Test Equipment

Sprague TO-3 Tel-Ohmike calibration

This article discusses repair and calibration of the Sprague model TO-3 Tel-Ohmike Resistor-Condenser Analyzer.    Serious electrical voltages are present, repairs should only be attempted by a qualified technician. Copyrighted by Bob Putnak, all rights reserved. Model TO-3 Tel-Ohmike “Capacitor Tester” is based on the older Sprague design.It is a balanced-bridge design with the following specifications:

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Testing panel meters

©2009, All rights reserved. The article will discuss a cheap and easy way to test panel meters. The meter in your tube tester is an example of a panel meter. Occasionally you see flaky meter operation and suspect that the panel meter may be defective.  Most techs know that it may not be safe to

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