The handheld digital multimeter (DMM) is a basic tool for ham radio applications. It is called a multimeter because it combines multiple meter functions into one unit: voltmeter, ammeter and ohmmeter. These days, almost all of these meters are digital, which makes them very easy to use.
Being a bit of a test equipment junkie, I own quite a few DMMs. One of my favorites for hobby use is the Equus 3320, with a price tag of about $20. In addition to the normal current, voltage and resistance ranges, the 3320 has auto-ranging, diode check, continuity check and battery test mode included. A great little meter for twenty bucks.
Here is a list of 10 things you can do with a DMM.
1. Check the power supply voltage on the new power supply you just purchased.
2. See if your HT battery pack is fully charged.
3. Measure the current that your transceiver draws to estimate how long your emergency power system will last during a blackout.
4. Sort the bag of resistors you purchased at the swapfest.
5. Check a fuse to see if it is blown.
6. Troubleshoot your broken rig by checking the bias voltages against the service manual.
7. Figure out if the AA batteries the kids left for you are dead.
8. Verify that your coax is not shorted between the shield and center conductor.
9. Check the level of the power line voltage in the ham shack.
10. Check for good DC continuity between the ends of the TNC cable you just soldered.
Let me know your ideas to add to the list.
73, Bob K0NR