Old moving coil multimeter question (2025 Update)

Unfoirtunately that is probably teh resistnce if its interneals being old and corroded. Try spraying ccontact ckeaner isnide of all te swticehs etc

I like analogue meters for many things, but that is not a great meter. Handy for checking the car battery.

Yeah, 'Eagle' were never a great make.

The movement spring needs re-adjustment. Turn the black screw head just under the centre of the meter.

And you might find it's supposed to be used lying down. No, not you, the meter.

yes, good point, I had forgotten about that possibility

Tried that. Only made it worse.

Tim

I said:L contract cleaner in the switches, Fresh battereis

Perhaps that is the resistance of your leads and probes. Open circuit it should read infinty.

The original picture looks like the meter offset is centred. Try turning it the other way.

Naah. Feet on the bottom, plus the symbol for "use upright" on the face of the meter.

No, the screw slot adjuster is to set the meter pointer to zero, with no reading. The zero for volts and amps, on the left - the zero for resitance, is at full scale, with pointer on extreme right.

If with shorted leads, and on the resistance range - the pointer cannot be adjusted to zero, and assuming no fault, it usually means the battery voltage is too low.

Could be. Google suggests it uses 4 AA cells and 1 D cell.

Scrub that. Should have read the OP properly.

IME it usually means there is more resistance in the leads and switches than there should be

Multimeter sockets and their leads do not tend to be gold-plated, and twisting the plugs in the sockets a few times may produce an improvement. I have had a (digital) meter where long-term movement of the leads broke the solder joints of the sockets. There was still a connection, but with undefined resistance.

This is a schematic from a similar era. Really nothing inside of merit, a meter movement with a 50uA full scale. Shorting the leads together then, puts 50uA through the meter and drives the pointer towards the right side, (0 on ohms).

There is no real amplifier in there, in that example.

You can connect a digital meter on "volts" to the two leads when the Eagle is on "ohms", and that should give the battery voltage being used to test ohms-like things. A meter like this is not particularly "low-power ohms" and could bias a transistor junction to the ON state.

Toys like this would be fun with a small solar cell and a flashlight, where you want an indicator that does not draw power, and can respond all day long if necessary. (Like if the idea was to measure relative insolation using a little solar cell, all day long.)

My digital meter has a timer on it (which has malfunctioned once but recovered on its own), and the digital meter will stay on if you connect the RS232 cable to the meter and record digital meter readings. A digital meter can also be used for a toy indicator, with a wall adapter for power for it. As long as you have a mechanism for overriding the timer. A digital meter can draw 8mA from 9V battery, while making readings, which gives some idea how/why it can run for a while, but not forever. The RS232 digital readout interface is usually optoisolated, which is why the meter can be connected to 500V and to the computer, at the same time. But the opto also draws a significant amount of current, which is where the wall adapter in place of the 9V battery comes into play.

I don't happen to like autoranging meters, and if all I could find in the house, was autoranging ones, I'd dig out the analog one just so I could have fixed scaling :-) But in terms of "sensitivity", the analog meter is about as elegant as an angle grinder, when working on electronics.

I think I got more fun out of a 9" meter movement, 50uA or so full scale, and using that in circuits as a readout, for little breadboard projects. As a teen, I got a few nice finds when buying surplus electronics, then going down to customs and excise to get the staff to "work out what I owed".

Paul

If you can't set Zero on the meter movement then sometimes its possible for small metal particles to get wedged in the meter movement itself, had that on a few meters over time!.

Even Sifam panel mounted ones!..