HDTenEightyP/NetNews huggingface dataset:
From: curt@oasys.dt.navy.mil (Curt Welch)
Newsgroups: sci.electronics
Subject: Re: Phone line monitor
Date: 11 Nov 92 15:37:50 GMT
Reply-To: curt@oasys.dt.navy.mil (Curt Welch)
Organization: Carderock Division, NSWC, Bethesda, MD

I asked:
> So, my question.  How do I use a scope to look at a phone line?  Do I
> need an isolation transformer between the power and wall outlet?  Or is
> there some type of probe I could buy that would provide the needed
> isolation?

ch@eiaut2.tuwien.ac.at (Christian Kral) answered:
>There is a simple possibillity of getting rid of this kind of problems,
>using a two channel scope which can add both inputs and invert one.
>If you hook up both probes to the two telefone lines, leaving the
>GND-connectors of the probes away, you can measure simply the
>differencial signal which is just what you want, regardless of the
>common voltage.

Yes, a few people have suggested this. (Thanks to all of you).

I tried it last night and it works great.  It was just a matter of
learning how to use my scope! (I always wondered why they had
the channel 1 + 2 add function and the channel 2 invert switch!)

Curt
Newsgroups: sci.electronics
From: chrysler@psych.umn.edu (Susan Chrysler)
Subject: SUN Monitors
Organization: University of Minnesota
Date: Thu, 5 Nov 1992 17:12:12 GMT


I have a couple of SUN monitors that suffer from the exact
same kind of problem.  When they are turned on, you can hear a high
pitched oscillation.  Their is no picture, and when you turn the monitor off
the oscillation slows down as the power leaves the monitor.

I'm pretty sure the sound is coming from the high voltage transformer.

Could anybody help me diagnose this problem?  It sounds like this
is a common occurrence among older SUN monitors (circa 1987).

I am posting this from a remote terminal so please E-mail responses
to:
	rob@dexter.psych.umn.edu

Thanks in advance

Robert Stephens
Human Factors Lab
University of Minnesota
Newsgroups: sci.electronics
From: massoud@chemteca.sdsu.edu (Massoud Ajami)
Subject: Re: Heat conduction vs. electron conduction?
Organization: San Diego State University
Date: Wed, 11 Nov 1992 17:54:08 GMT

In article <1992Nov10.180223.25291@galileo.cc.rochester.edu> mh001b@uhura.cc.rochester.edu (Matthew W. Hacker) writes:
>From: mh001b@uhura.cc.rochester.edu (Matthew W. Hacker)
>Subject: Heat conduction vs. electron conduction?
>Date: 10 Nov 92 18:02:23 GMT
>
>Are there any substances that conduct electricity well, but
>conduct heat poorly?  This sort of material would be pretty
>well suited to thermacouple (Sp?) design...
>
> 
>
>-- 
>Matthew W. Hacker                           mh001b@uhura.cc.rochester.edu
>                                            AppleII forever!

Platinum which is used for thermocouples (types S, R, and B) has almost the 
least thermal conductivity in metal group (pure).
Platinum    0.73    watts/cm C  @ 25 degree     0.79  @ 100 degree
copper      3.98      "              "          4.83       "
Stainless steel has also very poor thermal conductivity.



Peace and Prosperity!
  ---==< 110 >==---
Newsgroups: sci.electronics
From: schaerer@isi.ethz.ch (Thomas Schaerer)
Subject: Re: Questions about NiH Battery? PADS? (I'm new in this group)
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL6]
Date: Fri, 6 Nov 1992 12:30:26 GMT

Mato Hattori (hattori@convex.com) wrote:
: 
: 	1.  I'm not familiar with Nickel Hydrogen Battery.  
: 	    How does it different from Nickel Cadmium Battwry?
: 

If you want know more about these new accutypes you should read the
Technical Reference  "Nickel-Metal-Hydride Rechargeable Batteries"
from "THE FURUKAWA BATTERY CO., LTD". The problem I don't know an
address where you can order this paper. Try it through a battery-
distributor.

Bye Thomas
Newsgroups: sci.electronics
From: msunde01@mik.uky.edu (Mark  Underwood)
Subject: Re: 12 V -> 3V, 0.6 A
Reply-To: msunde01@mik.uky.edu
Organization: University Of Kentucky, Dept. of Math Sciences
Date: Tue, 10 Nov 1992 16:13:57 GMT

In article <1992Nov9.231617.28042@b30.ingr.com>  
medin@catbyte.NoSubdomain.NoDomain (Dave Medin) writes:
> In article <sehari.721280522@class1.iastate.edu>, sehari@iastate.edu  
(Babak Sehari) writes:
(both say lots of stuff about running a CD player in car)

I hate to throw a bucket of cold water on everything, especially in a  
newsgroup full of people who just LOVE to design their own gadgets, but  
wouldn't it be easier to get a cigarette-lighter power adaptor for about  
$10 or so from an electronics store like (dare I mention the R-S phrase?)  
or somewhere, or, heaven forbid, get the one the manufacturer recommends  
and save your warrantee??  Caveat:  I tried to find a SONY adaptor for my  
SONY discman, and have yet to find a place that can keep them in stock  
long enough . . ..  I ended up with the R-S model, and rigged a "pigtail"  
plug adaptor using the plug from my A-C adaptor (since the plug on SONY is  
non-standard) and fixed it so I could switch the pigtail from the AC to  
the DC adaptors.  It works, though I admit it took all the fun out of  
devising a solution . . ..

Feeling bad for suggesting store-bought goods in a home-built newsgroup,
I am

--
Mark Underwood
EE Student, University of Kentucky
Lab Assistant, UK Library Microlabs
Internet address:  msunde01@mik.uky.edu

"Cogito, ergo Sum." - Descartes
"Non Cogito - poof!" - Anonymous
Xref: sparky sci.electronics:18850 sci.physics:18828 news.admin.misc:330
From: walter@ee.ubc.ca (Walter Wohlmuth)
Newsgroups: sci.electronics,sci.physics,news.admin.misc
Subject: Re: RFD: sci.solid-state.electronics
Date: 13 Nov 92 17:52:44 GMT
Followup-To: sci.solid-state.electronics
Distribution: sci.electronics, sci.physics, news.admin.misc
Organization: University of BC, Electrical Engineering

In article <BxnGI5.FD5@uunet.uu.net> sehari@iastate.edu (Babak Sehari) writes:
>In observation of the guidelines for usenet group creation a request for
>discussion on creation of sci.solid-state.electronics is being
>cross posted to sci.electronics, sci.physics, and news.announce.newsgroups.
>The name of this group is still open for discussion. Each field of this 
>new proposed newsgroup name should be less than 15 characters long, a field 
>is the combinations of words between two ".". Also, there should be no bogus 
>character such as "&" in the field.
>
>This new newsgroup, which is **not** to be moderated, is to focus on various
>areas of microelectronics, solid states, semiconductors, semiconductor
>devices, lithography, quantum electronics, semiconductor processing
>(such as CVD, MBE, etc...), different IC technologies (such as VLSI,
>ULSI, WSI, 3DI etc..) , digital, AF, RF, MMIC technologies, optical
>components (such as LED, LCD, Lasers), optical fibers and ...
>
>Please, post your support for creation of this newsgroup and any comments
>you might have about this newsgroup to sci.electronics and/or sci.physics.
>
>                     With highest regards,
>                          Babak   Sehari.

I support the creation of this group, but why not just call it
sci.microelectronics since it will focus on 'various areas of
microelectronics'.  Or even sci.microstructural.electronics.

Walter A. Wohlmuth
Tri-University Meson Facility (TRIUMF)
Microelectronics Lab
 
Newsgroups: sci.electronics
From: medin@catbyte.b30.ingr.com (Dave Medin)
Subject: Re: 12 V -> 3V, 0.6 A
Reply-To: medin@catbyte.b30.ingr.com
Organization: Intergraph Corporation, Huntsville AL
Date: Tue, 10 Nov 1992 19:20:23 GMT

In article <1992Nov9.114833.26094@bernina.ethz.ch>, schaerer@isi.ethz.ch (Thomas Schaerer) writes:

|> Sorry but all this is nonsense bcause of the high current. If you realise
|> a linear regulator you will generate very high lostpower. In this example
|> will be 0.6A * 9V = 5.4W. The better way is to build a switched regulator.
|> The advandage is the high efficiency ang therefore less powerdissipation.
|> There are many ic which can do this with a few additional components. 
|> Take the Switching-Regulator L296 from SGS-THOMSON. There is a kit with
|> pcb-board and the needed components. Ask a SGS-THOMSON-Distributor.

The poster is right about the power dissipation, but the idea is not
a good one for audio devices (which the first poster was inquiring
about). The high frequency garbage and ripple (even from converters
operating in the 100 KHz to 1 MHz region) wreaks havoc on audio
circuitry both through direct amplification and also detection as
RF. This is, unless the supply is carefully designed and installed.
The L296 (of which I have the evaluator kit mentioned) holds no
special cards in the noise department.

My CD player (Philips/Maggotbox) is a good example of switch mode
technology in audio. The logic and transport have a very heavily
filtered switching supply, while the analog split supply is linear.
It works well.

I've had incredibly bad luck with switching supplies and audio. I'd
caution others to avoid possibly wasting time with it.

-- 
 --------------------------------------------------------------------
       Dave Medin			Phone:	(205) 730-3169 (w)
    Intergraph Corp.				(205) 837-1174 (h)
       M/S GD3004
  Huntsville, AL 35894 		Internet: medin@catbyte.b30.ingr.com
				UUCP:  ...uunet!ingr!b30!catbyte!medin

   ******* Everywhere You Look (at least around my office) *******

 * The opinions expressed here are mine (or those of my machine)
From: cgordon@vpnet.chi.il.us (gordon hlavenka)
Newsgroups: sci.electronics
Subject: Re: IC to isolate device from telephone line?
Date: 5 Nov 92 07:21:02 GMT
Article-I.D.: vpnet.1992Nov05.072102.21129
Organization: Vpnet Public Access


 kehoe@netcom.com (Thomas David Kehoe) writes:
>I heard that someone, maybe Motorola, makes a chip
>that isolates devices from telephone lines, allowing
>a device that has not been certified under FCC Part 68
>to connect to the network.

Try Cermetek at +1-408-752-5000.  I've used a device called the CH1812
which provides part 68 certification.  It also includes the hybrid,
incoming ring detect, and offhook circuitry -- these features are a
side-effect of the certification requirements.  The module actually
comes with a sticker you attach to the outside of your finished
product.

The CH1812 is a PCB approximately 2" square.  They may have something
newer now, it's been at least 5 years.  I've seen a cermetek modem
which was smaller than the CH1812 and included all the 1812 features
PLUS a 2400bps hayes AT compatible modem.

-- 
----------------------------------------------------
Gordon S. Hlavenka           cgordon@vpnet.chi.il.us
Vote straight ticket Procrastination party Dec. 3rd!
Newsgroups: sci.electronics
From: ac94691@dunix.drake.edu (The Dark Kitty)
Subject: Hidden antenna designs...
Organization: Drake University, Des Moines, Iowa, USA
Distribution: sci.electronics,alt.radio.pirate 
Date: Fri, 13 Nov 1992 19:33:22 GMT

I have a problem that I'd like to get suggestions for solving.  I have
a two meter radio for which I'd like to have an outdoor antenna.  My
problem is that my father is neurotic and thinks that putting an
antenna outside is like putting up a lightning magnet.  So I'd like to
run the antenna outside in such a way that he couldn't tell it was
there.  I do have some advantages in this endeavor:

1.  Several years ago I drilled a second hole under the one where the
phone cable came into the house so I could have a second line installed.
The second line is now defunct and I could easily run the antenna cable
out through the hole in such a way that it would appear to be the same
cable that has been there for years for the second line.

2.  There are two telephone cables running up the side of the house.

What I was thinking was that I could make a vertically polarized dipole
and hang it behind/nestled-in the two telephone cables so it'd look
like part of them.  Might confuse telephone repairmen but oh well!  =-)
By the way, I mean hang it on the side of the house, not from the cable
run hung from the phone pole to the house.  ;-)

I do know enough, however, to know about a special gift from God called
induction.  =-)  Would I have to worry alot about the antenna inducing
current in the phone line?  The transmitter will run at no more than
about 1 watt (which is why an outdoor antenna would be helpful).

Anybody else have any suggestions?
If you do please email them to me and I'll compile the results and post
them on the net if people want.

Anthony Clifton
ac94691@dunix.drake.edu

Newsgroups: sci.electronics
From: klimasewski@fccvde.enet.dec.com (My name is...)
Subject: LOGICAL DEVICES,adapters needed
Organization: Digital Equipment Corporation
Date: 11 NOV 92 13:45:55    


I am looking for adapters for a LOGICAL DEVICES PROM PRO 8 prom 
programmer. If you have any for sale or know where I can buy 
them please respond.

                                      thanks,
                                       Ken Klimasewski
                                       508-467-2663
                                       401-647-9632 (5:30pm-9:00pm)
Newsgroups: sci.electronics
From: schaerer@isi.ethz.ch (Thomas Schaerer)
Subject: Re: 12 V -> 3V, 0.6 A
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL6]
Date: Mon, 9 Nov 1992 18:56:59 GMT

Babak Sehari (sehari@iastate.edu) wrote:
: In <1992Nov9.114833.26094@bernina.ethz.ch> schaerer@isi.ethz.ch (Thomas Schaerer) writes:
: 
: >Babak Sehari (sehari@iastate.edu) wrote:
: >: 
: >: There are many ways to do this the cheapest way is to put:
:                                       ^^^^^^^^^
: 
: >Sorry but all this is nonsense bcause of the high current. If you realise
: >a linear regulator you will generate very high lostpower. In this example
: >will be 0.6A * 9V = 5.4W. The better way is to build a switched regulator.
: >The advandage is the high efficiency ang therefore less powerdissipation.
: >There are many ic which can do this with a few additional components. 
: >Take the Switching-Regulator L296 from SGS-THOMSON. There is a kit with
: >pcb-board and the needed components. Ask a SGS-THOMSON-Distributor.
: 
: >So I hope I can help you.	Greeting from Thomas
: 
: You can spend 1000s of $s on a voltage transformer to make it as efficient as
: possible.  However, 5.4W in a car is not really that important.  You
: lose much more, just by not having a new battery in your car, or just
: by turning on your lights.  Here, the question is Engineering compromise.
: 
: I guess you could use gold wire to wire up your car, too! -:) Even though,
: it has less resistance than regular wire;  the costs does not justify the
: savings in this case.
: 
: However, If you want to do this most efficient way, you should change it
: to AC, using a Class B Amp, then send it through step down transformer
: , with super conducting wires a ferrite core -:), than convert it back
: to DC.  The efficiency would be %85*%98*%85=%70.  That is 0.7W Vs. 5.4W
: loss.  However, it costs more than $500 Vs. $5 of my design.  This does not 
: justify 4.7W power saving in a car, which more power is consumed for 
: ornamental reasons.  For example an extra stop light consumes 30W alone. -:)
: 
:                              With highest regards,
:                                   Babak   Sehari.
: -- 

I see you are right! I have forgotten to regard the car-powersystem. But
one point is wrong. A selfmade switched power-supply doesn't cost $500.
If you take L296 it's much cheaper, about $50 -$70.

Greeting Thomas
Newsgroups: sci.electronics
From: doherty@melpar (Kevin Doherty)
Subject: Re: doherty@melpar R DETECTOR TUBE WANTED
Organization: E-Systems, Melpar Division
Date: Mon, 9 Nov 1992 12:58:28 GMT

  Yes, you're right; I suffered a temporary mental lapse.  The IR tubes ARE
a good deal cheaper; I picked up two (horribly obsolete) Vietnam vintage
tubes a few years back for $70 each.  They require a fairly powerful IR
illuminator to work, though.  I keep hoping the cost of MCP-based devices
will drop......

  Incidentally, I've heard that US military image intesifiers are availble
on the Saudi black market for $1600 per; guess a few boxes of 'em fell off
a truck......
From: motoyama@harl.hitachi (Hiroshi Motoyama)
Newsgroups: sci.electronics
Subject: Re: Mystery japanese transistor
Date: 6 Nov 92 07:48:02 GMT
	<1992Nov2.091321.5410@nessie.mcc.ac.uk> <govender.720858538@shannon>
Organization: Advanced Research Laboratory, Hitachi, Ltd
In-reply-to: govender@shannon.ee.wits.ac.za's message of 4 Nov 92 06:28:58 GMT


   >look under 2SC3261. japanese transistors commonly omit the 2S prefix in 
   >their markings.

Here is more information.
In Japanese naming system,

   1S****   Semiconductor devices with two electrodes
   2S****   Semiconductor devices with three electrodes
     2SA****  NPN RF
     2SB****  NPN AF
     2SC****  PNP RF
     2SD****  PNP AF
     2SJ****  N-channel FET   
     2SK****  P-channel FET
   3S****   Semiconductor devices with four electrodes  
     
--
Hiroshi Motoyama
From: helfman@aero.org (Robert S. Helfman)
Newsgroups: sci.electronics
Subject: Re: Touchtone Phone
Date: 6 Nov 1992 18:23:13 GMT
Organization: The Aerospace Corporation, El Segundo, CA
NNTP-Posting-Host: aerospace.aero.org

In article <1992Nov5.143003.10585@phx.mcd.mot.com> schuch@phx.mcd.mot.com (John Schuch) writes:
>In article <1992Nov3.033724.26351@msdrl.com> karkan@msdrl.com (Jim Karkanias) writes:
>>I would like to be able to dial into a PC from a touchtone phone, wade through
>>a menu or two ("...press 1 for ..., 2 for ...), and THEN have my keystrokes
>>(buttonstrokes?) from the phone saved to some sort of file on the PC for later
>>processing (e.g. the file could contain ASCII 14325 or whatever was pressed,
>>etc.).  The whole thing could be terminated by a pound sign or hang-up, etc.
>>(upon which any files which were opened would be closed, etc.)
>>
>>Anyone know how to do this??  Thank you.
>>

BigMouth is a voice-mail card and software that allows you to build
menu trees. The card/software package is $179 at Fry's. A package of
utility libraries (usable with C, Pascal, etc.) costs $99 and provides
all the TSR-able functions to build your own applications.

The card has all the capabilities you need: it can read DTMF from the
line, control on- and off-hook, detect ringing, etc. It does NOT,
however, PRODUCE DTMF tones. But any Hayes-compatible modem on the 
same line can do that. For your described application, you don't need
to make DTMF, just read it.
Newsgroups: sci.electronics
From: rahhelp@rigel.tamu.edu (Ronald A. Huizar)
Subject: microcontrollers
News-Software: VAX/VMS VNEWS 1.41    
Keywords:  sizes? External Memory Capability
Organization: Texas A&M University, Academic Computing Services
Date: Thu, 12 Nov 1992 01:37:00 GMT

Hey folks,

I am preparing for a senior design project that I am going to be 
taking in the Spring semester. I am planning to use a microprocessor 
or microcontroller to perfrom our task. 

We my partner and I are planning to make an answering machine that 
will take messages for an individual person. For example: 4 people 
live in one house. The phone rings and no one is home so the machine 
picks up and says it's message and then says "press 1 to leave message 
for ---, press 2 to leave message for ----, etc" Then say when I get 
home I go to a keypad enter my number and hear my messages instead of 
having to hear all the other peoples messages. 

One problem that I am already see is that the microcontroller I was 
planning to use the MC68HC811E2 can only address about 64K of external 
memory, and we are planning/contemplating storing the message 
digitally. I have not had much DSP, my partner has had more than I, 
but I figure that for the telephone we will need to sample at least 
6000 Hz (since the phone BW is 30-3000, you remember Nyquist don't 
you). For a 1 minute (kinda long I know) message that will require 
about 3 Meg of memeory. To much for the E2. So I know that the 
microprocessors can handle the amount of memory I would need but I did 
want to have build my own computer first. 

Now my question.

Is there some sort of MCU available that can address enough space for 
me to build this device? I have heard about Motorola having a new 
improves MCU that was 32 bits. Is this true, does anyone have any part 
numbers and/or prices.

Sorry about the length of this post.  

Ronald A. Huizar
User Services Assistant
Academic Computer Services
Texas A&M University
College Station, Tx 77840
RAHHELP@rigel.tamu.edu
From: stanb@hpnmdla.sr.hp.com (Stan Bischof)
Date: Thu, 5 Nov 1992 19:46:58 GMT
Subject: Re: beryllium copper
Organization: Hewlett-Packard, Santa Rosa, CA
Newsgroups: sci.electronics

In sci.electronics, Allen Wallace <allen@dtint.dtint.com> writes:

>The real nasty problem is with beryllium oxide heat sinks!
>The white ceramic looking heaksinks on TO-3 transistors is really nasty.
>I have heard it said that if anyone takes a file and grinds away at one of
>these BeO heatsinks, it might kill that indivdual!
>-- 

Yeah, And I've heard that Clinton won't raise our taxes. rumor != truth.

In the first place, BeO is NOT white (it's black).

Stan Bischof
HPSR
From: lsls00@iliad.Kodak.COM (Ilia Levi)
Newsgroups: sci.electronics
Subject: Re: Cable TV Rules
Date: 5 Nov 92 20:15:32 GMT
Distribution: na
Organization: Eastman Kodak Co


Actually you are not buying the whole spectrum of frequencies. Cable company
is offering you service with certain conditions attached. If you don't like
those conditions(more money for the extra extensions) you have a right to
refuse to buy the service. If you CHOOSE to buy their service, you must, morally
and legally, abide by their rules. If you don't like their rules, get a dish,
don't watch TV, etc. This is a free country not only for the consumer, but for
the business as well.
-- 

--------------------
Ilia, levi@kodak.com
Xref: sparky sci.electronics:18506 alt.privacy:2132
From: dave@frackit.UUCP (Dave Ratcliffe)
Newsgroups: sci.electronics,alt.privacy
Subject: Re: Big Brother Radio Shack
Summary: Dare I say it?
Date: 7 Nov 92 03:48:29 GMT
Followup-To: sci electronics
Organization: Data Factory Services, Harrisburg, Pa.


 In article <2NOV199221010232@utarlg.uta.edu>, b645zhy@utarlg.uta.edu (Mark Luckstead) writes:
 > 
 > What I know is that I applied to work at Tandy's Incredible Universe in 
 > Arlington, Texas.  I interviewed for the software department.  I have a 
 > B.S. in Computing Science from Texas A&M and 24 hours toward an M.S. from
 > The University of Texas at Arlington.  And Tandy never even called me back 
 > after the interview.

That's easy...

                              Overqualified


-- 
 ...uunet!wa3wbu!frackit!dave -or-                       |  Dave Ratcliffe  |
 frackit!dave@uunet.UU.NET -or- dave@frackit.uucp -or-   |  Sys. <*> Admin. |
 vogon1!compnect!frackit!dave@psuvax1.psu.edu            | Harrisburg,  Pa. |
Newsgroups: sci.electronics
From: massoud@chemteca.sdsu.edu (Massoud Ajami)
Subject: Re: 12 V -> 3V, 0.6 A
Summary: Poratble CD player in a car.
Organization: San Diego State University
Date: Sat, 7 Nov 1992 17:45:00 GMT

In article <1992Nov7.141550.538@ludd.luth.se> d89-ahg@ludd.luth.se (Anders Hedberg) writes:
>From: d89-ahg@ludd.luth.se (Anders Hedberg)
>Subject: 12 V -> 3V, 0.6 A
>Summary: Poratble CD player in a car.
>Date: 7 Nov 92 14:15:50 GMT
>A friend wants to listen to his CD player powered from the car.
>
>The CD-player wanna have 3Volts at max 600 mA, and the car has a battery
>of 12 volts.
>
>I thought of a LM317 or something similar, but I've never designed something
>alike, and I need to know how to calculate the resistor values.
>
>/Anders Hedberg

R1= from output to adj. pin =240 ohms.
R2= from adj pin to ground = 330 ohms.

Peace and Prosperity!
  ---==< 110 >==---
Newsgroups: sci.electronics