Where have all the analogue men gone?

Al Clark wrote:

   ...

> I was (am) an analog engineer well before I did my first DSP application. 
> I had exactly one course in DSP in college (1977) and I didn't really 
> understand the material even though I could solve the problems. I decided 
> in school that I wanted to be an analog guy because everyone else was 
> interested in digital stuff. I used to tell my friends that they only had 
> to know two numbers, while I dealt with an infinite number. I once had a 
> business partner who said, I was the only analog engineer without gray 
> hair (unfortunately no longer true).  

   ...

I had exactly one college course in digital electronics. (I learned, 
among other circuits, about phantastrons.*) In other courses, I studied 
strength of materials, thermodynamics, turbine design, power-plant 
management, design in timber, steel, and concrete, how to calculate 
antenna radiation patterns and the appropriate size of power-supply 
chokes, and other professionally useless baggage. I regret none of it.

Jerry
__________________________________________
* http://www.tpub.com/neets/book18/81b.htm

Trick question: which is stronger; white oak or white pine?
-- 
... the worst possible design that just meets the specification - almost
a definition of practical engineering.                     .. Chris Bore
������������������������������������������������������������������������

Rune Allnor wrote:

   ...

> Well... I took a class on HF analogue electronics some 15 years ago, 
> at a college of engineering. We were handed a HF transistor and was given 
> the task to make a print card, a coil, find some resistors and some other 
> stuff to get this amplifier to work at 800 MHz or so. 

   ...

What a load of plant-growth accelerator! I had an instructor in graduate
school who taught audio transistor circuits, with great emphasis on
thermal stability. (With germanium transistors, that can have an
overriding influence on the design.) His method for calculating the
emitter-bypass resistor to meet a particular frequency response was to
determine the RC time constant, then multiply the capacitor by 10.
(Reading ahead, I learned that he got that from our textbook!!) I showed
him the right way to do it (which I'm happy to share), finished the
semester and dropped out.

On the off chance that long winter nights leave you hungry for something
analog to do, investigate http://www.electrokits.com/electronic-kits/.
About the only advice I can offer is to use a good temperature-
controlled soldering iron. I gave away my Heathkit oscilloscope when I
got the Tektronix, but it served well for a long time.

Jerry
-- 
... the worst possible design that just meets the specification - almost
a definition of practical engineering.                     .. Chris Bore
������������������������������������������������������������������������

Jerry Avins <jya@ieee.org> writes:

> About the only advice I can offer is to use a good temperature-
> controlled soldering iron. I gave away my Heathkit oscilloscope when I
> got the Tektronix, but it served well for a long time.

I bought a used Tek 475 on Ebay a couple years back. Back in the 80's I
would've never dreamed I'd own my own 475. Now it seems like a relic. It
still works great, though!
-- 
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
randy.yates@sonyericsson.com, 919-472-1124

In article <xxppt5oxo1o.fsf@usrts005.corpusers.net>,
Randy Yates  <randy.yates@sonyericsson.com> wrote:
>Jerry Avins <jya@ieee.org> writes:
>
>> About the only advice I can offer is to use a good temperature-
>> controlled soldering iron. I gave away my Heathkit oscilloscope when I
>> got the Tektronix, but it served well for a long time.
>
>I bought a used Tek 475 on Ebay a couple years back. Back in the 80's I
>would've never dreamed I'd own my own 475. Now it seems like a relic. It
>still works great, though!

I have an old Tektronics 310 - a portable scope using tube
electronics.  It's the smallest tube scope they ever made, and made
before the invention of printed circuit boards, apparently.  Loosen
two scres and the whole thing unfolds, elegantly revealing all the
components inside.  It gets as hot as an oven, but has always worked
great, until recently.  A capacitor has gone bad somewhere.

The trace appears on the display as it warms up and then it suddenly
moves off, never to return.  It's like a cap was charging up and
then shorting out at some critical voltage.  Short of clipping the
leads of each cap until the behavior stops, I don't know how else to
find the problem.  All the tubes are fine.

Anyone want it?

-A

Jerry Avins <jya@ieee.org> wrote in message news:<4123a02c$0$21760$61fed72c@news.rcn.com>...
> Al Clark wrote:
> 
>    ...
> 
> > I decided 
> > in school that I wanted to be an analog guy because everyone else was 
> > interested in digital stuff. I used to tell my friends that they only had 
> > to know two numbers, while I dealt with an infinite number.>    ...
> 
> I had exactly one college course in digital electronics. (I learned, 
> among other circuits, about phantastrons.*) In other courses, I studied 
> strength of materials, thermodynamics, turbine design, power-plant 
> management, design in timber, steel, and concrete, how to calculate 
> antenna radiation patterns and the appropriate size of power-supply 
> chokes, and other professionally useless baggage. I regret none of it.

You are right, both of you. When I took that class in electronics, being
an analog amongst digitals was presented as a competitive benefit when 
applying for jobs. What I was conserned, I found that my teacher at the 
time was not able to teach me (or rather, help me learn) even the most 
basic HF electronics competence.

Rune

Jerry Avins wrote:
>  
> I had exactly one college course in digital electronics. (I learned, 
> among other circuits, about phantastrons.*)

What! No magnetic amplifiers?
I've some of my father's appnotes [somewhere] from your era.
P.S. He also operated a spark-gap transmitter at one time.

> 
> Trick question: which is stronger; white oak or white pine?

OK, I'll bite. What's the trick?

Richard Owlett wrote:

> Jerry Avins wrote:
> 
>>  
>> I had exactly one college course in digital electronics. (I learned, 
>> among other circuits, about phantastrons.*)
> 
> 
> What! No magnetic amplifiers?
> I've some of my father's appnotes [somewhere] from your era.
> P.S. He also operated a spark-gap transmitter at one time.
> 
>>
>> Trick question: which is stronger; white oak or white pine?
> 
> 
> OK, I'll bite. What's the trick?

Any wood worker will tell you that oak is stronger. What circumstances
make his answer wrong? (Hint: pine makes a better mast than oak.)

Jerry
-- 
... the worst possible design that just meets the specification - almost
a definition of practical engineering.                     .. Chris Bore
������������������������������������������������������������������������

axlq wrote:

> In article <xxppt5oxo1o.fsf@usrts005.corpusers.net>,
> Randy Yates  <randy.yates@sonyericsson.com> wrote:
> 
>>Jerry Avins <jya@ieee.org> writes:
>>
>>
>>>About the only advice I can offer is to use a good temperature-
>>>controlled soldering iron. I gave away my Heathkit oscilloscope when I
>>>got the Tektronix, but it served well for a long time.
>>
>>I bought a used Tek 475 on Ebay a couple years back. Back in the 80's I
>>would've never dreamed I'd own my own 475. Now it seems like a relic. It
>>still works great, though!
> 
> 
> I have an old Tektronics 310 - a portable scope using tube
> electronics.  It's the smallest tube scope they ever made, and made
> before the invention of printed circuit boards, apparently.  Loosen
> two scres and the whole thing unfolds, elegantly revealing all the
> components inside.  It gets as hot as an oven, but has always worked
> great, until recently.  A capacitor has gone bad somewhere.
> 
> The trace appears on the display as it warms up and then it suddenly
> moves off, never to return.  It's like a cap was charging up and
> then shorting out at some critical voltage.  Short of clipping the
> leads of each cap until the behavior stops, I don't know how else to
> find the problem.  All the tubes are fine.

Check out

http://www.industrycommunity.com/ee/ee-2/messages/20.html
and
http://www.industrycommunity.com/ee/ee-2/messages/36.html

My first guess would be you're losing accelerating voltage.
But I've not been inside a scope for 30 years.

> 
> Anyone want it?
> 
> -A

Jerry Avins wrote:

> Richard Owlett wrote:
> 
>> Jerry Avins wrote:
>>
>>>  
>>> I had exactly one college course in digital electronics. (I learned, 
>>> among other circuits, about phantastrons.*)
>>
>>
>>
>> What! No magnetic amplifiers?
>> I've some of my father's appnotes [somewhere] from your era.
>> P.S. He also operated a spark-gap transmitter at one time.
>>
>>>
>>> Trick question: which is stronger; white oak or white pine?
>>
>>
>>
>> OK, I'll bite. What's the trick?
> 
> 
> Any wood worker will tell you that oak is stronger. What circumstances
> make his answer wrong? (Hint: pine makes a better mast than oak.)
> 
> Jerry

Hmmm
Would I be close saying it was similar to concrete vs steel

ie
concrete:oak::steel:pine

Richard Owlett wrote:

> Jerry Avins wrote:
> 
>>  
>> I had exactly one college course in digital electronics. (I learned, 
>> among other circuits, about phantastrons.*)
> 
> 
> What! No magnetic amplifiers?

Not only magamps, but amplidynes. We also learned how to design
alternators and DC machinery. A supersybchronous motor (the name isn't
really descriptive) is a nifty gadget. It's cleverly adapted to the
rigors of the logging industry, just like a Shay locomotive.

> I've some of my father's appnotes [somewhere] from your era.
> P.S. He also operated a spark-gap transmitter at one time.

They were made illegal on land around when I was born. But I did build a
coherer out of the filings of a dime (nickel? I forget), glass tubing,
sealing wax, and a door bell.

Jerry

P.S. http://www.mrollins.com/shay.html http://www.shaylocomotives.com/
One I rode: http://www.shaylocomotives.com/data/lima3354/sn-3314.htm

Regular steam locomotives rock from side to side as the fore-and-aft
pistons move 90 degrees out of phase, hammering the rails and
necessitating robust track construction. Sheas have vertical pistons
driving a drive shaft connected to swiveling trucks with wheels the same
size as on flat cars. All wheels are powered. The engine can negotiate
sharper bends than long distance haulers, are geared to negotiate
steeper grades, and can run on temporary track that other engines would
tear up.
-- 
... the worst possible design that just meets the specification - almost
a definition of practical engineering.                     .. Chris Bore
������������������������������������������������������������������������