Real estate is at a premium in the lab. I don't have much bench space for test gear.
That's why I purchased a Metex test system.
It's a DMM, 3 power supplies, a function generator and a counter in one box.
I bought it second hand. It was owned by someone who stopped his electronics studies.
Left Side: Function Generator and Universal Counter
The generator and counter can be used separately, but it's also possible to let the counter show the settings of the function generator. There's an internal connection that can be switched on and off at will.
Function Generator
The generator can deliver sine, square and triangle waves up to 2 MHz. You can add a dc offset and sweep the frequency.
It's possible to manipulate the symmetry of the signal. Turning the SYM pot changes a triangle to a sawtooth, and alters the duty cycle in square wave mode.
There's an input to manipulate the frequency with an external dc voltage, and there's a TTL output.
Universal Counter
The 3-channel counter can show frequency and time of a signal. And as the name indicates, it can also count pulses.
It's possible to do some calculations between channel A and B in count mode.
A and B can handle 100 MHz. Channel C can measure inputs up to 1.3 GHz.
The gate button lets you choose the display update frequency.
Right Side: Power Supplies and Multimeter
Power Supplies
The kit comes with 3 isolated power supplies. One is 0V - 30V variable and can deliver 2A. It has a digital meter that can be switched to Volts and Amps.
Then we have a fixed 15V 1A and a 5V 2A supply. Because all 3 are floating, we can combine them.
The GND connector can be used to make the supplies ground referenced. The variable channel is by default ground referenced, but can float by removing a plate interconnect between the negative input and GND.
Digital Multimeter
This is a modded version of the Metex 3640. The manufacturer has done some funny things to fit it into the housing.
The meter is battery powered and fully separated from the rest of the instruments (except the display light - that gets its power from the PSU unit).
We can measure V, A, resistance, capacity, diodes, continuity and logic hi/lo. There are options for hold, min and max. There's a separate smaller .
part in the corner of that display that you can assign to these functions.
This test set is my daily work horse. Certainly the PSU, counter and generator get used very frequently.
I use the DMM a bit less. In most cases I find a handheld DMM more convenient. But when I need to do multiple measurements, I use the built-in Metex meter.
Maybe I'll do a follow up blog on the mod I've done to the function generator. I've externalized the sweep ramp and sweep pulses.
Very handy if you want to do Bode plots on your scope.
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