This Precision EV-10A was brought to me by a Customer wanting to get it fixed and working again. When this tester was made, they installed .01 uf RF filter capacitors across the AC line and ground. The paper capacitors used then were not made to withstand the 115 Volt 60Hz power line voltage and the capacitors were known to destroy themselves. This unit had one capacitor that had blown apart. I re-capped the power supply and found a loose connection on the back of the main PC connection board. The unit would not zero on ohms testing. The meter in this unit had some Bakelite debris floating around in it that interfered with the mechanical operation of the meter. I had to remove the meter, take off the cover and remove the debris. I am constantly amazed at the accuracy this old equipment. This unit is no exception.
Precision EV-10A Vacuum Tube Multitester
Categories:
Finding your article regarding the EV-10A, I bought one from eBay to restore. Mine, has had its power cable cut off leaving only battery connectors left. The zero ohms pot is frozen and someone punched a hole in it hoping to clean it out, I guess. I was wondering if you might have a decent schematic for this unit. I did find one online but it is very small and very fuzzy if I zoom in on it. Thank you – Richard