Murphy A4 with A24 chassis.

[Murphyv310]

I suppose a bit of an emotive subject and one we will never really agree with, each to their own I suppose.

At the end of the day how we preserve our sets is our own decision.
I also have a CR100 that I got a few years ago, it had been modified my a Radio Amateur, the two RF amps were ripped out and two EF95's had been fitted in place of the KTW63 valves. In principle the idea is sound enough but whoever did the job didn't calculate that the replacement valves would have different inter-electrode capacitance to the originals, different cable runs would cause instability etc. Now to my mind this is a bodge, the CR100 performs well enough as standard until it get over 21mhz then it tails off. The mod though does not track correctly, you can align each end of the band OK but half capacitance on the tuning cap and the tracking is way off.
It's on my list to rebuild the set back to its original and then I need to look for a cabinet or get one made as I don't have it.
In 50 odd years of Radio & TV I haven't thrown out much, I'd rather pass on a Radio or TV free to someone that can get some pleasure from it than sell or dump it. My loft is full of stuff but as often as not if someone is looking for something I can help, mind you I'm in constant trouble from the missus as i can never find her stuff

[Radio Fixer]

I guess you have looked up what a good A4 is worth Geordie and compared it to the value of the chassis?  Might be worth the money ... A4's used to sell at quite high prices, it may sound daft but I think it was the propeller

Could use Auction Sniper on it?

Gary

[Geordie McBoyne]

Unfortunately, I missed out on the A4 chassis, and it sold for only £40 + £18 postage.
So it follows I'll just have to repair the A24 chassis. The mechanical demands to enable the A24 chassis to fit in the A4 cabinet are nothing more than fitting 12mm spacers to the tuning capacitor.

Yesterday the laptop computer decided to pack in just at the point when I was about to make the final bid on a Premier Radio type of Bakelite cabinet. The idea was to use the cabinet to house the chassis of my minimalist superhet radio receiver project.

Geordie Mcboyne

[Geordie McBoyne]

After a hiatus of more than seven years I have decided to restart the Murphy A4 restoration using the A24 chassis. All the mechanical requirements have been taken care of so it is time to attend to the electrical repairs to the chassis. For starters the capacitor block. This unit also contains eight resistors which have changed in value. A replacement volume control will have to be found, not so easy because it is a unique Murphy component which has a securing nut to keep the knob in position. See first attachment.

Geordie McBoyne.

[Mike Watterson]

Epoxy insides of a modern pot to rear of the existing pot? Or cut shafts and join shafts with splice (solder or glue or sleeve)?

Or tap end of new shaft?

I'm sure you'll figure it out.

[Geordie McBoyne]

Another picture of the faulty volume control.

Geordie McBoyne.

[Mike Watterson]

Interesting. Never seen anything like it! I've pots going back to 1928 (older ones are of course wirewound).
Is that a flat on the shaft too?

[Geordie McBoyne]

The control shaft has two flats. These strange controls were fitted on all models made up to 1935. The models A30 and D30 might be the last sets to use the special controls.

Geordie McBoyne.

[boater sam]

Nothing that a bit of lathe work won't sort.
Or, how about grafting a new pot working part onto the back of the old pot with a dog clutch type drive?

[Geordie McBoyne]

The rebuilt capacitor block. This assembly will be fitted in the chassis later this week.
Also receiving attention, the HT smoothing capacitors. These will will be ready for fitment in a matter of a few days.

Geordie McBoyne.