Chris Hornbeck notes in
rec.audio.tubesll83711p212879hthcq7rljgs0sip8lmi2 @4ax.com:

: On Thu, 28 Apr 2005 16:54:49 -0500, DougC
: wrote:
:
: chapter 23, page 925, halfway down the page they have a list of
: variables and what they signify. They have one capital-R
: subscript-?something? for "valve input resistance at working frequency".
: I can't see what this is, in either the CD or my copy, in either the
: useage in the equation or the definitions. IS this an "i" or a "t"? Or
: smoething else? The only relevant entry I can find is in chapter 38,
: page 1366, under (B) Valve and circuit, which lists a lowercase-r
: subscript lowercase-i for "input resistance".... ?:|
:
: This is a Greek letter that I have long forgotten, and am too
: lazy to look up. It stands for the equivalent input resistance
: caused by cathode circuit inductance (I **** thee not), and
: doesn't matter at audio frequencies.

Hard to see a likeness from RDH to even lower case tau, the most obvious, or
iota, perhaps the next best without a cross bar - are you sure? I say "t" !

[there is a greek alphabeta[1] at p1397 RDH4]
[and on the web, along with useful pages on rendering t' same & maths ;-})]

: Good fortune,
:
: Chris Hornbeck
: "Don't panic."

Fine advice!
--
RdM

"Space isn't remote at all. It's only an hour's drive away
if your car could go straight upwards." -- Fred Hoyle