Murphy V118C restoration

[sortedradio]

Thanks to Colourstar, see https://www.vintage-radio.net/forum/showthread.php?t=220629 , I was made aware of this set on Facebook Marketplace, located in Stockport. I collected the chassis, minus CRT and mask,
with the cabinet yesterday.
After lifting the chassis onto the bench, all 21.5kg of it, if was time to see what I had let myself in for!
So far, the good bits :-
1. All valves and other components are present.
2. Cold checks on the mains transformer look promising and there is no sign of overheating.
3. Everything looks original and unmessed with.
The not so good bits:-
1. The rare CRT CRM121 is missing along with its mask.
2. There are some pretty rusty areas on the chassis and frame.
3. A fair amount of rubber insulated wiring has perished and will need replacing.
4. Some of the pots are either siezed, or broken, and will require repair.

Johns excellent V114 writeup, which is a very similar chassis, will be a very useful guide I think.
https://www.vintage-radio.net/forum/showthread.php?t=116325


All in all not too bad I think!

More to follow...........

[Colourstar]

Well saved Martin!

I was hoping the brown finish on the chassis was some sort of Hammerite, but it's just plain old rust (it was hard to tell on the original photos). It sounds like you have the makings of a good project, especially if the transformer has survived. Locating a suitable crt will be the key thing, but you never know what members on here may have lurking in their sheds and attics.

Incidentally, the speaker looked like it was in some sort of sealed acoustic enclosure in the cabinet- is that correct?

Steve

[sortedradio]

Originally Posted by Colourstar

Well saved Martin!

Incidentally, the speaker looked like it was in some sort of sealed acoustic enclosure in the cabinet- is that correct?

Steve

Thank you Steve, yes the box houses the speaker. I haven't checked it yet as the cabinet is still in the back of the car!

[Lloyd 1985]

Looks pretty good! The wirewound pots on my V180C were all toast, most of them had lost their wipers.

If you get desperate, I have a CRM121, but it's very dim! I'd certainly call it a last resort!!

Regards,
Lloyd

[sortedradio]

Well I have been lucky and collected a CRM121B tube from Huntingdon at the weekend, thank you Dermot. It was tested about 40 years ago, and is believed to be low hours. It has a poor conditiom mask fitted which I may be able to utalize. I have also checked the speaker successfully for continuity. Mike Barker thinks he has a set of suitable knobs, so things are looking up.
The cabinet is still in the back of my car, and has had 2 doses of woodworm treatment so far. I have bought some syringes to inject Cuprinol into each flight hole, and there are a lot of them!
The lower power supply chassis, which is the most rusty part, looks like it can be separated from the upper chassis. I will strip and treat the metal work, and replace the perished wiring next.

[Colourstar]

That sounds very encouraging Martin, with some key parts sourced already! Excellent news indeed.

Shame about the woodworm but hopefully the Cuprinol- and a lot of patient work with the syringe - will see the little blighters off.

Steve

[Niechcial,Steve]

Myself and another restorer of this model experienced a quirky effect with the EHT whereby EHT is produced, but unstable and blooming with picture content. In both cases the fault turned out to be an o/c EHT winding on the mains transformers. Needless to say, the mains EHt on these is potentially lethal!

[Heatercathodeshort]

Pic 2 shows the dodgy .1uf EHT smoothing cap. Do not switch it on with this in circuit! It will be leaky and tends heat up and pop violently with mains EHT sending lumps of Bakelite, foil, paper and muck everywhere!! Check the continuity of the EHT bleed resistors on the double tag board at the front of your pictures before you think of applying any power. Take care. John.

[sortedradio]

Thanks John,
The 0.1uF Visconal tests pretty leaky at just 1kV. I need to make up or find an alternative. The bleed resistors measure between 5.5M & 6.5M.
I have seperated the power supply chassis from the top half to deal with the rust and perished wiring.