There is nothing digital about a vintage Roller-Smith bridge ohmmeter. It can measure from 0.5 ohms to 50,000 ohms using 4 ranges. This is a beautiful antique test instrument. It has an attractive hardwood case, leather handle, and quality construction. The meter operates on 3 vdc, which can be supplied using two D-cell batteries or …
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: …
©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 …
(©2008 Bob Putnak, all rights reserved.) This article discusses repair and calibration information for a number of vintage capacitor testers that all use the same fundamental test circuit. The article currently covers the EICO 950-series, PACO C-20, Knight KG-670, Heathkit C-2 and C-3, etc. (More models will be added on an ongoing basis as I …
