Hackaday (unofficial) November 7, 2021 9:00am Heathkit IM-13 VTVM Repair #repairhacks #teardown #heathkit #vacuumtubevoltmeter #voltmeter #vtvm #hackaday posted by pod_feeder_v2 Heathkit IM-13 VTVM Repair If you are under a certain age, you might not know the initialism VTVM. It stands for vacuum tube voltmeter. At first glance, you might just think that was shorthand for “old voltmeter”…