18 Dec
2005
18 Dec
'05
7:33 p.m.
Stiill 74xx family of stuff! Well almost now that
CMOS has taken over,
we have a whole lot
of custom tristate buffers and latches but not much more. Where do you
find High Threshold Logic
for Industrial Applications.
HTL was never popular at all, and died when PLCs took over. I would
venture to say that HTL is the hardest family of logic to find parts
for. I have found more MECL I than HTL.
What about your aging aircraft like the SST
that used 70's componernts?
There are specialty dealers that buy up old surplus for just this
reason. The aircraft people will pay HUGE amounts to get the correctly
rated parts, and these guys know it.
I just found a whole box of new TI high rel gold surface mount TTL
(something boring like a latch), still sealed. It is actually worth a
pretty good sum, being that the mil spec gold surface mount packages are
very hard to find. If they were plain old 74xx TTL, they would be worth 17
cents a pound.
William Donzelli
aw288 at osfn.org