HDTenEightyP/NetNews huggingface dataset:
From: dt@yenta.alb.nm.us (David B. Thomas)
Newsgroups: sci.electronics
Subject: Re: Need Help with Two Phone Projects
Date: 14 Oct 92 07:43:59 GMT
Organization: yenta unix pc, rio rancho, nm

STATRAA@YaleVM.YCC.Yale.Edu writes:

>I need to build a Hold circuit for a phone line.

Easy... just put a 600 ohm (or so) resistor across the line.  The line will
stay connected.  If you put a transformer in series with this resistor,
and then pipe audio into the other end, presto! you've got music on hold.

>Also, if anyone knows how to do this easily, I would like to build a
>multi-line adaptor for my single line phone.

This wouldn't be complicated.  The line is 0V when not connected, about 9V
when in use, about 48V when available, and 90VRMS 20Hz AC when ringing.
These are easy to tell apart!  In fact, if you make a 'window' type
comparator circuit with two comparators so that the "line unavailable" light
comes on whenever the voltage is less than 4V (say) or greater than 25...
the wildly fluctuating ring voltage will make the indicator flutter without
any more effort on your part!  Make sure you use diode clamps to protect the
inputs to your comparators.

I built something like this for two lines.  Each line had a status indicator
and a hold switch (music on hold if you want it).

							David
-- 
I'm a poet and I'm unaware of it.
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Newsgroups: sci.electronics
Subject: Re: Sam's Photofacts
Date: 8 Oct 92 23:27:08 GMT
Article-I.D.: athena.1992Oct8.232708.13459
Organization: AI Programs, University of Georgia, Athens

In article <1992Oct8.225455.3016@col.hp.com> cab@col.hp.com (Chris Best) writes:
>Not a secret at all.
>
>> 1-800-USA-SAMS, or order through Radio Shack.
>
>Could be, but the number that worked for me a few months ago is:
>(800) 428-7267, customer service.

Hmmm, that's 1-800-GAT-SAMS.  Wonder what they mean by GAT?

-- 
:- Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:- Artificial Intelligence Programs       phone 706 542-0359
:- The University of Georgia                fax 706 542-0349
:- Athens, Georgia 30602 U.S.A.          amateur radio N4TMI
From: schumach@convex.com (Richard A. Schumacher)
Newsgroups: sci.electronics
Subject: Re: Soldering using flux!
Date: 14 Oct 92 23:47:33 GMT
Article-I.D.: convex.schumach.719106453
Organization: CONVEX Computer Corporation, Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1992Oct14.010119.6107@u.washington.edu> whit@milton.u.washington.edu (John Whitmore) writes:

>	Of course, the flux operates at high temperature; at room
>temperature, it's pretty innocuous stuff.  Rosin (pitch from trees)
>and zinc chloride and borax are typical flux components.  For
>stainless steel, add sulphuric acid to the list...

Not all fluxes are innocuous! Fluxes for aluminum which contain
amines [amines? why amines? I don't know] are serious carcinogens
and not to be toyed with.
From: rwc@ius4.ius.cs.cmu.edu (Randy Casciola)
Newsgroups: sci.electronics
Subject: Tech 2000 (or whatever) film again!
Date: 9 Oct 92 16:50:52 GMT
Article-I.D.: cs.Bvv5Gt.87y.2
Organization: CMU Vision and Autonomous Systems


I realize that we just finished a long discussion about the iron-on
PCB film a couple months ago, but I had not saved the information
because I had no need for it.  Now, I would like to use this method
to make a few small boards; boards that I can't justify spending
$400-$500 on.  So if anyone has a list of the companies that make
this film and a phone number for anyone who sells it, I would greatly
appreciate it.  Or even if you don't have a list and just know of
one, could you send mail.

Thanks,
Randy
From: cyberman@toz.buffalo.ny.us (Cyberman)
Newsgroups: sci.electronics
Subject: Re: electron orbitals
Date: 11 Oct 92 01:40:48 GMT
X-Maildoor: WaflineMail 1.00r


   Jason Goga was espousing about 'electron orbitals',
   on [10-08-92  21:16] to All!
 JG> I was in chem class the other day (as usual) and we were discussing
 JG> the various shapes of orbitals at the various energy levels of
 JG> electrons. Now we discussed S, P, D, and F. However no 3d picture of
 JG> an 'F' orbital was given. I was wondering if such a plot exists and if
 JG> so can I get a copy. 
 JG> ALSO, the S orbital is symetrical, so is the P. However in 3dx2 there
 JG> is this 'dougnut' shaped orbital, whereas it's counterparts are
 JG> ovalish. Why is this?

    This is a good question for a phyisics newsgroup.  I would
    explain it but unless you've had Differential Equations and
    several years of calculoous it would appear a shear gibberish
    to you.  It's not very simple unfortunately.  It also has a
    bit to do with chaos theory.

            Stephen Cyberman@Toz.Buffalo.NY.US
            Scripted at Sat  10-10-1992  16:09:01

... Rubber bands are hazardous to pets if swallowed.
--- Blue Wave/QWK v2.10
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Newsgroups: sci.electronics
Subject: Re: why is one prong on plug wider than the other?
Date: 14 Oct 92 01:42:13 GMT
Distribution: usa
Organization: AI Programs, University of Georgia, Athens

In article <92836@netnews.upenn.edu> george@mech.seas.upenn.edu writes:
>:
>:In older metal appliances, before the 3rd grounding pin, one of the
>:120 lines were attached to the case of the appliance to be used as a
>:ground.  Back then there was no standard side of the 120 to be used as
>:ground so either one was used.. 
>
>but..but.. polarized plugs ( it seems ) weren't common until
>the mid 70's ( remember the little explanatory tags ).  Three prong
>grounded plugs were available long before that ( no? )

You're right.  Under no circumstances was it _ever_ permissible to
connect one side of the 120V line to the case of the appliance.

In 1950, you used a 3-prong grounded plug if you wanted/needed to ground
the case of the appliance; otherwise you used a 2-prong UN-polarized plug.

Gradually it was realized that lots of things could be made safer
(w.r.t. likely short circuits, effects of blown fuses, etc.) if you
could be sure which side of the line was closer to ground potential.
Hence the polarized plug.

-- 
:- Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:- Artificial Intelligence Programs       phone 706 542-0359
:- The University of Georgia                fax 706 542-0349
:- Athens, Georgia 30602 U.S.A.          amateur radio N4TMI
From: neal@cmptrc.lonestar.org (Neal Howard)
Newsgroups: sci.electronics
Subject: Re: electron orbitals
Date: 10 Oct 92 04:06:27 GMT
Organization: CompuTrac Inc., Richardson TX

In article <718623068.5@mailbox.bison.mb> Jason.Goga@mailbox.bison.mb.ca (Jason Goga) writes:
>I was in chem class the other day (as usual) and we were discussing the various
>shapes of orbitals at the various energy levels of electrons. Now we discussed 
>S, P, D, and F. However no 3d picture of an 'F' orbital was given. I was wonder
>ing if such a plot exists and if so can I get a copy.
>
>ALSO, the S orbital is symetrical, so is the P. However in 3dx2 there is this '
>dougnut' shaped orbital, whereas it's counterparts are ovalish. Why is this?
>
>-Jason

I don't have the specific answer to the shape of the "d" orbitals, but I can 
tell you that it has something to do with Scroedinger's Equation (the oe is
really an "o" with an umlaut over the top) and the square of the wave function
which is included four times within the equation. The value represented by the
square of the wave function is related to the probability of finding an electron
in some certain region in space around the nucleus of the atom (actually the
electron density in that region). The "shape" of an orbital, or "boundary
surface" is only a diagram of the areas where the electron density is highest
according to about a 90 percent probability. The actual shape of the orbitals
may actually be different, the shapes we see in our textbooks are only those
areas corresponding to probability functions. I can see I'm fast getting out
of my area of familiarity on this topic and suggest you might want to post
to sci.physics for better explanations on why these probability functions are
shaped the way they are. That subject gets into the area of quantum mechanics,
wave mechanics, sub-atomic particle interactions, etc. which makes my brain
hurt. I better just stick to making electrons flow thru circuitry without 
worrying about how atoms work internally.

Peace,
Neal
=============================================================================
Neal Howard (neal@cmptrc.lonestar.org)        CompuTrac, Inc. (Richardson,TX)
DoD #686   '91 XLH-1200      '70 Kawasaki G4-100cc    '69 Cougar XR7-GT390
	   Ensoniq VFX-SD    Kramer Pacer guitar      '70 429CJ(needs a home)
Disclaimer: The only above mentioned toys I play with on the below mentioned
	    Friday nights are the musical ones 8*}
"how often you get much more drunk than you ought to on a Friday night...
...about once a week" -  Tom Yates
=============================================================================
From: ridder@zso.dec.com (Hans Ridder)
Newsgroups: sci.electronics
Subject: Re: Thunderstorms
Date: 8 Oct 92 21:13:41 GMT
Article-I.D.: ninja.1992Oct8.211341.10686
Organization: Digital Equipment Corporation - DECwest Engineering
Originator: ridder@zowie.zso.dec.com

In article <71@gobi.UUCP> stevek@gobi.UUCP (Stephen Kogge) writes:
>	My dad's theory is that anything plugged in has a clean
>path to ground, anything with an unplugged cord was charged up and sparked
>to ground.

Good theory, IMHO.

>	About 3 years ago I was on my way to the Red Sea and lightning
>decided to hit another of those little 30 inch diameter oaks. This was
>just over our property line on park land. The top 50 feet of the oak
>was turned to tree bits... This time the TV cable box was history one
>Sony VCR had a cute little hole blown in the tuner board and a small TV
>in another room has a tuner that no longer works.  The discharge path
>was a strange one since other receivers were not touched. The antenna
>distribution amp was also history with the bleed resitors connected to
>the coax charred.

I'll wager that the cable TV/antenna ground wasn't (well) bonded to the
power system ground, so that the little components in the various TV,
VCR, and cable box tuners became a handy path to the power system
ground (via the neutral on 2-wire devices.)

To all you folks grounding your antennas after hearing the stories here,
I (and the NEC) suggest that you make sure that you either ground them
to the power system ground, or bond the two grounding systems together
well.  The same goes for cable TV, and telephone.

>	My advice. Be sure you have a clean path to ground == leave
>everything plugged in. When ligthning stikes it will take out what it
>wants (actually electronics evolution at work as the poor ground path
>designs demonstrate their faulty "genes").

That's always been my (unpopular) thinking.

>Those one-use 30cent MOV's are of questioanble use when lightning is
>measured in a megawatts. I have never met anyone who actually replaces
>all the MOVs after every storm, or season. When I have asked about
>testing MOVs I get the answer there is no way to test them so you just
>replace them often if you expect them to work.

I wonder how many of those supposed "surge suppressors" are purchased in
the name of "lightning protection?"  ;-) What *are* those things good
for?

>	Steve Kogge

-hans
-- 
  Hans-Gabriel Ridder				Digital DECwest Engineering
  ridder@rust.zso.dec.com			Bellevue, Washington, USA
  {pacbell,pyramid,uunet}!rust.zso.dec.com!ridder
Newsgroups: sci.electronics
From: rick@cs.sunysb.edu (Richard Spanbauer)
Subject: Re: FM Receiver Project Plans?
Organization: State University of New York, Stony Brook
Date: Mon, 12 Oct 1992 14:22:30 GMT

In article <1992Oct11.014028.3158@norfolk.vak12ed.edu> fmathews@norfolk.vak12ed.edu (Frank Matthews) writes:
>I am an electronics teacher in a high school.  I am always on
>the lookout for fresh project ideas for the students to build.
>I felt that a simple fm receiver capable of picking up the
>local police, fire, or rescue would be fun and interesting to
>make.  I thought that it might even generate some interest in
>the 2 meter ham band as well.  If anyone has any schematics or
>plans for such a project...I would appreciate hearing from
>you.  Even if it is not a tunable circuit (such as a crystal
>controled frequency) that would be fine. I found a kit through
>Ramsey electronics, but as you know....schools are on a tight
>budget.  Thanks,
>		Frank Matthews
>		Indian River High School
>		Chesapeake, VA  23325


	You might check out the ARRL Publication call "QEX" - there was
	a simple 2M receiver project in the April 1991 issue.  The receiver
	consists of 3 inexpensive chips and about 50 discretes.  If you
	changed the discretes to through hole parts (author used SMD), it
	would make an appropriate project for a HS electronics
	class (at least we used to build things of similar complexity in 
	my HS electronics class).  It should be possible to tweak the circuit
	to cover the VHF police/fire, etc range.

	You can reach the ARRL at (203) 666-1541.

					Rick Spanbauer
					State University of NY
From: brown@vidiot.UUCP (Vidiot)
Newsgroups: sci.electronics
Subject: Re: RF to A/V
Keywords: cable, RF, A/V
Date: 16 Oct 92 04:52:27 GMT
Article-I.D.: vidiot.4278
Reply-To: brown@vidiot.UUCP (Vidiot)
Distribution: na
Organization: Vidiot's Hangout

In article <1992Oct15.133811.7126@cbfsb.cb.att.com> wee@cbnewsb.cb.att.com (william.e.erickson) writes:
<
<The set top box supplied by my cable company is RF output only.  Is there
<a device available to 'convert' this to baseband (A/V jacks)?  The cable
<box must be used as channel selector, this cable company scrambles 
<everything.
<
<                   ----------        ----------          -----------
<      From         | Cable  |        |        |---(A)--->| Monitor/|
<      Street(RF)-->|  Box   |-(RF)-->|?device?|          |   TV/   |
<                   |        |        |        |---(V)--->|   VCR   |
<                   ----------        ----------          -----------

Why bother.  Your TV and VCR will perform that function for you.
-- 
      harvard\                          spool.cs.wisc.edu!astroatc!vidiot!brown
Vidiot  ucbvax!uwvax..........!astroatc!vidiot!brown
      rutgers/            INTERNET:vidiot!brown%astroatc.UUCP@spool.cs.wisc.edu
                                   brown@wi.extrel.com
Newsgroups: sci.electronics
From: tchannon@black.demon.co.uk (Tim Channon)
ReplyTo: tchannon@black.demon.co.uk
Subject: Re: Stumped by op-amps
Distribution: world
X-Mailer: cppnews $Revision: 1.18 $
Organization: null
Date: Fri, 9 Oct 1992 01:47:26 +0000

There is a paper published in Electronics World + Wireless World October 1992 
(current issue) for a superb microphone amp aimed at professionals using DAT 
where the average mic amp is terrible.

The design is simple and is battery powered.

There is a bit of history to this: we were offered the design for manufacture 
some months ago but for various reasons it seems to have been declined. My 
view after examining the circuit in depth is that the basic design is good 
with few opportunities to improve it without resorting to significantly 
increased complication and cost. 

  TC. 
    E-mail: tchannon@black.demon.co.uk or tchannon@cix.compulink.co.uk
From: george@coral.micro.umn.edu (Rogers George)
Newsgroups: sci.electronics
Subject: Re: HELP! what's a SYSTEMIZER
Date: 13 Oct 92 15:32:18 GMT
Article-I.D.: news2.1992Oct13.153218.15762
Distribution: usa
Organization: University of Minnesota CIS

In article <1992Oct4.224658.8815@phx.mcd.mot.com> hbg6@phx.mcd.mot.com (John Schuch) writes:
>
>At an auction this past weekend I picked up 10 devices and can not
>quite figure out what they are.
>
>The box is about the size of an old external modem and is labeled
>"SYSTEMIZER  Applied Creative Technology Inc."

>Simple, some kind of smart print-spooler. Problem is I am terribly
>curious about the RJ-11 connector and the DIP switch. If this is some
>kind of printer network, I can use it. If not, I'll gut them out for
>the chassis' and power supplies which is why I bought them in the
>first place.

>John Schuch              hbg6@phx.mcd.mot.com              (602)438-3008
>Motorola Computer Group - Technical Systems Division - Manufacturing Eng

Absolutely correct. at the 3M fluorochemical tech center, they're used for
printer sharing. Each computer gets one, and they're all hooked together
through the RJ-11- I'm not sure about the topology, or about what the
'tape' functions do. I'll see if I can get ahold of a manual and scan it;
if anyone has these beasts and wants manual material, mail me.

Rogers George (in that order)
geor0007@student.tc.umn.edu
Newsgroups: sci.electronics
From: arm@helix.nih.gov (Andrew Mitz)
Subject: Re: electron orbitals
Followup-To: sci.electronics
Keywords: physics, chemistry, headache
Organization: National Institutes of Health, Bethesda
Date: Sat, 10 Oct 1992 21:38:35 GMT

In article <Bvw0qr.5qu@cmptrc.lonestar.org> neal@cmptrc.lonestar.org (Neal Howard) writes:
>In article <718623068.5@mailbox.bison.mb> Jason.Goga@mailbox.bison.mb.ca (Jason Goga) writes:
>>I was in chem class the other day (as usual) and we were discussing the various
>>shapes of orbitals at the various energy levels of electrons. Now we discussed 
>>S, P, D, and F. However no 3d picture of an 'F' orbital was given. I was wonder
>>ing if such a plot exists and if so can I get a copy.
>>
>>ALSO, the S orbital is symetrical, so is the P. However in 3dx2 there is this '
>>dougnut' shaped orbital, whereas it's counterparts are ovalish. Why is this?
>>
>>-Jason
>
>I don't have the specific answer to the shape of the "d" orbitals, but I can 
>tell you that it has something to do with Scroedinger's Equation (the oe is
>really an "o" with an umlaut over the top) and the square of the wave function
>which is included four times within the equation. The value represented by the
>square of the wave function is related to the probability of finding an electron
>in some certain region in space around the nucleus of the atom (actually the
>electron density in that region). The "shape" of an orbital, or "boundary
>surface" is only a diagram of the areas where the electron density is highest
>according to about a 90 percent probability. The actual shape of the orbitals
>may actually be different, the shapes we see in our textbooks are only those
>areas corresponding to probability functions. I can see I'm fast getting out
>of my area of familiarity on this topic and suggest you might want to post
>to sci.physics for better explanations on why these probability functions are

Just to make things worse (I am outside of my expertise, for sure), it is my
understanding that the same equations have different solutions.  The chemists
choose one set of solutions because that produces some nice shapes that are
easy to visualize mentally.  There are other "shapes" that offer equally-
good solutions to the same system of equations.  Now, will someone who really
knows this stuff straighten us out, please?



-------------------------------------------------
Andrew Mitz          |    NIH Animal Center
Biomedical Engineer  |    Poolesville, MD
-------------------------------------------------

All opinions expressed are my own.


Newsgroups: sci.electronics
From: kranburg@hlunx3.uto.dec.com (Otto van Kranenburg)
Subject: IR-det. module GP1U52X (Sharp, Radio Shack) & Sony BX1407
Reply-To: kranburg@hlunx3.uto.dec.com (Otto van Kranenburg)
Organization: Digital Equipment Corporation
Date: Thu, 8 Oct 1992 10:33:09 GMT


I'm trying to build a PC-based IR-remote controller, using schematics
I've found on the
net. The device basically works by re-playing a previously recorded
command-signal.  

The IR-signal to be recorded is fed into an IR-detection module sold by
Radio Shack 
(Sharp GP1U52X, Radio Shack RS 276-137) . This "little silver cube"
produces a TTL-level
demodulated version of the IR signal it detects.

I've found no source for this module in Holland.  The only comparable
(?)  thing I came 
across was a "little silver cube", manufactured by Sony, the BX1407. 
However the shop 
I went to, had no data whatsoever about it.

Does anybody know how this thing compares to the Radio Shack/Sharp module ?

*****************************************************************
**  Name : Otto van Kranenburg                 Organisation: 
**  Email: kranburg@hlunx3.uto.dec.com   Digital Equipment BV
**                                                                 P.O.Box 8810
**  Tel (Office): 31 10 453 8213                 3009 AV Rotterdam
**  Tel (Home  ): 31 78 510 245                  The Netherlands
*****************************************************************
Newsgroups: sci.electronics,rec.autos.tech
From: wpeloqui@medar.com (Willie Peloquin)
Subject: Re: GM diagnostic harness
Organization: Medar, Inc.     Farmington Hills, MI
Date: Wed, 7 Oct 1992 20:17:54 GMT

In article <1992Sep24.134143.23375@ll.mit.edu> jth@ll.mit.edu (Joe Healey) writes:
>
>
>I have an 87 Chevy Cavilier and am interested in building a circuit
>that can capture, decode, and display ( in some fashion ) the data
>comming out of the car's diagnostic harness.
>
>Does anyone know of where I can find a technical specification 
>describing the dignostic interface and data stream or if a circuit 
>allready exists ( ie Radio Electronics ) to do this.
>
>I know that these scan tools can be bought, but they are too 
>expensive for me to purchase. 

I just saw a ECM diagnostic tool at a local discount auto parts store. The
cost was @ $40.00. There were three models available. One for each American
car manufacturer.

So they are available and they are fairly inexpensive!

Willie
-- 
Willie Peloquin		      | I'm not a kid anymore, but this ain't no
wpeloqui@medar.com	      | midlife crisis, because whiskey and women
uunet!medar!n8mdy!wpeloqui    | have always been my vices!       Bocephus
Newsgroups: sci.electronics
From: tomv@s20.msi.umn.edu (Tom Varghese)
Subject: Re: f-f-f-fast roms
Organization: University of Minnesota
Date: Fri, 9 Oct 1992 04:27:34 GMT

cyberman@toz.buffalo.ny.us (Cyberman) writes:


>    Masked ROMS are the fastest you can get them at <5ns I
>    suspect ecl versions can be <1ns.  The reson being is that
>    they are much simpler than an EPROM or PROM and merely use
>    diodes that are MASKED programed instead of LINKED.

Anybody out there want to venture a guess on what it costs to make a masked ROM
say a 2Kx8 (or smaller), in a reasonably small quantity  -- a few thousand pcs?
Sources, etc.
From: asdf@Eng.Sun.COM (Glenn Scott)
Newsgroups: sci.electronics
Subject: Re: Need small tool to cut pcb board
Date: 8 Oct 92 17:13:32 GMT
Organization: SunConnect - A Sun Microsystems Business
NNTP-Posting-Host: ono-sendai
In-reply-to: mbevan@ersys.edmonton.ab.ca's message of 8 Oct 92 05:50:06 GMT

In article <820asB1w165w@ersys.edmonton.ab.ca> mbevan@ersys.edmonton.ab.ca (Mark Bevan) wrote:
> vnelson@ccu.umanitoba.ca (Gerald Vernon Nelson) writes:
> 
> - 
> - >>  I am working on a device that I want to manufacture in short numbers.
> - >>The pc board dimensions are roughly 3*3 inches. Its much easier
> - >>to cut my own from stock. Is there a cheap or inexpensive tools that
> - >>could cut 1/16th inch double sided clad board neatly?

  Try using a laminate trimmer.  It's a small router with a base
attachment suitable for cutting glass and phenolic laminates like
Formica or Wilsonart.  This makes beautiful, burr-free cuts.

  I paid about $150 mail-order for a Porter-Cable laminate trimmer kit.
Newsgroups: sci.electronics