Rusty Murphy A48 chassis

[audion_1908]

I have recently got a very poor looking Murphy A38 chassis, it has a full set of valves and all parts, but also a lot of water damage, I decided to risk washing it in a dishwasher, it got 2h with a washing cube, and about 1h upside down. It's done wonders with the mould dirt and rust, I washed it without valves and tuning dial plastic

[audion_1908]

I have found some problems, the electrolytic capacitors were badly leaking and will be replaced with some polyester film capacitors and a 2 or 3 ohm series resistor.

[audion_1908]

One big problem is the IF cans, the ferrite has been badly rusted and is crumbling off, I have a data sheet but it doesn't tell me the inductors or trimmer values, can anyone help?
The transformer is drying with a small fan on it

[stevehertz]

To be honest, unless you're doing this as a labour of love, something you just feel you have to do, the condition of that chassis (is it only a chassis - nothing else?) seems like a gross waste of time and effort to me. You can get complete sets for a fiver in second hand shops, from other collectors, on auction sites etc etc. To me, they would seem a much preferable project than attempting to revive 'just a chassis' that as described seems like it is a herculean project (rebuilding IF cans?!) - to end up with what? If it was the chassis to a rare and/or collectable set, I perhaps get it. No offence meant by the way and best of luck if you go through with this, just my honest opinion.

[vinrads]

I agree with parts of the above, but sometimes you just have to restore it for your own satisfaction , not sure about leaving washing the transformers though . Mick.

[MurphyNut]

I must admit I've spent a lot of time on sets that aren't really of any value. But a Murphy A38 is a lovely and rare set, but only if it's more or less complete with it's cabinet.
Good luck anyway, as long as you're enjoying the project.

[audion_1908]

Before cleaning pics, I know it's a bit extreme to put it in the dishwasher, but I had little to lose.

[vinrads]

Now that,s bad! looks like you are a crazy as I am , are you going to restore the cabinet yourself ? when fitting the smoothing capacitors remember the neg are not common , good luck with it . keep us posted. Mick.

[MurphyNut]

Looking at those pictures it looks like you have a Murphy A48 not a 38. These are certainly not as rare.

[audion_1908]

More pics of the radios underside

[ms660]

Originally Posted by MurphyNut

Looking at those pictures it looks like you have a Murphy A48 not a 38. These are certainly not as rare.

Agreed.

Lawrence.

[audion_1908]

Crazy paving cracked ceramic capacitors, can electronic capacitor that has had a bad leak

[audion_1908]

I only have the chassis, but I have a free speaker that's about the right size I got from the bin, and when I get it working I will build a wooden tomestone or cathedral case so making a Frankenstein but some one could restore it fully and put it in the correct case, and to why I am working on it is I want a challenge and have wanted to build a tomestone style radio and was curious to see if the dishwasher would work, I did not remove the transformer due to the screws rusted solid and the large number of wires going to it, and it had already had a lot of water damage, the transformer looks to be unvarnished? I will dry it out and vanish it.

[audion_1908]

Woops it's a Murphy A48 chassis, admin can you I fix my typo in the subject line?

[PJL]

I would guess those are ceramic containers for mica capacitors and it's just possible they will have survived.

It will be interesting to see if any of the RF/IF coils still have continuity!

[audion_1908]

I think you are right about the capacitors being mica, I have order some replacement 1% mica capacitors as another user on this site had problems with these round cracked mica in ceramic capacitors in the same radio, and the dishwasher made them much worse

[audion_1908]

Originally Posted by PJL

It will be interesting to see if any of the RF/IF coils still have continuity!

Some of the coils look good, some where long dead, pics after washing, the if coils ferrite is crumbling away! I have a service manual with schmatics but it dose not list the if trimmer capacity or much on the crumbling inductor, any one have some info on them?

[audion_1908]

On the plus side the mouldy wiring looks good now and is not to brittle so can stay, I have been putting vanish on them to stabilise them

[PJL]

Probably an iron dust core. It might still work as the bulk of the material surrounded by the coil is probably still there. It needs to be stabilised as it would have been waxed covered.

[audion_1908]

OK! I can try vanishing them then entombing in two part epoxy, if this doesn't work do you have any suggestions?