Heathkit IM-13 VTVM : Test and Calibrate

Описание: Heathkit IM-13 VTVM : Test and Calibrate
In this video I finally get round to having a look at the Heathkit IM-13 VTVM that I bought from Ebay before Christmas last year. Built sometime between 1964 and 1968 this vacuum tube voltmeter is a very clean example of the model. It hasn't suffered badly from leaky battery syndrome and has a fairly damage free meter.

The first thing to be done is a basic safety check to see that internally there are no loose wires, broken components or stray bits of metal that could lead to a fatal electric shock. After that is done I decide to replace the 50 plus year old capacitors rather than test them because it seemed pointless to have to remove them to test only to have to replace them at a later date. Some of the resistors have changed value but not to any significant amount so I decided against doing a full rebuild as I had done in the V-7A meter that was shown in a previous series.

I then go into a full calibration, showing that the meter itself isn't too bad after a bit of a cleaning of the potentiometers. Without doing the rebuild, the accuracy is not as good as some more modern test equipment but it is ideal as an indicative meter and actually is better for some tasks than modern digital equipment. I plan to use this on the bench for amateur radio, vintage radio restoration, general radio repair and any other task that requires an analogue meter.