had cut in the diaphragm. I used diluted PVA glue, amd cut small squares out of a single ply of kitchen paper and dabbed these with more PVA over the rear of the cuts to reinforce the glue.
Slipping it all back into the special cloth bag was as difficult as removing the speaker from the bag in the first place.
The radio sounds much nicer now and the volume has about doubled.
The chassis is back in the cabinet and I have given the outside of the cabinet a rub down with Danish Oil.
When that has dried I will take some photos for you.
Mike
I had to be a bit brutal with the speaker by cutting 4 holes in the diaphragm to enable me to access the screws to release the magnet assembly.
There were some large lumps in and around the speech coil there was no wonder it was sounding poorly,
and you could see where the speech coil had been rubbing.
Some of the larger lumps I was able to flick out with a thin jewellers screwdriver, using a vacuum cleaner to suck them up.
But the smaller chips and dust were impossible to get out.
I had the idea to use a thin piece of plastic with medium hard wax rubbed into the tip. This worked well and eventually I could see no more bits in the gap.
There were 4 brass spacers to fit between the basket and the magnet, to help prevent them from moving I put a small drop of superglue on the edge of each.
Once I had got all 4 screws fitted, before tightening them, I fitted my trusty spider centering shims in the speech coil gap,
then tightened the 4 screws diagonally and then the centre screw in the spider.
At this point I made the repairs to the 4 flaps I had cut in the diaphragm. I used diluted PVA glue, amd cut small squares out of a single ply of kitchen paper and dabbed these with more PVA over the rear of the cuts to reinforce the glue.
Slipping it all back into the special cloth bag was as difficult as removing the speaker from the bag in the first place.
The radio sounds much nicer now and the volume has about doubled.
The chassis is back in the cabinet and I have given the outside of the cabinet a rub down with Danish Oil.
When that has dried I will take some photos for you.
Mike
