Trying to figure out the pins on an old walkman volume wheel

Hi,

I am trying to reuse the volume control from an old GE Walkman. It is a thumbwheel with 5 pins. I am trying to identify what the function of each of the 5 pins would be when hooked up to the headphone jack which has 3 pins.

Any help would be greatly appreciated. :slight_smile:

GE_thumbwheel.jpg

Do you have a VOM?

Can you describe the tactility of the control when it's rotated from one extreme of its travel to the other extreme?

Hi dougp, thank you for taking the time to help. Yes, I have a VOM but I am not very experienced using it.

The wheel moves freely about 180 degrees with stops at both ends. I'm thinking there's a ground and a left in and out and a right in and out?

Pin 1 and 5 are probably a switch, and 2-4 the actual pot.
Force it a bit past one end, and you might hear the switch click.

50k lin (503 = 50 with 3 zeroes) is no good as volume control for 32ohm earbuds.
Leo..

Hi Wawa,

There is a separate switch for on/off, the wheel is just volume, no click at top and bottom.

:slight_smile:

Could also just be for mechanical strength, when soldered to the circuit board.
Leo..

Hi;
This may help as a starter to test for.
If the control has come out of a stereo walkman.
FGMZ53ZGB288KIF.LARGE.jpg

Tom… :slight_smile:

arduinokov:
Hi dougp, thank you for taking the time to help. Yes, I have a VOM but I am not very experienced using it.

Get a piece of paper and a writing implement. Set the meter on a 2000 Ohm scale. Connect one lead to pin1, the other to pin 2. Move the control through its entire range and record the results.* Move the pin 2 lead to pin 3 and do the same. Continue this way 'til you have data for all pin-to-pin combinations. When you're done you'll have a better idea of what's inside the control.

Check out some YT videos about using a meter. If you don't already have them, something that can clip onto small components will make your life a lot easier.

https://www.pomonaelectronics.com/products/dmm-test-leads-and-probes/test-leads-and-probes

  • If you see only slight variations on the meter drop down a scale.

The results of the meter testing were as follows (setting at 2000 ohm)

PIN 1 to PIN 5 - 027

Minimum volume setting:
PIN 1 to PIN 2 - 027
PIN 1 to PIN 4 - 785

Maximum volume setting:
PIN 1 to PIN 2 - 696
PIN 1 to PIN 4 - 026

What is the resistance reading:

From pin 2 to pin 4

From pin 2 to pin 3

From pin 3 to pin 4

You may find that pin 1 and 5 are simply mounting lugs, and that is a single potentiometer made up of pins 2, 3, and 4. Generally I would expect pin 2 and 4 to be the end points, and pin 3 the wiper, but can vary. Stereo output wouldn't necessarily need two volume pots, if the amplifier had a common gain control, and you didn't implement a balance control.

david_2018:
What is the resistance reading:

From pin 2 to pin 4

From pin 2 to pin 3

From pin 3 to pin 4

You may find that pin 1 and 5 are simply mounting lugs, and that is a single potentiometer made up of pins 2, 3, and 4. Generally I would expect pin 2 and 4 to be the end points, and pin 3 the wiper, but can vary. Stereo output wouldn't necessarily need two volume pots, if the amplifier had a common gain control, and you didn't implement a balance control.

Setting at 2000 ohm:

PIN 2-3 and PIN 3-4 is nil

PIN 2-4 is 785

It looks like PIN 2 and PIN 3 are connected. Also, it looks like PIN 5 doesn't go anywhere?

Tested all possible connections.

PIN 1 connected to PIN 5 always gives the same reading. PIN 3 does nothing ever. The only variation is what PIN 2 or PIN 4 is doing.

Those personal cassette players generally worked in stereo, so I'd expect this to be two pots in one package. Something like in reply #6.

Hi,
It looks like its just a mono wiring configuration.
Are there any copper tracks on the other side of the PCB?

Thanks… Tom… :slight_smile: