Volume Control with Center Tap - Printable Version
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+--- Thread: Volume Control with Center Tap (/showthread.php?tid=24650)
Volume Control with Center Tap - Hymie023 - 10-17-2023
Hello all,
My 46-1213 has a Center tap volume control. It is 2 Meg with the Center tap at 1 Meg. The Center tap goes to the 500K bass control. The bass control is OK ohming it out. The volume control is 0 ohms at minimum, 300k half way, the drops to 30k at 3/4, then up to 900k at full volume.
The problem is as I turn it about half way down the volume control itself squeals, I can't hear it through the speaker, and the stations (FM, AM, and SW) fade out. Turn it down further, and it motorboats through the speaker and the squealing stops. It motor boats at minimum volume.
This is the first Center tap volume control I have worked on. Is this thing acting correctly ohms wise? The radio has other issues with FM hum and low volume, I don't know if that is causing the issues with the volume control.
Thanks.
RE: Volume Control with Center Tap - morzh - 10-18-2023
If your measurements were done in-circuit, make sure you disconnect your centertap before declaring drops to 30K etc taking place. Once you know your volume ctl is good, go further, if not - then replace it or fix it.
RE: Volume Control with Center Tap - Hymie023 - 10-18-2023
Thanks morzh, I had not disconnected the Center tap. I will do that and go from there.
RE: Volume Control with Center Tap - morzh - 10-18-2023
Best to disconnect all pins. Maybe except the wiper as it is disconnected for DC by the capacitor. But if not difficult, disconnect all.
RE: Volume Control with Center Tap - Hymie023 - 10-18-2023
Thanks morzh, the pot checks out OK, so I will start there and work my way back to see what is going on with it.