And what happened when the management/sales team decided they were
going to deliver anyway, and asked you in a _meaningful_ manner
whether you thought that your objections to the milestone being declared
were really in the company's best interests or in your own personal
best interests?

"Roy Lewallen" wrote in message
...
When this design was complete, a meeting was held. Attendees included
representatives from design engineering, marketing, product safety,
component and evaluation engineering, and others. Only by consensus of
this group was the milestone declared to have been completed.

On Sun, 17 Oct 2004 13:55:15 +0100, "Airy R. Bean"
wrote:

And what happened when the management/sales team decided they were
going to deliver anyway, and asked you in a _meaningful_ manner
whether you thought that your objections to the milestone being declared
were really in the company's best interests or in your own personal
best interests?

"Roy Lewallen" wrote in message
...
When this design was complete, a meeting was held. Attendees included
representatives from design engineering, marketing, product safety,
component and evaluation engineering, and others. Only by consensus of
this group was the milestone declared to have been completed.


apart from Tek and certain others which Roy describes, I believe that
some economists look at the balance between number of components used
and trade-off in production, so much more equipment would pass the
control if certain components were added.

What I actually meant, but perhaps didn't fully express was that you
may study the circuit diagrams and have a feeling which manufacturer
has designed it, they follow certain techniques and technical
management.

On the other hand one may experience that HP and Tek uses some extra
components which are difficult for the average constructor to explain
or understand the function for, and one may experience that even among
the amateurs somebody manage some technique which almost nobody else
can copy - not even very experienced persons, may I mention SM5BZR
Leif's techniques, it is many constructions, they may look so easy,
but one often need some more deeper understanding to succeed, what
say's G3SEK?

73
Jan-Martin
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

J M Noeding wrote:
On the other hand one may experience that HP and Tek uses some extra
components which are difficult for the average constructor to explain
or understand the function for,

They don't have a legal obligation to explain their detailed circuit
design... but you can learn a lot by trying to work it out for yourself.

and one may experience that even among the amateurs somebody manage
some technique which almost nobody else can copy - not even very
experienced persons, may I mention SM5BZR Leif's techniques, it is many
constructions, they may look so easy, but one often need some more
deeper understanding to succeed, what say's G3SEK?

I don't have any personal experience of copying Leif's designs (assuming
this is SM5BSZ we're talking about) but they have been widely copied. It
just takes everyone else a whole lot longer... so he's still way out
ahead.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

This is to be expected. The engineers who work at the job all day, every
day, know and understand a lot more about the circuits they're designing
than someone to whom it's only a hobby.

And, considering the incredible time and effort that goes into the
design of each product, Tektronix and similar companies can't afford to
be making instruments that can be perfectly copied within days. I never
saw any conscious effort to obscure a design, but the normal process of
developing state-of-the-art equipment required use of techniques out of
the reach of amateurs or even most manufacturing companies. Let me give
you just a few examples.

1. Circuit board layout becomes critical for many high performance
circuits, and sometimes several iterations are required before all
problems are solved. There are also mechanical considerations such as
maintaining necessary air flow. In a product I worked on, we had to
solder the turns of a delay line together to reduce coupling from a CRT
deflection circuit. In another, the ground was broken in a critical
point to interrupt ground current flow.

2. Design techniques are used which aren't well known outside the
industry. For example, look at the schematic of the vertical amplifiers
in older Tek analog scopes. You'll find series RC combinations,
sometimes with a thermistor as the R, between the emitters of the
differential stage transistors. These served two functions. One was to
compensate for the delay line loss which increases as the square root of
frequency. The other is to compensate for thermals -- the fact that a
common-emitter stage gain changes as the transistor heats up in response
to a signal voltage change. This can usually be ignored in a time-domain
application, but can cause serious distortion of a voltage step or other
time-domain waveform. Changing the transistor type or sometimes even its
package type changes the compensation requirements.

3. Component selection and design are often critical, as is material
selection. As an example, some high impedance attenuators are built on
special circuit board material such as polysulfone, because of a
nonlinear property of FR4 and other materials called "hook" which causes
signal distortion.

4. Manufacturing techniques. The list of these is almost endless. It
becomes a major determining factor in circuit performance particularly
at very high frequencies, such as the 20 - 50 GHz sampling heads I
helped design.

I recall showing a photomicrograph of a new sampling head to a company
which was very sensitive to security, and telling the surprised
engineers that I'd be happy to give them a copy. I also told them
truthfully that even if I gave them the schematic and parts list, they
still wouldn't be able to build it. I'd guess that a competing company
with world-class engineers might be able to do so in about a year. There
were just too many special and selected components and manufacturing tricks.

So it's wishful thinking to believe that you can duplicate one of these
high-performance circuits by soldering parts together from a circuit
diagram. There's a very lot that goes into these products that most
people have no idea of.

Roy Lewallen, W7EL

J M Noeding wrote:
. . .
On the other hand one may experience that HP and Tek uses some extra
components which are difficult for the average constructor to explain
or understand the function for, and one may experience that even among
the amateurs somebody manage some technique which almost nobody else
can copy - not even very experienced persons, may I mention SM5BZR
Leif's techniques, it is many constructions, they may look so easy,
but one often need some more deeper understanding to succeed, what
say's G3SEK?

73
Jan-Martin
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

In my experience, never. And I never heard of it happening, ever.

When the heat got turned up, everyone worked nights and weekends until
the goal was met. If we couldn't do it, the project was canceled.

Roy Lewallen, W7EL

Airy R. Bean wrote:
And what happened when the management/sales team decided they were
going to deliver anyway, and asked you in a _meaningful_ manner
whether you thought that your objections to the milestone being declared
were really in the company's best interests or in your own personal
best interests?

"Roy Lewallen" wrote in message
...

When this design was complete, a meeting was held. Attendees included
representatives from design engineering, marketing, product safety,
component and evaluation engineering, and others. Only by consensus of
this group was the milestone declared to have been completed.