Avometer Model 7 Mk2 Range Switches

The AVO 7 Mk2 has locking range switches, which are deep within the electronics. They usually require a good clean with a contact cleaner when they become stiff. This type of switch was very desirable because it made a clicking sound when it locked and had a positive feel. The later AVO 8 Mk5 had a cheaper construction where the switch contacts were etched on the printed circuit board, and I did not think they were as good.

Since this meter has a divide-by-two function, the number of available ranges increases making it simple to take a reading. The DC current ranges are 2 mA, 10 mA, 100 mA, 1000 mA, and 10 A. Using the divide-by-two function provides the following additional ranges 1 mA, 5 mA, 50 mA, 500 mA, and 5 A.

The AC voltage range is 10 V, 100 V, 400 V, and 1000 V. Pressing the divide-by-two button provides the following additional ranges, 5 V, 50 V, 200 V, and 500 V. As you can see, the Model 7 has more range options making it very desirable to have.

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