HDTenEightyP/NetNews huggingface dataset:
From: pieterh@sci.kun.nl (Peter Herweijer)
Subject: Re: Heat gun pcb cannabalization
Keywords: Heat gun, charring, lack_of_skill, try_again_maybe
Organization: University of Nijmegen, The Netherlands
Date: Mon, 25 Jan 1993 12:56:44 GMT

In <651@rins.ryukoku.ac.jp> will@rins.ryukoku.ac.jp (William Reiken) writes:

>In article <1jebh6INNie7@clover.csv.warwick.ac.uk>, cstadbg@csv.warwick.ac.uk (Mr M J Brown) writes:
>>only if you heat ALL the legs. I have also managed to strip boards previously
>>to getting the Black and Decker with a butane blowtorch. It is a) a question
>>of practice, and b) remembering it is the PARTS you want to save and not the
>>board they are on. This will be pretty much damaged by large scale desoldering
>>

>	I was told that microchips will be damaged if you use this approach.
>Does it really matter?
>
>							Will...

Using the very same method, I have successfully stripped a bunch of
computer boards of their components, including Z80 CPU's and 8255 PIO's.
Everything worked fine.  I did it with a friend, he heated the PCB, I
pulled out the components and immediately threw them in a bucket of
water to cool them off, but I don't know if that's necessary.  One tip
though: do it outside.  The fumes stink and are probably not healthy.

Peter Herweijer
pieterh@sci.kun.nl
Newsgroups: sci.electronics
From: hinz@bonfire (David Hinz (hinz@picard.med.ge.com))
Subject: Re: Wanted : Nicad Charger Plans
Organization: GE Medical Systems, Magnetic Resonance
X-Newsreader: TIN [version 1.1 PL8]
Date: Tue, 26 Jan 93 11:00:59 GMT

Scott Dorsey (kludge@grissom.larc.nasa.gov) wrote:

: I would bet that the charger you saw was for standard carbon-zinc cells.
: The carbon-zinc batteries can be recharged somewhat, but they won't work
: terribly well afterward and you can only get one or two rechargings out
: of them.  Rechargers for these batteries were quite popular back before
: NiCds and alkaline cells came out.

I don't know if I go along with this one.  My dad uses carbon-zinc cells,
and recharges them many many times before they don't take a charge.  I
don't know the details on the charger, but it's a cheapie, so it can't be
anything TOO special.

Perhaps the type of load you are driving with the battery effects how well
it responds to charging?  He uses the batteries mostly in a radio, low
current, non-inductive load.

--

Dave Hinz  -  Opinions expressed are mine, not my employer's.  Obviously.
Ask me if I have an opinion on this! \ Don't blame me; I voted for Perot!
SAAB - Because you get what you pay for.     \       Pherrets are Phun!!!
From: ahmadz@newton.ccs.tuns.ca (Zakaria Ahmad)
Newsgroups: sci.electronics
Subject: simulation of a gate oscillator start-up
Date: 26 Jan 93 04:15:27 GMT
Organization: Technical University of Nova Scotia, Halifax, N.S.

HELLO NETTERS,
I HAVE POSTED RECENTLY ASKING ABOUT THE SAME SUBJECT. THANK YOU FOR THOSE WHO
REPLIED TO ME..THEY WERE QUITE HELPFUL TO MY PROJECT. FROM MY UNDERSTANDING SO FAR, PSPICE OR SPICE DOES NOT WORK REALLY WELL TO SOLVE THE "START-UP" PROBLEMS.
I MAINLY FOCUS ON CRYSTAL OSCILLATORS, PARTICULARLY PIERCE OSCILLATORS.
DOES ANYBODY OUT THERE KNOW HOW TO AT LEAST MINIMIZE THE PROBLEM?
I HEARD THERE ARE SOME OTHER SUITABLE SIMULATORS THAT COULD DO THE TASK.
SO IF ANYBODY KNOWS THE SUITABLE SIMULATORS (OTHER THAN SPICE) TO TACKLE THE PROBLEM,WOULD YOU LET ME KNOW.
THANK YOU.


AHMADZ@NEWTON.CCS.TUNS.CA
Newsgroups: sci.electronics
From: pjh@mccc.edu (P. J. Holsberg)
Subject: Car Phones?
Organization: The College on the Other Side of U. S. 1
Date: Sun, 24 Jan 1993 16:19:26 GMT

My, wife, who is a real estate agent, has decided that she needs a
telephone that she can use on the road.

How does one go about deciding what type and what brand to buy?

Thanks.
Newsgroups: sci.electronics
From: gary@mario.inmos.co.uk (Gary Morton)
Subject: Re: Recording sound on chip
Reply-To: gary@inmos.co.uk (Gary Morton)
Organization: INMOS Limited, Bristol, UK.
Date: Wed, 27 Jan 1993 13:18:06 GMT

In article <1993Jan25.214046.9622@hplabsz.hpl.hp.com> sivaram@hplabsz.hpl.hp.com (S. Sivaramakrishnan) writes:
>I am looking for a cheap method to record and playback about 15 seconds of
>sound on a chip.
>
>The whole setup, I GUESS, will comprise:
>1) A microphone
>2) An A/D converter that digitizes the sound
>3) A unit that accepts the commands "record" and "playback"
>4) Some memory that holds the sound image
>5) A D/A converter to generate an analog signal
>6) A speaker for playback
>7) Power supply
>
>Does a chip that has most/all the features except the power supply exist?
>
Maplin Electronics (in the UK) sell a chip which has all the features (just
about) that you describe. You need to add a 256k byte static ram to store the
digitised data. A project based around this chip has appeared in Electronics
"the Maplin Magazine", and a kit of all parts including PCB is available
from them. They give an example circuit in their catalogue anyway. I keep
my catalogue at home, so I don't have a price ($20-$30 I guess), or their
phone number (it was posted recently). Mail me if you would like further
details.

I am amazed the number of times people ask questions about the availability
of parts, and the solution is available from Maplin. Has anyfrom from outside
the UK ordered from Maplin, and if so what was their service like ?

BTW - no connection - just a satified customer.

--Gary
+---------------------------( Gary Morton )-----------------------------+
|Disclaimer: The opinions above are my own personal views etc.          |
|Inmos Ltd, 1000 Aztec West, Bristol, UK         Email : gary@inmos.com |
+-----------------------( +44 454 616616 X526 )-------------------------+
Newsgroups: sci.electronics,rec.audio,rec.audio.car,rec.audio.pro
From: ljkong@napier.uwaterloo.ca (Lennard J. Kong)
Subject: Re: 12V Power Amplifier Design
Organization: University of Waterloo
Date: Tue, 26 Jan 1993 18:28:22 GMT

In article <thomasd.33.727991442@tps.COM> thomasd@tps.COM (Thomas W. Day) writes:
>Can anyone give me some advise on power amplifier design for 12VDC power 
>supplies (automotive applications)?  Specifically, what kinds of power 
>supplies are typically used in high power (50W+) designs?  I am hoping to 
>find a practical way to get a high voltage (>+/-25VDC) supply for a bipolar 
>amp.

   This is not a very trivial thing to do, this is proabably one of the reasons
that home amps are easier to fix than auto amps. You will need some kind of
circuit to alternate or switch the 12v and use a power transformer to boost it
up. Also when yoiu boost voltage, the current consequently drops, so you need
to have a circuit which is quite beefed up to provide a high current. Thats a
major selling point of many manufacturers now, they claim their amps not only
provide the high voltage but the high current power source. I have considered 
doing his many times myself since I had many different designs for simple to
complicated amps. I don't think itt is possible from scratch unless you use the
exact components and circuit you would find in a presently available amp. From
my experience I think the highest power you can get from 12V without raising the
voltage is abou 33Wrms, which was a Clarion Eq/Amp.
Lennard
From: will@rins.ryukoku.ac.jp (William Reiken)
Newsgroups: sci.electronics
Subject: Re: Heat gun pcb cannabalization
Summary: What about Microchips?
Keywords: Heat gun, charring, lack_of_skill, try_again_maybe
Date: 23 Jan 93 05:14:27 GMT
Organization: Ryukoku Univ., Seta, Japan

In article <1jebh6INNie7@clover.csv.warwick.ac.uk>, cstadbg@csv.warwick.ac.uk (Mr M J Brown) writes:
>only if you heat ALL the legs. I have also managed to strip boards previously
>to getting the Black and Decker with a butane blowtorch. It is a) a question
>of practice, and b) remembering it is the PARTS you want to save and not the
>board they are on. This will be pretty much damaged by large scale desoldering
>

	I was told that microchips will be damaged if you use this approach.
Does it really matter?

							Will...

Newsgroups: sci.electronics
From: careyj@spot.Colorado.EDU (CAREY JOSEPH M)
Subject: Re: RADAR, RADAR ECM, and RADAR ECCM
Organization: University of Colorado, Boulder
Date: Mon, 25 Jan 1993 20:10:36 GMT

np4@prism.gatech.EDU (Nick Pomponio) writes:

>The ECM device can be a simple repeater applying amplitude modulation to
>the received signal. The AM frequency would be a function of the actual
>velocity, the desired (deception) velocity, and radar signal wavelength.
>Simple AM will produce two false velocity "targets"; the undesired one
>could be supprssed by using a single sideband AM scheme.

>-- 
>POMPONIO,NICHOLAS A

Okay, in theory I'll buy this, but lets see how it would work in
practice.  You'd need to detect (very quickly) the signal, have some
kind of a system wired up that would determine how much frequency
(i.e. apparent doppler) shift to apply, and retransmit that signal
(presumably with something that radiates independently of phi, like
a dipole).  Further, you would need to make sure that you would not
detect the signal that you would be transmitting, which is only
a few hundred Hz (if memory serves we're talking about 30 Hz/mph,
but I could be wrong) off the one you received, or your repeater would
lock up.  And keep in mind that you'll be transmitting significantly
more power than that which is received.

Yeah, I'll believe that it can be done.  It would even provide some
interesting engineering challenges, but this strikes me as the kind
of problem people solve for the fun of solving it, not because they
really need ECM for their CAR (an F-16, yeah, but not my Plymouth).
Also, to design this properly, you would need some pretty expensive gear.

Just a thought.  I'd sure like to see the results somebody else comes
up with, but for me this reminds me of hacking computers -- an interesting
problem that I don't want to spend too much time on.


Sure is an interesting discussion, though.

Joe Carey
joe@lobos.colorado.edu

Newsgroups: sci.electronics
From: jjj@mits.mdata.fi (Joni Jarvenkyla)
Subject: Want to buy a laser
Organization: Microdata Oy, Helsinki, Finland
Date: Thu, 28 Jan 1993 18:24:52 GMT


Want to buy a laser.

Any visible color, any power between 1 mW -- 1 W will do.

Even a plain tube would be ok, although I'd prefer a whole setup with
the power supply. Or if you have somethins special, make an offer, I
might like it.

--
jjj@mits.mdata.fi | PGP 2.0 key available | PGP 2.0 avain saatavilla
From: bob@kc2wz.bubble.org (Bob Billson)
Newsgroups: sci.electronics
Subject: Re: T.V. and magnets, how to fix damage
Date: 22 Jan 93 05:27:48 GMT
Distribution: na
Organization: Color Computer 3: Tandy's 'game' machine

paj@uk.co.gec-mrc (Paul Johnson) says:
>>I put my pair of car speakers (18 oz. magnets)
>>on top of my t.v. for approximately an hour, and now half my
>>screen is green!!
>
>Tee hee hee

Not nice to laugh. :-)

>>I need to know, is my t.v. permanently damaged, or does it just
>>need to be "degaussed" (I'm not sure what that does...?) ???
>>Will it go away?  Will I have to junk my t.v.??
>
>You have magnetised the mask in your tube.  This distorts the path of
>the electrons from the gun to the phosphor, causing them to hit the
>wrong colour of phosphor dot.  Degaussing is the process of
>demagnatising the mask.  A degausser is basically a large
>electromagnet with AC mains flowing through it.  This generates an
>alternating magnetic field which demagnetises things around it. 
                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Including floppy disks, hard disks, video/audio tapes if one isn't careful,
no? :-)
-- 
  Bob Billson, KC2WZ                          | internet: bob@kc2wz.bubble.org
  $nail:  21 Bates Way,  Westfield, NJ 07090  | uucp:     ...!uunet!kc2wz!bob

  "Professional ear piercing--while you wait!"  --sign in local jewelry store
Newsgroups: sci.electronics
From: kevin@clsi.COM (Kevin Cameron)
Subject: Re: 110V -> 220/240Vconversion for appliances
Originator: kevin@dubhe
Reply-To: kevin@clsi.com
Organization: CAD Language Systems Inc.
Date: Sat, 23 Jan 93 23:11:10 GMT


In article <ERIC.93Jan22165058@kilo.mks.com>, eric@kilo.mks.com (Eric Gisin) writes:
> 
> 3KW kitchen appliances must be wonderful. We don't have anything
> in north america over 1750 watts, and they all are much lower power than
> an electric or gas range.
> 

I havn't seen an electric kettle since I arrived in the US (from the UK).

Kev.
--
From: kludge@grissom.larc.nasa.gov (Scott Dorsey)
Newsgroups: sci.electronics
Subject: Re: 150 - 200 W. Amplifier
Date: 27 Jan 1993 15:48:43 GMT
Organization: NASA Langley Research Center and Reptile Farm
NNTP-Posting-Host: grissom.larc.nasa.gov

In article <1993Jan27.054335.20450@dmapub.dma.org> snydert@dmapub.dma.org (Tony Snyder) writes:
>David Hinz (hinz@picard.med.ge.com) (hinz@bonfire) wrote:
>: Brad Siim (siim@waterloo.hp.com) wrote:
>
>: state-of-the-art is multi-sized wires in a non-twisted bundle, low O2 copper,
>: etc. etc. etc.  OK, you might not be able to hear much, if any difference.
>: But someone can.
>
>Those are the samepeople who think
>spirits run down the wires.  If the O'scope doesn't see it it is not there.

I recommend you try using a scope then.  Run some square waves down into a
low impedance load.  You'll see differences between different cables, having
to do both with the dielectric effects and with the resistivity of the
material.
--scott
Newsgroups: sci.electronics
From: adler@netcom.com (Bruce Adler)
Subject: How makes the 65816 cpu?
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Thu, 28 Jan 1993 12:22:16 GMT

I know that Mostek made the 6502 but who makes the 65816?

adler@netcom.com
Newsgroups: sci.electronics
From: rduta@nyx.cs.du.edu (Radu)
Subject: Crystals!
Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept.
Date: Thu, 21 Jan 93 18:34:04 GMT

Can someone please tell me some more info about crystals.  I need to make
a electronic switch to select between two crystlas (2MHz, and 8MHz -about),I
tried using a 4016 (IC switch), and it didn't work.  Can someople please
give me another solution.  I'm desperate.

Radu
--
********************************************************************************
I only kill to know I'm alive!
Newsgroups: sci.electronics
From: szopinsk@picard.med.ge.com (Jerry Szopinski Mfg 4-6983)
Subject: Re: Recommendations for Digital Multimeter
Organization: GE Medical Systems, Magnetic Resonance
X-Newsreader: TIN [version 1.1 PL6]
Distribution: usa
Date: Thu, 28 Jan 93 09:51:58 GMT

garland@ohstpy.mps.ohio-state.edu wrote:
: In article <C1FqqK.2vt@taligent.com>, kayshav_dattatri@taligent.com (Kayshav Dattatri) writes:
: > I want to buy a digital multimeter for my hobby set. I have seen models
: > from Philips, Funa etc. I'm willing to spend about $100.
: > 
: > Can the gurus recommend a good model and source to get it cheap (mail order or
: > in the SFO bay area market).
: > 
: > Thanks
: > 
: > Kayshav
: > Kayshav_Dattatri@taligent.com
: > 
: 
: I recommend the Beckman series of DMM's. There are several in the $100 price
: range. I've found them to be very rugged, and they have large LCD displays with
: good contrast -- better than the Fluke line in that regard.  Also, a point
: frequently overlooked, is that they have extremely long battery life -- about
: x10 longer than the Fluke's, and they're also well-shielded against rf.


Not to mention Beckman's are very rugged.  You can drop them a few times, bang
them around a lot, even spill stuff all over them; they're like the Energizer
Bunny, they keep going and going and going...

I don't know, to me something called a Fluke just doesn't inspire thoughts of
reliability.


Jerry


"It riles them to believe that you perceive the web they weave and keep on
thinking free!"  --  Moody Blues
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: Power Amplifiers
Date: 26 Jan 93 01:30:25 GMT
Organization: University of Washington, Seattle
NNTP-Posting-Host: carson.u.washington.edu

In article <1993Jan25.135100.46744@kuhub.cc.ukans.edu> rsl09@kuhub.cc.ukans.edu writes:

>  I am interested in a power amplifier that could drive a DC motor/actuator.
>I am using the actuator in a slow-response feedback loop. The power amplifier
>should interface an OP-AMP, that produces the error signal, and the
>actuator that demands up to 3 Amps for input voltages up to 20 volts.
>Therefore, I need a push-pull 60 W DC power amplifier. I have been able
>to find couple of power OP-AMPs that seem to to able to do the job. But,
>they are expensive - price is around $100. 

	And, power op amps can usually NOT handle an inductive load
(like a motor).  They will burn up (no, internal current limiting
is NOT a solution here: the problem is reverse-biasing the output
transistors' emitter junction, and kills the amplifier at LOW current).

	If the motor doesn't need to reverse, a PWM switching
regulator + pass transistor can do a good job.  In the general
case, you might consider buying a computer-controlled stepping
motor for the task (but that doesn't interface nicely with
an op amp feedback circuit...).

	John Whitmore
Xref: sparky sci.electronics:23484 misc.consumers.house:17436
From: barker@wd0gol.WD0GOL.MN.ORG (Bob Barker)
Newsgroups: sci.electronics,misc.consumers.house
Subject: Home Alarm Supplies
Date: 26 Jan 93 14:06:58 GMT
Followup-To: poster
Organization: Robert Barker & Associates, Eden Prairie, MN.

I posted a request for info. on suppliers of home alarm accessories
about a week ago.  I only received 1 reply which leads me to believe
that either my message didn't make it to most of the net or that there
aren't many places (besides Radio Shack) selling home alarms.

As my house is getting closer to completion, my request has now become
a plea for help!  I need to order some things ASAP and can't find any
decent leads on suppliers of things like pressure pads, motion sensors,
keypads, etc.

Does anybody know of a mail-order home alarm outfit?  Your help is
very much appreciated!

-Bob

------------------------------------------------------------------------------
Bob Barker                                ...!uunet!umn-cs!tcnet!wd0gol!barker
Robert Barker & Associates                                barker@wd0gol.MN.ORG
(612) 949-0140
From: tnnigf@rw8.urc.tue.nl (Gijs Fehmers)
Newsgroups: sci.electronics
Subject: NNSS satellite receivers
Date: 22 Jan 93 09:46:26 GMT
Reply-To: tnnigf@urc.tue.nl


Hello,
Here are some questions about the antique NNSS (Navy Navigational
Satellite System), or Transit, receiving equipment.

I am a Ph.D. student working on an ionospheric-geodetic project.
I am working with NNSS (Navy Navigational Satellite System) receivers
that cause some problems. The equipment consists of 8 geodetic NNSS 
(2 CMA-751 and 6 CMA-761) receivers, all built by the Canadian 
Marconi Company.

I am facing problems loading programs in the CPU's of the receivers.
The software is stored on digital cassette tapes which were recorded 
about 10 years ago. The information has faded and reading the tapes 
causes checksum errors.

Can anyone help me with the following questions:
1 How to obtain the programs CMA-751.000.X, 751.004.X, 761.201.X, and
  761.210.X (X is wildcard), in any code?
2 Can you give me some information on the IM6100 CPU that is built 
  in the receivers (compiler, manufacturer etc) ?
You would help me greatly,

Gijs Fehmers,   e-mail: tnnigf@urc.tue.nl
Technical University of Eindhoven, Department of Applied Physics
P.O. Box 513,  NL-5600 MB  Eindhoven,  the Netherlands
From: gst@dcs.ed.ac.uk (George Taylor)
Newsgroups: sci.electronics
Subject: hard disk orientation
Date: 26 Jan 93 10:11:38 GMT
Organization: Department of Computer Science, University of Edinburgh

Could anyone tell me if running a hard disk vertically instead of horizontally
(e.g.using a desktop machine on it's side like a 'tower' system)
is likely to decrease it's lifetime?

-- 
George
From: cmh@eng.cam.ac.uk (C.M. Hicks)
Newsgroups: sci.electronics
Subject: 150 - 200 W. Amplifier
Date: 27 Jan 93 16:35:00 GMT
Organization: cam.eng

wtm@uhura.neoucom.edu (Bill Mayhew) writes:

>The biggest problem is that there is not very much high quality
>source material available.  Most commercially available recordigns
>are bad enough that they don't sound much better on a multi
>kilobuck stereo than a cheap boombox.

I disagree - if you know where to look there is a large number of excellent
recordings around. Generally I look for the name of the engineer on the
sleeve, as well as the artists, before deciding what to buy.
The Chandos label springs to mind - it is a family-run
label with father and son as producer and engineer respectively, working
with the top orchestras in the UK. I've never bought a duff CD from them. 

However, I know nothing about rock/pop etc - "classical" and jazz for me :-)
 
>The biggest problem I've seen in cheap sound equipment is woefully
>lousy power supplies.  Plenty of improvement can be had without
>resorting fancy polyproylene dielectric capacitors, but with
>properly sized transformers and capacitors.  Active regulation does
>wonders.

I can't agree with this enough - good power supplies are expensive, and tend
to get left out of cheap equipment. Does anyone have experience with
switchmode power supplies for audio power-amps? It seems a good idea on
the surface (low weight, high efficiency, low output impedance up to
several MHz), but I can see problems with interference from the high-energy
switching circuits.

Christopher Hicks
--
 ==============================================================================
 Christopher Hicks    |    If it doesn't fit...
 cmh@uk.ac.cam.eng    |                        ...you need a bigger hammer.
 ==============================================================================
Newsgroups: sci.electronics
From: u009@csx.cciw.ca (G. Stewart Beal)
Subject: Sound Chips used in SEGA or SNES?
Organization: Canada Centre for Inland Waters
Date: Mon, 25 Jan 1993 03:14:55 GMT
Summary: looking for info and availability
Keywords: D/A FM Synth Sound Music Speech SEGA NES NINTENDO SNES

I'm looking for a state of the art type sound chip to use in a project. Is
there any information available about the chips used in any of the newer
video game machines, or possibly arcade machines? I'd like to take a look
at what's available, possibly something with minimal glue required, for a
small footprint, high performance sound source for a portable PC.
Post introductory material or suggestions here, and if you've got anything
large to send, feel free to email.

Regards, Stu Beal, VE3MWM, U009@csx.cciw.ca,
National Water Research Institute.
From: mruddick@joule.elee.calpoly.edu (Michael Ruddick)
Newsgroups: sci.electronics
Subject: Up/Down Counter w/o clock?
Date: 22 Jan 93 08:24:44 GMT
Organization: California Polytechnic State University, San Luis Obispo

I am trying to locate an up/down counter that does not require a clock to be
present in order for it to work.  Would this be considered an 'asynchronous
counter , or do I have some wrong terminology?

Ideally I would like to have a 0-15 up/down counter.
'
Newsgroups: sci.electronics
From: nagle@netcom.com (John Nagle)
Subject: Re: DC to AC on large scale???
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Tue, 26 Jan 1993 05:26:43 GMT

schumach@convex.com (Richard A. Schumacher) writes:
>In <1k0rksINNc34@rave.larc.nasa.gov> kludge@grissom.larc.nasa.gov (Scott Dorsey) writes:
>Sure, but the original question was about regional power distribution.
>Did anyone ever use MG sets to convert AC to DC to feed more than a
>few city blocks?

     Yes.  Entire subway systems (including NYCs) were driven by MG sets
at one point.  The original NYC subway power plant was DC, with giant
reciprocating steam engines, and operated into the 1950s.  One of the
20' long pistons can be seen in the Smithsonian.  When the steam
engines were replaced, MG sets replaced them, to produce the 600VDC
used by the subway system.  I assume they've upgraded since the 1950s.

     But do we really care?

					John Nagle