Walter Maxwell wrote:
Good response, Roy, but concerning rho and gamma to represent reflection
coefficient, I refer you to Reflections, Sec 3.1,

"Prior to the 1950s rho and sigma, and sometimes 'S' were used to represent
standing wave ratio. The symbol of choice to represent reflection coefficient
during that era was upper case gamma. However, in 1953 the American Standards
Association (now the NIST) announced in its publication ASA Y10.9-1953, that rho
is to replace gamma for reflection coefficient, with SWR to represent standing
wave ratio (for either voltage or current), and VSWR specifically for voltage
standing wave ratio. Most of academia responded to the change, but some
individuals did not. Consequently, gamma is occasionally seen representing
reflection coefficent, but only rarely."

Most interesting. I have on my library shelf 14 texts which deal
primarily or in a major way with electromagnetic waves and/or
transmission lines, and two with microwave circuit design. Of those,

8 (including both microwave design texts) use Gamma
4 use rho
2 use K
2 use k

If NIST's pronouncement had any effect at all, it was the opposite of
what was intended -- the four texts using rho were copyrighted in 1951,
53, 63, and 65; the 8 using Gamma were copyrighted in 1960 - 2000, 6 of
them after 1965. So it appears from my sampling that Gamma is becoming
more, not less, prevalant.

Hope this clarifies any misunderstanding concerning the use of gamma for
reflection coefficient.

I'm afraid it doesn't, unless my collection is very atypical. I don't
think it is, because it includes many of the classics.

Incidentally, Roy, I recently mailed you a CD containing Laport's book, "Radio
Antenna Engineering." I'm wondering if you received it, or did it go astray?

I did indeed, Walt, and please forgive me for not acknowledging your
very kind and thoughtful gift more promptly.

Roy Lewallen, W7EL