I'm not sure I've figured out how to reply on this forum yet. I'd
replied previously to the #445 OP as I am now "465M Flaky vertical
height" figuring that it would end up in the queue at the end, but
somewhere, the reply got lost. It had to do with "is the 465M better
thean the 465?". I'll try again.
Phil, the T900's look nothing like any TQ scope. The T900-series is
a Beaverton development and TQ is completely European, and never do
the two meet. Like Stan, I never remember the Tek name or logo ever
appearing on a TQ product.
Someone mentioned a TQ that they used that had a horizontal layout.
I think that was the D75, but I remember the CRT in the center,
vertical on the left, horizontal on the right, but that's been a long
time ago .... I think that there was a CRT-over-electronics version
of the D75 ... maybe D85? I can't remember. But these were plug-in
scopes for which there were only the one plug-in that I know of for
each side. I did an April Fools Day Marketing Sales Release when I
was in the Dallas Service Center that said that TQ was coming out
with a sampling system plug-in for that scope, selling for $1500 or
some such, and was unusual in that it had TV trigger. One sales
engineer took it hook, line and sinker. I still have a copy of that
thing somewhere.
The entire T900-series product line:
T921: single channel, single timebase, 15 MHz
T922: dual channel, single timebase, 15 MHz
T922R: rack-mounted T922
T912: dual channel, bistable storage, 10 MHz
T932: dual channel, single timebase, 35 MHz
T935/A: dual channel, dual timebase, 35 MHz
As I recall, the T900-series was introduced in late 1975, early
1976. The T921 was used as the primary illustration in the
original "Basic Oscilloscope Operation" (1978), AX-3725-1 The T922
and T935A were also shown in cameo appearances.
Stan, in the field, transistor sockets were some of the handiest
things for us service technicians. Suspect a bad transistor? Just
pluck it out, pop it in the curve tracer and check it. I think
that's where you're coming from when you lamented the lack of such
sockets in the T900-series (the TQ stuff had sockets). However,
transistor and IC sockets were the one greatest source of warranty
work, repairs and intermittents in the field. When Tek got rid of
the sockets (RAM and expensive ICs still had sockets) and most of the
ribbon cable connectors, intermittents plummeted. At the bench, you
might have a dead circuit. You'd pluck out a transistor, check it,
it was good, put the transistor back, the scope started working. An
intermittent. So, you had to replace the socket AND the transistor
to insure that you weren't going to be sending an intermittent back
out in the field. Sockets didn't save Tek any money. It cost more
to buy and install them and it cost more on the repairs and callbacks.
I believe that the 455, T900-series, TM500-series and the 5000-series
and later the 465M were the first Tek products to not use sockets.
It looks like later posts already mentioned the reasons for the 465M
coming into existance, the pre-existance of the 455, the fact that
the 455 is a T900 in lineage, etc.
Dean
