Wes Hayward's "other" book...
 

Hi guys,

Many time here we've heard plaudits for "Experimental Methods in RF
Design" and no one to my recollection has derided it. But Hayward also
wrote "Introduction to Radio Frequency Design" which never seems to
get a mention. Does anyone have a copy of this other book and/or an
opinion on it? I've been offered a copy and would value the Panel's
view on it.

p.
--

"What is now proved was once only imagin'd." - William Blake, 1793.

Many time here we've heard plaudits for "Experimental Methods in RF
Design" and no one to my recollection has derided it. But Hayward also
wrote "Introduction to Radio Frequency Design" which never seems to
get a mention. Does anyone have a copy of this other book and/or an
opinion on it? I've been offered a copy and would value the Panel's
view on it.

Absolutely! Both hard cover and soft. It ought to be in your library. Look
at page 216 in the soft cover, my personal favorite. If you're too young for
it, there was an earlier one that was an all time classic, "Solid State
Design for the Radio Amateur" by DeMaw and Hayward. Called SSD by those who
slept with it, the latest is often referred to as SSSD, "Son of Solid State
Design".

W4ZCB

I've had a copy since it was first published in 1982. It's intended to
be more of an engineering textbook than the more cookbook-like
_Experimental Methods. . _ and its predecessor _Solid State Design for
the Radio Amateur_. (Although those books are much more than
cookbooks.) Now published in a second edition by the ARRL, it's an
excellent reference. It also contains insights into the fundamental
workings of circuits that you'll find in few other texts. As just one of
many examples, the discussion of oscillators presents some unique
insights into the similarities between oscillator types and an
understanding of the fundamentals requirements of oscillators.

I highly recommend it for anyone interested in understanding electronic
circuits on a more basic level. It nicely complements his other books,
and it's a bargain at the price.

Roy Lewallen, W7EL

Paul Burridge wrote:
Hi guys,

Many time here we've heard plaudits for "Experimental Methods in RF
Design" and no one to my recollection has derided it. But Hayward also
wrote "Introduction to Radio Frequency Design" which never seems to
get a mention. Does anyone have a copy of this other book and/or an
opinion on it? I've been offered a copy and would value the Panel's
view on it.

p.

"Paul Burridge" wrote in message
...
Many time here we've heard plaudits for "Experimental Methods in RF
Design" and no one to my recollection has derided it. But Hayward also
wrote "Introduction to Radio Frequency Design" which never seems to
get a mention. Does anyone have a copy of this other book and/or an
opinion on it? I've been offered a copy and would value the Panel's
view on it.

It's great; definitely get a hold of a copy if you're interested in radio
design.

"Introduction to Radio Frequency Design" is somewhat unique in that the
level it's written at is sort of inbetween the "cookbook" approach and the
"highly theoretical, filled with math" approach. It's aimed at individuals
who have something of a formal background in engineering but who (1) don't
want to get bogged down in the math just to get some results and (2)
appreciate having the references to the hard core material so they can
investigate further if need be. This is unlike, say, Joe Carr who seems to
want to target a similar audience, but usually his 'reference' list is
non-existant or pretty generic; Wes will direct you right back to Zverev,
Matthei, Rhea, etc. if you're so inclined. (And whereas someone who only
reads Zverev is probably a LONG way from actually being able to build
anything outside of a SPICE simulator.)

Check out Wes's web page he http://users.easystreet.com/w7zoi/books.html
.... for information on all of his books. His books are also still quite
reasonably priced. (It's not out of line, but I'm still surprised that in
ten years the ARRL handbook has gone from $25 to $55... essentially from 'a
real bargin' to 'about the usual price' for such books.)

---Joel Kolstad

Paul Burridge wrote:

Hi guys,

Many time here we've heard plaudits for "Experimental Methods in RF
Design" and no one to my recollection has derided it. But Hayward also
wrote "Introduction to Radio Frequency Design" which never seems to
get a mention. Does anyone have a copy of this other book and/or an
opinion on it? I've been offered a copy and would value the Panel's
view on it.

p.

Buy it, it's worth it.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

On Fri, 15 Oct 2004 11:39:27 -0700, Roy Lewallen
wrote:

I've had a copy since it was first published in 1982. It's intended to
be more of an engineering textbook than the more cookbook-like
_Experimental Methods. . _ and its predecessor _Solid State Design for
the Radio Amateur_. (Although those books are much more than
cookbooks.) Now published in a second edition by the ARRL, it's an
excellent reference. It also contains insights into the fundamental
workings of circuits that you'll find in few other texts. As just one of
many examples, the discussion of oscillators presents some unique
insights into the similarities between oscillator types and an
understanding of the fundamentals requirements of oscillators.

I highly recommend it for anyone interested in understanding electronic
circuits on a more basic level. It nicely complements his other books,
and it's a bargain at the price.

Oh, blast! You were doing so well there for a while, Roy. Now you've
gone and spoilt it all by using that word "basic." I was hoping for
something at least "intermediate" and I don't really see how "basic"
and "RF design" sit easily together in a single description. Please
tell me it's useful for more advanced stuff too!
--

"What is now proved was once only imagin'd." - William Blake, 1793.

"Paul Burridge" a écrit dans le message de
...
On Fri, 15 Oct 2004 11:39:27 -0700, Roy Lewallen
wrote:

I've had a copy since it was first published in 1982. It's intended to
be more of an engineering textbook than the more cookbook-like
_Experimental Methods. . _ and its predecessor _Solid State Design for
the Radio Amateur_. (Although those books are much more than
cookbooks.) Now published in a second edition by the ARRL, it's an
excellent reference. It also contains insights into the fundamental
workings of circuits that you'll find in few other texts. As just one of
many examples, the discussion of oscillators presents some unique
insights into the similarities between oscillator types and an
understanding of the fundamentals requirements of oscillators.

I highly recommend it for anyone interested in understanding electronic
circuits on a more basic level. It nicely complements his other books,
and it's a bargain at the price.

Oh, blast! You were doing so well there for a while, Roy. Now you've
gone and spoilt it all by using that word "basic." I was hoping for
something at least "intermediate" and I don't really see how "basic"
and "RF design" sit easily together in a single description. Please
tell me it's useful for more advanced stuff too!

Maybe is it that someone's basic level is someone else' intermediate level ?
;-)


--
Thanks,
Fred.

"Paul Burridge" wrote in message
...

Oh, blast! You were doing so well there for a while, Roy. Now you've
gone and spoilt it all by using that word "basic." I was hoping for

You guys must be reading a different IRFD than me, or maybe I'm just dumber
than I thought. That book has more math in it than my college EE text. OK,
admittedly the math isn't as weird, but I wouldn't call it "basic".

...

On Sat, 16 Oct 2004 15:31:40 +0100, Paul Burridge
wrote:

On Fri, 15 Oct 2004 11:39:27 -0700, Roy Lewallen
wrote:

I've had a copy since it was first published in 1982. It's intended to
be more of an engineering textbook than the more cookbook-like
_Experimental Methods. . _ and its predecessor _Solid State Design for
the Radio Amateur_. (Although those books are much more than
cookbooks.) Now published in a second edition by the ARRL, it's an
excellent reference. It also contains insights into the fundamental
workings of circuits that you'll find in few other texts. As just one of
many examples, the discussion of oscillators presents some unique
insights into the similarities between oscillator types and an
understanding of the fundamentals requirements of oscillators.

I highly recommend it for anyone interested in understanding electronic
circuits on a more basic level. It nicely complements his other books,
and it's a bargain at the price.

Oh, blast! You were doing so well there for a while, Roy. Now you've
gone and spoilt it all by using that word "basic." I was hoping for
something at least "intermediate" and I don't really see how "basic"
and "RF design" sit easily together in a single description. Please
tell me it's useful for more advanced stuff too!

Paul, maybe you should stay away from it because apparently you can't
read.

At the beginning, Roy said, "It's intended to be more of an engineering
textbook than the more cookbook-like _Experimental Methods. . _"

At the end he said, "I highly recommend it for anyone interested in
understanding electronic circuits on a more basic level." This is
apparently where you got confused. Oh, and he never specifically
mentioned "RF design".

English can be tricky. In the context of the rest of the message, I take
Roy's, "understanding electronic circuits on a more basic level," to
mean at the level of the basic principles that define the circuit's
functions, not less than advanced. As Roy and others have said it is
MORE rigorous and mathematical than the other books.

If you were trying to make a joke, you should have ended with a happy
face.

Rex ) writes:

At the beginning, Roy said, "It's intended to be more of an engineering
textbook than the more cookbook-like _Experimental Methods. . _"

And of course, it was published as a text book. It came out in 1982 from
a text book publisher, Prentice Hall. I seem to recall it carrying a
text book price. I think the only reason many of us took note of it
was because it was by Wes Hayward. I seem to recall it getting coverage
in the ham magazines at the time. I'm not so sure ARRL would have published
a second printing but for the fact that Wes Hayward is well known to hams,
and has had a book or two published by the ARRL.

It covers what it does well, and yes it is a much more involved explanation
than ham books. But it's field is quite limited. It's not so practical,
You can get very detailed explanation of the Colpitts oscillator, but
little about oscillators beyond that.

It's not cutting edge. It wasn't back in 1982, it was supposed to give
a grounding so one could take up other books and get the latest, and it's not
now; I gather there was very minimal changes in the ARRL printing.

This book came up in the other newsgroup in the context of someone wanting
to design a wideband VHF amplifier for his tv set. And no, he was not
advanced in his technical knowledge. It was indeed a lousy suggestion for
his purpose, because not only would he be better off with a cookbook type
book, but Intro to RF Design isn't about a lot of specifics.

On the other hand, the ARRL priting came with a flopppy disk of some basic
programs for designing circuits. I've really only glanced at them, but they
are a bonus for those buying the book.

Michael VE2BVW

That was a poor choice of word on my part -- I apologize. I meant
"fundamental". Wes explains how things work on a fundamental level. But
it isn't a textbook of pure basic theory. It relates working circuits to
their fundamental roots.

I took an expensive advanced microwave design short course some years
ago. The instructor was a person who'd worked in the field for many
years. With disturbing frequency, he would come out with statements I
knew to be false and, after some questioning, I discovered that he
didn't have any idea of the fundamental (or basic) criteria for
oscillation. He'd been designing oscillators for years without really
knowing what made them oscillate. This might have been a case of someone
who read the "intermediate" texts without ever reading the "fundamental"
ones.

This isn't to say that people can't design useful things without fully
understanding what they're doing -- I'm convinced that a majority of
useful things are created this way. But you can do an awfully lot more
if you have a real fundamental understanding of how things work. The
most truly creative and innovative engineers I've known have this
understanding -- and an intense curiosity about things they don't know.

I guarantee there's plenty of "intermediate" and "advanced" level
information in that book, and even without knowing anything of your
background, I also guarantee there's plenty of "fundamental" knowledge
you missed somewhere along the line and will pick up from this book. If
I'm wrong, let me know and I'll buy the book from you. I can always use
another copy.

Roy Lewallen, W7EL

Paul Burridge wrote:
On Fri, 15 Oct 2004 11:39:27 -0700, Roy Lewallen
wrote:
. . .
I highly recommend it for anyone interested in understanding electronic
circuits on a more basic level. It nicely complements his other books,
and it's a bargain at the price.


Oh, blast! You were doing so well there for a while, Roy. Now you've
gone and spoilt it all by using that word "basic." I was hoping for
something at least "intermediate" and I don't really see how "basic"
and "RF design" sit easily together in a single description. Please
tell me it's useful for more advanced stuff too!

On Sat, 16 Oct 2004 13:36:59 -0700, Roy Lewallen
wrote:


I took an expensive advanced microwave design short course some years
ago. The instructor was a person who'd worked in the field for many
years. With disturbing frequency, he would come out with statements I
knew to be false and, after some questioning, I discovered that he
didn't have any idea of the fundamental (or basic) criteria for
oscillation. He'd been designing oscillators for years without really
knowing what made them oscillate. This might have been a case of someone
who read the "intermediate" texts without ever reading the "fundamental"
ones.

This isn't to say that people can't design useful things without fully
understanding what they're doing -- I'm convinced that a majority of
useful things are created this way. But you can do an awfully lot more
if you have a real fundamental understanding of how things work. The
most truly creative and innovative engineers I've known have this
understanding -- and an intense curiosity about things they don't know.

well, said! But isn't this the very frequent feeling one gets from
reading amateur radio magazines? The constructors (I wouldn't use the
word "designer") should have constructed and tested at least 10 equal
constructions, or have similar experience before publishing an idea,
which may later turn out that might not be repeatable

Too often constructions are published when it is a hope rather than
experience that it is a good idea. For somebody it is more important
to use wellknown devices than trying to propose something else

73, Jan-Martin

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

On Sat, 16 Oct 2004 13:36:59 -0700, Roy Lewallen
wrote:

[snip]

Thanks for the clarification, Roy. I'm sure your kind offer won't be
necessary, though, as it now sounds like pretty much the kind of
source I'm looking for. The companion diskette is included, but I
doubt there will be anything on it that Reg hasn't already covered in
his amazing collection of programs for radio and ariel design.

p.
--

"What is now proved was once only imagin'd." - William Blake, 1793.

Few people appreciate the vast difference between making something that
sort of works, once, and a design that can be produced by the thousands
with nearly every one working, fully meeting specifications, and being
reliable under a wide range of operating conditions. Those of us who
have made a living by developing quality products such as test equipment
have a full appreciation for this, and go about the design process in a
very different manner than a person accustomed to making a one-off
circuit for home use.

Many, or most, of the books oriented toward amateurs are written by
people who haven't developed the background or discipline to produce
reliable, repeatable circuits. Magazine articles are even more in this
category. Some circuits found in handbooks have perhaps never been
actually built or tested by the author, even in a quantity of one.
That's not a condemnation -- after all, this is amateur radio, most
offerings are free, and the designs are adequate for a lot of users.
Hopefully -- although I'm afraid a bit wishfully -- some builders at
least have enough technical know-how to take care of minor design flaws.
Nonetheless, it's really a treat when we're given a circuit or an
explanation by a truly professional engineer whose approach to circuit
design is one of making reliable, repeatable circuits. The chances of a
copy of the circuit working the first time, as predicted and claimed,
are much higher than for a design built once with little understanding
of how it works or what its limitations and weak points are. And the
deeper the designer's understanding of the fundamental principles
involved, the greater the chance that he's accounted for and designed
around potential problems in repeatability and operating environment.

That's one of the reasons I like and heartily recommend Wes' books and
other writings. I've known him as a friend and as an engineering
colleague for 30 years now. He's one of the very best, and we're lucky
to have access to a fraction of what he's learned.

Roy Lewallen, W7EL

J M Noeding wrote:

well, said! But isn't this the very frequent feeling one gets from
reading amateur radio magazines? The constructors (I wouldn't use the
word "designer") should have constructed and tested at least 10 equal
constructions, or have similar experience before publishing an idea,
which may later turn out that might not be repeatable

Too often constructions are published when it is a hope rather than
experience that it is a good idea. For somebody it is more important
to use wellknown devices than trying to propose something else

73, Jan-Martin

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

On Sat, 16 Oct 2004 15:17:47 -0700, Roy Lewallen
wrote:



Many, or most, of the books oriented toward amateurs are written by
people who haven't developed the background or discipline to produce
reliable, repeatable circuits. Magazine articles are even more in this
category. Some circuits found in handbooks have perhaps never been
actually built or tested by the author, even in a quantity of one.
That's not a condemnation -- after all, this is amateur radio, most
offerings are free, and the designs are adequate for a lot of users.
Hopefully -- although I'm afraid a bit wishfully -- some builders at
least have enough technical know-how to take care of minor design flaws.
Nonetheless, it's really a treat when we're given a circuit or an
explanation by a truly professional engineer whose approach to circuit
design is one of making reliable, repeatable circuits. The chances of a
copy of the circuit working the first time, as predicted and claimed,
are much higher than for a design built once with little understanding
of how it works or what its limitations and weak points are. And the
deeper the designer's understanding of the fundamental principles
involved, the greater the chance that he's accounted for and designed
around potential problems in repeatability and operating environment.

That's one of the reasons I like and heartily recommend Wes' books and
other writings. I've known him as a friend and as an engineering
colleague for 30 years now. He's one of the very best, and we're lucky
to have access to a fraction of what he's learned.

When amateur constructors are mentioned, it is not only those who do
strange things. While many large telecommunication and instrument
factories like HP, Tektronic, Siemens, Wandel&Goltermann,
Rohde&Schwartz, LME, Philips, Telettra seem to have certain rules to
follow and you may even see certain ways the different factory solves
the problems, it is some very large companies in Norway, Great
Brittain and elsewhere who make rather strange solutions.

One Italian company forgot to put transient protection over a relay,
and the driver transistor was damaged ever so often. I've maintained
many different transmitters which were almost impossible to tune up
after replacing parts because the impedances changed a lot, adding a
resistor in the base circuit improved on this. A wellknown Norwegian
radiolink manufacturer designed local oscillators in 6-8GHz using
2N3866 with over 1.5W power consumption, a buffer with the same and
operated in class C, the next doubler to 200MHz in class C and a
2N3866 as well, and a 2N3375 in class C. The first and third
transistors were critical and had to be replaced every two years, and
the signal on 6cm was so noisy that SM6ESG couldn't find any beat
note. He modified the stages to class A, reduced the drive level on
all stages and the heat was considerable lower, and at least the
oscillator noise very much improved

So, one shouldn't only blame the amateurs for bad constructors, but
sometime the manufacturers may even be worse

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

I obviously can't speak for the Italian or Norwegian companies you
mention, but I do have the direct experience of 17 years of circuit
design and project engineering management at Tektronix. It's hard to
imagine experiences like yours happening with Tek equipment.

During the time I worked there, and presumably up to the present, Tek
had what they called the "phase" system. The engineers would do their
very best to design the product to meet all the advertised
specifications, plus additional non-advertised in-house specs. These
included temperature, vibration, shock, humidity and other environmental
specs; certification by various safety agencies; and EMC requirements,
in addition to detailed electrical performance specs.

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.

This was just the beginning, though, of the first phase, called "A
Phase". A number of instruments were built, typically around 25 to 50.
Some were sent to the environmental lab to test performance over the
range of specified environmental conditions. Others were shaken and
shocked. Others were studded with temperature probes and tested for
excessive temperature at many internal points. A few were put on
accelerated long-term reliability testing at a greatly elevated
temperature. Some were cycled on and off at high temperature. The design
was carefully analyzed by the evaluation engineering group, looking for
overstressed components. And many of the units were tested against the
full specification list, to insure that they fully met every spec.

During this phase, many problems were of course found and fixed. The
engineers would generate change orders describing the fixes, and the
test units were modified accordingly.

When it was believed that the units all met the many requirements,
another milestone meeting was held. Again if the attendees agreed, the
milestone was declared met, and "B Phase" began.

B Phase was largely a re-run of A Phase. Again, a sizeable number of
instruments were built and fully tested. Problems which were found were
corrected. Only at the end of this phase was production started.

Production often started with a pilot build. The first hundred or so
instruments were given extra scrutiny, temperature cycled, and otherwise
tested in a way to overstress them. These instruments normally became
demo units for the sales force, and some were retained by engineering
for internal use.

After pilot production, volume shipment finally commenced. Some large
companies required an incoming inspection test where every one of the
electrical performance specifications was checked, and the instrument
rejected if any failed. I once had the job of collecting test equipment
and writing a procedure for customers to use for testing our 50 GHz
bandwidth sampling head to specification, and it was very difficult to
find equipment capable of verifying the performance. We weren't able to
claim 60 GHz bandwidth even though we were pretty sure our units would
do it, because we couldn't find a way for us or the customer to verify
it at the time.

After the units were in production, each field service center kept
records of repairs, and which components failed. They were sorted by
circuit number (e.g. Q123) and part number, as well as by instrument and
board. If any part showed a high failure rate, the design was modified
and future instruments were built using the new design.

I know that other quality manufacturers have similar development systems.

That's why a Tektronix instrument costs a lot more than some others. The
existence of companies putting out the shoddy sort of stuff you mention
shows that some people are willing to trade quality for price. That's
their choice.

But the environment I described is the one I, and Wes, are accustomed
to, and it's what our designs had to get through.

Roy Lewallen, W7EL
(formerly Principal Engineer, Tektronix)

J M Noeding wrote:
On Sat, 16 Oct 2004 15:17:47 -0700, Roy Lewallen
wrote:

When amateur constructors are mentioned, it is not only those who do
strange things. While many large telecommunication and instrument
factories like HP, Tektronic, Siemens, Wandel&Goltermann,
Rohde&Schwartz, LME, Philips, Telettra seem to have certain rules to
follow and you may even see certain ways the different factory solves
the problems, it is some very large companies in Norway, Great
Brittain and elsewhere who make rather strange solutions.

One Italian company forgot to put transient protection over a relay,
and the driver transistor was damaged ever so often. I've maintained
many different transmitters which were almost impossible to tune up
after replacing parts because the impedances changed a lot, adding a
resistor in the base circuit improved on this. A wellknown Norwegian
radiolink manufacturer designed local oscillators in 6-8GHz using
2N3866 with over 1.5W power consumption, a buffer with the same and
operated in class C, the next doubler to 200MHz in class C and a
2N3866 as well, and a 2N3375 in class C. The first and third
transistors were critical and had to be replaced every two years, and
the signal on 6cm was so noisy that SM6ESG couldn't find any beat
note. He modified the stages to class A, reduced the drive level on
all stages and the heat was considerable lower, and at least the
oscillator noise very much improved

So, one shouldn't only blame the amateurs for bad constructors, but
sometime the manufacturers may even be worse

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

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

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.

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

my favorite commercial design "oops" was a pricey multi-port TTY
(teletype) i/o board for the then new Nova 4/X minicomputer (data
general). Worked great, as long as you only used video terminals
emulating a TTY on a current loop. Put on a _real_ teletype, and you
quickly fried the board, every time. No protection against counter-EMF.
After two board exchanges (in warranty, thankfully), we finally just
put in opto-isolators on our own TTY lines and it worked thereafter. ;-)

grins bobm
--
************************************************** *********************
* Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 *
********************Standard Disclaimers Apply*************************

On Fri, 15 Oct 2004 20:43:13 -0700, Tim Wescott
wrote:

Buy it, it's worth it.

I just have and it is. Especially since I got a brand new copy for
just over 5 quid! ($30 cover price)
Next target: "Experimental Methods...."
:-)

--

"What is now proved was once only imagin'd." - William Blake, 1793.