Driver to drive?

[Clarence]

"Joel Kolstad" <JKolstad71HatesSpam@Yahoo.Com> wrote in message
news:08idnfDVBN1W4e3cRVn-tQ@comcast.com...

"Clarence" <no@No.com> wrote in message
news:Xo_bd.31094$QJ3.5263@newssvr21.news.prodigy.com...
Since I have implemented a telephone system on an aircraft with Internet
access, I can say that there was nothing in any of those web sites to
inform
anyone except at a marketing level......

Not to worry, plenty of the kids getting BSEE's today are going to end up in
marketing anyway.

So they FLUNK Engineering?

 

[me]

Edwards was quoted afterward: "I refuse to fly on a plane older than I
am!"

I guess he's never been in the military.


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---

 

[Jens Tingleff]

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Hash: SHA1

czh wrote:

2n+1 -order low-pass filter synthesis always gives you n conjugate
pairs and 1 real pole. If it is 2n order it will always be n conjugates.
For some strange reasons, for 2n order
filter I would like n-1 conjugate pairs and 2 real pole.

That's OK

How can I design such filter that meets given brick wall specification?

The best way is to use an optimisation package. Some Spice-like simulators
give you the ability to optimise component values and are quite well suited
for this task (you can then also use proper models of active and passive
elements and get better correspondence between simulation and circuit).

I've had luck using Aplac, HSpice and Eldo for similar problems.

There are also dedicated filter optimisation packages, I'm sure someone else
can point you at some.

An important part of using an optimiser is to provide a good initial guess.
In this case, if the order is not too small, I would use a normal 2n+1 -
order lowpass filter and a seperate duplicate real pole. The optimiser
should then be able to move the poles around until you get a better
response.

Hope this helps

Jens

- --
Key ID 0x09723C12, jensting@tingleff.org
Analogue filtering / 5GHz RLAN / Mdk Linux / odds and ends
http://www.tingleff.org/jensting/ +44 1223 211 585
"If I had known it was harmless, I would have killed it myself" P K Dick
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[Winfield Hill]

Dr. Polemic wrote...

Fred Bloggs wrote:

John Larkin wrote:
Winfield Hill wrote:
John Larkin wrote...

I'm working on some stuff to test radars on B-52s. The plan
is to keep them in service until 2044, at which point many
of the planes will be 80 years old.

Let's see; the web site quoted below says that the first of 102
B52H's was delivered in May 1961, and the last was delivered in
October 1962. It also says that only the H model is still in the Air
Force inventory. Therefore in 2044 *all* of the planes still in the
inventory will be slightly more than 80 years old. Looks like John
got it right to me.

I'm reminded of the old Jimmy Stewart metal fatigue movie.

There's a bunch on airframe fatigue in here:
http://www.globalsecurity.org/wmd/systems/b-52.htm

The official figure is 90 year operational life. Get it right.

Quotes from http://www.globalsecurity.org/wmd/systems/b-52-life.htm

"The limiting factor of the B-52’s service life is the economic limit of
the aircraft's upper wing surface, calculated to be approximately 32,500
to 37,500 flight hours. Based on the projected economic service life and
forecast mishap rates, the Air Force will be unable to maintain the
requirement of 62 aircraft by 2044, after 84 years in service. ...

"The airframe life for the current fleet is estimated to be between
32,500 and 37,500 hours, depending on the usage history of the individual
aircraft. The estimate is based upon scaling measurements from a full-scale
test structure using assumed mission profiles along with historical and
projected usage information. The upper wing surface is expected to be the
life-limiting structural member. As of 1999 the average airframe had 14,700
flight hours. Boeing believes with high confidence that the average number
of flight hours left is 17,800, at a minimum. The “oldest” B-52H is at
about 21,000 hours and only experiences about 380 flight hours per year."

Several stories of specific failures, mostly crack and corrosion based,
and their fixes, here, http://www.globalsecurity.org/wmd/systems/b-52h.htm

An interesting B-52H procurement factoid, "The 102 B-52Hs accepted by the
Air Force, like the B-52Gs, were built in Wichita. The Air Force accepted
20 B-52Hs in FY 61 (from March through June 1961); 68 in FY 62 (between
July 1961 and June 1962); and 14 in FY 63 (the last 5 during October
1962). Cost per aircraft was: $9.28 million: Airframe, $6,076,157; engines
(installed), $1,640,373; electronics, $61,020; ordnance, $6,804; armament
(and others), $1,501,422." Well under $10 million, a real bargain.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Winfield Hill]

Spehro Pefhany wrote...

Tam WB2TT wrote:

Don't know anything about the C1815, but I have built wideband amplifiers
and found the 2N2369 to be much superior to the 2N2222 as far as bandwidth
goes; that is, if you can live with the 15 V breakdown. For PNPs, the 2N5771
works well. In any case, you will have to frequency compensate the feedback
loop for good video response. You should be able to find an IC that will do
the job.

Here's the jellybean C1815
http://www.semicon.toshiba.co.jp/td%5Cen%5CTransistors/Bipolar_SmallSignal_Transistors%5Cen_20030328_2SC1815_datasheet.pdf

Hey, Spef, I thought you preferred the Philips pc1815. I do like the
Toshiba data sheet better though. Checking a few distributors, I didn't
find much interest in the 2sc1815, only Farnell had some in stock, at a
high price. Maybe the 2sc1815's jellybean days are over.

Mouser recommended the bc546b instead. Hmm, the bc546 family is well
stocked at distributors, as is its nice little bc556 pnp complement.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Tony Williams]

In article <pan.2004.10.16.02.34.30.80879@example.net>,
Rich Grise <rich@example.net> wrote:

And if they let the intake end go empty for too long, it breaks
the siphon, right? ;-)

I think if the 'syphon' reduced then the induction
motors would automatically slip back to motoring.

--
Tony Williams.

 

[Phil Hobbs]

Mike Monett wrote:

skavanagh72nospam@yahoo.ca (Steve Kavanagh) wrote in message news:<5249fb3f.0410141603.6ef8f825@posting.google.com>...

I am contemplating the use of a limiter at the output of a noise
source (to be used for rough noise figure measurement) to create a
noise source which doesn't need calibration, assuming the limiter
characteristics are known. The source would consist of a diode in
reverse breakdown (or whatever) to generate noise, followed by an
amplifier and a limiter. The amplifier would have to have enough gain
so that the majority of the time the limiter is active. The output
would then look (most of the time) like a digital signal with random
rise and fall times.

Can anyone comment on what issues there might be with this approach ?
In particular, the effect of the limiter on the noise spectrum is of
interest.

73,
Steve VE3SMA


Steve, this might be more difficult than it seems. Dr. Terry Ritter, a
recognized crypto expert, analyzed the characteristics of different
noise sources and published the results:

http://www.ciphersbyritter.com/NOISE/NOISRC.HTM

So if the noise source isn't very good, anything you do to it may
produce strange results.

However, I hasten to add that I spent years measuring the noise
distribution after the limiter in hard disk read channels, and
observed it was a very good fit to gaussian down to a BER of about
10^-13. In other words, several months of data collection. So you
might be ok if your source is gaussian.

Regards,

Mike Monett
Gaussian noise and white noise are often confused with each other, but they

are actually independent ideas--as shown here.

| Gaussian | Non-Gaussian
---------+--------------------------+-----------------------------
| High-current shot noise | Low-current shot noise
White | Johnson noise | Clipped Johnson noise
| | PRBS noise (below Nyquist)
---------+--------------------------+-----------------------------
| PRBS noise (0-order hold)|
Coloured | Filtered Johnson | Popcorn noise
| Flicker noise | Atmospherics
---------+--------------------------+---------------------

"Gaussian" means that samples of the instantaneous noise signal form a random
process whose probability density is Gaussian--i.e. that a histogram of the
amplitude has a round top and wings that die off rapidly but that have no
sharp cutoff.

A good limiter produces flat-topped pulses of uniform height, with slightly
sloping sides. This produces a histogram that has two huge peaks at the
positive and negative clip levels, plus a low, flattish region in between
corresponding to the nearly-straight sloping sides.

- ^ ^
/ \ | | | |
_______/ \_____ vs ______| +--------+ |_______

Not very close at all.

If you stick the clipped noise through a narrow bandpass filter, it will get
more Gaussian-looking, and (IIRC) it will become Gaussian as the bandwidth
goes to zero.

Cheers,

Phil Hobbs

 

[Paul Burridge]

On Fri, 15 Oct 2004 17:49:20 -0700, John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

I'm working on some stuff to test radars on B-52s. The plan is to keep
them in service until 2044, at which point many of the planes will be
80 years old.

Yeah, but they're still a great site to see in flight. It must be
*amazing* being bombed by one!
--

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

 

[John Larkin]

On 16 Oct 2004 04:18:05 -0700, robin.pain@tesco.net
(robin.pain@tesco.net) wrote:

John Larkin <jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote in message news:<t1qvm095fevnt365vuc4m6inlie9jbreuh@4ax.com>...
On 15 Oct 2004 01:12:23 -0700, robin.pain@tesco.net
(robin.pain@tesco.net) wrote:

"Pat Ford" <pat.ford@nrc.ca> wrote in message news:<ckloc5$dtl$1@nrc-news.nrc.ca>...
robin.pain@tesco.net> wrote in message
news:bd24a397.0410132318.7aa5fbff@posting.google.com...
"Pat Ford" <pat.ford@nrc.ca> wrote in message
news:<ckj2m6$ru0$1@nrc-news.nrc.ca>...

If I press <escape> to abort the start-up memory test, then the result
is always the same i.e.

2^n bytes OK

...you see! They have no pride, no one cares, it's just a job for
getting money. That's why it will always be ugly and unreliable.

Cheers
Robin

That happens before the OS is loaded, that is BIOS not M$.

Pat

I agree, M$ do not have full control of the operating system.

Cheers
Robin

M$ is the operating system! The bios is below that, M$ has it's problems
( I'm a unix type) but this example isn't one of them.

Oh, I thought the BIOS was integral. Who else uses it then? (obviously
UNIX don't because you would have said so)


I use the bios to boot IBM's Dos2000. Works fine.

This is the rub: If you make something beautiful on the outside then
it is more likely beautiful inside. M$ don't give a damn e.g. the Caps
lock key, a useless thing is made larger and inserted between two
(three) of the most often used keys.

Caps lock is indispensable, as real programmers code in uppercase.

John

Ah yes, make big goof about BIOS - so I learn something - thanks to
all, presumably there is a spec somewhere for BIOS and anyone can
write there own "OS" to connect with it, even something incredibly
trivial because it would be so much cheaper than making your own
controller from scratch?

UPPER CASE verses lower case:-
If you want to provide the maximum meaning for the minimum effort ya
gotta have as much variety as possible. The same thing applies to
prose as well as code so lower case is not a stylistic thing, it is a
better thing:-


LDX INPUT //INPUT IS A CONSTANT
STX INPUT_CACHE


ldaa INPUT //no comment necessary
staa input //no qualification necessary


Which example is easier for the brain to decode and contains more
information in less text?

Cheers
Robin

6803 code? Wow, I did a lot of that. I actually wrote an RTOS for the
6800 once, which was a nuisance because the stack operations were even
more limited than for the 6803.

Is less text good?

But I comment every line. Here's some 68K code. The formatting may get
messed up by the newsgroup stuff, but it looks real nice on paper.


.SBTTL . LMAX : LOAD A MAXIM SERIAL DAC

; WE SHIFT 16 BITS INTO A MAXIM DAC, MSB FIRST. FOR THE SINGLE
; 16-BIT MAX5205, THIS IS JUST DATA. FOR THE QUAD-12 MAX5742,
; OUR INPUT IS 4 COMMAND BITS FOLLOWED BY 12 DATA BITS.

; D0 IS BOARD SUBADDRESS
; D2 IS SLOT NUMBER
; D4 IS 16-BIT DAC CMD+DATA (FOR QUAD-12) OR DATA (FOR 16)
; D7 IS LOOP COUNTER
; A5 USED AS BAWD LATCH POINTER

; CARDCAGE D0 IS SERIAL DATA
; D1 IS CLOCK, ALWAYS RISING EDGE, COURTESY PEELS.


LMAX: MOVEA.W # BAWD, A5 ; AIM AT BUS WRITE DATA LATCH
CLR.B (A5) ; ZAP THE DATA LATCH
MOVE.B D0, BADD.W ; SET 'A' LINES AND ENABLE WRITE DRIVER
MOVE.B D2, PORTD.W ; DO THE SLOT SELECT

MOVE.L # 16-1, D7 ; PREPARE TO DO 16 BITS

L280: LSL.W # 1, D4 ; TEST MS BIT OF DACDATA
BCS.S L281 ; SKIP FOR A '1'

CLR.B (A5) ; SHIFT A 0 : DATA LOW, CLOCK LOW
MOVE.B # B1, (A5) ; DATA LOW, CLOCK HIGH
DBF D7, L280 ; AND LOOP
BRA.S L289

L281: MOVE.B # B0, (A5) ; SHIFT A 1 : DATA HIGH, CLOCK LOW
MOVE.B # B1+B0, (A5) ; DATA HIGH, CLOCK HIGH
DBF D7, L280

L289: CLR.B (A5) ; FINALLY DROP CLOCK
MOVE.B # 0Fh, PORTD.W ; DESELECT THIS SLOT,
MOVE.B # B7, BADD.W ; KILL 'A' LINES, AND ZAP WRITESTUFF

RTS


The .SBTTL directive creates an entry in the program table of
contents, which appears first in the listing, with page and line
number appended.

John

 

[Phil Hobbs]

Mike Monett wrote:

skavanagh72nospam@yahoo.ca (Steve Kavanagh) wrote in message
news:<5249fb3f.0410141603.6ef8f825@posting.google.com>...

I am contemplating the use of a limiter at the output of a noise
source (to be used for rough noise figure measurement) to create a
noise source which doesn't need calibration, assuming the limiter
characteristics are known. The source would consist of a diode in
reverse breakdown (or whatever) to generate noise, followed by an
amplifier and a limiter. The amplifier would have to have enough gain
so that the majority of the time the limiter is active. The output
would then look (most of the time) like a digital signal with random
rise and fall times.

Can anyone comment on what issues there might be with this approach ?
In particular, the effect of the limiter on the noise spectrum is of
interest.

73,
Steve VE3SMA



Steve, this might be more difficult than it seems. Dr. Terry Ritter, a
recognized crypto expert, analyzed the characteristics of different
noise sources and published the results:

http://www.ciphersbyritter.com/NOISE/NOISRC.HTM

So if the noise source isn't very good, anything you do to it may
produce strange results.

However, I hasten to add that I spent years measuring the noise
distribution after the limiter in hard disk read channels, and
observed it was a very good fit to gaussian down to a BER of about
10^-13. In other words, several months of data collection. So you
might be ok if your source is gaussian.

Regards,

Mike Monett

Gaussian noise and white noise are often confused with each other, but
they are actually independent ideas--as shown here.

| Gaussian | Non-Gaussian
---------+--------------------------+-----------------------------
| High-current shot noise | Low-current shot noise
White | Johnson noise | Clipped Johnson noise
| | PRBS noise (below Nyquist)
---------+--------------------------+-----------------------------
| | PRBS noise (0-order hold)
| Random sums | Flicker noise
Coloured | Filtered Johnson | Popcorn noise
| | Atmospherics
---------+--------------------------+---------------------

"Gaussian" means that samples of the instantaneous noise signal form a
random process whose probability density is Gaussian--i.e. that a
histogram of the amplitude has a round top and wings that die off
rapidly but that have no sharp cutoff.

A good limiter produces flat-topped pulses of uniform height, with
slightly sloping sides. This produces a histogram that has two huge
peaks at the positive and negative clip levels, plus a low, flattish
region in between corresponding to the nearly-straight sloping sides.

- ^ ^
/ \ | | | |
_______/ \_____ vs ______| +--------+ |_______

Not very close at all.

If you stick the clipped noise through a narrow bandpass filter, it will
get more Gaussian-looking, and (IIRC) it will become Gaussian as the
bandwidth goes to zero.

Cheers,

Phil Hobbs

 

[Phil Hobbs]

Clarence wrote:

"Joel Kolstad" <JKolstad71HatesSpam@Yahoo.Com> wrote in message
news:08idnfDVBN1W4e3cRVn-tQ@comcast.com...

"Clarence" <no@No.com> wrote in message
news:Xo_bd.31094$QJ3.5263@newssvr21.news.prodigy.com...

Since I have implemented a telephone system on an aircraft with Internet
access, I can say that there was nothing in any of those web sites to
inform
anyone except at a marketing level......

Not to worry, plenty of the kids getting BSEE's today are going to end up in
marketing anyway.



So they FLUNK Engineering?


No, no, no--that's where pointy-haired engineering managers come from.

Cheers,

Phil Hobbs

 

[Fred Bloggs]

Dr. Polemic wrote:

Let's see; the web site quoted below says that the first of 102
B52H's was delivered in May 1961, and the last was delivered in
October 1962. It also says that only the H model is still in the Air
Force inventory. Therefore in 2044 *all* of the planes still in the
inventory will be slightly more than 80 years old. Looks like John
got it right to me.

That 80 year nonsense is some kind of fuzzy-headed anthropomorphism of
the actual bomber and has nothing to do with the engineering reality.
The Air Force logistics O&M is in fact 90 years- and that is all that
matters. The existing fleet could top out in four years of high
intensity conflict.

 

[Fred Bloggs]

Paul Burridge wrote:

Yeah, but they're still a great site to see in flight. It must be
*amazing* being bombed by one!

This is the one you don't want to see coming your way:
http://www.globalsecurity.org/wmd/world/russia/tu-22m.htm

 

[John Larkin]

On Sat, 16 Oct 2004 16:14:28 GMT, Fred Bloggs <nospam@nospam.com>
wrote:

Why haven't you made your company bigger?

Probably because I'm not a businessman, and I certainly couldn't
manage a big company. I spend most of my time designing things, and
don't really know how to play the corporation and stock games to get
big. My figure of merit for a company is dollars revenue per employee,
which I place no upper limit on, and not just dollars, which requires
wheeling and dealing and squeezing all you can out of the troops.

I know a couple of technologists who have got swept up in the
business/VC/go-for-IPO thing, and I think they've lost their souls
over it. They certainly lost their companies, and now just shill for
the Sand Hill Road Toads who have the money and the power.

John

 

[John Larkin]

On Sat, 16 Oct 2004 15:16:03 GMT, "Tom Del Rosso"
<ng01@att.net.invalid> wrote:

"John Larkin" <jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote in
message news:dsr0n0ha51al2cma2j6gme42a8p50ouikl@4ax.com...

I'm working on some stuff to test radars on B-52s. The plan is to keep
them in service until 2044, at which point many of the planes will be
80 years old.

Once I saw a beautiful picture in Aviation Week of a B-52 sitting on top of
an all-wood tower platform, for radar profile tests. (I realize that's not
at all what you're doing.)

Read "Skunk Works" by Ben Rich for some fascinating stuff about spy
planes and radar cross-sections.

John

 

[Fred Bloggs]

Julie wrote:

Just out of personal curiosity, excluding Bush, US policy, UN policy, etc. for
the moment, what do you think of Saddam and his established genocidal behavior?

You ought to be able to understand by now that the Middle East is a very
violent place. Saddam could care less about killing Kurds and Iranians
unless they become a threat to his existence. The US has a history of
stirring up trouble between the Kurds and Saddam going way back to the
1960's- we armed and helped Kurds organize a guerilla war against Saddam
to divert Iraqi resources away from Israel. Then when that situation
passed, the US cut the supply line to the Kurds, clearing the way for
Saddam to exact his revenge upon them at low cost to himself. We did the
same thing in the mid-90's when the CIA funded Chalabi's INC to start
organizing another guerrilla movement among the Kurds, inciting Saddam
to cross into Kurdistan and wipe them out again. All of the mass graves
being discovered contain victims that are there directly as a result of
US policy to agitate the situation. The reputation of the US among the
Iraqis in general is not good. The initial reception of the Shiites
during the March 2003 invasion was characterized by mistrust and
uncertainty as to whether the US would sell them out yet again like we
did in the First Gulf War- this is their belief anyway.

 

[YD]

On 16 Oct 2004 00:57:11 GMT, Jim Yanik <jyanik@abuse.gov.> wrote:

"Frank Bemelman" <f.bemelmanx@xs4all.invalid.nl> wrote in
news:41705630$0$566$e4fe514c@news.xs4all.nl:

"Julie" <julie@nospam.com> schreef in bericht
news:41704F6C.43FCA600@nospam.com...

[snip]

Do any nationals care about what outsiders think about their leader?
For 99.999% of outsiders, their opinion of an extranational leader is
based
solely
on news/media -- hardly suitable to make an informed decision.

What do you base your opinion on, besides news/media?



It all depends on *which* "news/media".
The mainstream news/media is clearly biased and twists their reporting.
CBS news is just the latest example.

Aren't they all. Which is which only depends on your POV.

- YD.

--
Remove HAT if replying by mail.

 

[Clarence]

"Phil Hobbs" <pcdhSpamMeSenseless@us.ibm.com> wrote in message
news:41714245.50005@us.ibm.com...

Clarence wrote:
"Joel Kolstad" <JKolstad71HatesSpam@Yahoo.Com> wrote in message
news:08idnfDVBN1W4e3cRVn-tQ@comcast.com...

"Clarence" <no@No.com> wrote in message
news:Xo_bd.31094$QJ3.5263@newssvr21.news.prodigy.com...

Since I have implemented a telephone system on an aircraft with Internet
access, I can say that there was nothing in any of those web sites to
inform
anyone except at a marketing level......

Not to worry, plenty of the kids getting BSEE's today are going to end up
in
marketing anyway.



So they FLUNK Engineering?


No, no, no--that's where pointy-haired engineering managers come from.

Cheers,
Phil Hobbs

Oh, aren't those the one's who take all the credit for your work?

 

[ChrisGibboGibson]

"Wayne" wrote:

Hi

I have calculated the following network using the cosine law.
___SIGGEN (Vs)_
Ś Ś
Ś--/\/\/\/\-----Ś Ś----Ś
Ś Vs Vc
Ś
---
GND

Vs^2=Vr^2+Vc^2 - 2VrVc Cos(theta1)
theta1=80deg
Vs=1v
Vr=0.25v


I am being dumb... but how do I get this into complex format e.g. a+jb.
Please give an example using my data.

Thanks

You could have at least made an attempt to pretend it wasn't your homework.

Gibbo

 

[Fred Bloggs]

Clarence wrote:

Sorry. I thought you would understand. Since that is not the case I'll go
back into the lurker mode.

Please do- you even lie about that...