Knight VTVM

This is a Knight KG-620 vacuum tube voltmeter (VTVM). Along with Heath, Knight sold many different types of test equipment in kit form—a few hours assembly time could save considerable money. For instance, the KG-620 sold in 1962 for $25.95, but it was $35.95 factory assembled.

This particular meter was a kit. Here is a PDF of the manual, assembly instructions, and all of the other paper that came in the box.

A closeup of the meter.

A closeup of the front panel.

A fresh filter cap and a new diode for the power supply.

A view of the printed circuit board with a brand new 22uF electrolytic filter cap and a large diode.

This is the original selenium rectifier.The rectifier is marked 3L and has a large plus sign on the cathode.

This kit was well assembled and had nothing wrong with it, apart from some loose hardware that caused a flaky ground connection to the printed circuit board. A closeup of the selector switch with high precision resistors.

The meter has two Knight branded vacuum tubes: a 12AU7 and a 6AL5.

The tube bears an orange Knight "K" logo.A view of the PCB, showing hte Knight logo in copper.