HDTenEightyP/NetNews huggingface dataset:
From: jvannes@vms.macc.wisc.edu
Subject: Re: Circuit to vertically crop NTSC video (letterbox)
Organization:  University of Wisconsin Academic Computing Center
Distribution: usa
Date: 18 NOV 92 02:49:50    

In article <1992Nov17.165051.13069@cis.ohio-state.edu>, fontana@apache.cis.ohio-state.edu (Mark Fontana) writes...

>I'm interested in constructing a circuit to place in line while
>dubbing video between two standard NTSC VHS VCR's that would allow
>variable cropping of the image for a "letterboxed" effect.  There would

Your on the right track.  Unfortunately, to modify a video signal you need to 
separate the video info from the sync pulses, modify the video, then mix the
sync back in.  Check out the video scene switcher project by Graf/Sheets in
the November 89' Radio-Electronics.  This has the basic circuit you need.
They also did a special effects generator (R-E 9/87, 10/87) that  may have
some useful info.  Good Luck!
Newsgroups: sci.electronics
From: dhina@dxcern.cern.ch (Mourad Dhina)
Subject: capacitor's norm
Summary: capacitor ATC 100
Keywords: capacitor, norm
Organization: CERN European Lab for Particle Physics
Date: Fri, 20 Nov 1992 16:21:12 GMT

Hello,
i want to build a circuit (RF amplifier). this requires
capacitors labelled ATC 100 (most of them are ceramic chip
capacitors). what does ATC 100 mean? what would be the
replacement in europe?
thanks!
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: How do constant voltage (ferroresonant) transformers work?
Date: 18 Nov 92 05:29:39 GMT
Article-I.D.: u.1992Nov18.052939.25480
Organization: University of Washington, Seattle

In article <1992Nov15.031727.25053@imax.imax.com> dave@imax.imax.com (Dave Martindale) writes:
>I just bought an old Sola CVS-series constant-voltage transformer.

>1. How does it WORK?  I can't explain how it does its voltage regulation
>   trick with just a transformer and a capacitor. 

	That isn't a transformer.  It's a constant voltage
transformer and the two are VERY DIFFERENT.  The constant voltage
transformer has two separate, loosely-coupled magnetic circuits,
the second of which is capacitor-tuned to the line frequency.
Saturation of the core limits the amplitude of the resonant
secondary, and this secondary usually has 90 degrees phase
shift from the primary.

	Amplitude change on the primary causes the secondary
to change its phase with respect to the primary (because
the saturated link does NOT transmit an undistorted waveform),
and one can make a tertiary winding which sums the voltages 
on the primary and the secondary: this sum (actually a weighted
sum, the secondary usually runs at conveniently high voltage
for inexpensive power capacitors) can then be made independent
of the input voltage, to first order.

>2. The label says that the transformer is "harmonic neutralized".  What
>   would the output waveform look like without this?

	Because saturation is a kind of regulation in itself, it
is possible to make a third-harmonic resonant circuit to give
roughly square-wave output from a ferroresonant transformer (the
design is slightly different from what I described above, I think).

>3. What sort of winding temperature would the transformer be designed for?
>   I've had it running at a little under 1/2 rated load for a few hours,
>   with the input voltage at the lower end of the regulation range,
>   and the temperature inside the core is about 70 degrees Celcius.
>   This seems a bit high to me for only half load.

	Losses in the iron are circa 20% of full rated load, and they
DO NOT GO DOWN when the load is lessened.  You are still running
a lot of quiescent current in the resonant secondary, after all.
Temperature limit on these devices is roughly that of the varnish
that insulates the wiring, unless it has soldered connections that
would melt first.  

	Reliability is very high.  I have black crinkle-finish
CV transformers that work just fine (estimated 40 years old).
Also, as surge-protectors go, this kind of device has
my vote: it absorbs a surge with a few dozen pounds of steel and
copper, not just a wimpy ten-gram MOV.

	John Whitmore
Organization: The Pennylvania State University
Date: Tue, 17 Nov 1992 23:03:34 EST
From: Ernie Oporto <EAO102@psuvm.psu.edu>
Newsgroups: sci.electronics
Subject: Re: Is lead solder bad for me?

In article <1992Nov17.175550.14583@netcom.com>, kehoe@netcom.com (Thomas David
Kehoe) says:
>
>Will I get lead poisoning from breathing the smoke
>from solder?  I work next to an open window, and leave
>the soldering iron on the window sill, but when I'm
>doing close soldering work, I can't avoid breathing
>the smoke form the solder.
>
>My father got lead poisoning last year when burning
>paint off his house, so I know that lead can vaporize
>in smoke.  I think his symptoms were headaches and
>dizziness.
>
>I've switched to lead-free solder, which is 97% tin and
>3% silver (available at Radio Shack).  The label still
>says to avoid breathing the smoke.  Why doesn't everyone
>use th

Oh my God!  He died while soldering and typing on the keyboard!
Quick someone go check his dormroom.  He's probably stinking up
the place even as we read this.
---
"See this button?  It's the history eradicator button." -- Ren
  _____)           ______        _)       _)  EAO102@PSUVM.PSU.EDU
                               __       __    OPORTO@CORVETTE.ECE.PSU.EDU
______    ______            ___      ___      Ernie "SHOKK" Oporto
                               __       __    Computer Lab Attendant
(_______ _      _ ________ _     _) _     _)  for PSU's CAC Department
From: cmh@eng.cam.ac.uk (C.M. Hicks)
Newsgroups: sci.electronics
Subject: Re: CD ROM and D.A.T. Sample Rates
Date: 16 Nov 92 12:25:30 GMT
Distribution: sci
Organization: cam.eng

cmwolf@mtu.edu (christopher m. wolf) writes:

>I believe CD's are sampled at 42.7kHz

Please don't reply to such an elementary question unless you
are sure of the answer. This is not intended as a flame, but rather a way
of keeping up the signal to noise ratio in this group :-)

Standard sampling rates are:

    CD: 44.1kHz
   DAT: 48, 44.1, 32kHz

There are still a very few recordings around at 44.05kHz, but these are rare.

With reference to the original question, I'm not sure what is meant by "the 
sampling rate of CD ROM", since a CD ROM can contain anything - the sampling 
rate of a dictionary or map doen't make much sense...

Info regarding sample rate conversion can be found in any of the standard DSP
texts. In general, conversion from one rate to a higher rate can be done with
insignificant information loss, provided that the word length is long enough.

Christopher Hicks (cmh@uk.ac.cam.eng)
From: smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC)
Newsgroups: sci.electronics
Subject: Re: imaging system
Date: 18 Nov 1992 15:25:23 GMT
Organization: SunConnect
Distribution: world
NNTP-Posting-Host: hardy.france.sun.com
Keywords: rocket, photos

In article <8685@lee.SEAS.UCLA.EDU>, annette@boole.seas.ucla.edu (Annette K. Nasif) writes:
> Hello, I am involved with a group of UCLA students who are attempting to
> build an amateur rocket capable of climbing to 200,00ft and transmitting
> images back to the ground.  I would appreciate any input anyone could give
> me on what type of imaging system would be the best to use.  I would like
> to have a videocamera, but the people working on telemetry say that it would
> be too difficult to transmit back that much information.  I therefore need
> to find some sort of camera, the lighter and smaller the better, that can
> take a series of snap shots (at least 8 bit resolution) which can then
> be transmitted and received on the ground.  Any suggestions, ideas, or
> starts in the right direction will will be greatly appreciated.  Thanks
> 

You could try getting in touch with the University of Surrey, in Guildford,
England. They have a space science department which is quite involved with
small non-commercial satellites, some of which carry video imaging
equipment  which can be recieved on fairly simple ham radio type gear. The
university helps build the satellites & has a small ground station, they
should know what kind of imaging devices can stand up to rocket-launch
stresses, etc.

I don't have their address handy, I should have it at home. You may be able
to get an email address for them, possibly by asking in one of the
ham.radio groups (some of the satellites carry ham radio equipment as well),
or in a group like soc.culture.british.

Steve

-- 
Steve McKinty
SUN Microsystems ICNC
38240 Meylan, France
email: smckinty@france.sun.com	   BIX: smckinty
From: paula@nlbbs.UUCP (Paula Stockholm)
Newsgroups: sci.electronics
Subject: Help! Converting 2400 to 9600 baud.
Date: Mon, 23 Nov 92 02:39:02 GMT
Reply-To: paula@nlbbs.UUCP
Distribution: world
Organization: The Electronics Workbench

        Back when I had time to do a load of laundry while downloading a
        file; I, too, was intrigued by this "legend".

        When I finally got a 9600, one look at it's complexity told me
        that the 2400 to 9600 tale was a lot of hooey.
Newsgroups: sci.electronics
From: nagle@netcom.com (John Nagle)
Subject: Re: Possible to upgrade PC from FCC Class B to A?
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Tue, 17 Nov 1992 20:05:50 GMT

mcovingt@aisun3.ai.uga.edu (Michael Covington) writes:
>Seriously, the FCC has been known to raid exhibits at COMDEX.  The FCC
>has been involved in regulating incidental emissions ever since the 1950s,
>when there was a rash of TV sets interfering with each other via their
>local oscillators.  Uncertified computers are rather uncommon on the market
>in this country.

       And a good thing, too. The FCC has done a good job in this area.
Remember when a TRS-80 model I and a Milton Bradley Big Trak toy would
crash each other if brought within a few feet?  In the late '70s, there was
real fear that a big chunk of the electromagnetic spectrum would be
completely unusable for radio in urban areas.  Tight standards by
the FCC and the comparable German and Japanese authorities avoided this
fate, and now you can fill offices up with electronic equipment without
worrying about electromagnetic compatibility.

       Think of the alternative: long lists in the computer magazines of
what interferes with what, running around offices with field strength
meters trying to find out what's knocking what off the air, inability to
use a computer and a TV in the same apartment building, landlords 
prohibiting computer use...

					John Nagle

					John Nagle
From: sl@nessie.mcc.ac.uk (Stuart Lea)
Newsgroups: sci.electronics
Subject: Rugby clock code receivers - help ?
Date: 17 Nov 92 16:22:03 GMT
Organization: Manchester Computing Centre

Does aanyone have the address/phone no./fax no. of the Atomic clock in
Rugby.  These are the people who transmit their highly accurate time code
on 60 Khz

If you haven't got an address but know what I'm talking about, could you tell
me what the D.U.T codes are ?



-- 
+Stuart Lea---Tel:061 200 4809--Fax:061 200 4019---UMIST University-----------+
| JANET   :   sl@uk.ac.mcc.nessie                  B22, Main Bldg., PO Box 88 |
| INTERNET:   sl%nessie.mcc.ac.uk                  Manchester, UK M60 1QD     |
|                 "Weather is here, wish you were beautiful"                  |
Newsgroups: sci.electronics
From: chrism@col.hp.com (Chris Magnuson)
Subject: LCD Display Recommendation Needed
Date: Mon, 16 Nov 1992 17:34:29 GMT
Organization: HP Colorado Springs Division

 Can anyone recommend a vendor for a 256x128 pixel LCD display?  I have
found Optrex but am looking for another vendor.

 e-mail would be great!

chrism@col.hp.com
719 590 2963
From: andreww@uniwa.uwa.edu.au (Andrew Williams)
Newsgroups: sci.electronics
Subject: Re: CCD camera questions
Date: 20 Nov 1992 15:05:36 +0800
Organization: The University of Western Australia
NNTP-Posting-Host: uniwa.uwa.edu.au

sysrick@starbase.spd.louisville.edu (Rick McTeague) writes:

>In <1992Nov12.235528.2939@elroy.jpl.nasa.gov> jack@robotics (Jack Morrison) writes:

>>>The second CCD camera question deals with the CCD's response to IR.
>>>What is the response curve of a CCD camera?  How quickly does the CCD's
>>>sensitivity taper off as the frequency of the light drops below visible
>>>and into IR?   And how come I can see the IR on my monitor/view-finder?
>>>(try pointing your TV remote at the cam-corder).  My potential application
>>>is a pseudo-night-vision device.

>>It depends on the CCD used, and the optical filters in front of it that
>>make specific CCD elements sensitive to red, green, or blue. But as you've
>>observed, they do see some IR. Your monitor displays this signal as
>>visible image (TV remote IR LED's are actually pretty bright).

>CCDs are reasonably sensitive to near IR at room temperature. Get them
>cold (liquid nitrogen), and they're even more so; I have an astronomer
>friend who uses cooled CCDs as his IR image sensors.

CCD's get less sensitive to IR as you cool them, not more. The incoming
photon must combine with a 'packet' of heat energy (a phonon) to be
absorbed. The sum of the photon and phonon energies must exceed the
silicon band-gap to excite an electron. Lower temperatures mean fewer
high energy phonons, so the cutoff wavelength decreases. The reason
astronomers cool CCD's is to reduce the 'dark current' caused by those
(few) high energy phonons energetic enough to excite an electron by
themselves. This dark current limits exposure times to milleseconds at
room temperature, or centuries at -150 deg C or so. Usually the CCD's
are cooled as little as is necessary to give reasonably low noise within
the exposure time they require.
	If it weren't for this 'indirect' absorbtion process, CCD's
would only be sensitive to photons energetic enough to excite electrons
directly- the traditional 'LED red' color, and up.

(all the above applies to silicon CCDs only- as far as I know, the more
exotic materials aren't CCD's as such, but standard detector arrays
anyway).


>Rick McTeague
>Electrical Engineering Department, Speed Scientific School
>University of Louisville, Louisville, KY 40292
>(502) 588-7020

>Internet: sysrick@starbase.spd.louisville.edu


	Andrew Williams,
	Physics, Uni of West Australia.
From: u009@csx.cciw.ca (G. Stewart Beal)
Subject: Re: measuring milli-gauss a.c. magnetic fields
Organization: Canada Centre for Inland Waters
Date: Mon, 23 Nov 1992 16:23:42 GMT

In article <JOHN.92Nov20144516@django.think.com> john@django.think.com (John Richardson) writes:
>Does anyone know of a *simple inexpensive* circuit or device for
>measuring milli-gauss a.c. magnetic fields? 
>
How about a small, 1 layer coil of specified cross section, connected to a
high gain, calibrated (AC) amplifier and full wave rectifier?
Do the calculations to figure the coupling, and therefore the flux from the
DC voltage on the output.
 
Regards, Stu Beal, VE3MWM, U009@CS.CCIW.CA,
National Water Research Institute, Burlington, Ontario, Canada.
 
"She was a savage beauty - wild, untamed (or at least not house-broken yet)."
From: drp40@cd.amdahl.com (Doug Puchalski)
Newsgroups: sci.electronics
Subject: Re: Smoke Theory and Dark Suckers
Date: 18 Nov 92 22:55:02 GMT
Reply-To: drp40@cd.amdahl.com
Organization: Amdahl Corporation, Sunnyvale, CA

In article <1992Nov18.004532.612@panix.com>, schuster@panix.com (Michael Schuster) writes:
>A while back some inventive folks posted documents here on two
>para-scientific theories:
>
>-that light bulbs are really "dark suckers"

They sure are!  When they're off, that is.

-- 
Doug Puchalski       You have the right to your opinion, even though it's wrong
drp40@cd.amdahl.com	        My opinions are my own, and are fact, of course
dpuchals@engin.umich.edu                                   Death to all smileys
Organization: Penn State University
Date: Tue, 17 Nov 1992 09:47:02 EST
From: <GNR100@psuvm.psu.edu>
Newsgroups: sci.electronics
Subject: Re: making mono from stereo

         Just wondering......is there any way to go the other way?

  I know that there is no way to tell which channel a part of the waveform cam
from,  but is there some way to create "artificial" stereo, say, by having a
computer divide the signal up into two channels so is sounds halfway decent?
                     Gordon Rogers
                     gnr100@psuvm.psu.edu
Newsgroups: sci.electronics
Subject: Pin Layout Help Needed
From: <DI3QC@CUNYVM.BITNET>
Date: Monday, 16 Nov 1992 22:40:51 EST
Organization: City University of New York/ University Computer Center

      I just purchased an 1x16 lcd screen and the data sheets I received with
them have a different pin layout then on the LCD screen I got. By that I mean
they show all the pins 1-14 in a row. The package I received is labeled
           14o o
             o o
          more connectors
             o o 1
Does that mean it goes 14 13
                       12 11
                       etc.
                        2 1
Or  14  7
    13  6
    etc.
     8  1?
Any help would be great. Thanks.

Alex.
Newsgroups: sci.electronics
From: lester@naomi.b23b.ingr.com (Les Bartel)
Subject: Re: Big NASTY Brother Radio Shack
Reply-To: lester@naomi.b23b.ingr.com
Organization: Intergraph Corporation
Date: Wed, 18 Nov 1992 15:19:18 GMT

In article <1ebbu9INN349@grapevine.EBay.Sun.COM>, smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC) writes:
|> In article <1992Nov17.071923.7429@njitgw.njit.edu>, dcg5662@hertz.njit.edu (Dave Grabowski (KxiK)) writes:
|> > 
|> >   Well, seeing this blooming thread, I just HAD to put in my two cents.
|> > I'm sure everyone is SICK of "RS Sucks" stories.. well, TOO BAD, because
|> > here's another:
|> > 
|> >   A few months ago, a visited a RS store that I've frequented since I
|> > was old enough to crawl in the front door. I needed a 3-amp fuse for my
|> > car radio. Grabbed a pack off the shelf, and noticed the price: a
|> > whopping 79 cents. A small price to pay for good tunes in the ol' Honda.
|> > The salesman scans it, and asks for $1.05 (99 cents plus 6 cents NJ
|> > sales tax). Being the consciencious (sp) consumer, I mentioned the
|> > twenty cent discrepancy. He refused to do ANYTHING about it -- said that
|> > "we're going through price changes." I'm sure that some of you have had
|> > similar problems, and what they are SUPPOSED to do is merely take off
|> > the difference as "Customer Satisfaction."

I went into RS about a year ago to buy an ammeter.  They had a sale price
on the shelf by the display unit.  When the entered the part number into
their computer, the regular price came up.  When I enquired about it, they
said that the sale was over a couple of days ago, but that since the sale
price was still posted, they would honor it.  The sale price made it a
fair deal instead of a ripoff (overpriced).  I had to say something, but
there was no hassle whatsoever after that.  They did ask if I wanted to
purchase the extended warrenty (I declined) and also asked me for my phone
number (I declined).  No hassles - this time.

 - les "my 2 cents" b

 Look, lets make a deal:
 You stop telling lies about me,
 I'll stop telling the truth about you.

Newsgroups: sci.electronics
From: halberst@world.std.com (jerry halberstadt)
Subject: adapt input devices for mouse replacemnt
Summary: seek device(s) to ergonically replace mouse for editing
Keywords: glove, trackball, mouse, pointing, adapt, interface
Organization: The World Public Access UNIX, Brookline, MA
Date: Sun, 15 Nov 1992 20:37:08 GMT

I'm seeking someone who a) has already adapted a glove or ther input device
to do the work of a mouse or b)knows how to do this and is willing to try.

People like me who do a lot of keyboard and mouse input may be crippled by
pain due to RSI (repetitive stress injury). Reading about many solutions
suggests that the problem doesn't go away, and my own anlysis suggests it
is because the nature of the task -- constrained by the input device --
generates the injury. Trackballs exist but don't always work. Tablet & pen
combinations ( I am trying the PenMate) based on a graphics tablet with
magnetic field sensor can replace the mouse with a pen-like device. Good,
butr some drawbacks remain. 

What about using and adapting some of the game devices such as the Nintendo
*power glove*, or a joystick? The requirements would be to gen erate inputs
that are the equivalent of the Microsoft Mouse on the PC for the Windows
environment. Additional functions might be nice so that the mouse functions
would be the base set and it would be possible to select a variety of
commands otherwise from the keyboard, or the sensitivity/speed of the
cursor movement could be adapted on the fly. The ideal solution would allow
one to intuitively move one's hand or a joystick and thus control the
cursor motion.

The most obvious probelms are that the game devices are made for game
device ports. There needs to be some kind of electronic adapter so that the
computer gets the kinds of inputs it expects on the mouse port.

I am currently working in a PC/Windows environent but may switch to a Mac
or a UNIX environment so the solution should be general.

A couple of years ago there was apparently a lot of interest in the
Nintendo power glove, however I don't know if there are better things out
there today.

-- 
Jerry Halberstadt	New Technology Publishing, Inc.
POB 9183: c/o Mailboxes Etc.(#110)
955 Mass. Ave., Cambridge MA 02139 USA
617-661-3851		halberst@world.std.com
From: george@mech.seas.upenn.edu
Newsgroups: sci.electronics
Subject: Re: Old phone
Date: 18 Nov 92 21:54:20 GMT
Distribution: usa
Organization: University of Pennsylvania, Mechanical Engineering

me too. i even have it in the garage.
I never even worried about it 'cause i can hear the
phone in the house ring.   I would be interested to find
out how to make it work though.

--
  /   george jefferson
\/ *  george@mech.seas.upenn.edu
From: rjudy@dime.cs.umass.edu (Judy Ruot)
Newsgroups: sci.electronics
Subject: record turntable troubles
Date: 18 Nov 92 20:09:14 GMT
Reply-To: rjudy@dime.cs.umass.edu (Judy Ruot)
Organization: University of Massachusetts, Amherst

Pioneer PL518 and PL400 turntables have a similar problem. They will
play ok at 33 1/3 rpm but then intermittantly slow down for a bit then
go back up to speed again. Suspect phase locked loop chip. Anyone know
which chip it is in these models? Please send me email as I don't
read this group regularly. Thanks.

Judy

rjudy@cs.umass.edu


Newsgroups: sci.electronics
From: wlsmith@valve.heart.rri.uwo.ca (Wayne Smith)
Subject: Re: police laser radar
Organization: The John P. Robarts Research Institute, London, Ontario
Distribution: usa
Date: Mon, 16 Nov 1992 20:51:42 GMT

In article <1992Nov16.164531.2036@phx.mcd.mot.com> schuch@phx.mcd.mot.com (John Schuch) writes:
>>Does anyone know what fequencies the police are using for their speed  
>>detecting lasers?
>>
>
>My guess would be about 1.5E+11 Hz
>
>:-)
>John
But seriously, if Lidar detection is as difficult as it seems to be
(thanks to the way its used; quick and close), could an incoherent
but strong IR source (heat lamps?) interfere with the readings, or
would you need a laser IR source of your own, pointing back?
Newsgroups: sci.electronics