HDTenEightyP/NetNews huggingface dataset:
From: Jeff.Lindstrom@ofa123.fidonet.org (Jeff Lindstrom)
Newsgroups: sci.electronics
Subject: Cable losses
Date: Tue, 14 Apr 92 04:14:08 PDT
Organization: Universal Electronics Inc. (Public access BBS)

U>Shouldn't the long cable attenuate the signal or even roll of the high
U>frequencies?

  It IS attenuating the signal, but too little to notice for the low frequencies you mentioned and the moderate cable lengths you are using.

U>How can I determin the maximum cable length before signal degradation begins?

  First, determine an acceptable degradation.  Then look at the specs for the cable you wish to use.  The major loss will be distributed capacitance (commonly expressed as picofarads/foot or nanofarads/foot).  Multiply by the cable length and take the RC time constant from the circuit (can you say Thevenin's Rule?  I knew you could.).
  Another source for degradation is outside noise coming through the shielding.  That will be a function of the shield's construction.

___
     Amiga MailMan v0.9


--  

Jeff Lindstrom
Internet: Jeff.Lindstrom@ofa123.fidonet.org
Compuserve: >internet:Jeff.Lindstrom@ofa123.fidonet.org
Xref: sparky sci.electronics:8624 sci.crypt:1893
From: pdh@netcom.com (Phil Howard )
Newsgroups: sci.electronics,sci.crypt
Subject: Re: VCR+ Algorithm?
Date: 16 Apr 92 19:14:20 GMT
Distribution: na
Organization: Netcom - Online Communication Services  (408 241-9760 guest)

spud@apple.com (Dave "Spud" Kalin) writes:

>Sorry if this topic has been through here before, but does anybody know the
>format of the codes for those VCR-Plus machines?  If you know the proper
>coding sequence, please e-mail me; I keep misplacing my TV-Guide, and if a
>calculator or PC can do the trick, that'd be way cool, dude... :-)

Are the VCR's that have VCR+ built in only allowing you to program based
on the VCR+ code?

It seems to me that you could use an alternate coding scheme which would
of course involve more numbers in place of VCR+ (or just program the VCR
the old way).

Simplified code:

1 digit  - day the program is on [0=Sun .. 6=Sat, 7=all days, 8=M..F, 9=S+S]
2 digits - start hour [00..23 or 38..61 (add 50 to PM hours)]
2 digits - start minute [00..59]
3 digit  - hours and minutes run time
2 digits - channel number

So to record channel 7 at 8:30 PM on Tuesday night for 1 hour and 30 minutes:

    2 58 30 130 07

To record the weekday news each day at 6 PM on channel 13:

    8 56 00 030 13

But TV Guide and others of course would rather you buy their publication to
get the numbers (which is why it is encrypted and they are trying to protect
the algorithm).  With such a simple system like this, people would not buy
TV Guide just for the numbers.

I don't buy TV Guide and I just program my VCR the old fashioned way from
advertising about future programs or the ones I regularly know about.
-- 
/***********************************************************************\
| Phil Howard  ---  KA9WGN  ---  pdh@netcom.com   |   "The problem with |
| depending on government is that you cannot depend on it" - Tony Brown |
\***********************************************************************/
From: Jeff.Lindstrom@ofa123.fidonet.org (Jeff Lindstrom)
Newsgroups: sci.electronics
Subject: Hex-FET's and loads
Date: Sat, 11 Apr 92 04:11:20 PDT
Organization: Universal Electronics Inc. (Public access BBS)

C>The reason they say this is it may build up a charge on the
C>internal capacitors that exceed it's dielectric strength and
C>internal voltage limits.  thus it would SELF destruct.

  Yeah... right.  HexFETs should not be run without a load for the same reason power BJTs (regular Bipolar Junction Transistors) should not be run without a load.  Driving the transistor into high conductivity with no load to drop the voltage vastly increases the power it has to dissipate, causing the junction temperatures to exceed allowable limits.

___
     Amiga MailMan v0.9


--  

Jeff Lindstrom
Internet: Jeff.Lindstrom@ofa123.fidonet.org
Compuserve: >internet:Jeff.Lindstrom@ofa123.fidonet.org
Newsgroups: sci.electronics
Subject: Re: kxp1124 printer
From: allen@eagle.wesleyan.edu (Allen D. Alonzo)
Date: Mon, 13 Apr 1992 12:41:55 GMT
Distribution: na
Organization: Wesleyan University, Middletown, CT USA

In article <1992Apr8.172326.24814@gdwest.gd.com> stlucas@gdwest.gd.com (Joseph St. Lucas) writes:

>Hello,  I have a panasonic kxp-1124 printer hooked to my computer.  The
>manual says it has 6k print buffer memory, expandable to 32k.
>Has anyone done this expansion themselves, or know how to do it, etc.
>I don't mind playing with the innards of the machine if I know new chips
>(and where to put them) will do it.  THanks.
>stlucas@gdwest.gd.com

I remember ordering the kit, and was disappointed when it arrived.  It was 
just a standard 32K x 8 static ram chip.  I believe it installed in the only 
available socket.  

Hope this helps.
Allen
From: day@william.vancouver.wsu.edu (Steve Day)
Newsgroups: sci.electronics
Subject: Re: Need help with Sony TV remote control
Date: 15 Apr 92 01:43:02 GMT
Article-I.D.: clark.1992Apr15.014302.5916
Organization: Washington State University, Vancouver Campus

In article <14058@acorn.co.uk> agodwin@acorn.co.uk (Adrian Godwin) writes:
>In article <1992Apr11.010124.6186@newstand.syr.edu> ldstern@rodan.acs.syr.edu (Larry Stern) writes:
>>To all: a neighbor of mine has a 6-7 year old Sony Trinitron, which works
>>well except for the remote control. The remote had an intermittent problem
>>where it would work fine for a few weeks, not work at all for a few days,
>>start working ok again, etc. It seems it is now, finally, dead. There is
>>one IC, a crystal, a few resistors and caps, and an LED inside. My question
>>is, what usually goes? Is this worth fixing? And finally, can this LED be
>>tested with an ohmeter like a "regular" diode?
>>
>
>It's often the keypad that goes, not the electronics. The conductive rubber
>pads on the buttons wear out, and don't connect any more. Check the buttons 
>that you don't use much, and see if they don't work either. Also, clean the
>PCB  under the keypad - if one of the buttons is permanently shorted, the
>others won't work.
>
>I don't know how reliable the LEDs are, but they tend to have a much higher
>forward voltage drop than an ordinary silicon diode - about 1.6V. This may
>be too high for an ohmeter, so it will indicate open circuit both ways.
>Test it by connecting up a voltage source & series resistor to limit the
>current to about 10mA, and measure the voltage drop over the diode.
>
LEDs are very reliable!  About the only way an LED could die is to give
is too much current (typically more than 25mA) or too high of a reverse
voltage (don't they have a lower PIV than "regular" diodes?).

In a remote, too high of a PIV is probably impossible; too much current is
also very unlikely.  It would require the current limiting resistor to go
bad and at the power level in a remote control that should never happen.

As for testing the LED... The forward voltages on LEDs range from about
1.6 volts to over 2 volts depending the the type (I don't have anything
exact to quote, but I seem to remember some green LEDs being about 2.2v).
The voltage source and resistor method above will work though.

I seem to remember a post saying to look for hairline cracks in the pcb.
You should use a magnifying glass and a good light source for this since
they can be very tiny and hard to spot.  You can also try testing the
continuity of the traces on the pcb, but some small cracks can give you
an intermittant signal (sometime they test ok, sometimes not) so you may
want to try this under SLIGHT stress. (Don't you too much or you may actually
cause problems!)

Good luck!


-- 

Steve Day
N7VHY
Xref: sparky sci.electronics:8491 comp.dsp:1121 sci.engr.biomed:252 sci.math:6026
From: francis@ircam.fr (Joseph Francis)
Newsgroups: sci.electronics,comp.dsp,sci.engr.biomed,sci.math
Subject: Re: quaternians, tracking, 3 dimensions
Date: 13 Apr 92 16:14:33 GMT
Organization: IRCAM, Paris (France)

In article <1992Apr9.174048.11924@aio.jsc.nasa.gov> berrier@sweetpea.jsc.nasa.gov (K. Berrier 283-4125) writes:
>A quaternion is a transformation matrix consisting of a scalar 
>and a vector.  The scalar is the angle of rotation about the 
>axis represented by the vector.
>
>They are often used to represent the relationship between two 
>coordinate systems since there are only four elements instead 
>of the usual nine. (Decreasing the number of calculations 
>required and increasing speed of computation.)

I believe quaternions are rational extensions into threespace of
imaginary numbers, you get from "x + iy" to "x + iy + jz" (or I guess
for EE's, it would be "x + jy" and "x + jy + kz") where i,j have
traditional square-root-of-negative-one meanings. I can't remember
exactly, it was only interesting to me for playing with 3d extensions
of the ordinary Mandelbrot set graphics generator functions.
-- 
| Le Jojo: Fresh 'n' Clean, speaking out to the way you want to live
| today; American - All American; doing, a bit so, and even more so.
Newsgroups: sci.electronics,rec.video
From: kazel@aries.scs.uiuc.edu (mitchell kazel)
Subject: Re: Consumer Electronics Show info?
Organization: School of Chemical Sciences, Univ. of Illinois at Urbana-Champaign
Distribution: na
Date: Wed, 15 Apr 1992 13:48:01 GMT

In article <1992Apr15.024539.7134@elroy.jpl.nasa.gov> hyc@hanauma.jpl.nasa.gov (Howard Chu) writes:
>Howdy - a while back someone posted info about the Summer CES, which I thought
>I saved, but apparently not. Could someone please email me info on registration
>and such? Thanks.
>-- 
>  -- Howard Chu @ Jet Propulsion Laboratory, Pasadena, CA

1992 International Consumer Electronics Show
May 28-31, 1992
McCormick Place
Chicago, IL

Trade Only Days:

Thursday, May 28    10 AM - 6 PM
Friday, May 29       9 AM - 6 PM
Saturday, May 30     9 AM - NOON

Trade/Consumer Days:

Saturday, May 30    NOON - 9 PM
Sunday, May 31      9 AM - 6 PM

For more information:

Consumer Electronics Shows
Electronics Industries Association
2001 Pennsylvania Avenue, NW
Washington, DC   20006-1813
-------------------------------------------------------------------------
Mitch Kazel (N9HDQ)                                PHONE:  (217) 333-1259
Department of Journalism                             FAX:  (217) 244-3348
University of Illinois                          INTERNET:  KAZEL@UIUC.EDU

Newsgroups: sci.electronics
From: wrt@wow.cray.com (William Taylor (1446))
Subject: Tango vs. OrCad
Organization: Cray Research, Inc.
Date: 15 Apr 92 08:40:03 CDT


I'm wondering if someone could post the differences between OrCad
	and Tango.

I recently received a Tango sales brochure which compared itself
	to OrCad so I presume the two manufactures are major competitors.

Thanks,

William Taylor.
wrt@steve.cray.com

--
William Taylor
Cray Research, Inc.
wrt@steve.cray.com
Newsgroups: sci.electronics
From: jeffj@krfiny.uucp (J. Jonas)
Subject: Re: Intel Ad shows static-proof CPU! :-)
Summary: Intel and other April fool jokes
Organization: Jeff's house of computer pieces
Date: Thu, 9 Apr 1992 16:26:41 GMT

Scott A Evans posted
> ... At least they stopped the Vacancy add campaign.

I'd love to have run an April fool's ad with the vacancy sign
pointing to the Intel designer's head
(or the marketer that's trying to convince people
"you *WANT* a machine with missing parts so you can add them in later".)

>I was beginning to worry about all of the electronic noise from that flashing
>neon!

Better yet - the old neon displays (particularly the genuine Nixie tubes)
were radioactive!  Yup - a small amount of radioactive element was used
to make the gas ionize faster.
That'll be great to place next to the semiconductor memories!

>From article <9bqjdqq@lynx.unm.edu>, by dmckeon@hydra.unm.edu (Denis McKeon):
>> There is an Intel ad on pages 10 and 11 of the April 13 Newsweek (USA
>> news-stand edition) that shows two Van de Graaf generators on either
>> side of an i486 (tm) with dual "lightning" paths jumping between them.
>> Caption reads: "The affordable power source for today's software."

Mixed up metaphor department, can you hold up please?
"lightning fast" and "as powerful as a thunderbolt" are desirable
traits, but "as destructive as a lightning strike" or
"as destructive as static discharge" are not.
The ad was obviously made by graphics designers, not EEs and
not aimed at anybody with any EE knowledge,
which is the bulk of the PC users today.

-- Jeffrey Jonas
jeffj@synsys.uucp
From: jmarin@messi.uku.fi (Jukka Marin)
Newsgroups: sci.electronics
Subject: Dead rechargeable batteries
Date: 16 Apr 92 06:08:17 GMT
Organization: University of Kuopio, Finland
Originator: jmarin@messi.uku.fi

I have a portable CD player (Sony) with rechargeable batteries (not NiCd
but some kind of a sealed lead battery).  I didn't use the batteries for
6-8 months and now their internal impedance seems to be very high.  The
batteries were fully charged and their rest voltage is still about 4V
(the same as their nominal voltage) but their impedance is so high that
even when short-circuited they supply only 20-40mA of current.

Is there any way to wake up the batteries?  I tried charging them for
some time but they don't take much charge as the charging current is
very small at voltages below 6V.  There has to be a way...

Please e-mail as I don't follow this group all the time.  Thank you!

  Jukka Marin
  jmarin@messi.uku.fi


-- 

| Mail: Jukka Marin           | E-Mail: jmarin@messi@uku.fi                |
|       Metsurintie 17 B 8    |         There's God above computers -      |
|       70150 Kuopio, FINLAND |                       Love beyond the hate |
Newsgroups: sci.electronics
From: chuck@pierre.mit.edu (Chuck Parsons)
Subject: Re: Color monitor problems; got a magnet near it by accident.
News-Software: VAX/VMS VNEWS 1.4-b1  
Organization: MIT Lab for Nuclear Science
Date: Sun, 12 Apr 1992 23:10:00 GMT

In article <dac.0334@dacami.UUCP>, dac@dacami.UUCP (David Culberson)    writes...
>  I accidently got a large magnet near the front of my monitor, a
>Mitsubishi Diamondscan.  I didn't think the magnet in my smallish speakers
>were very large, but they are.  Now bottom right corner of my monitor has
>a little blurring and some discoloration.  Nothing SERIOUS, but I am
>pissed as hell at myself, and I'd like to know how to get it fixed.  Can I
>do it myself?  If not, what is a good price to get it done by someone
>else, and what should I ask for?  Thanks alot!
> 
>  Reply via E-mail, and I will summarize, if you wish.
> 
>		-David

  We did this to a monitor once, holding a big magnet up and wathcing
the rainbow color effects. Unfortunately the effect was permanent,
the built in degausser wouldn't work.

  I wouldn't recommend fixing it the way we did but it worked. 
We had to fix it fast to avoid catching heat for ruining that $4000
monitor. We got a big spool of 16 gauge wire and hooked it up to 110 AC
USING A HOT PLATE IN SERIES AS A LOAD, to limit the current to less
than 10 amps. Holding it close to the screen and slowly pulling
it away degaussed the screen and fixed the problem.

  After about 15 minutes the spool of wire got hot enough to soften
the plastic core of the spool. It would be real easy to
electricute yourself doing this.

 You need the screen 'degaussed'. This takes about 5 minutes
with the right tools. They should only charge you $10-$20, 
they don't even have to open the monitor up.

Regards, chuck@pierre.mit.edu
From: Jeff.Lindstrom@ofa123.fidonet.org (Jeff Lindstrom)
Newsgroups: sci.electronics
Subject: Sony remote
Date: Mon, 13 Apr 92 04:13:00 PDT
Organization: Universal Electronics Inc. (Public access BBS)

LS>To all: a neighbor of mine has a 6-7 year old Sony Trinitron, which works
LS>well except for the remote control. 

  When my Sony remote went bad, it was the button.  It went flaky, then non-responsive, and now it works fine.

___
     Amiga MailMan v0.

--  

Jeff Lindstrom
Internet: Jeff.Lindstrom@ofa123.fidonet.org
Compuserve: >internet:Jeff.Lindstrom@ofa123.fidonet.org
From: sowellrm@memstvx1.memst.edu
Newsgroups: sci.electronics
Subject: Re: How to estimate 9V Alkaline Battery life ?y
Date: 10 Apr 92 07:50:16 GMT
Distribution: sci
Organization: Memphis State University

In article <JON_SREE.92Apr6094821@world.std.com>, jon_sree@world.std.com (Jon Sreekanth) writes:
> 
> I'm using a 9V alkaline (Duracell, or some similar store brand) battery
> in a circuit which has a fairly low current drain. I estimate 100uA 
> constant drain, and about 0.5 mA for maybe 6 hours per day. Also,
> the circuit will be functional down to about 4V from the battery. 
> 
> Is there some magic formula for estimating, from your experience, or 
> any  published specs (where do I find them ?) battery life ? Battery 
> life is defined in this case as # of days between buying an average-aged
> battery from a drugstore to voltage dropping below 4V ? 
> 
> (Right now, I have a 500maH estimate from Panasonic, and I've looked at
> Horowitz and Hill. I'm hoping I can get more maH because of the low
> drain, and because the circuit can go down to about 4V at least.)
> 
> Thanks for any pointers, 
> 
> / Jon Sreekanth
> 
> Assabet Valley Microsystems, Inc.           |  Fax and PC products
> 5 Walden St #3, Cambridge, MA 02140         |  (617) 876-8019
> jon_sree@world.std.com                      |
> 
> 

Kodac used to sell a 9V lithium battery that would probably last longer than
the alkaline.  It costs around $5 though.
Xref: sparky sci.electronics:8582 sci.crypt:1879
From: spud@apple.com (Dave "Spud" Kalin)
Newsgroups: sci.electronics,sci.crypt
Subject: VCR+ Algorithm?
Date: 16 Apr 92 01:23:23 GMT
Distribution: na
Organization: Apple Computer Inc, Cupertino, CA


Sorry if this topic has been through here before, but does anybody know the
format of the codes for those VCR-Plus machines?  If you know the proper
coding sequence, please e-mail me; I keep misplacing my TV-Guide, and if a
calculator or PC can do the trick, that'd be way cool, dude... :-)


Thanks in advance.
From: klg@mc.duke.edu (Kim Greer -- rjj)
Newsgroups: sci.electronics
Subject: Re: Stereo FM demodulation question
Date: 7 Apr 92 11:16:23 GMT
Organization: Duke Medical Center - Radiology

In article <202-PCNews-120beta@hacktic.nl+ bill@hacktic.nl (Bill Squire) writes:
+
+        First get the signal right off the discriminator and you should
+buffer it with an emitter follower or opamp.  Take this wideband signal and
+put it into a PLL like the Exar XR2211/12/13.  SCA's are normally at 67kHz
+or 92kHz.  The deEmphasis of the SCA is 150uS.  I found that with the
                ^^^^^^^^^^
+                                                        Bill

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


-- 
Kim L. Greer                       
Duke University Medical Center		 klg@orion.mc.duke.edu
Div. Nuclear Medicine  POB 3949		 voice: 919-681-5894
Durham, NC 27710  		         fax: 919-681-5636
From: sowellrm@memstvx1.memst.edu
Newsgroups: sci.electronics
Subject: Re: Mail order source for lasers
Date: 10 Apr 92 08:08:47 GMT
Organization: Memphis State University

In article <1992Apr8.090040.39128@kuhub.cc.ukans.edu>, wellison@kuhub.cc.ukans.edu writes:
> 
>>I would appreciate any information on mail order companies selling
>>laser accessories in small quantities. Preferably situated in Europe,
>>but others will do quite nicely too.
>>
>>
>>Thanks 	Samu Mielonen, f1sami@uta.fi
> 
> Two of the best laser resale companies in the states are:
> 
> MWK Industries
> 198 Lewis Court
> Corona, CA 91720
> 1-800-356-7714
> 1-714-278-0563
> FAX 1-714-278-4887
> 
> 
> Meredith Instruments
> P.O. Box 1724
> 6403 N. 59th Ave.
> Glendale, AZ 85301
> 1-602-934-9387
> FAX 1-602-939-3369
> 
>
Another company that sells lasers and accessories (even kits) cheaply in the
USA is:

Mega Products
2671 McKelvey Rd.
St. Louis, MO  63043

VOICE (314)291-7618
FAX   (314)291-7619
From: lairdkb@mentor.cc.purdue.edu (Kyler Laird)
Newsgroups: sci.electronics
Subject: Re: Cellular control head protocol?
Date: 17 Apr 92 00:33:45 GMT
Article-I.D.: mentor.45839
Organization: Purdue University Computing Center

In article <1992Apr16.032821.2247@vpnet.chi.il.us> cgordon@vpnet.chi.il.us (gordon hlavenka) writes:
>First:  My application for this is _definitely_ commercial.   But I'm
>not asking for the information, I just want to know where to _get_ the
>information.

My applications are _definitely_ not commercial.

I'd sure appreciate this information.  Controlling the handset sounds
interesting, but I'd rather go the other way for now.

--kyler
Xref: sparky sci.electronics:8388 rec.bicycles:9276 rec.motorcycles:12971
From: thad@btr.BTR.COM (Thaddeus P. Floryan)
Newsgroups: sci.electronics,rec.bicycles,rec.motorcycles
Subject: Re: Sticky Demand Traffic Light problem solution
Keywords: inductive vehicle detectors, traffic lights
Date: 12 Apr 92 11:16:23 GMT
Followup-To: sci.electronics
Distribution: na
Organization: BTR Public Access UNIX, Mountain View CA


This "thread" is becoming wearisome.

If a bike rider really wants to trigger the damned traffic light sensors:

(1) wear a suit of chain mail and/or a "King Arthur" Knight Suit.  That much
    mass is guaranteed to trigger the sensors.

(2) now that it's Spring, tire chains should be inexpensive.  SO buy about
    50 pounds' worth and drape them over the frame and handlebars (re: mass
    to trigger sensors)

(3) if you're worried about the chains scuffing your bike, then buy 50 pounds
    worth of steel ball bearings and swallow them before riding (re: mass to
    trigger sensors).

(4) get a good strong length of nylon rope.  Tie one end through the holes
    of a manhole cover (in the street).  Tie the other end to your bike's
    frame.  Pedal hard, really H-A-R-D, the first time to break the cover
    loose (may be tar sticking it to the road surface :-)  Dragging that much
    mass around should definitely trigger the light sensors!  :-)

    Besides, the manhole cover is ALSO a great safety item:

	daytimes it'll make so much noise it'll alert others to your presence

	nighttimes it'll make so many sparks that cars will keep their distance

	at all times it'll act to keep your speed reasonable (preventing radar
	tickets) and prevent you from performing stupid stunts in traffic (as
	bikees are wont to do :-)

(5) Get a clue, buy a car.  Problem solved!  :-)


[ Hope y'all have a sense of humor! :-) ]

Thad

P.S. I ride bikes, too.  Dirt bikes.  On the dirt and trails.  I don't trust
automobile drivers around bikes (all kinds), especially in this area (Silicon
Valley) since the past several years has seen a plethora of blind and stupid
people tooling around in their autos. :-(

Thad Floryan [ thad@btr.com (OR) {decwrl, mips, fernwood}!btr!thad ]
Newsgroups: sci.electronics