This is a repair of a Philips PM5127 Function Generator and a teardown of this unit. These frequency generators were manufactured in 1975. They have a frequency range of 0.01Hz to 1MHz with an output variable up to 30 volt peak to peak.
Review and teardown of a Keithley Instruments model 225 Current Source which dates back to 1976. These units are still very accurate today, with an accuracy of ±0.5%. A range switch and 3 decade switches can provide a current output from 0.1 nanoamps to 100 milliamps.
This is a teardown of a “Micronta” Digital Multimeter which was manufactured by Sinclair Radionics Ltd for Radio Shack (Tandy Corporation) in 1978. Sinclair launched the meter in 1977 and also supplied this meter directly under its own brand name with the model number PDM35 (derived from “Portable Digital Multimeter 3.5 digits). The Sinclair models […]
Here we review two Time Electronics Ltd. DC Millivolt Source calibration units. They use a precision reference zener diode, low temperature coefficient resistors and thumb switches to select a precise voltage accurate to 1 Micro Volt. They have 3 ranges and an accuracy of ± 0.05%.
Teardown of a Keithley 178 Digital Multimeter manufactured in 1979. This multimeter was one of a number at that time which used the Intersil ICL7103A and ICL8052A chip set which simplified multimeter design and manufacture.
The Keithley 168 autoranging digital multimeter. Manufactured in the early 1970’s. Used the 74360N multimeter chip which is now obsolete. D.C. voltage range from 0.1mV to 1000V. A.C. voltage from 0.1mV to 500V. Current ranges from 0.0001mA to 1A. Ohms from 0.1 ohm to 20 mega ohm. Input resistance is 10 mega ohm.
Review and teardown of the Thurlby 1905A Intelligent Digital Multimeter was designed and manufactured in the 1980’s by Thurlby Electronics Ltd. The meter is a 5½ digital manual ranging multimeter with keyboard programmable computing and data logging facilities. The basic accuracy is ±0.015% on the D.C. ranges.