Nuts & Volts - September 2004

by Gerard Fonte

In The Trenches

The Business of Electronics Through Practical Design and Lessons Learned

In The Trenches

Specifications

There is probably no other profession that depends upon specifications as much as engineering does. You create something to meet some set of requirements or you rely on the performance data of various components. Very often, both aspects are employed at the same time. Knowing how to make, read, and understand specifications is an important part of engineering.

Conflict of Interest

the competition. There was no question that their quality was superb. However, would you spend $20,000.00 on an H/P oscilloscope when LeCroy would sell you one for $5,000.00 that did the "same thing?" The "same thing" was defined by the specifications. Suppose both machines were spec'd with a bandwidth of 500 MHz. Which one would you buy?

The truth is that the H/P oscilloscope was clearly better and every engineer knew it. The LeCroy 'scope was certainly good and it performed as specified.

However, the H/P performed better than specified. Yet, when the justification for the expense of an oscilloscope came, H/P had trouble competing. It's hard to convince

financial administrators to spend four times as much for the "same" instrument.

H/P sales started to decline and their name became associated with "over-priced" test equipment. I suspect that this is a major reason behind the changing of their universally recognized name, which they worked so hard to get, in the first place. Agilent now sells test equipment that still is excellent, but it is more reasonably priced and specified.

Arguably, the most important aspect of specifications to understand is their inherent conflict of interest to the company. Engineers want the most conservative specifications possible. This makes the product easy to produce, repair, and design.

Obviously, it's easier to make a 25 watt amplifier with 1% distortion than a 100 watt amplifier with 0.01% distortion, but who wants a 25 watt amplifier with 1% distortion? It won't sell. It's easy to make, but there's a small market.

On the other hand, there is a good sized market for the better amplifier. Clearly, there must be a balance between what people want and what you can make. Different companies have different points of view on this matter.

Hewlett/Packard (now called Agilent) is a good example. For decades, they have been recognized as producers of world class test instruments. However, in the 1980s and 1990s, their products became more and more expensive relative to

SEPTEMBER 2004

Specifications are Not Black and White

It's important to realize that specifications are not always fixed, although specifications are — some-

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