开云体育

"See this 1961 GE TD manual:"

I remember that manual from long long ago. I did high school at the end of the 60's and was the first class in college in EE to not study "tubes", EEs were going all solid state! The Esaki TD was only invented in '57, that manual published in '61, and essentially un-mentioned until my grad school studying from Simon Sze Physics of Semiconductor Devices.
My point is that the TD is a good historical example of industrial exuberance in addition to a fascinating device. At the time that manual was published the TD was going to revolutionize logic switching design it was so fast. Tubes were out, now there was something better than the transistor! Ah, but that was a "discrete" world view. As it quickly became evident, you couldn't really integrate with them, the on/off states had poor noise margin compared to other logic and in less than a decade they were relegated to discrete applications in oscillator, tuner and gating apps. Three terminal devices are just better at noise margin and I/O isolation.
It is interesting to note that the TD effect is a majority carrier action, unlike a conventional PN junction. There is another majority carrier diode that, while older than the transistor, was rapidly assimilated into power devices and integration and is still in use today. That would be the Schottky barrier diode! Two very interesting junction barrier effects with quite different commercial outcomes.

Still, it is a bit cool to hold a TD knowing the amazing physical phenomenon that the simple little device demonstrates.

Kjo

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Chuck Harris
Sent: 30 April 2018 20:15
To: [email protected]
Subject: Re: [TekScopes] Nuvistors/TD

I read that manual from cover to cover, over and over again, as an information starved boy will. I
was
all ready to conquer the world with tunnel diodes, and went off to Radio Shack to buy some, and....

RATS!

They had no idea what the heck I was talking about. Neither did Capitol Radio...

Radio Shack of the late 1960's was vastly more interesting then it was in later years... but still
no tunnel
diodes.

Then the Motorola Semiconductor Reference Manual, the TI TTL manual, and MECL manuals came to
me, and I forgot all about tunnel diodes.... Until tektronix scopes brought them back into my life
(585A).

-Chuck Harris

Kevin Oconnor wrote:

"See this 1961 GE TD manual:"

I remember that manual from long long ago. I did high school at the end of the 60's and was the
first

class in college in EE to not study "tubes", EEs were going all solid state! The Esaki TD was only
invented
in '57, that manual published in '61, and essentially un-mentioned until my grad school studying
from
Simon Sze Physics of Semiconductor Devices.

My point is that the TD is a good historical example of industrial exuberance in addition to a

fascinating device. At the time that manual was published the TD was going to revolutionize logic
switching design it was so fast. Tubes were out, now there was something better than the transistor!
Ah, but that was a "discrete" world view. As it quickly became evident, you couldn't really
integrate
with them, the on/off states had poor noise margin compared to other logic and in less than a decade
they were relegated to discrete applications in oscillator, tuner and gating apps. Three terminal
devices are just better at noise margin and I/O isolation.

It is interesting to note that the TD effect is a majority carrier action, unlike a conventional
PN

junction. There is another majority carrier diode that, while older than the transistor, was rapidly
assimilated into power devices and integration and is still in use today. That would be the Schottky
barrier diode! Two very interesting junction barrier effects with quite different commercial
outcomes.

Still, it is a bit cool to hold a TD knowing the amazing physical phenomenon that the simple
little

device demonstrates.

Kjo

From: Brad Thompson <brad.thompson@...>

Hello--

The late (and not often lamented) surplus-component business
known as "Poly Paks" offered tunnel diodes in "bargain pak [sic]" format.

From: Brad Thompson <brad.thompson@...>

Hello, Michael--

I too was a long-time PolyPak customer, and I too found that
one could get some real bargains with some judicious inspection
of the Paks. Poly Pak was then located in Wakefield, MA, and
a stop on a Saturday surplus tour which typically included Meshna's
and the place in Newburyport with the pigeon-friendly loft.

The floor sweepings were educational, too-- I built a simple curve
tracer and pored through the "we bot thousands-- no time to test"
packs of top-hat silicon rectifiers and unmarked transistors.

Also located in Wakefield was Transitron-- a source of fodder for the Paks.

73--

Brad AA1IP

From: "ebrucehunter via Groups.Io" <Brucekareen@...>
Sent: May 1, 2018 10:44 AM
To: [email protected]
Subject: Re: [TekScopes] Nuvistors/TD

In the late 1960s a surplus dealer near the Oakland, California airport was obtaining barrels of rejected and sometimes unmarked semiconductors, presumably from scrap yards where the Silicon Valley semiconductor manufacturers were dumping them. He was retesting and selling these to people like Radio Shack. I recall him saying that many of the i.c.s had failed infrared heat distribution tests, but would be fine for non-military use.

Bruce, KG6OJI