Test equipment
How does one explain why one is a test equipment fanatic? Is is the idea
of measuring quantities that are so small that it boggles the mind? Or
is it the idea that you're able to see the trace of electrons behaving
strangely? For whatever the reason, I'm passionate about old test
equipment, particularly of the late 1960s to the late 1970s. Basically,
post tube (valve) and pre- and early computer. In this era, both
Hewlett-Packard
(now Agilent ) (sigh, why
didn't the test and instrumentation company keep the historical
name? Answer: branding)
and
Tektronix
produced large volumes of interesting and (now) affordable test
equipment. I'm referring specifically to the
HP 8410 network analyzer and the
Tek 7000 oscilloscope series .
The Tektronix TM500 series is also extremely useful
and affordable.
Another reason this era is
golden is the quality of the manuals; you can learn a lot of
design from reading the schematics. Right now, the manuals from
HP and Tek are vapid. If you want to use the instrument, you'll survive,
but if you want to know how it works, forget it .
Sampling techniques
The idea of stroboscopic analysis of waveforms dates back to the
beginning of the century.
Sampling forms the basis of DSP and also microwave test equipment
and has been used extensively in network analyzers.
The HP 8410 is an example of such
an instrument (technically, the HP 8405 Vector Voltmeter
preceded the 8410 in its use of sampling for magnitude and
phase measurements).
Sampling has also been used in oscilloscopes. The first successful
commercial sampling 'scope was the HP 180 series. This was superceded by the
still incredible 1430 sampler. Tektronix followed HP by introducing
the 661 and then sampling plugins, beginning with the 4S series
and then the 1S series, 3S and finally 7S. More recently, both
Tek and HP have eliminated the use of general purpose 'scopes
as the base for sampling oscilloscopes. Furthermore, the manuals
are just appalling.
Annotated bibliographies
I have two annotated bibliographies:
one on
sampling techniques
and the other on
network analysis of scattering parameters .
Note! These bibliographies are severely out of date and
may only be published with permission.