Eico 950B Resistance-Capacitance-Comparator Bridge s/n 54062 *Rebuilt*

Description

This EICO 950B was found at an estate auction in poor operating condition.  To restore this unit to a semblance or original operation the electrolytic and paper capacitors were replaced with modern equivalents.  Out of tolerance resistors and the eye tube were also replaced.  After cleaning the switch contacts, the voltage control and power factor control this unit returned to nominal operation.  A 1/2 Amp fuse was added after the power switch to help protect the power transformer.
As with most of this style bridge the reference capacitor is the center of the dial scale.  As the dial is turned away from the reference the accuracy of the dial is reduced.  Photos were taken at the extreme ends of one scale to show the variation typical on all scales. (Please remember this bridge was made for the service industry, not a design lab.)  In addition to testing for capacitor leakage, this test has been used by some to reform electrolytic capacitors.  Should you do so, please keep in mind the voltage control is rated at 4 watts.
**Note: this unit produces High Voltage at the test terminals.  Do not purchase this unit unless you are experienced in the voltages found in vacuum tube electronics.  This was a kit designed in the 50s when safety standards were much different than they are today.  Buyer assumes all risk from operation.***
From the Manual:
The Model 950B is a highly flexible ac-powered bridge which measures ca
pacitance in the range from 10 pf to 5000 mf and resistance from 0.5 Ohm to
500 Megaohm on direct reading scales, employing an electron-ray ("magic eye")
tube as a visual null indicator.  Measurement of resistance, capacitance, and
inductance by comparison with an external complementary standard is also
possible, in which case a special ratio scale is read. An invaluable feature
for service work is a dual-sensitivity leakage test employing a built-in source
of polarizing voltage, continuously variable from 0 to 500 volts dc. The high
sensitivity leakage test is used for testing paper, mica, and ceramic capacitors and the low sensitivity test for electrolytic capacitors. The electron-ray tube
is the leakage indicator in both tests. In addition, this instrument provides
direct power factor measurement on the higher capacity ranges in which
electrolytics
are measured. The Model 950B, by the nature and accuracy of its
testing and measurement facilities, will be found extremely valuable in the
servicing of TV, FM-AM radio, and other electronic equipment.