HDTenEightyP/NetNews huggingface dataset:
From: kludge@grissom.larc.nasa.gov ( Scott Dorsey)
Subject: Re: requesting CD player advice
Organization: NASA Langley Research Center And Storm Door Company
Date: Mon, 13 Apr 1992 19:17:15 GMT

In article <1992Apr11.171059.4664@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>My dictionary defines distortion as a deviation from the orginal signal
>waveform. It doesn't define "muddy" in any useful way. When you get the
>same signal out of a recording that was put into it originally, that's
>no distortion. A machine with .03% total distortion is over 200 times
>more faithful to the orginal recording than a system with 7% distortion.
>Whatever "muddy" means, it has to show up in the total distortion figure,
>or you are describing the orginal signal, and there's no helping that.

How are you measuring distortion?  I gather that you are talking about a
THD rating, but a system that has a poor slew rate may have excellent THD
and still sound poor because it doesn't follow transients well.   On the
other hand, if you define distortion as any deviation from the original
waveform, every CD player will have 100% distortion because there is a 
major phase shift (sometimes as much as 30 years or so with the CDs that
I buy) in the waveform.

Therefore, you basically need to find what particular rating is required
to account for a particular type of audible distortion.

This basically comes down to the argument as to whether people can hear
differences in CD players.  I can definitely hear them.  More than that,
I can measure them.  The group delay that is produced by the filters on
some CD players is really shocking.  I am sure that other things also may
be mangling the sound, but I don't know what so I can't give you an 
accurate measurement yet.

By the way, when people say something sounds "muddy" it generally translates
as excessive IMD.  I am starting to get better at guessing what is wrong with
systems ased upon very vague and subjective commentary.  Of course, it takes
an objective measurement to be sure.
--scott
Newsgroups: sci.electronics
From: helfman@aero.org (Robert S. Helfman)
Subject: Re: HV shocks (was: Jacob's ladder)
Organization: The Aerospace Corporation, El Segundo, CA
Date: Tue, 14 Apr 1992 02:57:31 GMT

In article <1992Apr13.063137.18999@u.washington.edu> pollock@milton.u.washington.edu (Joe Pollock) writes:
>In article <1992Apr12.140143.420@cmkrnl.com> jeh@cmkrnl.com writes:
>>
>>I agree with Mike.  In fact I think you can get a deadly shock from such a
>>transformer even if you are standing on the semi-mythical dry wood on glass
>>insulators (do you know anyone who actually works that way?), and even if you

>BTW - I found out about all of this the hard way.  I was in the eight or
>ninth grade, and messing around with a sign transformer in the basement.
>attempting to draw a fine corona from the other *terminal* off the 
.................
>screwdriver point.  The result was a fat yellow arc about an inch long.
>My arm snapped back, and the screwdriver stuck in the wall behind me.
>My arm and legs hurt for several days.  I learned to be a *lot* more
>careful very quickly :-)  One of the worst shocks I ever received.
>
>Amazing some of us ever reach legal maturity, isn't it?

Funny, I was exactly the same age when I got my first (and last) shock from
a sign transformer. I was at a junior high carnival and I set up a
Jacob's Ladder. It was nighttime and I was moving it around with the power
on. (It seems everyone is sure they're immortal at that age!).

I remember that when I made contact, I was living proof that it's only a
myth that "White Men Can't Jump"! I must have gone three feet straight up.
My arm, legs, back, everything hurt for a week afterwards - and it WAS 
the worst shock I ever received. (It was right-arm-through-body-to-leg.) 

I don't think I've gotten over 500 volts since that had 
ANY current capacity - that was in the days of 450 vdc supplies driving
tube equipment. I've had some CRT bites but nothing that could deliver
serious current. I'm almost 54 and I can still remember that shock at
age 13 like it was yesterday. It's one of the few memories from that age
that I still have!
Newsgroups: sci.electronics
From: mac1@Ra.MsState.Edu (Mubashir Cheema)
Subject: Re: Pioneer SX-1600 Probelm. Please Help !!!
Keywords: Help !!!
Organization: Mississippi State University
Date: Tue, 7 Apr 1992 03:12:25 GMT

mac1@Ra.MsState.Edu (Mubashir Cheema) writes:




>  I bought a Pioneer SX-1600 pretty cheap  basically to play with
>  its electronis. It has a problem : No sound !
>  All the digital display pop up just fine but no sound.
>  I connected speakers to both A and B connectors but no luck.
>  Connected the headphones again no luck.
>  Looks like its not the connectors. Just wondering where to start ...
>  Any clues/help will be greatly appreciated. 

> Thanx alot !
> 
> Mubashir
> P.S: If possible, please email : mac1@ra.msstate.edu

> 
>=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>Mubashir Cheema: Computer Engineering student at Mississippi State University.
>Amiga User and Star Trek Fan (me too :)
>I can be reached at Fax/phone : (601) 325-5869  
>Internet : mac1@ra.msstate.edu          Bitnet   : mac1@msstate.bitnet
>US mail  : PO Box 4887, MSU             UPS/FedEx: 721 Hamlin, MSU
>           MS State, MS 39762-4887                 MS State, MS 39762
>=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

>  
Newsgroups: sci.electronics
From: cces@bullet.ecf.toronto.edu (Congress of Can Eng Students)
Subject: Re: Ohm's law for AC?
Followup-To: cces@ecf.utoronto.ca (Brian Campanotti)  
Organization: University of Toronto, Engineering Computing Facility
Distribution: na 
Date: Mon, 13 Apr 1992 17:18:08 GMT

In article <oduNdSC00UhB81Orc1@andrew.cmu.edu> "Raymond C. Chick" <rc4n+@andrew.cmu.edu> writes:
>I record classical music and have recently begun to investigate the
>affects of cable resistance on mic. level audio signals.  I used two
>cables, one about 20' and the other about 350'.  I passed identical
>signals through each cable and measured the  outputs levels for various
>frequencies.  I found no difference in output level between the two
>cables for frequencies from 100Hz. to 16Khz. Yet, the restistance of the
>short cable was .5 ohms and the long cable was 5.5 ohms.
>
>Shouldn't the long cable attenuate the signal or even roll of the high
>frequencies?
>
>How can I determin the maximum cable length before signal degradation begins?
>
>Raymond Chick

Simple cable problems become transmission line problems (attenuation, 
reflection of incident wave, length dependent impedance, etc.) when the
length of the cable is greater than 0.25 * wavelength of the incident wave.

This means (assuming the incident wave propigates through the cable at c):

	100Hz -> 2997km (wavelength)
	16kHz -> 18.7km (wavelength)

so, if your cable were at least 4.684km long, you would have to worry about
attenuation and the other fun transmission line stuff!

Also, a resistive element will not cause high frequency roll off...only a
a complex impedance will alter the signal at high frequencies.  The small
resistances you noted in your cable do not really effect the signal since
there are also output and input resistances of your source and amp in 
series/parallel with this.

___________________________________________________________________________
| Brian Campanotti           | campano@ecf.utoronto.ca  | "I live for my    |
| Electrical Engineering 9T3 | campano@ecf.toronto.edu  |  dreams and a     |
| University of Toronto      | cces@ecf.toronto.edu     |  pocket full of   |
| Toronto, Ontario           | cces@ecf.utoronto.ca     |  gold."           |
| Canada                     |                          |        Zeppelin   |
|____________________________|_ANY_ONE_OF_THESE_WILL_DO_|___________________|
From: pgf@cayman.COM (Paul Fox)
Newsgroups: sci.electronics
Subject: parallel port distance limits?
Date: 10 Apr 92 19:46:47 GMT
Article-I.D.: cayman.7806
Organization: Cayman Systems Inc., Cambridge Ma


	How far can a typical PC's parallel port be extended?  I haven't
	looked at the drivers...  I'd love to go about 50 feet...


	paul fox, pgf@cayman.com
-- 
		paul fox, pgf@cayman.com, (617)494-1999
		Cayman Systems, 26 Landsdowne St., Cambridge, MA 02139
Newsgroups: sci.electronics
From: bae@hplsdll.col.hp.com (Bruce Erickson)
Subject: Cable TV ch 3 shifted to ch 65?
Date: Mon, 13 Apr 1992 19:49:31 GMT
Organization: Hewlett-Packard Logic Systems Operation

I am looking for a circuit which would take cable tv inputs
(one is the regular cable, the other the output of the converter
box on channel 3) and output the regular cable up to (about) 
channel 60, then put the converter channel on a high channel
(say 65).  

I know Radio Shack sells a block converter to shift cable TV channels
to non-cable channels, but I need a way to not only shift the channel
but to merge the two signals together.
Basically I am looking for a way to use the cable box for HBO, and
yet still allow my VCR's tuner to tune in HBO plus any other non-
scrambled channel...

Anybody have this or know where I could find one?  Or, for that matter,
if anybody has a box to do that for sale?


                  - Bruce Erickson
                     Hewlett Packard
                     bae@col.hp.com
Xref: sparky sci.electronics:8598 rec.audio:7508
From: rsd@sei.cmu.edu (Richard D'Ippolito)
Newsgroups: sci.electronics,rec.audio
Subject: Re: Slew Rate & distortion was (Re: requesting CD player advice)
Date: 16 Apr 92 13:32:02 GMT
Followup-To: sci.electronics
Organization: Software Engineering Institute

In article <se0biINNaaa@network.ucsd.edu> Matt Kennel writes:

> I don't understand.  How is having a 'poor slew rate' any difference from
> high-frequency dropoff in response?  Intuitively, they seem to be
> two ways of describing the same thing, though "poor slew rate" provides
> a bit more physical intuition.


It's intuition that kills this group and makes it so frustrating to read!

What you are asking cannot be simply answered.  A short answer is that the ability of a system to follow a an input is a function of both frequency AND amplitude.  Differentiate cos(wt) or graph two superimposed sinusoids of same frequency and different amplitudes and look at the slopes at zero crossings.

For an in-depth treatment, you will need to consult a basic text on control systems where order (type) and errors are discussed.  One designs and stabilizes control systems by the type of driving functions expected, but a good characterization can be made by analyzing response to three command
types: a step change in position, a step change in velocity (ramp) and a step
change in acceleration (parabolic function).

For systems of order 3 or higher, there will be no steady-state position, velocity, or acceleration error.  For a second-order system, which is typical of most feedback-stabilized amplifiers, there will be a finite but constant
acceleration error, meaning that the output will follow the input with a constant position error (lag). 
 
 

Rich


Good taste is timeless.
Why is a good time often tasteless?
From: xxxxajh@brunel.ac.uk (Alan J Holmes)
Newsgroups: sci.electronics
Subject: Re: Sony walkman antenna
Date: 9 Apr 92 11:12:37 GMT
Reply-To: xxxxajh@brunel.ac.uk (Alan J Holmes)
Organization: Brunel University, Uxbridge, UK

In article <1992Apr4.152438.16307@hamblin.math.byu.edu> richard@ee.byu.edu (Richard Christensen) writes:

>When I opened my walkman radio I was surprised to find that it
>had no AM antenna.  I understand that the antenna is part of 
>the earphone cord, but how does this work?  Also how could
>I attach a secondary FM or AM antenna to make the reception
>better?

As I understand it, there is no provision for any additional
antenna,  the Walkman was designed (?) as you have discovered
to use the earphone cord as the antenna.  I do not find it
particularly efficient except in areas of high signal
strength, and even then the way you sit or walk can affect the reception.

Sorry if this does not really answer your query, but I think you
will find, that (like me) you've been caught.

I too would like to know if anyone has foung a solution to this
problem.

Regards

Alan Holmes
From: mulligan@coral.bucknell.edu (MULLIGAN, EDMUND LUCIAN)
Newsgroups: sci.electronics
Subject: 68hc11EVB to TWO stop bit communications
Date: 17 Apr 92 19:11:00 GMT

I need to run a Rhine robot from an EVB.  How do I configure
it for 2 stop bit communications through either port?
Organization: Bucknell University, Lewisburg, PA, USA
News-Software: VAX/VMS VNEWS 1.4-b1  


Ed Mulligan
From: jing@resmel.bhp.com.au (Jian Feng)
Newsgroups: sci.electronics
Subject: Re: MC68000
Date: 6 Apr 92 03:32:14 GMT
Organization: BHP Research - Melbourne Laboratories, AUSTRALIA

roberts@CMR.NCSL.NIST.GOV (John Roberts) writes:


>>From: agulhati@willamette.edu (Ashish Gulhati)
>>Newsgroups: sci.electronics,rec.bicycles,rec.motorcycles
>>Subject: MC68000
>>Date: 1 Apr 92 01:50:35 GMT
>>Organization: Willamette University, Salem, OR

>>Has anybody designed a system using a 68000? I need some info on how it
>>operates. The bally reference manuals will go on and on about exception 
>>processing, DMA, and supervisors without telling you what happens when you 
>>power the thing up - and how you interface MEMORY to it so it has a program
>>to run (seems like all they want to interface to it are 6800 peripherals -
>>no memory).

>Do you have a *hardware* data sheet, or just the software references?
>I'm designing a simple 68010 system in my spare time, mostly for practice
>on Motorola processor and VMEbus-related interfaces.

>It's really pretty straightforward, at least for static memory devices.
>The main complications appear to be that:
>  - On powerup or hard reset, the bottom of the address space should be ROM,
>    but later on you need at least a few bytes of RAM there. This requires
>    some switching of address ranges by control signals to the address
>    recognizer.

Easy. MC68000 reads in the Stack Pointer (SP, the system stack pointer)
and the Program Counter (PC) from address $0. It takes 4 read cycles on
the 16b bus. Just use a simple 2 bit binary counter which is reset on power-up
and on counter-overflow it can switch the address.

J.Jing jing@resmel.bhp.com.au

>  - The timing from address ready to first opportunity for acknowledgement
>    is a little tight, so an extremely stupid circuit won't work - you have
>    to delay acknowledgement until your hardware is ready for it.

>If you want something tricky like zero-wait-state DRAM, then of course it's
>a nightmare. (How's that implemented, anyway? Does it require software
>supervision to handle the refresh? I normally use a store-bought DRAM
>controller chip.)

>John Roberts
>roberts@cmr.ncsl.nist.gov
From: pierson@cimcad.enet.dec.com (Dave Pierson)
Newsgroups: sci.electronics
Subject: Re: HV shocks (was: Jacob's ladder)
Date: 15 Apr 92 21:25:09 GMT
Organization: Digital Equipment Corporation

In article <vmyjt9b@dixie.com>, jgd@dixie.com (John De Armond) writes, in part:

>helfman@aero.org (Robert S. Helfman) writes:
>>Funny, I was exactly the same age when I got my first (and last) shock from
>>a sign transformer. I was at a junior high carnival and I set up a
>>Jacob's Ladder. It was nighttime and I was moving it around with the power
>>on. (It seems everyone is sure they're immortal at that age!).

>Yeah.  You and I both.  You'd have loved our electric chair I built when
>I was a yound teenager.  The chair was simple.  A sraightback wooden
>chair had an aluminum plate fastened to the seat and another fastened
>to the back.  The plates were connected to a 15,000 volt neon
>transformer.
	Well, i never got beyond the model-t Tesla Coil stage, at that age, that
	and the school (36" high) Van deGraff.  But some mention seems caled for
	of a reliable friend.  Who tells the story (he was ca 15 years old) of
	stripping a power transformer from a discarded XRay machine...
	'bout 100KV 60 Hz.  Current unknown.  He was drawing arcs from one
	electrode to another when he dropped one.  Energizing the ground.  So
	he couldn't turn it off.

thanks
dave pierson			|the facts, as accurately as i can manage,
Digital Equipment Corporation	|the opinions, my own.
200 Forest St			|I am the NRA.
Marlboro, Mass		01752	pierson@cimnet.enet.dec.com
"He has read everything, and, to his credit, written nothing."  A J Raffles
From: misra@matt.ksu.ksu.edu (Boo!)
Newsgroups: sci.electronics
Subject: PC parallel port
Date: 16 Apr 1992 13:11:23 -0500
Organization: Kansas State University
Distribution: world
NNTP-Posting-Host: matt.ksu.ksu.edu

	Does anyone how to write and read to/from the parallel port
of a IBM AT/XT and other machines. I posted this question on
comp.sys.ibm and got no response. I would like to connect an intrument
to the parallel port and use the port to read and write data and control
it. Thanks..

Xref: sparky sci.electronics:8623 rec.audio:7528 rec.audio.pro:535
From: gt3281c@prism.gatech.EDU (TABLER,JOHN ALEXANDER)
Newsgroups: sci.electronics,rec.audio,rec.audio.pro
Subject: Re: VCAs wanted.
Date: 16 Apr 92 19:46:47 GMT
Followup-To: sci.electronics
Organization: Georgia Institute of Technology

>Does anyone know who makes good quality VCAs (voltage controled amps).
>I'd like to do a few things with and equalizer.


SSM (solid state micro technology for music), which is now owned by PMI
(precision monolithics) makes a very good line of vca's.  We have used them in
several designs, such as multiband dynamics proscessors for brodcasting use.
I seem to remember the SSM 2224, and 2244 as being good, but they may not be
avaliable any more, and the newer stuff is better anyway.

    PMI (Santa Clara CA) 408 727-9222 ( this may be an old number )

Bye

John T.

.
From: mcovingt@athena.cs.uga.edu (Michael A. Covington)
Newsgroups: sci.electronics
Subject: Re: Parallel and Serial Ports
Summary: Bidirectional (input/output) parallel ports
Date: 7 Apr 92 00:47:07 GMT
Organization: University of Georgia, Athens

Bidirectional (input/output) parallel ports are found on many laptops
and most if not all IBM PS/2's.

Even a unidirectional parallel port has several "printer status" lines
that can be used as input.

Parallel ports are much faster than serial ports, which is why the
external disk drive connects to the parallel port rather than the
serial port.

-- 
==========================================================================
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.
==========================================================================
From: Jeff.Lindstrom@ofa123.fidonet.org (Jeff Lindstrom)
Newsgroups: sci.electronics
Subject: Info on iron-on PCBs??
Date: Mon, 13 Apr 92 04:13:18 PDT
Organization: Universal Electronics Inc. (Public access BBS)

AP>I missed saving the fairly recent thread on iron-on PCBs, and now I
AP>need the data. Could someone email me on this please?
AP>    - Andrew Palfreyman

  Amazing timing.  I just learned about this last week.

The distributor's name and address is:

     Meadowlake Corp.
     (516)757-3385
     25 Blanchard Dr.
     Northport, NY  11768

The product is:  Tec-200 film

It is a clear acetate and comes as 10 8"x10" sheets for $7.50.

Generate your 1X artwork and put it through the copier with the
 acetate in the paper tray.

Clean the PCB with 600 grit sandpaper or soapless steel wool
  or use denatured aclohol to clean the soap from a soapy steel
  wool pad.

Slap on PCB and use a thin cloth between the iron and acetate

Set the iron for 270-280 Fahrenheit (Cotton)

Iron for 2-2.5 minutes

Let cool and peel off film.

The PCB is now ready to etch with Ferric Chloride.

___
     Amig

--  

Jeff Lindstrom
Internet: Jeff.Lindstrom@ofa123.fidonet.org
Compuserve: >internet:Jeff.Lindstrom@ofa123.fidonet.org
From: tuttle@drsmbx.uu.ch (Georg Holderied)
Newsgroups: sci.electronics
Subject: parity-error!
Date: 12 Apr 92 14:30:46 GMT
Organization: Schweizer Radio und Fernsehen (SRG)

Since I got my brother's Olivetti M21 Personal Computer while
he's enjoying himself in Australia, this terrible "parity error
on system board" message is haunting me in my dreams. Not that
it would be seriously interfering with the overall performance
of that poor thing, but I can hardly tolerate it.
After startup, the computer displays the following messages, (in
80 char mode) which are coming from the diagnostic routines, I
hope:
 
Resident Diagnostics
Rev. 1.43
 
CPU (i8086) Pass
ROM Module  Pass
DMA Timer   Pass
DMA Control Pass
Interrupts  Pass
640 K RAM   Pass
RT Clock    Pass
Optional ROM at C800:0000
Floppy (A:) Not Ready
 
So far, everything is fine. Now the screen clears and in a
different font (40 char) this disgusting message appears:
 
Parity error on system boardMicrosoft MS-Dos Version 3.20...
 
There is no space between the two messages, the error message
comes right before the DOS Version message. The rest is normal,
if not for date / time:
 
As the date and time were lost each time I turned the computer
off, I thougt that it was just a matter of an exhausted backup
battery for the real-time clock. Indeed the Ni-Cd battery was
dead, so I replaced it with a new and previously loaded one.
Now I got another interesting phenomenon: The computer can keep
track of month and day, but it looses the year information each
time it is turned off, meaning that it always likes to be in
1984, which I find another disgusting thing. The time of day is
correct.
I suspected a faulty real-time clock chip and opened the bastard
again, finding a National Semiconductor MM58174AN, being backed
up by the battery.
I invested about $33 to get this chip from the local dealer,
replaced it and cried out in agony as there is still the same
Parity-error-on-system-board message, the month, day and time
correctly held while losing year information.
Is it because my brother has replaced the CPU with a V30 CPU ?
(what is a V30 anyway ?) Is it because he's got a coprocessor
installed (8087), or is it because of his hard-disk controller
(added later). Is it a hardware or a software problem ? (a
program like CheckIt does find no RAM or ROM problems, however
it says, it "cannot read the AT&T / Olivetti Clock"). If I had
an original 8086, I would try downgrading, but first : HAS
ANYBODY GOT ANY SUGGESTIONS FOR STUPID ME ?
 
Thank you for your replies.
 
Xref: sparky sci.electronics:8584 comp.sys.m6809:230
From: lharris@hubcap.clemson.edu (Larry Harris)
Newsgroups: sci.electronics,comp.sys.m6809
Subject: LCD displays and HC11's
Date: 16 Apr 92 04:46:17 GMT
Organization: Clemson University

I need a little help from anyone who has interfaced a LCD display based
on the Hitachi 44780 driver to a 68HC11.  I can't seem to get the darn
thing to work, so if anyone out there has done this before, or has a
program I can try to make sure the #$%& display does in fact work, I'd
appreciate it!

-- 
-Larry Harris-                |  '86 Mustang lx 5.0 notchback
lharris@hubcap.clemson.edu    |  Meyer's Tow'd Dune Buggy
lharris@clemson.bitnet        |  OS-9, a leaner meaner UNIX
Clemson Computer Engineering  |  RUSH, YES, R.E.M, The Who
From: root@galaxy.prime.com (Joe Polcari)
Newsgroups: sci.electronics
Subject: what are these chips?
Date: 6 Apr 92 14:56:53 GMT
Reply-To: root@galaxy.prime.com (Joe Polcari)
Organization: Prime Computervision, Bedford MA

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
===============================================================================