FPGA VAX update, now DIY TTL computers

[Paul Koning]

>>>>> "Chuck" == Chuck Guzis <cclist at sydex.com> writes:

 Chuck>  ... the other was a low-voltage tube
 Chuck> used in automobile receivers that were specified for 12.6
 Chuck> volts on the plate (e.g. 12AE7 dual triode).  These would be
 Chuck> coupled with a solid-state driver and power amplifier for a
 Chuck> auto radio with no vibrator supply.

 Chuck> ... the second would seem to substantially reduce
 Chuck> the power requirements.  To anyone's knowledge were either of
 Chuck> these two components ever used in digital applications?

I doubt it for the 12 volt tube case.  For car radios they make sense,
for the reasons you gave.  (I built a radio for our camper using
those, as a boy scout project.  Tubes for the RF/IF stages, a very
early (1971 or so) op amp as AF preamp, and totem pole transistor AF
final amp.)

But I don't think the electrical parameters were all that good, given
the unusually low anode voltage.  And I don't see any reason for the
power consumption to be less.  Lower voltage, sure, but the current
may go up in proportion.  And the filaments were still the usual,
which accounts for a fair chunk of the power.

      paul