23 Apr
2011
23 Apr
'11
11:30 a.m.
On 2011 Apr 23, at 8:58 AM, Chuck Guzis wrote:
On 23 Apr 2011 at 0:09, Brent Hilpert wrote:
Yes, and he started with a flame detector - not a detector of flames,
but trying to detect radio-waves by passing them through a flame, as he
was hacking around trying to make a radio-wave detector that wouldn't
infringe on other's patents. It was some years later that people
realised the audion could amplify.
Armstrong was the more impressive in actually putting the tube to work.
- The control grid is usually but not always the
first grid after the
cathode.
Interestingly, some early models of the Audion put the grid on the
opposite side of the filament from the plate. If you look at
DeForest's patents, it's pretty clear that he had no idea of how his
Audion really operated. There's a web site, showing how to emulate an
audion using a 6AX5
full-wave rectifier (no "grid" per se):
http://www.angelfire.com/electronic/funwithtubes/Build_an_Audion.html
Fun writeup, I'll have to look at some 6AX5s to see if they're all
constructed that way.