Murphy A24C.

[Geordie McBoyne]

When the restoration table version of the A24 is completed another Murphy A24 can receive attention. Except for the larger loudspeaker the console cabinet A24C is electrically identical to the the A24.
Expecting a delivery of capacitors this week which will be fitted inside the capacitor block. Most likely the console set will need the same servicing procedures as the table model.
Picture of the A24C will be taken later this week.

Geordie McBoyne.

[Geordie McBoyne]

The Murphy A24C. A very strange looking set. It will look a lot better after the cabinet has received some attention.

Geordie McBoyne.

[Radio Fixer]

A friend of mine used to say "Whats that set? Oh! its really ugly so must be a Murphy". There are few that I like although on those that have passed through I have to say the build quality is the best.

Gary

[Geordie McBoyne]

Also found upstairs above the shop another Murphy console cabinet radio, the model A70C. Note the drop-down loudspeaker baffle which I believe is used to house the cable remote control unit.
But, before any attempt to restore this set is started the restoration of the two "24" models must be completed.

Geordie McBoyne.

[PerdioPal]

I like Murphy designs and I also think they don't take "patina" very well. So a complete, new refinish may offer the best look. They were new in their day, why not now?

[Geordie McBoyne]

The A24C I have seems to be the victim of cost cutting. The complex filter unit present in the table model A24 is absent in the console model.
Note the early production Mazda AC/HL/DD. Screw top cap terminal.
The similar looking A26C employs a much simpler superhet chassis. The double-diode-triode is replaced with a Mazda V914 double-diode. High slope output valve.

Geordie McBoyne.

[ppppenguin]

Also cheapskate is relying on the volume control as the grid leak resistor for the output stage. A coupling cap and resistor would have done the job properly and not cost much.

[Murphyv310]

Also cheapskate is relying on the volume control as the grid leak resistor for the output stage. A coupling cap and resistor would have done the job properly and not cost much.

Slider to Grid..... normal practice Jeffrey.
I'm more concerned about the placement of C33

[Mike Watterson]

Slider to Grid..... normal practice Jeffrey.

Yes, but it was always a cheapskate bad idea as it's unreliable and noisy compared to adding a capacitor and resistor. Especially as the pot wears or gets dirty.

Lots of things were or are "normal practice" but a bad idea.

[Murphyv310]

Slider to Grid..... normal practice Jeffrey.

Yes, but it was always a cheapskate bad idea as it's unreliable and noisy compared to adding a capacitor and resistor. Especially as the pot wears or gets dirty.

Lots of things were or are "normal practice" but a bad idea.

There are relatively few sets with the addition of an extra resistor and cap. The current through the grid leak is microamps, controls go noisy even if you add in the DC blocking cap.
Like I already said C33 is a much bigger issue than strapping the slider to Grid. A cooked output transformer is a major discrepancy, than how the volume control is wired.