HDTenEightyP/NetNews huggingface dataset:
From: rmintz@ecst.csuchico.edu (Rich Mintz)
Newsgroups: sci.electronics
Subject: Re: Telephone questions - the sequel
Date: 24 Jul 92 16:29:43 GMT
Organization: California State University, Chico

Myles:
    You'd probably have a lot better luck with nearly all 
kinds of telephone questions on comp.dcom.telecom; that's 
where they're supposed to go anyway. Check it out--if 
you're interested in phone stuff, you'll never stop 
reading there!
    Regarding your question about a "read back the number 
you're calling from" number for a certain area... someone 
posted this number recently that I think is supposed to 
work for just about anywhere in the U.S. It is:
10732 1 404 988 9664.
        First it reads the number you're calling from, 
followed by the check digit "2". Then the ANI is cleared 
and it reads back all zero's (the computer sounds like 
it's stuttering and needs to be kicked) followed by a 
check digit of "8".
        I'll pass along the warning of the original 
poster of this info that he doesn't know if there's any 
kind of charge associated with dialing this number. I've 
done it several times and haven't seen it on my bill. 
Plus, I'm on a college Centrex system that demands a 
six-digit personal long-distance code any time a toll 
call is made, and it doesn't request the code for this 
call. The poster also suggested that the number may not 
be intended for use by the general public, and not to 
over-use it, otherwise they might change it.
                                           
        Rich -> rmintz@cscihp.ecst.csuchico.edu
Newsgroups: sci.electronics
From: aduell@nyx.cs.du.edu (Tony Duell)
Subject: Re: Cable, Stereo, and VCR Questions
X-Disclaimer: Nyx is a public access Unix system run by the University
	of Denver for the Denver community.  The University has neither
	control over nor responsibility for the opinions of users.
Keywords: Cable TV Stereo VCR
Organization: Nyx, Public Access Unix at U. of Denver Math/CS dept.
Distribution: usa
Date: Wed, 29 Jul 92 19:47:36 GMT


A VCR that cuts out short after play probably has a problem with the reel
rotation sensor. I assume that  it doesn't tangle the tape - remove the
top, and loo to check that the reelis turning and that tape isn't spilling
oput. Then press play, and immediately press pause. If you get a still
picture fro a significant time, you have a problem with the rreel rotation
sensor. It is normally a reflective oto switch under the take-up spool,
but could be a slotted opto switch or a hall-effect device. If it's an
opto one try cleaning it, otherwise you'll need the service manual to find
out exactly what pulses it feeds to the syscon (SYStem CONtrol)
-tony 'PDP11 Hacker' Duell
ard@siva.bris.ac.uk
From: chbl@sbustd.rz.uni-sb.de (Christian Blum)
Newsgroups: sci.electronics
Subject: Re: good op amps for audio
Date: 27 Jul 92 13:19:59 GMT
Organization: Studenten-Mail, Rechenzentrum Universitaet des Saarlandes

If you are in need of a good J-Fet opamp, try the LF356N. It's slightly better
than the TL08x series.

Chris.
Newsgroups: sci.electronics
From: tchannon@black.demon.co.uk (Tim Channon)
Subject: Amplifier for 25K Hertz... 
Distribution: world
Organization: null
Date: Fri, 24 Jul 1992 22:44:27 +0000

>      What I have is a small box with a built-in speaker which
> emits a ~25K Hz (above the range us humans can hear) when I
> press a button.  The strength of the signal is very small.
> 
Have you considered using a high efficiency loudspeaker eg. a horn?

  TC. 
    E-mail: tchannon@black.demon.co.uk or tchannon@cix.compulink.co.uk
                                
Newsgroups: sci.electronics
From: eric@telebit.com (Eric Smith)
Subject: Re: 20 Bit Counter?
Organization: Telebit Corporation
Date: 22 Jul 92 20:19:43

>>On Tue, 21 Jul 1992 23:32:28 GMT, pegasus@csd4.csd.uwm.edu (David R Hucke) said:
> What I would like to be able to do is increment/decrement the counter
> by putting a pulse on a pin and sending the resulting 20 bit number to
> 20 pins.

> What I am trying to do is access 1 MByte of memory with a micro-controller.

If you are controlling this in software, such that the memory cycle time is
not a constraint, you can daisy chain some 74xx393 counters.  These are dual,
4 bit binary asynchronous up counters, so you'll need three of them, or two
of them and a separate 4 bit counter, like a 74xx93.

You could use a CMOS counter 14-bit counter like the 4040.  Remember that
it needs CMOS input levels on the clock and reset lines.  Two of these would
get you 28 bits.  These are really slow, and since you would need two of
them anyhow, I think you're probably better of with 74xx parts.

If you need the counter to be fast enough to be able to read or write
the memory "instantly" after incrementing, you need to use synchronous
counters, like the 74xx163.  For a fully synchronous 20 bit counter, you
would need to have four gates to generate the *ET (or was it *EP) inputs
to each '163 after the first.  In practice you can tie the ripple carry
output of each counter to the *ET and *EP inputs of the next counter up.

There are probably some 8 bit synchronous counters also, in the 74xx500-699
range, but I don't know them offhand.

If you aren't familiar with logic design and/or the use of 74xx parts, you
way want to obtain a copy of  _The_TTL_Cookbook_, by Don Lancaster.

Cheers,
Eric
Newsgroups: sci.electronics
From: paranjpe@leland.Stanford.EDU (Milind D Paranjpe)
Subject: Seeking TV Stereo FM IF Decoder
Followup-To: paranjpe@leland.stanford.edu
Organization: DSG, Stanford University, CA 94305, USA
Date: Sat, 25 Jul 92 03:46:12 GMT

Hi,

I'm looking for a chip to decode television FM IF to stereo (left and right
preferably).  Know of a good one?

Thanks,
Milind Paranjpe
paranjpe@leland.stanford.edu
From: jeh@cmkrnl.com
Newsgroups: sci.electronics
Subject: Re: PC masks from a laser printer??
Date: 28 Jul 92 05:50:40 GMT
Organization: Kernel Mode Consulting, San Diego, CA

In article <1992Jul27.065039.5734@lugb.latrobe.edu.au>, MATGBB@LURE.LATROBE.EDU.AU (BYRNES,Graham) writes:
> Dear Knowledgeable ones,

that remains to be seen.  :-)

> Up until now I have made my PCB's using donut and tape transfers on
> overhead proj film, exposing Electrolube +ve resist on the copper.
> However, as I have now entered the compuer age and bought a cheapy
> PCB CAD program, I need to produce masks from a laser printer.

Questions along this line come up every few months or so.  

I'll leave the explanations of the exact methodology for doing PC masks on a
laser printer to others, and stick to my own personal hobby horse:

	YOU SHOULD NOT ASSUME THAT A LASER PRINTER IS A PRECISION DEVICE!

Specifically, you should not assume that your laser printer will lay down toner
in the same place every time, not until you test it.  

Here's one test.  Coax your printer to printing a 6" square grid of 0.1-inch
squares.  Print two such grids onto separate sheets of white paper.  Find a
light table or something similar, lay the two grids on top of one another, and
see if you can make them match up *everywhere at once*.  Never mind getting
them to match up with the edges of the pages aligned -- that's not an issue,
that's what the crop marks on your PCB pattern are for.  No, I'm talking about
getting them to match up *at all*. 

	(If you really want to be shocked, copy one of these on an office 
	copier -- ANY office copier -- and try to make the copy match the 
	original.  Especially do this if you are planning on using a reduction 
	copier for doing reductions from the laser printer output for your
	PCB masks.)

If they match up, great!  No problem -- with your particular printer.  Don't
assume that other printers are as good.  

If they don't match up, you'll have to evaluate the degree of error and see if
the results are still acceptable for your particular PCB work. 

(The usual reason for the problems I'm alluding to is that laser printers,
especially low-cost ones, are not really precise paper-handling machines.  Not
only is the registration of the paper slightly different from one sheet to the
next, but the paper will shimmy and shake a bit as it goes through the rollers.
 Hence there is usually some error along the line of travel of the paper. 
There is usually very little error in the dimension at right angles to the
paper's line of travel, since points on that axis are spotted by the printer's
rotating prism, or LED array, or LCD shutter, or whatever, and these mechanisms
are usually fairly precise.) 

	--- Jamie Hanrahan, Kernel Mode Consulting, San Diego CA
Internet:  jeh@cmkrnl.com, hanrahan@eisner.decus.org, or jeh@crash.cts.com
Uucp:  ...{crash,eisner,uunet}!cmkrnl!jeh
Xref: sparky sci.electronics:13463 rec.audio:10938 alt.folklore.computers:11280
From: myjak@titan.ksc.nasa.gov (Michael D. Myjak)
Newsgroups: sci.electronics,rec.audio,alt.folklore.computers
Subject: Re: Two-sided CD's *DO* exist! (was Re: Life after CDs)
Date: 28 Jul 92 15:54:51 GMT
Organization: NASA, Kennedy Space Center

> Yes, Polygram recently issued a promo-only CD single that features music
> on both sides (one side features a track from A Man Called (E); the second
> side features a track from Shakespeare's Sister). The minimal information 
> printed on the CD is confined to the blank space around the spindal hole.
> I'm not sure how they manufactured it.
> 
>     David A. Pearlman
-- 

This is really nothing new... Laser Disks (grown-up CDs) have been
double sided for a very long time now.

- Michael D. Myjak			
  Senior Technical Specialist, Systems Analyst
  McDonnell Douglas Space Systems Company - KSC
  MYJAK@TITAN.KSC.NASA.GOV

Fea'ture N.  Distinction; Characteristic; Perculiarity (!)
             A bug with documentation.
Newsgroups: sci.electronics,rec.audio,alt.folklore.computers
From: eric@telebit.com (Eric Smith)
Subject: Re: Life after CDs
Organization: Telebit Corporation
	<14mdkjINNb4m@grapevine.EBay.Sun.COM>
	<1992Jul23.221924.681@news.columbia.edu>
Date: 23 Jul 92 18:22:26

>>On Thu, 23 Jul 1992 22:19:24 GMT, lasner@watsun.cc.columbia.edu (Charles Lasner) said:
> The part I heard was that this requirement wasn't going to work at the
> designated sample rate of 48 KHz, so they cut it back to 44.1 to squeeze it
> in.

I seriously doubt that, since PCM recording equipment already existed that
used 44.056 KHz sampling, whereas I don't think anything in mass production
used 48.0 KHz sampling at that time.

Cheers,
Eric
From: schuster@panix.com (Michael Schuster)
Newsgroups: sci.electronics
Subject: Re: Radar Detectors, and Radar Detector Detectors
Keywords: Radar
Date: 23 Jul 92 23:53:38 GMT
Organization: PANIX Public Access Unix & Internet, NYC

In article <92Jul23.162259edt.176@orasis.vis.toronto.edu> oliverb@vis.toronto.edu (Oliver Bengtsson) writes:
>
>   Could someone out there please tell me how a radar detector detector
>works? I thought that a radar detector was a passive device, nothing more
>than a receiver tuned into detect a certain radio frequency used in radar
>guns. If this is the case, how can they be detected?  

They detect the local oscillator in the radar detector, which usually
leaks enough stray radiation that it can be picked up within a few
hundred feet.

Remember the Radio Shack detectors that gave off so much stray RF
they triggered OTHER radar detectors? Remember when radar detectors had
"Radio Shack filters" to combat the result of this poor engineering?

>  Further, is it possible to detect radar detector detectors?

No, but it's possible to detect radar detector detector detectors :-)

-- 
_______________________________Mike Schuster________________________________
NY Pub. Access UNIX/Internet: schuster@panix.com | 70346.1745@CompuServe.COM
The Portal (R) System: schuster@cup.portal.com   | MCI Mail,GEnie: MSCHUSTER
From: aj@ib.rl.ac.uk (Andrew Jessett)
Newsgroups: sci.electronics
Subject: Help with capacitor markings please.
Date: 31 Jul 92 08:48:24 GMT
Organization: Rutherford Appleton Laboratory

Can anyone tell me the parameters of a capacitor marked thus:

    d_   224k

    1000  PPN

It has come from a device for zapping flies so it must be  a high voltage
device. 2240 volts 1000 pF I wonder?

TIA

Andrew F. Jessett
Rutherford Appleton Laboratory
aj@uk.ac.rl.ib
From: prg@dir.mcc.ac.uk (Pete Green)
Newsgroups: sci.electronics
Subject: Anyone know of 16+ bit delay registers ?
Date: 24 Jul 92 17:52:37 GMT
Organization: Network Unit, Manchester Computing Centre, England.


I need to implement a 4 bit, 24 stage shift register style delay register to 
be clocked at 20 MHz. Now I could build this using standard TTL shift 
registers but I have heard that there are some low pinout packages available
where you don't require parallel access to the register. Can anyone give me a
part number ?

Many thanks,

Peter Green.
From: nall@sun8.scri.fsu.edu (John Nall)
Newsgroups: sci.electronics
Subject: White noise generator.....
Date: 27 Jul 92 14:09:18 GMT
Followup-To: sci.electronics
Organization: SCRI, Florida State University

Since I did fairly well at getting my previous question answered
on this newsgroup, thought I'd push my luck and ask another :-)

I'm one of those people who has to have some "white noise" in the
background to sleep.  Something like a fan, or rain on the roof,
or wind in the trees, something like that.  I have a device which
I use at home, which is a combination radio/alarm-clock/noise-generator
with a couple of good sized speakers and runs on 110v AC.  It works
fine - generates sound (switch control to either a constant sound or
else the sound of surf breaking on a beach) which lulls me to sleep
and hides such things as dogs barking in distance, etc.

So far so good - this works fine at home.  But it is large and bulky,
and trying to carry it on a camping trip or on quick out-of-town
trips is a drag.  Some motels have room air conditions which serve
the purpose, but not always.

Anyway...finally....it seems to me that if there is a sound-generator
chip available, that a little portable unit could be made, which would
run on ni-cad batteries (so that it could be recharged), with a small
speaker such as is found in a cheap transistor radio.  If put close to
the ear when sleeping, it should do the trick.

Does anyone know of such a device?  If not, is there a such a noise-
generator chip available?  (I don't have access to any sort of technical
material on what chips are available these days).

BTW, if there is NOT such a device available, someone could probably
make money by making one.  There are zillions of people like me, who
have to have noise to sleep :-)

Thanks for any info.

John


--
John W. Nall              | Supercomputer Computations Research Institute
nall@mailer.scri.fsu.edu  | Florida State University, Tallahassee, FL 32306
    "You cannot be a beacon, if yo' light don't shine!"  
                                            - heard on the car radio...
Newsgroups: sci.electronics
From: tchannon@black.demon.co.uk (Tim Channon)
Subject: P-channel Mos-Power (equivalent to VN2410L, Siliconix) wa 
Distribution: world
Organization: null
Date: Fri, 24 Jul 1992 20:34:36 +0000

> I have been using a Siliconix VN2410L (also known as BS-107?),
> which is an N-Channel enhancement mode mos-power transistor.
> It comes in a TO-92 case.  I am activating the gate of this device
> by taking the output of a 54LS154F (4 line to 16 line decoder) and
> inverting it (74LS04).  The inverted output goes to the Mosfet.
> ...
> E-mail or post... Thanks ahead for any ideas...
> 
You don't describe the full circuit so would a complementary 4 to 16 do
the trick, 74HCx4514? This also has latching.

Have you looked at the Supertex line of high voltage array drivers some of 
which mention ultrasound imaging applications? Some of these have the 
decoding on chip.

  TC. 
    E-mail: tchannon@black.demon.co.uk or tchannon@cix.compulink.co.uk
                                
Newsgroups: sci.electronics
From: freudent@vlsi3.ultra.nyu.edu (Eric Freudenthal)
Subject: info on mastering of cd-roms
Organization: /a/users/freudent/.organization
Date: Mon, 27 Jul 1992 20:54:02 GMT

I am interested in mastering a cd-rom.  Please send me mail if you
have a pointer to any services that do this.  Thanks, Eric.
--
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
				Eric Freudenthal
				NYU Ultracompter Lab
				715 Broadway, 10th floor
				New York, NY  10003
				
				Phone:(212) 998-3345 work
				      (718) 789-4486 home
				Email:freudent@lab.ultra.nyu.edu
Xref: sparky sci.electronics:13264 rec.audio:10804 alt.folklore.computers:11089
From: chbl@sbustd.rz.uni-sb.de (Christian Blum)
Newsgroups: sci.electronics,rec.audio,alt.folklore.computers
Subject: Re: Life after CDs
Date: 24 Jul 92 19:52:49 GMT
Organization: Studenten-Mail, Rechenzentrum Universitaet des Saarlandes

smckinty@sunicnc.France.Sun.COM (Steve McKinty - Sun ICNC) writes:
> In article <1992Jul23.041115.20377@bilver.uucp>, bill@bilver.uucp (Bill Vermillion) writes:
> There is a story (probably apocryphal, anyone know?) that the 74 minutes
> time was chosen because it was just long enough to hold the Sony MD's wife's favourite piece of classical music...

Sorry that I don't know about your story, but I do know that I've got a CD
with 76 minutes of music on it... and I've seen one with 77 minutes!

Chris.
Newsgroups: sci.electronics
From: Barry Thomas <thomasb@ucs.indiana.edu>
Subject: Notebook batteries & desktop use
Organization: Indiana University
X-Useragent: Nuntius v1.0
Date: Thu, 30 Jul 92 21:03:47 GMT

We have both DOS and Apple notebooks that spend much of the time being
used as desktop machines (attached to A/C, large monitors and network
adaptors).  These machines may be plugged in 8-5 (or longer), then taken
home evenings and weekends.  None of manuals speak to this sort of
operation.  They generally talk about charging and conserving power (at
least this is the case for the Zeniths and Apple).  The Apple manual does
warn against using the machine with the battery removed.

Should we recommend that individuals "exercise" (i.e. run the machine on
battery power) their batteries on a regular basis?  If they aren't taking
the machine home, should they unplug the charger from the machine and the
wall socket?  Or does it really matter?


Barry Thomas
thomasb@ucs.indiana.edu
Indiana University

Opinions expressed our my own and do not represent the University
Newsgroups: sci.electronics
From: gutiea@aix.rpi.edu (Adolfo Osvaldo Gutierrez)
Subject: Low Cost Memory Tester
Organization: Rensselaer Polytechnic Institute, Troy, NY
Distribution: World
Date: Fri, 31 Jul 1992 19:24:38 GMT

I need to test memories at relatively low bandwlow speed (5 MHz at the most)
The tester must be small, very low cost, flexible enough as to enable
me to use various DUT carards up ds to test DRAMS, SRAM and different types of ROM.
A PC based system would be ideaal.
Can anyone help me to find one ?

Adolfo

Reply to : gutiea@rpi.edu using e-mail
.
Newsgroups: sci.electronics
Subject: Serial to Parallel conversion RS-232 --> 32 bit Parallel
From: gwestern@icaen.uiowa.edu (Gary Edwin Western)
Date: Wed, 29 Jul 1992 15:16:08 GMT
Organization: Iowa Computer Aided Engineering Network, University of Iowa

I was wondering if there is an easy way to "capture" 4 serial bytes from 
an RS-232 serial port on an IBM compatible machine to be output as 1 32 bit
wide latched byte.  Perhaps a combination UART and a count to 4 timer?
Any help on this matter would be greatly appreciated!  Please respond to
E-Mail:		gwestern@icaen.uiowa.edu

Thank you all-  Gary E Western

================================================================================
Newsgroups: sci.electronics
From: swanee@megadata.mega.oz.au (Geoff Swan)
Subject: UHF XMTR Chip
Keywords: IC, XMTR
Organization: Megadata P/L, North Ryde, Sydney, Aust.
Date: Wed, 22 Jul 1992 00:37:53 GMT

Greetings,
         Having just received the data sheets for the MC13175, MC13176
UHF FM/AM transmitter chips, I was wondering if anyone had used these
devices and were aware of any "undocumented features" or problems
associated with their use.
Thanks in advance,

    Sla/n go fo/ill,
                    Risky B.
--------------------------------------------------------------------------
Geoff Swan (research & development)   _--_|\         swanee@megadata.oz.au
Megadata Pty Ltd                     /      \ 
2/37 Waterloo Rd, North Ryde,        \_.--._/               +61-2-805-0899
NSW 2113, Australia.                       v           (AH) +61-2-477-6519
From: baker@westsd.dco.dec.com (Art Baker)
Newsgroups: sci.electronics
Subject: Re: 25KV (was: SHOCKING STORIES)
Date: 23 Jul 92 19:11:40 GMT
Organization: Digital Equipment Corporation

In article <1992Jul23.192145.1@research.ptt.nl> walvdrk@research.ptt.nl (KEES VAN DER WAL) writes:
>
>This morning there was a story on the BBC-news that a boy survived a 25KV 
>shock from an overhead railway line. I didn't catch how he came into contact 
>with the line; he's in hospital now.

 Yes, I'll bet his parents had to do quite a lot of coaxing to get him
to grab hold of it...  ;-}



-- 
	***********************************************************
	* Art Baker			| Joy and fierceness...	  *
	* baker@westsd.dco.dec.com	|  			  *
	***********************************************************
Newsgroups: sci.electronics
From: oski@leland.Stanford.EDU (L. Ravi Narasimhan)
Subject: Re: magnetic insulators and shape-memory alloys (was Re: PZT Excitation)
Organization: Department of Chemistry, Stanford University
Distribution: na
Date: Tue, 28 Jul 92 04:04:49 GMT

In article <1992Jul28.034438.3418@ennews.eas.asu.edu> gsulliva@enuxha.eas.asu.edu (Glenn A Sullivan) writes:
>> mece1xg@menudo.uh.edu (purna) writes:
>>> rhsomer@PacBell.COM (Bob Somers) writes:
>> > Is there any material that acts as an insulator
>> >from magnetic forces?  I was told some time ago
>> >that there is none, but perhaps some new material
>> >will do this.
>> >	Bob Somers, Pacific Bell, 510-823-9010
>

There is a nickel alloy, commonly called mu metal, that is used to shield
sensitive devices from stray magnetic fields.  This stuff is available
from many suppliers although their names escape me at the moment (I will
look up the info. and post later if there is interest.)  It can be
rolled, formed, cut etc. into a variety of shapes.  It requires
annealing in a hydrogen atmosphere after all the metal processing is
done.

The brochures I have seen show off-the-shelf shields for a variety of
photomultiplier tubes, magnetic recording media, and crts.  Entire rooms
made from mu-metal are also doable.  

Another possibility is to enclose the sensitive device in a
superconducting can such as niobium below the superconducting temperature.


				--- Ravi Narasimhan
				    AT&T Bell Laboratories
				    Murray Hill, NJ
			            oski@clockwise.att.com
Newsgroups: sci.electronics