Transistor Radio Problem

[Doofus]

I have a battery-powered RGD transistor radio in the garage. It's of great sentimental value, because I've had it since I was five and I'm now fifty-harrumph.

I went out there yesterday and the batteries were flat. Unusual, but not sinister. So I replaced them and all was well. But when I turned the radio off, I noticed if I wiggled the on-off knob, up against the detente, so it was still off, the speaker crackled.

Went to the garage this morning, and the batteries were flat, so the thing is evidently on all the time.

Do I have a hope of fixing this myself, and if so, how?

[xeny]

My immediate thought is how easy is it to get in and replace the bit that the volume/on-off knob turns?

[dontlookdown]

As it is old, it should come apart easily with ordinary screws etc so you do have a decent chance of fixing it.

The business end of the on/off/volume will be a potentiometer, either surface mounted to a pcb or possibly separate and attached to the case or chassis.

How are you with a soldering iron? If you can unsolder it and ID the part, its quite possible you will be able to find a replacement that is close enough to do the job. Lots are still used and thus they are available.

You don't have to be an electronics genius, just careful and methodical.

I used to make a bit of pocket money at school doing simple fixes on radios and early walkmen etc. If I could do it, so can you. Good luck!

Also, look on youTube for anyone who has done something similar.

[Doofus]

dontlookdown said:

As it is old, it should come apart easily with ordinary screws etc so you do have a decent chance of fixing it.

The business end of the on/off/volume will be a potentiometer, either surface mounted to a pcb or possibly separate and attached to the case or chassis.

How are you with a soldering iron? If you can unsolder it and ID the part, its quite possible you will be able to find a replacement that is close enough to do the job. Lots are still used and thus they are available.

You don't have to be an electronics genius, just careful and methodical.

Makes sense, thank you. Yes, I can use a spldering iron, and yes, the radio comes apart easily. Now I know what to look for, I'll have a look.

[dontlookdown]

If you need a finer point on your soldering iron, you can twist a bit of solid copper wire round it. From that hank of twin and earth cable you've got in a drawer somewhere;)

It's a lash up, but it works.

[Doofus]

Any ideas how I find a suitable replacement potentiometer?

Mine says

PS104 ND1 T-10k ohms N:

it's 15mm in diameter, with five pins.

[mike9009]

Can you get a decent picture of it and I will take a look..,

[Doofus]

mike9009 said:

Can you get a decent picture of it and I will take a look..,

Probably not

[Pothole]

I hope you also have a picture of it with wires attached so you know which goes where.

[plasticpig]

I would ask here: https://www.vintage-radio.net/forum

[Doofus]

Pothole said:

I hope you also have a picture of it with wires attached so you know which goes where.

I do. I don't know what any of the pins do though, so the replacement part has to be identical.

[Doofus]

plasticpig said:

I would ask here: https://www.vintage-radio.net/forum

Cheers.

[Dogwatch]

A bit late now but I assume the battery is a PP9, so possibly you could have temporarily wired an external on/off switch into the positive lead from the battery using a couple of chocolate block connectors.

[Doofus]

Dogwatch said:

A bit late now but I assume the battery is a PP9, so possibly you could have temporarily wired an external on/off switch into the positive lead from the battery using a couple of chocolate block connectors.

6 AAs.

I could wire in an external switch but, as I said, I'm pointlessly attached the the radio, and I'd like to fix it, rather than bodge it.

Back in the 1970s, when BBC radio went onto FM (or for some other reason), they gave out some stickers to help you find your favourite stations. It's still got those on it.

[Ydnaroo]

The off/on switch mechanism is the cam on the back of the control, looks like parts have come off.

How about: https://www.ebay.co.uk/itm/ON-OFF-VOLUME-CONTROL-C...

Or: https://www.ebay.co.uk/itm/Switched-Radio-Volume-C...

5k instead of 10k unlikely to make any difference.

[Doofus]

Ydnaroo said:

The off/on switch mechanism is the cam on the back of the control, looks like parts have come off.

How about: https://www.ebay.co.uk/itm/ON-OFF-VOLUME-CONTROL-C...

Or: https://www.ebay.co.uk/itm/Switched-Radio-Volume-C...

5k instead of 10k unlikely to make any difference.

The bit that's come off is the knob, which I removed.

That first link looks perfect, thank you!

I spent ages searching eBay for a 'potentiometer' under advice from this thread. Who knew I actually needed an 'an/off switch'?

[Ydnaroo]

Doofus said:

I spent ages searching eBay for a 'potentiometer' under advice from this thread. Who knew I actually needed an 'an/off switch'?

Well it is actually a potentiometer or a variable resistor or a volume control with an off/on switch.

[dontlookdown]

Doofus said:

Ydnaroo said:

The off/on switch mechanism is the cam on the back of the control, looks like parts have come off.

How about: https://www.ebay.co.uk/itm/ON-OFF-VOLUME-CONTROL-C...

Or: https://www.ebay.co.uk/itm/Switched-Radio-Volume-C...

5k instead of 10k unlikely to make any difference.

The bit that's come off is the knob, which I removed.

That first link looks perfect, thank you!

I spent ages searching eBay for a 'potentiometer' under advice from this thread. Who knew I actually needed an 'an/off switch'?

You can't win 'em all;)

Hope you find one, whatever they call it. There is something very satisfying about fixing things that are of no value to anyone but yourself.

[NDA]

Doofus said:

Nothing useful to add.... but I do remember those stickers!

[LunarOne]

NDA said:

Doofus said:

Nothing useful to add.... but I do remember those stickers!

Even less useful, but I don't remember those stickers!