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How Tek came to adopt HP's Signature Analysis concept


 

It was not always the case that Tek saw HP as a rival. At first things were
friendly since Tek held most of the scope patents and HP had no choice but
to use them (legally) when they started making scopes. But by 1970 HP was
Tek's arch rival. The "FoxTail" ad HP placed in Electronics Industry trade
publications mocking the just released 7000 series probably had a lot to do
with this. The ad is at:
https://groups.io/g/TekScopes/files/HP183A%20Foxtail%20Ad%20vs%207KSeries.pd
f

Signature Analysis was a very interesting troubleshooting concept that HP
developed. It had several important benefits:
* It was easy and inexpensive to incorporate this concept into products
under development.
* It made it possible for anyone, without prior knowledge or experience with
digital electronics, to troubleshoot the new digital circuitry that was
rapidly appearing in electronic instruments.
* HP freely shared the concept so others could incorporate Signature
Analysis in their products.
Because Signature Analysis was developed by HP, Tektronix would never use
it. This was the word from the very top at Tek.

Several years after the "FoxTail" ad appeared the initial problems of the
7000 series had been fixed, on-screen readout was a huge success, and Tek
had left HP in the dust with the first 500MHz scope By 1978 there were 18
mainframes and 57 plugins in this product line. One year later Tek
introduced the first 1GHz analog scope.

In 1978 Tek was developing a radically new analog/digital scope that had a
microprocessor, A/D converter, digital memory, programming capability, and a
GPIB interface (also originally developed by HP as the HPIB). All of this
complex digital circuitry was going to make these scopes virtually
impossible to be repaired in the Field Office Service Centers.

Tom Rousseau, the 7854 Project Manager, realized this was going to be a huge
problem for the Service Centers. When Tom read the May 1977 Hewlett Packard
Journal
https://doc.xdevs.com/doc/HP_Agilent_Keysight/journals/1977-05.pdf
which was entirely devoted to Signature Analysis, Tom realized this concept
would make it much easier for the Service Centers to troubleshoot the 7854.

But there was a problem: Howard Vollum was adamantly opposed to using
anything from HP. Tom eventually got Howard to budge a little when Tom made
it clear how difficult this scope would be to troubleshoot in the service
centers without a massive training program for all the field technicians.

Howard reluctantly agreed to allow Tom to incorporate Signature Analysis in
the 7854 provided Tek did not have to buy the HP 5004A Signature Analyzer.
Unfortunately there were no other signature analyzers.

As a result Tek developed their own 067-1090-00 Signature Analyzer
single-wide plugin for the TM500 mainframe. It was later renamed to the
SA501. You can see what it looks like on TekWiki at:
http://w140.com/tekwiki/wiki/SA501

Dennis Tillman


Greg Muir
 

Having used Tek scopes from an age that I will not reveal I eventually started using HP scopes as my profession progressed through the years. But I never felt that the earlier HP hardware possessed the “oomph” that Tek scopes provided. Yes, there were more bells and whistles on the Tek products and I found many of them to be very useful.

When I moved into the arena of needing spectrum analyzers I again had the chance to use early Tek products along with the more established HP line. In that vein I felt that HP had more to offer than Tek with regards to little nuances with the performance and feature issues.

During these early years I began to form a silent opinion that Tek should have stayed in oscilloscopes and HP should have stayed in spectrum analyzers. But over the later years both companies did manage to bring their products up to a more competitive level with one another.

There are now “foxtails” on both manufacturers products but with the advances in technology they can be quite helpful. It seems like the younger engineer generation revels in instruments somewhat akin to a Swiss army knife. But as that famous analog design engineer Bob Pease often said, using resources that take away a lot of the brainwork sort of pacifies the user into believing everything they see even if it is incorrect.

Greg


Paul Amaranth
 

On Wed, Nov 04, 2020 at 01:34:59PM -0800, Dennis Tillman W7pF wrote:
Howard reluctantly agreed to allow Tom to incorporate Signature Analysis in
the 7854 provided Tek did not have to buy the HP 5004A Signature Analyzer.
Unfortunately there were no other signature analyzers.

As a result Tek developed their own 067-1090-00 Signature Analyzer
single-wide plugin for the TM500 mainframe. It was later renamed to the
SA501. You can see what it looks like on TekWiki at:
http://w140.com/tekwiki/wiki/SA501

Dennis Tillman
That's a nice module, although they are pricey on ebay when they show up.

I have a Tek 308 data analyzer that I picked up along with a couple of HP
signature analyzers (including one I got in a buck a pound box at Dayton).

The 308 is cute and I've used the LA features quite a bit. 8 bits is a
bit small for many things but it can be useful for small projects. Besides
signature analysis it also can monitor serial data. Tough to find them
with all the probes though for reasonable money. I picked up a spare for
a parts unit without probes for $35 a couple years back.

Geez, I just looked at ebay asking prices for 308s and they're crazy too.

A fair amount of my gear has signature data so I picked these up in the event
of having to trouble shoot them. Haven't had to use them yet, so these are
in line with preventing winter snowfall by buying a snowblower. :-)

Paul
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@AuroraGrp.Com | Unix/Linux - We don't do windows