I learnt more about instrumentation and opamps when i worked with some instruments related to Telecommunications. Some telecom instrument prototypes also were made.
My exposure to T&M happened when i worked on the repair and calibration of such Instruments. This was before the year 1988 and later i remained in R&D Field of Test-Measurement and Process-Control for many years.
This instrument Prototype had Auto Range for the Voltage and
dB meter. Very rare in those days. I did it with a Window
comparator and miniature reed relays (oki). (National
Semiconductor and Intersil Chips)
Psophometer from Germany -
Below is a fully analog instrument, it must be using many transistors and probably Opamps. Maybe Hybrid Opamps, because this Instrument is after the Valve era but maybe before the Opamps came. By the size and front panel we can sense the period when this instrument was used.
The one above is a Psophometer which was a true RMS
auto-ranging AC dB level meter with weighted filters. The
weighted filter has to resemble the audio response curve of
With a built in signal generator in dB settings it becomes a Transmission Measuring Set shown right below. This was in the eighties.
30th Aug 2020
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