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Old September 14th 04, 11:48 PM
Reg Edwards
 
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"H. Adam Stevens, NQ5H" said -
Not to diminish Heaviside's contribution, it was Gibb's work that led to

the
present mathematical expression of Maxwell's equations.
The Heaviside equation survives to this day as the description of the
electromagnetic field of a moving charged particle.
But since Gibbs was American I'm sure you Brits will argue.


=======================================

I'll allow a wine-assisted imagination to wander around my own history.

I came across Gibbs around 1948 by accident while searching for more
information on transmission lines in general. Google had not been invented.
He appears to have made his name known (no doubt also in other matters)
because of his "Gibb's Phenomenon", an overshoot of some kind in an
extension of Fourier's Waveform Analysis. At the time I had no interest in
'overshoots' and forgot all about it. My ignorance about Gibb's other work
has continued ever since. I appologise for no mention of his name in
connection with tidying up Maxwell's work. And there's no reason at all to
resurect the Boston Tea Party.

Heaviside died in solitude in 1925. I was born during a freezing 6-feet
deep snow-storm 9 months later. I sometimes like to think there is a
spiritual connection.

Mother was a little hard-working woman who took in laundry and
clothes-ironing from the slightly better-off classes. Father was a
30-shillings a week iron-bolt header but the national General Strike was
imminent. In his spare time he taught himself to drill holes in ebonite
panels using a red-hot poker the smell of which began my technical
education. But he could solve quadratic equations in his head without the
use of pencil and paper or any knowledge of algebraic symbols. I never
understood how he did it. Although he lived to the age of 90 he could never
explain it himself.

snip

Around 1951, as a sideline with other duties, while working in the
Engineer-in-Chief's Office of the British Post Office, I first became
involved with the location of faults on transmission lines. Then, for a
period, I specialised in faults on the then new deep-sea coaxial cables with
submerged valve-type repeaters (amplifiers). Transistors were not good or
reliable enough.

I worked alone but with the facilities of a shared workshop and staff. My
boss was an ex-cable ship Cable Testing Officer, a Ph.D, I think next to the
captain in rank, who always said the only doctor in his family was his
brother, a doctor of medicine. His name was Bray and he had the knickname,
when not in his company, of "The Vicar".

snip

I became involved with reflection coefficients, etc., in the frequency range
0.1Hz up to HF using rectangular-waves and sinewaves. The Dollis Hill,
Research Depapartment laboratories (the PO Bell-Labs) made me a 0.1 to 100
Hz, balanced-and-screened output transformer, to be used in a power
amplifier, a test signal generator. The amount of 10-thou, mu-metal used in
it necessitated a special order being placed on the lamination manufacturer.

I had to make my own precision 0-to-11.111 microfarad, 5-dial, variable
capacitor entirely out of specially made polyethylene-dielectric metal-cased
capacitors. Absorption with all other dielectrics was far too high at 0.1Hz
to make accurate impedance bridge measurements. Mica was awful!

Incidentally, apart from research work, the only occasion this capacitor was
used for a practical purpose was to locate a fault on a land cable when I
was in Sweden. The embarrassed Swedish engineers were not aware the fault
existed. Needless to say I promised aboard the ship on my departure not to
include the incident in my report. And I didn't. The Vicar, with his cruel
sense of humour, was not altogether happy but for technical political
purposes I had him by the balls. He was really a kind fellow and before
retirement he ended up as Head of the PO Engineering Training College.

Some years later I had the idea of donating the transformer and capacitor to
the Science Museum in London. But some other equally sentimental collector
had already stolen them. I sometimes wonder (2004) where they are now.

snip

But this is a long way from the much neglected Heaviside.

During the course of my fault location research I ran into a mental
blockage. Ultimately, I had to translate the appearance of the reflected
waves, as appeared on a 10 second persistance cathode ray tube, a function
of time, into miles from one end of the cable. That is all the ship's
captain needs to know before he can leave port and set a course. He can then
retire to his lonely cabin with a bottle of duty-free scotch if he should so
wish.

Eventually I discovered Heaviside's Operational Calculus. Lo and behold,
winding the handle on a German mechanical calculating machine, there
appeared on a sheet of graph paper the same shaped curves as on the
long-persistence CRT. The fault locating equipment was eventually installed
at oceanic terminal stations. I had the oportunity to use it on the first
breakdown to occur on the relatively short Middlesborough-Gothenburg cable
which, as usual, was due to an unknown fishing trawler in the north sea.

All the learned arguments on this newsgroup about SWR, the various
reflections and virtual this that and the other, occur because time is
ignored. It is admitted time does complicate matters. But Heaviside sorted
transient matters out, versus time, many moons ago.
---
Reg.