For some reason it has large flakes of black card falling off the cone surface. What can I do.to fix it? Would varnish or PVA wood glue be the shot? Otherwise the cone has no damage. I guess the previous owner put the set somewhere damp. Any thoughts welcome.
Martin

I would tend to stay away from anything water based: PVA is water based and will set rigid. If you must use water based use Acrylic.

If you need to reinforce, or use something to hold say a tear, non woven frost cover, painted with acrylic adhesive (not in big wet blobs) works well.

Provided that the speaker is not poling, then the ideal is a thin, solvent based binder that will penetrate into the paper. The most important thing is for this binder, is to not make the cone too rigid, especially around the top edge where it must flex.


Marc

I will do as you suggest, Marc. I.ll try some spray lacquer. I need to remove the last flakes off the back of the cone first. I think I'll brush the stuff on and keep it off the wrinkly border. Will work on it next week when I get some time. The underlying cone is quite white. Looks weird.
Thanks
Martin

It would not be unreasonable to assume that, in order to get the desired characteristics, that the cone laminated. ie multi layered & compressed.

Keep an eye one the "wrinkly border" that's where they fatigue & tear.

Do not despair if this fails, most cones are replaceable. $$

Marc

Horrible poling when I tested it. Took it off the board to have a look. It had been got at. Half the cone had been replaced with white card and sticky paper. Dressed up for sale. That explains why there were two 5Y3 rectifiers on the main board. Looking good and faking it is not what I am about. I need another 6 inch speaker. I've got a 5 inch but that seems a bit too faked to use and I would need to fix the baffle hole to suite. I now need to test the transformer. The lights work but I need to check the secondary HT.. I'm off to do that now the skulduggery has been revealed.
Martin

Marc,
Transformers OK 350Volts after choke filter. all valves glowing. Recapped it but no sound. Need to look at the output stage. I'll try valve substitute first......gotto do it now Don't know how to recone a speaker.
Cheers
Martin.

All valves NOT glowing. The 6F6 was in the wrong holes because the guide on the bottom was missing! I carefully relocated it. And the 6U7G was burnt out which I replaced. I then got all the stations clear as a bell. Trouble is I loaned the speaker off another variety of theaterette which brings me back to how replace the speaker. The cone field coil was on the remains of the old one but there is nothing left to attach it to, Marc.
Martin

Appologies for the delay in getting back to you

OK two ways to go here.

Is it electrodynamic or permanent magnet?

6" actually 6 1/4" are not the easiest to come by but they are out there if you look. Some of the MItsubishi Magna's used these in the front doors, wrecker is therefore an option.

Do not get one of those horrid double cone ones as the inner cone can be too long & hit the grille.

If the speaker transformer is on the speaker, sometimes you can be lucky & can remount it on there, without boring a hole in the cone or filling it with metal. I had to replace a 6'' spkr in a Philips due to a clown wrecking the cone, by drilling.

Otherwise move the transformer to the chassis. Do be carefull with the big powerful magnets of today. I did have to shield one for arguing with the power transformer.

If its electrodymamic, there are people that advertise in the HRSA magazine that re-cone. Otherwise we modify for permag.

Marc