> The thing about batteries is they give great isolation. A > VTVM uses a differential amplifier for the metering. It may > be a problem getting another supply in place with the > isolation that is needed.
There was some discussion regarding this topic on the Tempe Heathkit reflector in the 10/04 timeframe. At lest on the Heath VTVM, there is apparently an issue wrt current draw from the power transformer, regardless of how simple or complex one chosses to go with the idea of feeding a 1.5v DC supply to replace the battery. I've kept a battery going in my v-7A since 1957. I had a bit of corrosion once, many years ago, but cleaned it up -- and have checked it once a year or so since, with no more problems. Grant/NQ5T
