Telecom or Communications Instruments
Psophometer Telecom Instrument
I learnt more about instrumentation and opamps when
i worked with some instruments related to
Telecommunications. Some telecom instrument
prototypes also were made.
Wikipedia. I learnt some basic
instrumentation when i worked on the Instruments
at TMPL. TMPL as it was known decades back was in
Service and Sales of many Brands like Racal Dana,
Genrad, Data I/O and Electronic Production
Machinery This was before the year 1988 and later
i remained in R&D Field of
Test-Measurement and Process-Control for
- Telecommunications Test
This instrument 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.
Noise and Hum in Audio Circuits
Transmission Measuring Set
The one above was also made at TMPL, it 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
the ear. With a built in signal generator in dB
settings it becomes a Transmission Measuring Set.
This was in the eighties..
Future Landline Phones