Job interview help! Good analog primer?

[maxfoo]

On 12 May 2004 10:22:58 -0700, larwe@larwe.com (Lewin A.R.W. Edwards) wrote:

Hi all,

I'm going to a second-round job interview next Monday, and I've been
forewarned by the first-round interviewer that I will be asked
questions on analog and RF topics (basic op-amp circuits, transistors
used in switching and amplification apps, superhet receivers and AM
transmitter).

I'm not being expected to demonstrate extreme skill (my primary
function is firmware and digital, analog and particularly RF are not
my strong point - and I made this clear to them before ever coming in)
but I would like to have as good a briefing as possible. He
recommended the ARRL Radio Comms handbook, which is totally
unavailable near me (libraries, bookstores, etc). I ordered a copy
from amazon, but I'm worried that it won't arrive in time.

Very strange...
Why would they want you to know RF?
We try like heck to keep the firmware and digital guys as far away from RF as
physically possible...






Remove "HeadFromButt", before replying by email.

 

[Anthony Fremont]

"Frank Bemelman" <f.bemelmanx@planet.invalid.nl> wrote in message
news:40a3d604$0$182$c3e8da3@news.astraweb.com...

"Anthony Fremont" <spam@anywhere.com> schreef in bericht
newshOoc.102272$hR1.6666@fe2.texas.rr.com...

[snip]

Who died and made you boss of the group? It could also be said that
you
could have shortened your posts by 100% and spared us all your
mindless
ramblings. Next time you get ready to accuse someone of something

I limit 92% of my posts by 100% - is that impressive or what ? ;-)

Believe it or not, I do too. I have written many a rant only to delete
them before sending. Perhaps I should try harder in the future.

 

[Tim Auton]

Joe Legris <jalegris@xympatico.ca> wrote:

Lewin A.R.W. Edwards wrote:
[snip]
You also appear to have a strong personal antipathy to me[...]

Oh well. As HAL said, "this conversation can serve no further useful
purpose".

Personal antipathy? It is your obsession with yourself that offends me -
the superfluous initials, the annoyingly verbose posts, the cloyingly
personal anecdotes - they make my skin crawl. I think I deserve some
credit for suffering in almost total silence these past few years.

You deserve credit for putting up with something you could have
silenced with basic knowledge of your news reader? For *years*? I now
have sufficient evidence to say what I felt when I first saw one of
your posts: You are a fucking moron.


Tim
--
Love is a travelator.

 

[Tim Auton]

Joe Legris <jalegris@xympatico.ca> wrote:
[snip]

I try to follow the advice of Strunk & White (The Elements of Style, 3rd
ed., p.23):

Omit needless words!

So why don't you just shut the fuck up?


Tim
--
Love is a travelator.

 

[Dave VanHorn]

Also, as you doubtless well know, most job descriptions read "The
ideal candidate will have 25 years' experience in designing spacecraft
and nuclear submarines, at least one platinum solo R&B album, a
distinguished military service record, a personal letter of
congratulation from the Pope, and will be a former champion sumo
wrestler and/or ballerina." Few hiring managers succeed in matching
all bullet points on their wishlist.

Ok, so someone's apparently having a worse time of it than I am..

I was just told that my 20 years + would be acceptable if I had obtained a
BS about 20 years ago.

 

[Dave VanHorn]

Have you had a spin through Art of Electronics?
If all you do is ping out all the "bad idea" circuits, you'll be ahead of
the pack.

 

[Dave VanHorn]

Either 50% of the people in c.a.e/s.e.d congenitally hate

me (which is fine; this is Usenet), or I approached this question
totally the wrong way.

Remember: Statistically speaking, half the people you meet are above average
assholes.

 

[Dave VanHorn]

Very strange...
Why would they want you to know RF?
We try like heck to keep the firmware and digital guys as far away from RF
as
physically possible...

I've noticed a disturbing trend in "miracle" antennas lately that appears to
be caused by firmware guys doing RF design. The idea that high return loss
figures equate to "good antenna" seem to come from that quarter.

 

[Al Borowski]

Fred Bloggs wrote:

Al Borowski wrote:

There's no reason to be condensending. And stereotyping an entire
generation as 'cheaters' is just arrogant.


Nah- it's called being realistic-

I'm sure most of your parents generation said the same about you


Al

most of your riffraff generation

signed up for an EE major to get a "high paying" job- and aren't worth a
sh_t- 80% are out of the industry within the first five years of
graduation. I'd say that 90% of the present undergraduate population
wouldn't have qualified for *any* education beyond high school by even
1960 standards...they just don't have the endowment or work ethic to
succeed in a legitimate curriculum.

 

[L. Fiar]

"Lewin A.R.W. Edwards" <larwe@larwe.com> wrote in message
news:608b6569.0405120922.39b363ef@posting.google.com...

I'm going to a second-round job interview next Monday, and I've been
forewarned by the first-round interviewer that I will be asked
questions on analog and RF topics (basic op-amp circuits, transistors
used in switching and amplification apps, superhet receivers and AM
transmitter).

I'm not being expected to demonstrate extreme skill (my primary
function is firmware and digital, analog and particularly RF are not
my strong point - and I made this clear to them before ever coming in)
but I would like to have as good a briefing as possible. He
recommended the ARRL Radio Comms handbook, which is totally
unavailable near me (libraries, bookstores, etc).

How about the Radio Handbook?

I had to specially order the copy I have (23rd edition), but it is not so
common on this side of the pond. The ARRL books are found here in libraries.
For other electronic issues, it really depends upon what your level is right
now, and if you want to learn or just jog your memory on the finer points.

For op-amp circuits, you could download some of the NS application notes for
their ICs, they give all kinds of info, including circuit examples.
As for transistors, if you don't already know enough for a basic test, you
may as well forget trying to study up as you don't have that much time.

Personally, I cannot see you having time for any meaningful studying, you
cannot cover such a large scope in such a short time.
Do you know exactly what they do, anything about their products, etc? This
is a good starting point, as it can tell you where to concentrate your
efforts.

 

[Paul Keinanen]

On Thu, 13 May 2004 22:07:16 GMT, maxfoo
<maxfooHeadFromButt@punkass.com> wrote:

Very strange...
Why would they want you to know RF?
We try like heck to keep the firmware and digital guys as far away from RF as
physically possible...

Unfortunately some radio receivers and transmitters appear as if they
were designed by firmware or digital hardware guys :-(.

Knowing something about RF is a good when dealing with EMC and
transmission line issues. For instance the firmware guy could
frequency modulate a long external clock line with a dither signal and
thus, keep the radiated noise density low enough, to hide it into the
thermal noise.

Paul

 

[Frank Raffaeli]

larwe@larwe.com (Lewin A.R.W. Edwards) wrote in message news:<608b6569.0405121947.4010399d@posting.google.com>...

How about applying for a job for which you are actually qualified? If

[snipped much of reply]

So, kindly don't make such accusatory statements without a solid basis
of fact. People who matter read public forums like this. I believe I
have a reasonably consistent and solid sense of ethics, and I KNOW I
have an excellent comprehension of my own limitations, and I don't
much care for people who jump to unwarranted conclusions and then
slander me in public.

You admit to knowing your own limitations? I find that is an admirable
quality in a potential employee, business partner, supervisor, etc
..... this point alone distiguishes you from many others. If I were
your interviewer and heard only this, and I believed you could learn
new things as required -- you'd be hired. I don't need to test your
"basic" skills with cheezy questions about superhets.

IME, most new RF applications are heavy on software / firmware ...
especially after the second IF (if not using direct conversion). In
many applications, software radios are cheaper and perform better than
their "analog" counterparts.

General RF constraints and properties in communications systems:

1) Link Margin - used to predict range and reliability given power,
antenna and sensitivity constraints.

2) Dynamic range / linearity - the un-desired vs. desired signal
levels at a reciever antenna may change by 1,000,000 to 1 or more. The
amplifiers, downconverters and the rest of the linear system must
accomodate this, or reliability and range will be compromised.

3) rho / quality factor - this is much faster to measure than BER. Rho
is a composite of many factors such as EVM (error vector magnitude),
Group delay, and intermodulation.

4) antennas - most have a resonant electrical length. Radiation
resistance of the antenna is the real part of the load. This power is
radiated. Any incident power not radiated is reflected back to the
source, causing problems in some systems.

All this fuss because when you apply a signal on a wire, the same but
less signal appears on a similar wire. Example: If you apply 1V RMS to
a resonant 50 ohm 18" dipole at 320 MHz, you will get about 0.125 VRMS
on a similar antenna placed 3 feet away and loaded with 50 ohms.

My grampa showed me this when I was 9 years old. Still haven't got a
good grasp on it ;-)

HTH

Frank Raffaeli
http://www.aomwireless.com/

 

[Terry Given]

"Anthony Fremont" <spam@anywhere.com> wrote in message
news:NzSoc.103350$hR1.1373@fe2.texas.rr.com...

"Frank Bemelman" <f.bemelmanx@planet.invalid.nl> wrote in message
news:40a3d604$0$182$c3e8da3@news.astraweb.com...
"Anthony Fremont" <spam@anywhere.com> schreef in bericht
newshOoc.102272$hR1.6666@fe2.texas.rr.com...

[snip]

Who died and made you boss of the group? It could also be said that
you
could have shortened your posts by 100% and spared us all your
mindless
ramblings. Next time you get ready to accuse someone of something

I limit 92% of my posts by 100% - is that impressive or what ? ;-)

Believe it or not, I do too. I have written many a rant only to delete
them before sending. Perhaps I should try harder in the future.

as have I. I have done worse though - written out a couple of careful, well
thought out answers to questions, then deleted them after realising that the
ideas are good enough to make money from....I tend to think about that
whenever post info about solving the practical problems that usually make
the difference between success and failure of a circuit - after all, a fair
chunk of my money comes from fixing things other people screw up, so
educating others is not necessarily a good idea. OTOH there are plenty of
idiots to provide me with work, many of whom are so dumb they wont
understand things even when carefully explained, so what the hell.

Terry

 

[Rich Grise]

"Lewin A.R.W. Edwards" <larwe@larwe.com> wrote in message
news:608b6569.0405130702.79bd9296@posting.google.com...

But as the other posters already suggested, I can only wish you luck in
reading that much info, let alone understand it. Would you be able to
tell a
Colpitts oscillator from a Hartley after reading the basics on
transistors
or opamps? I doubt it. Best is to be fit for the interview and keep an
open

Honestly, all I want to do is recognize some simple configurations
without having to sit down and puzzle it out from first principles. I
know the essential characteristics of bipolar transistors and, to a
lesser extent, FETs, and I understand what capacitors, resistors and
inductors do Gee, people. I didn't think I was opening a hornet's
nest here. Either 50% of the people in c.a.e/s.e.d congenitally hate
me (which is fine; this is Usenet), or I approached this question
totally the wrong way. Either way, I'm somewhat regretting making the
initial post, but I did get some useful responses, for which I am
grateful.

Well, even I noticed that your original post had sort of a "can you
help me cram for this interview?" tone to it.

In any case, good luck!
Rich

 

[Lewin A.R.W. Edwards]

How about the Radio Handbook?

William Orr? That's in stock at my local B&N, I'll grab a Starbucks
and browse tonight.

For other electronic issues, it really depends upon what your level is right
now, and if you want to learn or just jog your memory on the finer points.

Well, I don't plan on doing much *learning* for this. I want to be
refreshed in what I know and reminded of what I don't, and if I pick
up a few bonus points along the way, so much the better. You know how
it is - if you don't use information, it atrophies horribly quickly.
And I was never very learned in this field to begin with.

The reason I need reference recommendations from cae'ers is because
there are about ten billion books on these topics, and I'm looking for
one that's (a) general, and (b) covers most of the required territory.

For op-amp circuits, you could download some of the NS application notes for
their ICs, they give all kinds of info, including circuit examples.

Ah, good pointer. Thanks!

Do you know exactly what they do, anything about their products, etc? This

Oh, yes - I looked over their campus the other day in fact. The
context of all this is low-rate unlicensed data transceivers using a
proprietary signaling protocol (it's a high-volume consumer product).
My responsibilities would be the microcontroller code, some of the
digital design, and a lot of documentation work, marketing and Q/A
liaison, &c. By the time I get to see the data, it's ready to eat. I
Tx by wiggling a couple of GPIOs. Wiser heads build the RF front-ends,
but they want me to be able to understand in general terms what is
going on.

 

[FLY135]

"Lewin A.R.W. Edwards" <larwe@larwe.com> wrote in message
news:608b6569.0405121947.4010399d@posting.google.com...

It has also been stated to me that if I'm offered the position, it
will basically be conditional on my going back to school. Implication
from that being that they understand I'm not a perfect match for every
bullet point on their list, but they are willing to work with that.
Also, as you doubtless well know, most job descriptions read "The
ideal candidate will have 25 years' experience in designing spacecraft
and nuclear submarines, at least one platinum solo R&B album, a
distinguished military service record, a personal letter of
congratulation from the Pope, and will be a former champion sumo
wrestler and/or ballerina." Few hiring managers succeed in matching
all bullet points on their wishlist.

You forgot to add... "Have a masters degree and the position pays
$35,000/yr".

Good luck on your interview.

 

[Lewin A.R.W. Edwards]

Joe Legris <jalegris@xympatico.ca> wrote in message news:<40A3D9DB.2070305@xympatico.ca>...

I try to follow the advice of Strunk & White (The Elements of Style, 3rd
ed., p.23):
Omit needless words!

I thought my question made more sense when asked in its context.
Moreover, a fair percentage of the people who frequent c.a.e are
better than passing acquaintances of mine. The additional details
about this particular interview technique are an anecdote which some
people might find interesting. If all that offends you about my
original post is that it was too long or contained "irrelevancies",
perhaps you might want to reconsider.

How about those posts we see here once in a while which read like
this:

Re - Microcontroller

Hello i need microcontroller advise. it must to my application very
well at low cost. urgently need help. it with 6 buttons and laser
beam.

A low word count, and an unanswerable question.

 

[Lewin A.R.W. Edwards]

Well, even I noticed that your original post had sort of a "can you
help me cram for this interview?" tone to it.

Sorry. It wasn't my intention. There was kind of an urgency because I
needed an answer that I could refer to over the weekend, and I guess I
over-stressed that and under-stressed my actual goal. As it
transpires, the book I ordered arrived a few minutes ago (despite the
fact that amazon says it's still "being prepared for shipment), so I
should be in good shape with that and the other suggestions I
received.

In any case, good luck!

Thanks. It's an interesting position, I hope I get it.

 

[Alan Balmer]

On Fri, 14 May 2004 19:52:10 -0700, "Terry Given"
<the_domes@xtra.co.nz> wrote:

I have done worse though - written out a couple of careful, well
thought out answers to questions, then deleted them after realising that the
ideas are good enough to make money from..

And have you then gone on to make money from them?

Good ideas are easy to come by, but often the best use of them is as
currency in a free exchange with your peers.

--
Al Balmer
Balmer Consulting
removebalmerconsultingthis@att.net

 

[Lewin A.R.W. Edwards]

the superfluous initials,

I think you should demand an apology from my mother (who chose Lewin),
my father (whence R.W.) and my godfather (whence A). Warning: My
godfather is Sicilian, and my father is dead, so I don't think you're
likely to get much joy there.

My _physical signature_ (on checks, contracts, &c) is Lewin A.R.W.
Edwards. Typing it like that is, for me, very nearly as much an
automatic gesture as signing it like that. It's not a name embellished
with titles or genealogical information (e.g. "Dr. Monseigneur Fredick
W. Dunsford-Smythe III, M.D."), it is simply no more and no less than
my name. You begrudge me seven bytes of initials and punctuation? What
if I stop posting from larwe@larwe.com and instead set up a mailbox
for myself at my zws.com domain, called a@zws.com? I realize that only
saves six bytes, but maybe I can lose the space between A.R.W. and
Edwards, to even the score.

the annoyingly verbose posts, the cloyingly

You know (temporarily being completely serious here), I find the
insufficiently verbose posts annoying. A thread that consists of one
person asking "what transistor is good here", a second person saying
"ABC123", and the OP saying "thanks" - that's not very rich. I happen
to want to hear the "I'm building a ten-kilowatt electric screwdriver
on a dare" stories. Usenet is a source of _news_ to me about what
people in my field are doing, not merely a Q&A forum where strictly
limited technical questions are asked and answered. It's also a source
of relaxation where I can view and have low-stress input into
technical questions that don't have immediate life-and-death
consequences for me personally. And of course there are vast amounts
of practical information here waiting to be adsorbed. I don't believe
that my attitude is atypical of the general c.a.e. readership.

personal anecdotes - they make my skin crawl. I think I deserve some
credit for suffering in almost total silence these past few years.

Yes, you're absolutely right. Those guys that came over, tied you up
and clamped your eyes open in front of the screen, Clockwork
Orange-style - they were sent by me. You have unmasked me for the
vicious mastermind and international villain I really am.

BTW, you've said things here more than once that have got my hackles
up (recently, too). I didn't respond because I didn't think it would
be of value to anyone. By my quick guess, this thread is now about 80K
of text, and perhaps two-thirds of it (53K) follows on this little
firestorm you started. So, I should be able to have my little seven
extra bytes "A.R.W. " for my next 7,571 or so posts without any
further adverse reaction from you, right?

Please write another book - by all accounts the first one is technically
very good (seriously)

I'm glad you have heard positive things of it. I do intend to continue
writing books as long as I can. This has nothing to do with my
intention to continue writing - which includes Usenet posting - in the
style to which I'm accustomed.