HDTenEightyP/NetNews huggingface dataset:
From: louis@tronix.SignalPath.on.ca (Louis Bertrand)
Subject: Re: Metal film resistors and lower distortion
Newsgroups: sci.electronics
Date: 8 Apr 92 17:53:42 GMT
Distribution: world
Organization: Signal Path Designs

>From: v064mb9k@ubvmsb.cc.buffalo.edu (Neil Gandler)
>Newsgroups: sci.electronics
>Subject: Metal film resistors and lower distortion
>Date: 4 Apr 92 20:12:00 GMT

>I have heard that using metal film resistors in an audio power amp design
>give better s/n ratios and lower distortion than carbon film resistors.
>Is this true or just a myth. This is regarding using a power amp I.C.
>not using individual transistors.

Metal film resistors do have a lower thermal noise figure than carbon
film.  They also have lower temp. coefficient and, of course 1% tolerance
instead of 5%.  The difference may not be audible though, depending
on the quality of the IC power amp you are using.  The lower noise figure
might be more noticeable in a low level pre-amp application.

-- Louis
------
Louis Bertrand   *   Lynden, Ontario, Canada   *   (416) 648-8066
Signal Path Designs (Analog - Digital - Audio - Embedded uCs)
louis@SignalPath.on.ca (new -- may not work yet)
louis%tronix@maccs.dcss.mcmaster.ca (old -- still works fine)
Newsgroups: sci.electronics
Subject: HELP Needed with Wire Bonding to PCB's
From: srgpgct@grace.dsir.govt.nz
Date: 9 Apr 92 18:00:20 +1200
Organization: DSIR, Gracefield, New Zealand

We have an application where we are trying to make wire bonds from dice
to a copper-clad PCB. We have a standard thermosonic ball / wedge bonder,
which we normally use to bond dice into packages, and hybrid circuits.
We tried bonding onto a PCB, but without much success. One suggestion is that
the copper is oxidising, as we don't have an inert blanket gas.
If anyone has done this, or knows how, I  would really appreciate hearing
how!  Many Thanks,

Gary Turner                                         
                                                   
DSIR Industrial Development,     Fax: +64-4-569-0117
P.O.Box 31313,                  Work: +64-4-569-0220
Lower Hutt,  ( NZST : +12 )     Home: +64-4-475-8844
New Zealand.      Internet: srgpgct@grv.dsir.govt.nz
From: jstewart@Software.Mitel.COM (John Stewart)
Newsgroups: sci.electronics
Subject: Re: Dick Smith Electronics
Date: 13 Apr 92 21:21:06 GMT
Organization: Mitel. Kanata (Ontario). Canada.

In article <1992Apr12.194309.39284@kuhub.cc.ukans.edu> 2frlclover@kuhub.cc.ukans.edu writes:
>Does anyone know if Dick Smith Electronics still exist ?
>
>Mike

They were all over New Zealand when I worked there. It may be a bit
far for you to go during linch time, but if you do, you'll enjoy the
scenery. :-)


--
John Stewart
Mitel Corp.,
Kanata, Ontario.
1-613-592-2122
Newsgroups: sci.electronics
From: sukenick@sci.ccny.cuny.edu (SYG)
Subject: Motor connections
Organization: City College of New York - Science Computing Facility
Date: Tue, 14 Apr 1992 16:31:26 GMT


Can some one recommend a general procedure for determining motor
connections (and whether a capacitor is required, and where to stick it)
Recs on *good* books on the subject would be appreciated as well.
I have a few AC motors, brushless and universal with anywhere from
3 to a dozen wires hanging out of them. (The two wire and three
wire with the third wire going to the shell are pretty easy to
figure out :-))

thanks!


-- 
					-george
					sukenick@sci.ccny.cuny.edu

Doctor:  "60 milligrams!
From: mcovingt@athena.cs.uga.edu (Michael A. Covington)
Newsgroups: sci.electronics
Subject: Re: Front panel finish
Date: 9 Apr 92 19:22:44 GMT
Organization: University of Georgia, Athens

> take it to an engraving shop

How much _does_ engraving cost?  Sounds intriguing.  Presumably they
could also make engraved plastic panels out of plastic sign material.

-- 
==========================================================================
Michael A. Covington, Ph.D. |  mcovingt@uga.cc.uga.edu  |  ham radio N4TMI
Artificial Intelligence Programs | U of Georgia | Athens, GA 30602  U.S.A.
==========================================================================
Newsgroups: sci.electronics
From: routd@woods.ulowell.edu
Subject: CALL for a newsgroup on LIQUID CRYSTAL TECHNOLOGY.
Organization: University of Lowell
Date: Fri, 17 Apr 1992 17:44:05 GMT

CALL FOR A SCI. GROUP ON LIQUID CRYSTAL TECHNOLOGY.
--------------------------------------------------

Dear netters,

	Liquid Crystals are becoming a major part of our daily lives. Your
watch may have a LCD. Your Car might be having a couple of them! Are not 
they look sleek! If you are not a worker in this area, you might not have
a chance to look at them more closely. If you see Liquid crystals under a 
polarizing microscope, you probably would think,"I have never seen more beautiful
things in life!"
	Liquid crystals, though discovered by a botanist a century ago, only 
became very active by the 1950-60s.This field underwent a sea change in the
later half of this century! First fabrication of LCDs were around 1960-70. 
Discovery of Ferroelectrics, Polymeric Liquid crystals, attracted a lot of
attention to this feild!

	It becomes a meeting ground of so many Physical, chemical and biological
phenomena now. To name a few, There has been similarity in High Tc superconducti
vity and Twist grain boundary phase of smectic phase. Formation of galaxies can be
be understood from temporal observation of liquid crystal defects. etc. DNA
is found to have LC phases!The list is endless...................

	The purpose of this group would be to discuss and solve problems relating
to liquid crystals, new developments, new products, crazy but true ideas etc....

	I have already posted similar requests in the SCI.engr. and SCI.physics
news groups. The response so far has been good, though not terrific. Expectinng
a few more votes and suggestions in this regard.

	Thanx in advance.

	Deeleep K. Rout
==================================================================================
Dept. of Chemistry
U Mass. Lowell
MA 01854

(508)-934-3712 (Lab.)
routd@woods.ulowell.edu
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
From: levy@levy.fnal.gov
Newsgroups: sci.electronics
Subject: Intel 8749 cross-assembler/compiler
Date: 6 Apr 92 20:33:26 GMT
Organization: Fermilab Computing Division

Oops... forgot the title   :-)

I'm considering designing/building a project using the Intel 8749
microcontroller.  The problem is, however, that I can't seem to find a (good)
PC-based cross compiler.  If you know of any, please e-mail me.  This group
is so busy, as am I, that I'm afraid that a post might be missed.  If there
is any interest, I'll summarize the reponses for the group.

Thanks in advance.

================================================================================
[ Mark E. Levy, Fermilab          |                                            ]
[ BitNet:   LEVY@FNALD            | Unix is to computing                       ]
[ Internet: LEVY@FNALD.FNAL.GOV   |       as an Etch-a-Sketch is to art.       ]
[ HEPnet/SPAN: FNALD::LEVY (VMS!) |                                            ]
================================================================================
From: pzh@aeg.dsto.oz.au (P.Heuer-AEG)
Newsgroups: sci.electronics
Subject: Re: what are these chips?
Date: 10 Apr 92 16:30:44 GMT

root@galaxy.prime.com (Joe Polcari) writes:

>Does anyone know what these IC's are &/or can fax me data sheets?

>MB89715ap-310
>uPD7507hcu-203
>MAX232cpe
>TL1596cd
>uPD7564g-540

>Thanks, joe.


>===============================================================================
>	Joe Polcari, QCE Systems Group, Computervision, Bedford, MA USA
>jpolcari@galaxy.prime.com   Voice: 6172751800x4489  Fax: 6172710017  RF: WA1PQE
>===============================================================================
Joe,
The MAX232 is a +5 volt powered, dual RS232 transmitter/receiver chip. It is made by:	Maxim Integrated Products, Inc.,
			120 San Gabriel Drive, Sunnyvale, CA 94086, USA.
			Tel: 408-737-7600 Fax: 408-737-7194
			
That's the only one I can help with, and before any problems arise, I have no connection at all with MAXIM. We only use their chips.

Cheers,

Paul Heuer,										E-mail : pzh@aeg.dsto.oz.au
Avionics Engineering Group						Phone  : +61 8 259 6453
Aeronautical Research Laboratory				FAX    : +61 8 259 5507
Defence Science and Technology Organisation		Post   : Bld 37 TSAS
AUSTRALIA												 PO Box 1550 Salisbury
														 South Australia 5108
Newsgroups: sci.electronics
From: billw@regal.cisco.com (William )
Subject: Re: LED limitations on FPDs
Followup-To: sci.electronics
Organization: cisco Systems, Inc.
Date: Tue, 7 Apr 1992 10:10:36 GMT

huh?  The big problems with LEDs for displays is that they aren't subject
to nice manufacturing techniques to make big pannels of them.  On top of
that, they draw WAY more power than even a backlit lcd display.

BillW
Newsgroups: sci.electronics,rec.pyrotechnics,alt.locksmithing
From: jmaster@intelhf.hf.intel.com (Justin Masters)
Subject: Re: Proximity detectors, flash pots, smoke pots, radio control
Reply-To: jmasters@pcocd2.intel.com
Organization: Development Tools Operation, Intel Corp., Hillsboro  OR
Date: Fri, 17 Apr 92 03:34:52 GMT

kolstad@cae.wisc.edu (Joel Kolstad) writes:

>In article <66qaJB1w164w@obmarket> michaelc@obmarket (Michael Campbell) writes:
>>
>>On a related note, I've heard that modern fire alarms in buildings, (the
>>kind you set off, not the automatic kind) have the paint spraying
>>mechanisms similar to the ones in bank bags.  (Explode on you, literally
>>painting you red.  Sometimes blue.  Impossible to wash off).  True, not
>>true?

>Heh... sounds like a good idea for places where frequent false alarms are
>placed! (schools, dorms, etc.)

>I don't know if that's true, but I did here a somewhat similar story from
>my high school chemistry teacher: Their school was having problems with
><somebody> pulling false alarms.  So, they simply coated the pull levers
>with <some chemical> (a chemmies can probably say what) that turned the
>puller's fingers purple for days!

>Apparently they caught the scum who was doing it...

>						---Joel Kolstad

It was probably iodine crytals.
From: jasonh@aeras.uucp (Jason Harris)
Newsgroups: sci.electronics
Subject: Re: Dick Smith Electronics
Date: 14 Apr 92 19:19:20 GMT
Reply-To: jasonh@aeras.UUCP (Jason Harris)
Organization: Arix Corporation, San Jose, CA.

In article <1992Apr12.194309.39284@kuhub.cc.ukans.edu> 2frlclover@kuhub.cc.ukans.edu writes:

>Does anyone know if Dick Smith Electronics still exist ?
>
>Mike

I don't know if Americans are generally aware of this but Dick Smith 
Electronics is an Australian based electronic store. DSE started in Sydney
around 1970 and now has several shops in every major Australian city. Back in
the 1980's (forget what year) they decided to go international with a store
in Silicon Valley. Although I have not been there I seem to remember seeing
an ad for it recently.

As for Dick himself, he sold DSE years ago. Cashed up and ready for adventure
he took to flying his helicopter to unlikely places. Eg: Around the world, 
To the North Pole, etc. These days he is busy running The Australian Geographic,
a fine magazine, somewhat in the mold of the National Geographic.

DSE has, in my opinion, declined in standards since Dick left the helm. These
days it is virtually indistinguishable from Radio Shack, or Tandys as it is
known in Australia. DSE doesn't have much to offer the hobbyist these days
and the people that work there don't know a resistor from an LED. 
 
When in Australia you are better off going to Jaycar or Altronics.

*******************************************************************************
Jason Harris (22,Leo,ElectronicE)
 an ex-resident of Perth, Western Australia, lately of Milpitas, California

E-MAIL: apple.com!aeras!jasonh 
SNAIL-MAIL: Arix Corporation, 871 Fox Lane, San Jose CA, 95131 USA
VOICE-MAIL: (USA) 408-922-1839

I don't think. Therefore I am.
*******************************************************************************
Organization: Doctoral student, English, Carnegie Mellon, Pittsburgh, PA
Newsgroups: sci.electronics
Date: Wed, 15 Apr 1992 17:10:03 -0400 
From: Ken Zuroski <kz08+@andrew.cmu.edu>
Subject: Electronic Delays--how do they work?

Howdy--

I was listening to a radio talk show the other day; some caller who
was speaking to the host uttered some offensive word, and the
host hit the button, which presumably made the show jump to "real
time" from the seven-minute delay it had previously been running
under. 

Apparently it takes some time for the delay to "charge up" again,
as the host would not take another call until the delay light lit
up again. My question: how do these things work? Are the electronics
necessary to incorporate such a thing very complex? Even with my
limited understanding of electronics theory, I can understand how
a delay might work if the signal was digital, but how is an
analog signal delayed? In order for the delay to "build up" to the
seven-second mark again, the signal must slowly be delayed from
0 to 7 seconds; where does this extra time come from so that it
is not noticeable? Does it in any way affect the frequency of the
original signal, i.e., a voice might be imperceptibly lower in
pitch?

Thanks for any info. Just curious.

kz


~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ken Zuroski
Department of English
Carnegie Mellon University
Pittsburgh, PA 15213 USA
kz08@cmu.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Newsgroups: sci.electronics
From: gryzwa@mr.med.ge.com (Mark Gryzwa 4-6860)
Subject: Looking for Precision RC and R Networks
Keywords: Precision, Resistor, Capacitor
Organization: GE Medical Systems, Magnetic Resonance
Date: Thu, 16 Apr 92 20:28:07 GMT

I am looking for a source of precision Resistor-Capacitor
and Resistor-Resistor networks in the 500ohm 200-13000pf 
region and 500ohm/500ohm matched resistor pairs.  1/8 watt
0.1%tolerance.

If you have any experience with vendors of such parts, please
email me their company name and a contact with phone number.

My address is   gryzwa@mr.med.ge.com

Thanks in advance.  
-- 
Mark Gryzwa                  |       gryzwa@mr.med.ge.com
Analog and RF Engineer       |             
Magnetic Resonance Imaging   |   - These are only MY OPINIONS -         
         **  Slower traffic keep RIGHT  **
Newsgroups: sci.electronics,rec.music.cd,rec.audio
From: bill@verdix.com (William Spencer)
Subject: Re: requesting CD player advice
Organization: Verdix Corp.
Date: Mon, 6 Apr 1992 23:26:24 GMT

I'll volunteer a data point:

Carver TL-3100 vs. Pioneer PD-4350: Pioneer harshly bright, offhand I'd say
about as audible as 4 dB of treble boost. Unknown if this is a simple matter
of frequency response. Low end Sonys were about same as Pioneer; $1700 Sony,
Onkyo, Adcom slightly better. Carver best of lot, IMO.

Carver (unknown bitstream model, about $500) with and w/o Aragon D/A converter
($1200?): maybe difference would be important on my own system. Difference
more or less inaudible in store.

In article <1992Apr4.162807.2468@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>Listening on speakers for these defects is almost a lost cause since
>no speaker can approach the reproduction fidelity of even the worst
>CD player.

Bad reasoning.

bill

--
"Heavy metal fans tend to be quite conservative in nature" -Duffy
From: raghutp@hubcap.clemson.edu (Raghu Toppur)
Newsgroups: sci.electronics
Subject: need help identifying part
Date: 16 Apr 92 16:52:02 GMT
Organization: Clemson University





The fuse on my Qubie Hard Drive blew. I replaced the fuse, with a 5A fuse,
which is higher than the power requirement, and it blew too.

There are no schematics available, and the Technical Assistance number is
defunct. The problem is "obviously" :) in what seems to be a really fancy
power supply board. There is one part here on the 115V side,
which I have no idea what it is. 

It sort of looks like a NiCd battery which has been dipped in tar, and
has two leads emanating from it. Shows zero (or close to) ohms across it,
and I don't know what it is.  Says CAL-R 2SS40 on it...

Any idea what it is and how to find out its rating ? The leads are of equal
length but they've been snipped.


Thanks in advance !
--
Raghu Toppur                                Internet: raghutp@cs.clemson.edu
Department of Computer Science              Uucp:     !gatech!hubcap!raghutp 
Clemson University, Clemson, SC 29631       Tel:      (803) 654-3943 


-- 
--
Raghu Toppur                                Internet: raghutp@cs.clemson.edu
Department of Computer Science              Uucp:     !gatech!hubcap!raghutp 
Clemson University, Clemson, SC 29631       Tel:      (803) 654-3943 
Newsgroups: sci.electronics
From: kludge@grissom.larc.nasa.gov ( Scott Dorsey)
Subject: Re: RF energy (was: HV shocks)
Organization: NASA Langley Research Center And Storm Door Company
Date: Fri, 17 Apr 1992 15:29:37 GMT

In article <1992Apr16.164958.8442@kakwa.ucs.ualberta.ca> ulan@ee.ualberta.ca (Dale Ulan) writes:
>sat on...
>Anyways, the next day, the announcer said that the joke was on the 
>prankster, because with the amount of RF energy that he would have
>absorbed, he would probably not have to worry about having children for
>the rest of his life... I'm not sure if that RF zap would do that kind 
>of damage (maybe folklore??) but I wouldn't take the chance...

Strange, I climb an energized AM tower about once a month or so.  Has something
to do with being an engineer or something like that.  Hasn't seemed to do me
much harm, although I still have a few RF burns I am nursing from last week's
encounter with a sharp edge.
--scott
From: Jeff.Lindstrom@ofa123.fidonet.org (Jeff Lindstrom)
Newsgroups: sci.electronics
Subject: Pre- & De-Emphasis
Date: Sat, 11 Apr 92 04:11:12 PDT
Organization: Universal Electronics Inc. (Public access BBS)

BS>>  Would someone (Bill?)  mind giving an explanation of deemphasis, how it is
BS>>done, the reason for doing it, what is done the the signal, etc.?  Thanks.

  Your explanation left out the reason why pre- and de-emphasis is necessary.  The media on which we record (magnetic and essentially-obsolete vinyl) increases noise in the mid- and upper-treble.  Pre-emphasis increases signal strength in this frequency range to maintain the Signal to Noise Ratio (SNR).  During playback, de-emphasis restores the balance between Treble, Mudrange, and Bass.
  The Bass signals are often too strong and would overload recording media, so the signal strength is reduced (SNR is not a major consideration in this frequency range).  During playback, the Bass frequencies are boosted to resotre their balance with the Midrange and Treble.

___
     Amiga MailMan v0.9


--  

Jeff Lindstrom
Internet: Jeff.Lindstrom@ofa123.fidonet.org
Compuserve: >internet:Jeff.Lindstrom@ofa123.fidonet.org
Newsgroups: sci.electronics
From: ulan@ee.ualberta.ca (Dale Ulan)
Subject: RF energy (was: HV shocks)
Reply-To: ulan@ee.ualberta.ca (Dale Ulan)
Organization: University of Alberta Electrical Engineering
Date: Thu, 16 Apr 1992 16:49:58 GMT


A few years ago, as an October 31st prank (what was that day called again?)
someone decided it would be fun to climb up a local radio station's tower
and steal the red beacon lamp from the top. This was an AM transmitter, so
the entire tower was energized. There was a large insulator that the tower
sat on...
Anyways, the next day, the announcer said that the joke was on the 
prankster, because with the amount of RF energy that he would have
absorbed, he would probably not have to worry about having children for
the rest of his life... I'm not sure if that RF zap would do that kind 
of damage (maybe folklore??) but I wouldn't take the chance...

-----

When I was 14 or 15, I was working on building a tesla coil, using
six #807 beam power tubes as the final power stage. I never did finish it,
I didn't have the money to do it. Plus, I would suspect that tube life 
would have been a bit short, and I didn't have the power transformer
to feed the beast. Maybe I'll get it going later this summer... 

-----

Dale Ulan    ulan@ee.ualberta.ca
Computer Engineering Undergrad  (and former 'farm kid').
From: bill@hacktic.nl (Bill Squire)
Newsgroups: sci.electronics
Subject: Re: How do anti-theft systems in Shops work ???
Keywords: security shops theft
Date: 15 Apr 92 22:38:02 GMT


        The type you got is a half wavelength at about 915 MHz and has a
magnetisable ferrite backing.  If the ferrite is magnetised it is inessence
not there and will reflect at 915 MHz (like radar chaff).  If the ferrite
is demagnetised it will either lower the freq or asorb it or both.  To
defeat this system it stands to reason you wrap the item in foil or remove
the strip and coil it up!  A piece of wire about the same length as the
strip (say 16cm) will set off the alarm.  A simlpe pocketsized device could
be constructed to demagnetise the device, but if you know how to do that, I
think you got better things to do than shoplift!

                                                        Bill
Newsgroups: sci.electronics
From: kmd@aplcen.apl.jhu.edu (Kevin Doherty)
Subject: Plated thru holes
Organization: Johns Hopkins University
Date: Sun, 12 Apr 92 02:35:34 GMT

  There have been a few threads on here re: making PC boards in your
basement.  I do it myself, and get pretty good results using a couple
of different techniques.

  One thing I can't do, though, is make plated-through holes for my
two sided boards.  While a hunk of wire soldered on both sides works
fine for most applications, I would still like, on more complex boards
(eg, simple microprocessors), to be able to through plate my vias.

  I gather that there are several 'electroless' copper plating techniques
out there; just drop an object in the bath, and it gets covered with
copper: no electricity required.  Good (perhaps?) for thru-plating, and
possibly in an additive PC process also (where copper is added to the
board, rather than etched away).

  Is this a suitable technique for through plating?  If so, how do I do
it?  If not, what should I do instead?

  Thanks!