What do you want to measure? If its just car related stuff like DC volts, perhaps current up to 10 amps, resistance and continuity, a 5 pound analog job off the market. If you want to to measure things more accurately, a Digital meter for 15 pounds and upwards, but I find an analog meter is the best for the Austin's 6 volt system because it gives a better average voltage at 6 volts DC whereas the DVM is flying up and down and what does 0.1 volts mean with a dynamo system anyway. I carry a cheapo analog meter in both my old cars.
Ps - an old AVO would take almost as much space as the 6 volt battery !!
Ps - an old AVO would take almost as much space as the 6 volt battery !!