13 Aug
2014
13 Aug
'14
5:14 p.m.
On 08/13/2014 02:24 PM, Tony Duell wrote:
I once tired ot use an EF86 as an AND gate, with the
inputs on the
control grid and suppressor grid. It worked, but it needed a lot of -ve
bias o nthe suppressor grid to cut it off.
I think that the venerable 6888 pentode was designed specifically for
Grid 3 computer logic applications.
Then there were the tetrodes that were classified as "dual control grid".
All sorts of interesting stuff to be found in tube manuals. Did the
6BN6 gated-beam tube ever see computer application?
I've also noticed that the anode slope of a 6080
(big double triode used
as the series pass elemenet in Tekky 'scope PSUs, amongst other things)
is about 120 Ohms. I have wondered about paralleling up 15 or 16 sections
and directly drivign an 8 ohm speaker.... Or maybe a totem pole output
stage -- Philips tried them, with a UL84 on top of an EL84 driving some
high-impedance speaker (800 ohmes?) .It worked, but the very fine wire of
the high impedance speech coil was prone to going O/C
I remember seeing some circuits using paralleled triodes in a
cathode-follower configuration being touted as transformerless speaker
drivers. I don't know if they ever made any headway in the commercial
world as such.
--Chuck