In review I do make a point of salvaging speaker transformers. One always looks forward to betting on Kriesler sets & one HMV type, the former being one of the two in eight (or worse) irrespective of model, that won't have a dud speaker transformer.

Those black caps were superseded by axial ones used in many transistor sets (abt 8-10mm dia & 13mm long) that did a similar thing: Cracked their jacket, usually at the ends, and shorted. Otherwise the ones shown are Waxed Paper & the probability of them not electrically leaking like a sieve, is very low.

I have never seen one of those open type Mica caps made after around 1935 fail. Earlier ones did, especially if there were rivets.

Marc

Well today I rang the speaker hospital and they had only just finished rebuilding mine. They were able to demonstrate it over the phone . They picked a nice little ditty from the 30s and it sounded awesome.

Well the speaker has arrived back at my home and is ready to be rewired back into the old set. Am I impressed, yes I am. I might remind you that this is a situation where I paid a professional for his time and that professional needs to pay his rent.

Photos uploaded to Post 33.

There are the odd jobs you do buck-pass especially when you have not got the equipment to do the job, or a better one. I could have dismantled the tractors cylinder head & lapped the valves.. but no!

It blew at nr 4 cylinder; it is 34+ years since O/H and the stamps on the pistons show 1951. So the thing may have warped. No equipment to fix or check that. The head repairer has machinery that can drive out & in valve guides effortlessly in a fraction of the time I can and the machines can grind & seat the valves with precision.

More importantly these were a swine of a head for recessing valves and it was not designed for ULP: So it has now got what I could not do, install hardened seats on the exhaust valves. The head repairer did, so it can now handle ULP as well as Jet fuel.

Sometimes you just have to bight the bullet & get it done properly.

Agree completely Marc, the last head I overhauled included clean, crack test, valve guides, bigger seats, bigger valves, machine deck for high compression, crack test again, bush and reface rockers, new shafts, open up chambers and ports ect. All done lovingly by hand over a couple of months with Mill, Press, Grinder and Lathe.

You only do that once in your life and once is enough! (well I did do a Minor 1000 head as well when I was very young so that's twice).
The next time a head was needed to be done , off to the "Head Shed"!!!!
You walk in with the dirty oily piece of junk, leave some money behind, and walk out with a shiny accurate ready to bolt on and go unit.

Fred.

I get practice: The MII Zephyr has not had the head off since it blew it in 1983 & it is a first life motor that has done over 110,000 miles. Worst I have seen, (abt 2years ago) caused by people not using corrosion inhibitor was a poorly maintained MF35. I had onlooking at it & listening to it run: Decided that the head gasket was gone & it had around $1000 worth of issues without labour. So it was bought a lot cheaper than it would have been in good order.

So we did not rip the Lady off: We noted oil loss after driving it to its new home: 5 bolts in the sump missing; Thermostat missing; Radiator blocked; Head written off: corrosion ($500 for new); Water pump fail: Fulcrum pin bush on the front wheel beam pivot cracked; Heater for starting open. a few other minor aggravations

This is the only engine where I have ever recovered a quarter of a 20Litre pail of mud from the block. No wonder it cooked. It now sounds a lot happier.

The rear plate on the head had rusted out; Head had warped; it was blocked up with scale & rust; Cyl 2,blew to 3; 3 blew to atmosphere & water jacket 2 blew to water jacket minor leaks to sump. Number one did not blow anywhere: It had a crook valve.

I have another neglected TE-20 to look at, I shudder to think what it will be like. Many stories on engine disasters.

Marc

Apologies to Carl for hi-jacking the thread with old guys comparing mechanical disasters!!!!
(we need an off topic forum where we can enthrall people with our mechanical dare-ing do)

That speaker job looks pretty good to me, nice new cone skillfully spliced into the diameters and depths required.
In another time, on another planet, I used to rebuild speakers with cone kits or fudging things in that quite did not fit.

If any body was worried about the actual cone parameters or coil specifications for their radio, don't worry!!
We are looking at mass produced Rola's in open back cabinets here, not Wharfdales in Hi Fi boxes!

Nice job, and good supporting a local industry.

Fred.

I note a sheen across the corrugations, I do wonder if they are doing something similar to what do?

Trade secret? As I made quite a few tonne of Acrylic sticky stuff & PVA sticky stuff. I understand what is in it. Acrylic is actually my choice as a binder to stop the paper of a cone disintegrating, or disintegrating further.

Stuff that is too rigid will cause tearing.

Do note if the cabinet has been finished with NItro Cellulose? Metho will attack it. One of the things that makes this stuff give a good levelling finish, is the fact that the new layer melts into the old.

Marc

...we need an off topic forum where we can enthrall people with our mechanical dare-ing do

You are in it right now. It's called General Discussion. Any topic that is not excluded by the rules or covered by a specific forum can be discussed here.

So true: That's what you get when you post in this non specific area. It often gets very interesting by meandering off on many tangents.

It does not look like nitro.
It's dull, the cracking is more from the timber expanding and opening up over the years , not the clear expanding and contracting as temperature changers.
In the photos it looks like shellac.
Hard to tell looking at a photo though...

It's ok guys I'm happy to have a bit of friendly banter lol.

Well I have to say I'm pretty damned happy with this set now. It's a pretty good example of a set with a lot of stupid mistakes in it. Take for example those silly green and yellow terminals in the back. I decided after all other things had failed to get rid of the horrible distortion that was present to just remove the jumper between those terminals. Three things could happen (1) it would stop working (2) it would sound worse or (3) it would sound better. Well it was number three, not only did the volume go to full strength but the distortion disappeared as well. For the life of me I don't understand how anyone could have thought that was good for this set. Now it sings at full volume and is a real show stopper. I also installed a 500k volume switchpot and replaced the 500k tone control pot and now all I have to do is tidy it up in readiness for its restored cabinet .
It seems on more investigation that the terminals should be there ( albeit not green and yellow ) but the jumper should not be there.

That is the point I made back in Post #24.