Quote:
Originally Posted by zeno
In the tube days we fixed 95% of the sets with a VOM or VTVM.
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I agree that the 2 types of meters were essential in those days, but remember that the best VOMs (at 5,000 to 10,000 ohms per volt (AC) and 20,000 ohms per volt (DC) presented considerable loading to a high impedance circuit, especially when using the lower voltage ranges. A VTVM, with a constant 11 Meg-ohm input resistance was necessary for measuring these sensitive circuits.
Most modern high quality DVMs have a 10 Meg-ohm input resistance on *all* AC and DC voltage ranges and IMHO, makes the use of a VTVM unnecessary today.
jr