"Jim Kelley" wrote in message
...

For a more quantitative illustration of how distributed reactance in
transmission lines causes delay see
http://www.rhombus-ind.com/dlcat/app1_pas.pdf

73, ac6xg

In graduate school, more years ago than I care to admit, I scrapped a
surplus computer for parts. The computer had been custom built for the
Savannah River nuclear facility. In addition to the many hundreds of
2N404A germanium transistors, I found the core memory made of ferrite
cores about 0.1 inches in diameter and about 30 mils thick. But the most
unusual thing, at least to me, was a flexible coaxial cable about six
feet long made of a ferrite-loaded rubber core wound with 40 gauge
enameled wire, wrapped in a thin cellulose acetate film (Scotch tape?),
covered with a braid shield with a vinyl covering. Of course, it was a
distributed delay line. I never measured its impedance and delay
properties accurately, but the cable had a significant delay that could
easily be seen on a 5 MHz bandwidth scope. Even with an approximate
termination, the cable's losses were quite high.

This was obviously a commercial cable, but in all of the years since, I
have never seen anything like it.

By the way, after dismantling one panel covered with terminal strips, I
found a typed note inside that said, "Built by pigmies in darkest
Africa."

--
73, Dr. Barry L. Ornitz WA4VZQ