I have some collections of vintage meters. One of them have problem like shown below. The needle can’t be fixed on the zero position. It seems like the internal magnetic stabilizer parts have loosen its function or misplaced inside the meter. Let’s open it 😉
The good from a vintage meter is its accuracy, stability, and build quality. Many modern meters are available in cheap price but the quality is very poor. The meter moves in a very unstable manner. Far from what I say a smooth movement of the vintage meter. That’s why, even many modern meters are available in many store in affordable price, I still prefer to hunt vintage meter, usually from eBay.
After I open the meter, I realize that the spring which used to balance the needle on zero position by using the magnetic field is missing. I mark it with red circle.
Well, not just one, but two are missing. I highlight again the second part with another red circle.
Without the springs, the needle will not have “power” to stay in the zero position (or on idle position). The needle will move either way to far left of right, depends on the meter position (and gravity effect). The springs will hold the needle, prevent it from being affected by gravity, by using the balance of the magnetic field between those two springs. On the correct installation, the needle will “fix” on the zero position when idling.
Picture above shows the two springs, which used to maintain the needle “fix” on the correct position. The two springs will balance the needle position and fix it on the correct position (on idle position). How these small two springs could manage to balance the needle? By using the magnetic field from the magnet below the meter. It will prevent the needle from moving too left or too right – just balance.
Plug back those two springs. But remember, don’t insert the spring too deep inside the bar. It needs to be inserted on the correct position to get the exact magnetic field from the magnet below. You can try it first whether the needle already balance and not affected by gravity (by “shaking” or moving the meter orientation to see whether the needle “swing” or “fix” on it’s position). Add some resin or glue to fix the spring position. You are done! See below photo to see our work! Sorry for the light effect on the bottom left.
Some of my vintage meter collections… 😉