Can an electronics student join?

[Neon John]

On Sat, 19 Jul 2014 01:01:09 -0400, rickman <gnuarm@gmail.com> wrote:

On 7/18/2014 10:40 PM, Neon John wrote:
On Thu, 17 Jul 2014 15:57:55 -0700 (PDT),
michaelcovington670@gmail.com wrote:

Hello everyone. I am an electronics student and in the process of learning, and I was wondering if I could join this group? I am thinking it would be a good way to learn more from others with more experience and maybe help me if I have a problem in school that I can't get answered easily. LOL. I wanted to pop in and ask before I joined.

Hi Michael, welcome aboard.

Your thread has shown you the bad side of SED.

Does SED have a good side? Nearly every discussion I have read here has
had it's share of hostility and infantile argument. The more seriously
technical the discussion the more infantile the arguments.

Of course. I've refined my killfile over the years and now find this
group quite pleasant. And I've always gotten my questions answered.

There are some knowledgeable people posting here. But you would have a
hard time realizing that by reading many of their posts. The signal to
noise ratio is rather low which makes it hard to tell what they are
actually saying.

Possibly, but I never see that side of things. A few smart-assed
remarks and into the killfile they go. I've make a few exceptions
such as John Larkin (who should really act his age and stop the
bickering with what's-his-name) but mostly it's all good.

>I hope he does stay, but my guess is we won't see him again. We'll see.

I certainly hope so.

John
John DeArmond
http://www.neon-john.com
http://www.fluxeon.com
Tellico Plains, Occupied TN
See website for email address

 

[amdx]

On 7/18/2014 3:45 PM, Joerg wrote:

amdx wrote:


That abundance of caution is a good thing. I know a guy who almost lost
his ring finger when accidentally shorting out something like that. I
guess the wedding band is one of the risks of being married


I quit wearing mine many, many years ago, just because of the
conduction possibility. The wife was not pleased, she showed me!


Same here


A couple years later she stopped wearing hers. Somewhat different
though, I don't wear any jewelery, not even a watch. She wears all
kinds. Going on 34 years, I guess she's going to keep me.


You never know. One couple was close to 50 years and then got divorced
because of irreconcileable difference. Whatever those might have been.

Then there's the old joke about the couple getting a divorce after 78
years. When the lawyer ask, Why after all these years are getting divorced?
They responded, we wanted to wait until the children had passed.
Mikek

---
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http://www.avast.com

 

[amdx]

On 7/18/2014 10:32 PM, Bill Sloman wrote:

On Saturday, 19 July 2014 05:17:20 UTC+10, amdx wrote:
On 7/18/2014 12:19 AM, Reinhardt Behm wrote:
John Larkin wrote:
On Thu, 17 Jul 2014 19:36:12 -0700 (PDT), jurb6006@gmail.com wrote:

"This goddammed delusional narcissist again!"

You say that like it's a bad thing. I am used to it. If you think people are bad here, try alt.revisionism.

Isn't there a newsgroup just for flaming?

Other than SED?

Try rec.boats, much worse than here.

They also have a knee jerk liberal that hates any conservative thought.

"Conservative thought" has to be an oxymoron, comparable with "military intelligence".

I knew when I wrote the description I was describing you.

Mikek


---
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http://www.avast.com

 

On Friday, July 18, 2014 3:11:48 PM UTC-4, amdx wrote:

On 7/17/2014 9:11 PM, bloggs.fredbloggs.fred@gmail.com wrote:

On Thursday, July 17, 2014 7:41:32 PM UTC-4, k...@attt.bizz wrote:



You bet! I was working with ...



This goddammed delusional narcissist again!





You any kin to Phil the Aussie?

Mikek



---

This email is free from viruses and malware because avast! Antivirus protection is active.

http://www.avast.com

No, but I think you're a product of his sperm donation that the bank threw away as being not viable enough to support human life.

 

[rickman]

On 7/19/2014 10:24 AM, Neon John wrote:

On Sat, 19 Jul 2014 01:01:09 -0400, rickman <gnuarm@gmail.com> wrote:

There are some knowledgeable people posting here. But you would have a
hard time realizing that by reading many of their posts. The signal to
noise ratio is rather low which makes it hard to tell what they are
actually saying.

Possibly, but I never see that side of things. A few smart-assed
remarks and into the killfile they go. I've make a few exceptions
such as John Larkin (who should really act his age and stop the
bickering with what's-his-name) but mostly it's all good.

Yeah, that isn't going to happen. John has two faults, he loves to
argue over petty, personal issues and he can't admit when he makes a
mistake. But yes, he does know his field very well.

--

Rick

 

[John Larkin]

On Sat, 19 Jul 2014 16:57:28 -0400, rickman <gnuarm@gmail.com> wrote:

On 7/19/2014 10:24 AM, Neon John wrote:
On Sat, 19 Jul 2014 01:01:09 -0400, rickman <gnuarm@gmail.com> wrote:

There are some knowledgeable people posting here. But you would have a
hard time realizing that by reading many of their posts. The signal to
noise ratio is rather low which makes it hard to tell what they are
actually saying.

Possibly, but I never see that side of things. A few smart-assed
remarks and into the killfile they go. I've make a few exceptions
such as John Larkin (who should really act his age and stop the
bickering with what's-his-name) but mostly it's all good.

Yeah, that isn't going to happen. John has two faults, he loves to
argue over petty, personal issues and he can't admit when he makes a
mistake. But yes, he does know his field very well.

I thought the HV blinker was an interesting problem, if only because almost
every proposed circuit - including Jim's, including roughly 100 scribbles of
mine - had some insidious flaw. Discussing stuff like that isn't petty or
personal.

An electronics discussion group does need topics.

Heck, I probably won't even use the circuit. I've got a bunch of 6 to 22 volt
LEDs on order that may just work with a series resistor.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation

 

[Bill Sloman]

On Sunday, 20 July 2014 02:00:12 UTC+10, amdx wrote:

On 7/18/2014 10:32 PM, Bill Sloman wrote:
On Saturday, 19 July 2014 05:17:20 UTC+10, amdx wrote:
On 7/18/2014 12:19 AM, Reinhardt Behm wrote:
John Larkin wrote:
On Thu, 17 Jul 2014 19:36:12 -0700 (PDT), jurb6006@gmail.com wrote:

"This goddammed delusional narcissist again!"

You say that like it's a bad thing. I am used to it. If you think people are bad here, try alt.revisionism.

Isn't there a newsgroup just for flaming?

Other than SED?

Try rec.boats, much worse than here.

They also have a knee jerk liberal that hates any conservative thought..

"Conservative thought" has to be an oxymoron, comparable with "military intelligence".

I knew when I wrote the description I was describing you.

You thought you were. I have actually met some knee-jerk liberals. They are just as obnoxious as their right-wing counterparts,and no less silly.

Because they tend to be attached to silly ideas that haven't been tried in practice, I'd judge them to be marginally more dangerous than their right-wing counterparts, who tend to attached to ideas that more-or-less worked in times gone by. Of course burning fossil carbon for fuel is an idea that more or less worked in times gone by but has become too popular to allow it to persist.

The bottom line is that a knee-jerk reaction can save your knee in the short term, but more careful thought is required to preserve the world for the longer term. Liberals are prepared to contemplate change, while conservatives want to avoid it.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Sunday, 20 July 2014 06:57:28 UTC+10, rickman wrote:

On 7/19/2014 10:24 AM, Neon John wrote:
On Sat, 19 Jul 2014 01:01:09 -0400, rickman <gnuarm@gmail.com> wrote:

There are some knowledgeable people posting here. But you would have a hard time realizing that by reading many of their posts. The signal to noise ratio is rather low which makes it hard to tell what they are actually saying.

Possibly, but I never see that side of things. A few smart-assedremarks and into the killfile they go. I've make a few exceptions such as John Larkin (who should really act his age and stop the bickering with what's-his-name) but mostly it's all good.

Yeah, that isn't going to happen. John has two faults, he loves to argue over petty, personal issues and he can't admit when he makes a
mistake. But yes, he does know his field very well.

Parts of it. He could know a good deal more about the kinds of transformers you wind - or get wound - to deal with specific problems.

It's a rather specialised subject, but the right transformer can be remarkably useful in some projects.

--
Bill Sloman, Sydney

--



Rick

 

[Joerg]

rickman wrote:

On 7/18/2014 4:02 PM, Joerg wrote:
rickman wrote:
On 7/18/2014 12:35 PM, Joerg wrote:
rickman wrote:
On 7/17/2014 8:06 PM, Joerg wrote:

When I showed up for my first interviews I brought a thick binder
with
all my project documentation and photos in there. Couldn't bring much
gear because it was way too big and heavy. Folks at the university
said
that would be ridiculous and hiring managers wouldn't take me
serious.
Little did they know. It's too long ago but I believe out of six
interviews I got six offers. A few months later I gave one of the
hiring
managers who interviewed me a ride home because his car had a
problem.
"Hey, George, can we go by your house? I want to see that monster amp
you talked about back in summer."

I'm not sure 100% offer rate is much of an indicator. But I guess it
does indicate that you get the offers which means you can cull the
employers.

I used to get 100% offer rate. The headhunters always wanted me to
either accept or turn down an offer quickly without more
interviews, but
I wanted to see what else was out there. But now that I am over 50...
well over 50 it is actually hard to get an interview much less an
offer.
Age discrimination is real... very real. Fortunately I am not
in need
of a job.


I am finding the opposite. Once I approached 50 the number of
headhunter
calls increased but because I was already self-employed I had to turn
them all down. From my resume which is on the Internet it is very easy
to gauge my age. The usual, army service, year of degree, etc. when
they
look for consultants it becomes even more pronounced, they ideally want
someone who has seen it all and that requires having a few decades of
engineering under the belt.

Oh, there is no shortage of headhunter calls. lol That is a universal
constant even more-so than the speed of light.


Those were real jobs and we talked about them in some detail. In the
area of analog companies are sometimes desparate.

I'm not sure what your point is. Headhunters contact me all the time
about real jobs. That is what they do, find people for real jobs...
they get paid for that. That is very different from landing an offer.

The calls I get are usually for jobs where the situation is already
dire. Project hugely behind schedule, someone has royally screwed up,
something has hit the fan, things like that. If I'd say yes it would be
a matter of days and the paperwork and moving company would be lined up.
The best one so far was where they wanted to send an aircraft to our
local landing strip in town to pick me up for a meeting (I can walk
there in minutes).

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Adrian Jansen]

On 19/7/2014 4:31 PM, Sylvia Else wrote:

On 18/07/2014 8:57 AM, michaelcovington670@gmail.com wrote:
Hello everyone. I am an electronics student and in the process of
learning, and I was wondering if I could join this group? I am
thinking it would be a good way to learn more from others with more
experience and maybe help me if I have a problem in school that I
can't get answered easily. LOL. I wanted to pop in and ask before I
joined.

Thanks,

Michael


Hmm...

No further response from Michael.

I smell a troll.

Sylvia.

Maybe he has been overwhelmed by all the good advice.

--
Regards,

Adrian Jansen adrianjansen at internode dot on dot net
Note reply address is invalid, convert address above to machine form.

 

[Jeff Liebermann]

On Sat, 19 Jul 2014 16:31:30 +1000, Sylvia Else
<sylvia@not.at.this.address> wrote:

No further response from Michael.
I smell a troll.
Sylvia.

Quite likely, since reverse DNS of his posting IP address doesn't
resolve. Time to do some snooping:

C:\> dig +noall +answer 184.20.84.192
184.20.84.192. 0 IN A 184.20.84.192

C:\> host 184.20.84.192
Host 192.84.20.184.in-addr.arpa not found: 2(SERVFAIL)

C:\> nslookup 184.20.84.192

set type=ANY
server 8.8.8.8

Default Server: google-public-dns-a.google.com
Address: 8.8.8.8
> 184.20.84.192
Server: google-public-dns-a.google.com
Address: 8.8.8.8
*** google-public-dns-a.google.com can't find 184.20.84.192:
Non-existent domain

The block is owned by Viasat:
<http://whois.arin.net/rest/net/NET-184-20-0-0-1>
which means satellite internet on Exede/Wild Blue.


C:\> tracert 184.20.84.192
Traceroute puts him somewhere in the Phoenix AZ area:
14 38 ms 38 ms 38 ms ae-62-62.ebr2.LosAngeles1.Level3.net
[4.69.137.17]
15 66 ms 39 ms 39 ms ae-1-4.bar2.Phoenix1.Level3.net
[4.69.133.37]
16 38 ms 68 ms 37 ms ae-0-11.bar1.Phoenix1.Level3.net
[4.69.148.113]
17 39 ms 37 ms 37 ms VIASAT-INC.bar1.Phoenix1.Level3.net
[4.28.80.130]
18 * * * Request timed out.
19 * * * Request timed out.
20 * * * Request timed out.
21 661 ms 674 ms 682 ms 184.20.84.192


Ping returns a rather high latency. 650 to 750msec is typical of
satellite internet connections:
C:\dig> ping 184.20.84.192
Pinging 184.20.84.192 with 32 bytes of data:
Reply from 184.20.84.192: bytes=32 time=620ms TTL=47
Reply from 184.20.84.192: bytes=32 time=619ms TTL=47
Reply from 184.20.84.192: bytes=32 time=625ms TTL=47
Reply from 184.20.84.192: bytes=32 time=623ms TTL=47


C:\> nmap -sV -O -v 184.20.84.192
Starting Nmap 4.22SOC6 ( http://insecure.org ) at 2014-07-19 20:52
Pacific Daylight Time
Initiating Ping Scan at 20:52
Scanning 184.20.84.192 [2 ports]
Completed Ping Scan at 20:52, 0.72s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 20:52
Completed Parallel DNS resolution of 1 host. at 20:52, 0.64s elapsed
Initiating SYN Stealth Scan at 20:52
Scanning 184.20.84.192 [1705 ports]
Discovered open port 625/tcp on 184.20.84.192
SYN Stealth Scan Timing: About 47.88% done; ETC: 20:53 (0:00:32
remaining)
Completed SYN Stealth Scan at 20:54, 91.95s elapsed (1705 total ports)
Initiating Service scan at 20:54
Scanning 1 service on 184.20.84.192
Completed Service scan at 20:55, 75.03s elapsed (1 service on 1 host)
Initiating OS detection (try #1) against 184.20.84.192
Retrying OS detection (try #2) against 184.20.84.192
Initiating gen1 OS Detection against 184.20.84.192 at 179.734s
For OSScan assuming port 625 is open, tcp/1 and udp/38604 are closed,
and neither are firewalled
SCRIPT ENGINE: Initiating script scanning.
Host 184.20.84.192 appears to be up ... good.
Interesting ports on 184.20.84.192:
Not shown: 1701 closed ports
PORT STATE SERVICE VERSION
19/tcp filtered chargen
53/tcp filtered domain
625/tcp open apple-xsrvr-admin?
1720/tcp filtered H.323/Q.931
Device type: general purpose
Running: IBM AIX 4.X
OS details: IBM AIX 4.3.2.0-4.3.3.0 on an IBM RS/*
Uptime: 5.409 days (since Mon Jul 14 11:06:38 2014)
TCP Sequence Prediction: Difficulty=9999999 (Good luck!)
IPID Sequence Generation: Randomized
Read data files from: C:\ZIP\Nmap\nmap-4.22SOC6
OS and Service detection performed. Please report any incorrect
results at http://insecure.org/nmap/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 193.094 seconds
Raw packets sent: 1847 (85.588KB) | Rcvd: 1843 (86.482KB)

Summary: He's somewhere in the Phoenix AZ area. Nmap is returning an
AIX signature, probably because I'm using a 2007 version of nmap. My
guess is it's really an Exede satellite router. The computer is an
Apple something running Lion or before because of the open port 625
(Open Directory Proxy). Port 1720 might be an H.323 softphone on the
Mac or an Exede VoIP "voice adapter". No clue why port 19 (character
generator) is open.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Sylvia Else]

On 20/07/2014 2:32 PM, Jeff Liebermann wrote:

On Sat, 19 Jul 2014 16:31:30 +1000, Sylvia Else
sylvia@not.at.this.address> wrote:

No further response from Michael.
I smell a troll.
Sylvia.

Quite likely, since reverse DNS of his posting IP address doesn't
resolve. Time to do some snooping:

Well, if he is a troll, I think he'll be disappointed with what were, by
and large, very measured responses.

The desired response would have consisted of diverse lectures on the
nature of unmoderated Usenet groups, interspersed with claims about his
ancestry, personal hygiene habits, and mental health.

But trolls are not what they used to be.

Sylvia.

 

[John Fields]

On Thu, 17 Jul 2014 18:13:50 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:


>I get essentially no mail at the jlarkin address.

---
From:

news:vtlgs9ho37kcig8097m2qoj8p4ldbdnnkn@4ax.com

"Ignore any people that you don't like."

Sounds like people are taking your advice!

John Fields

 

[John Fields]

On Sat, 19 Jul 2014 14:26:35 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sat, 19 Jul 2014 16:57:28 -0400, rickman <gnuarm@gmail.com> wrote:

John has two faults, he loves to
argue over petty, personal issues and he can't admit when he makes a
mistake. But yes, he does know his field very well.

I thought the HV blinker was an interesting problem, if only because almost
every proposed circuit - including Jim's, including roughly 100 scribbles of
mine - had some insidious flaw. Discussing stuff like that isn't petty or
personal.

---
Nor does it negate the statement that you love to argue over petty,
personal issues - notice the specific, irrelevant, reference to JT -
and that you can't admit when you make a mistake; especially when
that mistake is found by someone other than yourself.

Well, you can, really, but only when you can be part of, and the
arbiter of, a group making mistakes.

John Fields

 

[Jeff Liebermann]

On Sun, 20 Jul 2014 17:03:14 +1000, Sylvia Else
<sylvia@not.at.this.address> wrote:

On 20/07/2014 2:32 PM, Jeff Liebermann wrote:
On Sat, 19 Jul 2014 16:31:30 +1000, Sylvia Else
sylvia@not.at.this.address> wrote:

No further response from Michael.
I smell a troll.
Sylvia.

Quite likely, since reverse DNS of his posting IP address doesn't
resolve. Time to do some snooping:

I made a mistake in my analysis. He's not in the Phoenix AZ area.
That's where one of the Exede satellite downlink gateways is located.
He could be anywhere in North America within LOS of one of the 4 Exede
satellites.

Well, if he is a troll, I think he'll be disappointed with what were, by
and large, very measured responses.

I didn't read all there responses, but I would have expected at least
one suggesting that beginning electronics students have more
appropriate and extensive resources at their school than on Usenet. At
least that was the traditional response to anyone asking for help with
his homework. I'm undecided if this is a good idea.

The desired response would have consisted of diverse lectures on the
nature of unmoderated Usenet groups, interspersed with claims about his
ancestry, personal hygiene habits, and mental health.

That's the traditional newsgroup hazing, most of which is a thinly
disguised probe attempting to determine the posters intellectual,
moral, political, and social standing. It really helps to know whom
I'm insulting. Posting in sci.electronics.design often adds probing
questions on one's position on RoHS solder, anthropogenic global
warming, Obamacare, and a few odd electronics related issues. It's
handy to know these because discussion topics invariably drift in
these directions, depending on a persons areas of interest and
expertise.

>But trolls are not what they used to be.

Yep, times have changed. These daze, a troll might really be a bot or
the NSA.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Bill Sloman]

On Monday, 21 July 2014 10:05:50 UTC+10, Clifford Heath wrote:

On 20/07/14 12:30, Bill Sloman wrote:

... the kinds of transformers you wind - or get wound - to deal with specific problems.

It's a rather specialised subject, but the right transformer can be remarkably useful in some projects.

Bill, I'm interested in anything you have to say on the subject.

I recently started looking at Tektronix' pulser/sampler design from e.g. the 1503C TDR unit, and their 1960's sampling scopes which use transformers in various interesting ways I hadn't seen before, and surely wouldn't know how to design. Can you summarise the field or point to some sources I could read?

Not really. The subject is really badly taught. I put in a request to Win Hill to get the transformer equations in the third edition of AOE.

The equations are

V1= L1.dI1/dt + M.dI2/dt

V2= M.dI1/dt + L2.dI2/dt

Where V and I are the voltages across the first and second coils in the transformer, and the currents through them. L1 is the inductance of the first coil, L2 the inductance of the second coil and M the mutual inductance, equal to the root of L1.L2 in a perfectly coupled transformer, and above 0.99 of that figure in many real ones.

The equations aren't magic, but I first came across them after I'd been playing with transformers - off and on - for about ten years, and they made everything a lot clearer.

Searching on the Blumlein Bridge isn't all that helpful. "Coaxial AC Bridges" by Rayner and Kibble gets you into the right ball-park, but it's basically about tricks you can play with very specialised transformers in a National Standards Lab - Rayner and Kibble both worked at Teddington at the UK National Standards Lab - so it's for rather advanced students.

The classic text

http://www.amazon.com/Alternating-Current-Bridge-Methods-Hague/dp/0273402919

is the sixth edition, published in 1971 long after Hague had died. The first edition apparently came out in 1923.

http://www.ietlabs.com/pdf/GenRad_History/A_History_of_Z_Measurement.pdf

Transmission line transformers are another interesting field of study. My favourite reference for that is

Matick R E 1968 "Transmission Line Pulse Transformers - theory and application" in the Proceedings of the IEEE volume 56, pages 47-62.

There are plenty of others, but I've yet to come across a decent text-book for that either

--
Bill Sloman, Sydney

 

[Clifford Heath]

On 20/07/14 12:30, Bill Sloman wrote:

... the kinds of transformers you wind - or get wound - to deal with specific problems.
It's a rather specialised subject, but the right transformer can be remarkably useful in some projects.

Bill, I'm interested in anything you have to say on the subject.
I recently started looking at Tektronix' pulser/sampler designs
from e.g. the 1503C TDR unit, and their 1960's sampling scopes,
which use transformers in various interesting ways I hadn't seen
before, and surely wouldn't know how to design. Can you summarise
the field or point to some sources I could read?

Clifford Heath.