HDTenEightyP/NetNews huggingface dataset:
From: root@torinet.com (Superuser)
Subject: Re: HV transformer sources?
Organization: Torinet Systems, Inc.
Date: Sun, 04 Oct 1992 20:02:11 GMT

In article <717929289.5@mailbox.bison.mb> Jason.Goga@mailbox.bison.mb.ca (Jason Goga) writes:
> > Anyone know of any mail order sources for reasonably priced HV
> > transformers suitable for Tesla coils? From what I've heard, neon sign 
> > transformers work pretty well.
>
>Could you explain, what practical use a Tesla coil has? Other than:
>- Scaring little children
>- popping small animals
>- lighting up flourescent tubes a few meters away
>- getting the attention of the FCC
>
>-Jason

Why does everyone assume that when someone wishes to experiment with high
voltage, pulsed current, etc. that the product of such an experiment is always
used in a negligent fashion? High voltage and other projects are always good
for teaching about electricity. 

If you can not think of any uses for High Voltage Tesla Coils other than the
ones you stated above, then YOU shouln't be contributing your comments.

For those who are interested, the easiest and by far, the cheapest method of
obtaining a high voltage transformer would be to use the ignition coil from
a car, or the flyback transformer from a television. In both cases, it always
helps to have the documentation for a particular device when designing around
it. Information Unlimited has a number of designs for High Voltage projects
that are based around a few not-so-hard-to-find television flybacks. Look in
any edition of RE toward the back for their number.
--
Torin Walker (Super)         root@torinet.com           Voice (416) 886-8054
Torinet Systems, Inc.       uunet!torinet!root          Fax   (416) 756-0720
Newsgroups: sci.electronics
Subject: Re: 128K MAC, What to do, what to do?
From: stuartw@ccu1.aukuni.ac.nz (Stuart Woolford)
Date: Mon, 5 Oct 1992 23:01:54 GMT
Organization: University of Auckland, New Zealand.
Keywords: 128k mac

pevzner@ceg.uiuc.edu (Vadim Pevzner) writes:

>I've got 128k MAC, one of the chips burnout.
>To fix it may cost upto $100. I also own
>a dotmatr. printer and a modem. What should
>I do with the MAC? Fix it? Upgrade it? Trash it?

>I would I appriciate your advice.
>Send me your mail at pevzner@hp720.ceg.uiuc.edu

>Many-many thanks.

>Vadim

find out if is bounces from 4 stories up ( I've always wanted to know... )

;-)

------------------------------------------------------------------------
stuartw@ccu1.aukuni.ac.nz


			>>>>More, Louder, Faster<<<<
------------------------------------------------------------------------
Newsgroups: sci.electronics,comp.robotics
From: martinez@rodan.acs.syr.edu (Kenneth Mtz. (YONIX))
Subject: Microprocessors
Originator: martinez@rodan.acs.syr.edu
Organization: Syracuse University, Syracuse, NY
Date: Mon, 28 Sep 92 08:48:06 EDT

 We are at the beginning stages of building a Micromouse and would 
greatly appreciate any help concerning the following microprocessors.
Any Tips and/or Bibliography would be most useful. Also, if you have any
idea of what the price of each device is please post. 

	Z80			6502
	8086			8088
	68000
	h8/532			NEC 78312A
	LM18293

 What speeds do they run at? Who markets them? Where can we purchase and
 or get a catalog of these things?

 Please respond to this account. We will post a summary if other users
 are interested.

 Thank you in advance,

 Kenn
From: CDHWilli@cen.ex.ac.uk (C.D.H.Williams)
Newsgroups: sci.electronics
Subject: TEK DSA600 (11000 Series) PSU R.I.P.
Date: 28 Sep 92 17:39:23 GMT
Distribution: sci
Organization: Computer Unit. - University of Exeter. UK


One of our DSA601's has just died (symptons later), and a quick poke
suggests that the A2 power supply board is sick.  This provides the
unregulated supplies for the beast which seems to have the same PSU as
the 11000 series oscilloscopes.  So we ring Tektronix in the UK and
ask if they can supply us with a service manual or circuit for the PSU
on this beast.  They say "We don't supply manuals; you pack up the
machine and send it to us, we fix it and charge you $UK1000, (two
thousand dollars) flat rate".

This seems a bit steep to me, particularly as our funding agency
doesn't pay repair bills.

Q1.  In view of the symptons described below does anybody recognise this
     fault and/or its cause or have any fault finding hints for these
     things.  Can we get the whole thing out to bench test it in isolation
     or does it have a very tricky set of protetcion/supervision circuits
     to prevent this?

Q2.  Is it really true that TEK won't supply manuals for these things,
     or is it just the UK office being a pain?

Q3.  Does anybody have a circuit diagram of the PSU in question they
     could fax me?

Symptons:  When the on/standby swith on the front is turned on there is
a quiet clicking from the PSU board (about 2clicks/sec).  The 24V cooling
fans judder by a couple of degrees in time with this and one of the front
panel leds flickers, also in time.


Thanks in advance for *any* advice.

Charles Williams         C.D.H.Williams@exeter.ac.uk

Physics Dept
Exeter University.  (FAX +44 392 264111)
From: CCEB001@UTXVM.CC.UTEXAS.EDU
Newsgroups: sci.electronics
Subject: Re: Cable TV bill (was Re: Cable "silver bullets")
Date: 6 Oct 92 20:12:39 GMT
Organization: The University of Texas at Austin

In article <7380077@hpnmdla.sr.hp.com>
stanb@hpnmdla.sr.hp.com (Stan Bischof) writes:
 
>
>In sci.electronics, davepat@flash.ATC.Olivetti.Com (Dave Patterson) writes:
>
>>Maybe this is a bit naive, but why not forget 'em all, and get a
>>satellite dish?
>
>Don't know if it passed, but I remember the Cable industry trying to get a bill
>through congress that forces dish owners to pay the local cable company
>for the privilege of using their dish. Anyone dish owners out there
>who know? (I believe that this was in the form of a 'tax' on receivers
>which was eventually forwarded to the cable folks).
>
>Stan Bischof
>Santa Rosa
 
This has already a defacto "law."  Cable companies have refused to carry
unscrambled signals.  Most, if not all, uplinks are scrambled.  You must
subscribe to the signal which you may do directly or via your "local"
cable company.  There are a lot of "cable companies" out there that do
not own a foot of coax.  You call them and they cause the program
provider to adress your descrambler.
 
Scrambling was originally developed as a way to deal with slow pay
cable companies.  This is truly a case of making lemonade when life hands
out lemons for the cable companies.
 
I consider tv so corrupted by the requirement to "be interesting" so it can
attract ad revenue, that it should be banned altogether.  Maybe people would
learn to read, play instruments, talk to their family, participate in sports,
etc.  They might even attend to politics for more than 60 seconds.
 
Mike.Coyne@utxvm.utexas.edu
From: royle@tekig6.PEN.TEK.COM (Roy W Lewallen)
Newsgroups: sci.electronics
Subject: Re: 25 ohm coax cable
Date: 6 Oct 92 19:37:36 GMT
Article-I.D.: tekig7.7203


In article <1992Oct5.142505.23001@dxcern.cern.ch> dhina@dxcern.cern.ch (Mourad Dhina) writes:
>Hello,
>i am trying to realize a circuit i found in an electronics magazine.
>one of the components it uses is a semi-rigid coax cable of
>25 ohms impedance. this is the first time i hear of this (i only
>knew 50, 75 and 93 ohms cables, which are standard). anybody
>knows where to find this?
>Mourad

>Two 50-ohm cables in parallel?

>-- 
>:- Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
>:- Artificial Intelligence Programs       phone 706 542-0359
>:- The University of Georgia                fax 706 542-0349
>:- Athens, Georgia 30602 U.S.A.          amateur radio N4TMI

Two 50-ohm cables will work as a 25-ohm cable, as suggested. However, if the
author is using semi-rigid cable it probably is for quite a high-frequency
application and you may have trouble making connections to it which will
be clean enough.

Most manufacturers of semi-rigid cable sell it in a variety of impedances.
The Precision Tube catalog shows cables from 15 to 95 ohms, and Micro-Coax
from 10 to 95. Both have 25-ohm cable. There are many others -- I just
have these two catalogs handy.

     Precision Tube: (215) 699-5801
     Micro-Coax: (215) 489-3700

Roy Lewallen
Newsgroups: sci.electronics
From: stettbac@isibee7 (Juerg Stettbacher)
Subject: Re: Soil Humidity Sensors
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL6]
Date: Thu, 1 Oct 1992 10:16:17 GMT

Gabriel Gonzalez (ggonzale@mtecv2.mty.itesm.mx) wrote:
: Hello there!
: 
: I'm working in an automatic watering system for this campus, and I need
: to know how can I measure the humidity level of the soil. I need to get
: an electrical signal representing this parameter. I've searched in
: catalogs (like Omegas's) and found nothing. I've thought about measuring
: the earths resistance, but found no easy way of doing it. It doesn't
: have to be a very accurate measurement, but I need a good (read it
: stable) signal to work with.


Hi Gabriel

Measuring the earths resistance would be the easyest and cheapest way
to estimate the humidity. You will get higher accuracy using a current
source but also just a FET with some temperature compensation (stick
the gate and a constant voltage pin into the ground, separated by
about 10 cm) will give you a 'good` signal.
But remember: resistance is not humidity!

juerg at ethz switzerland
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Newsgroups: sci.electronics
Subject: Re: Telephone interface
Date: 2 Oct 92 15:18:13 GMT
Article-I.D.: athena.1992Oct2.151813.14020
Organization: AI Program, University of Georgia, Athens

If you are taking output from the phone line and also putting audio into
the phone line, you need a "hybrid," which can be either a transformer
or a circuit with op-amps, to separate incoming from outgoing audio.

See the "ARRL Handbook for the Radio Amateur".

-- 
:- Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
:- Artificial Intelligence Programs       phone 706 542-0359
:- The University of Georgia                fax 706 542-0349
:- Athens, Georgia 30602 U.S.A.          amateur radio N4TMI
From: sldf3@pluto.ee.usu.edu (Weston R Beal)
Newsgroups: sci.electronics
Subject: Re: Spectrum anaylsers
Date: 5 Oct 92 20:14:31 GMT
Organization: Utah State Univ. EE


-- 

Most spectrum analyzers work by sweeping a test frequency over
the band specified.  The test frequency is multiplied with the 
input signal and the low-pass filtered.  If there is a frequency
component in the input signal, that is close to the test frequency,
the energy is passed.
The sweep frequency modulates the horizontal sweep, and the magnitude
of energy passed is displayed vertically on the scope.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%          							    %%
%%  Weston Beal			:  I have a piece of hard rock      %%
%%  sldf3@sol.ee.usu.edu	:  candy, but it's not for eating.  %%
%%  sldf3@cc.usu.edu		:  It's for looking through.        %%
%%                                                                  %%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Newsgroups: sci.electronics
From: kennehra@craft.camp.clarkson.edu (Rich"TheMan"Kennehan)
Subject: Electronics magazines & Mail order brides
Organization: Clarkson University
Date: Sun, 4 Oct 1992 22:07:43 GMT



Hi.  I was flipping through the back sections of one of my electronics
magazines when I saw these ads advertising "attractive asian ladies
who seek friendship, marriage..."  Could someone PLEASE tell me why
a company like that would advertise in an Electronics magazine?!?!
Has anyone ever answered these ads?!?!  This is something "consumer
reports" should definitely check out!!!

- Rich
  kennehra@logic.camp.clarkson.edu
From: bk233@cleveland.Freenet.Edu (Jack W. Weinmann)
Newsgroups: sci.electronics
Subject: Magnavox CD player "ERROR" problem - H E L P !
Date: 30 Sep 1992 16:39:42 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: bk233@cleveland.Freenet.Edu (Jack W. Weinmann)
NNTP-Posting-Host: slc10.ins.cwru.edu


A while back I posted this problem but only one person replied by personal
e-mail to wish me good luck if I sent it to Magnavox for repair (it seems
that they *lost* his unit!)

I'm posting this hoping that it was missed the first time.

My son has a Magnavox Model AZ6892 BK01 Digital CD player.  When he tries
to turn it on it whirrs for a while, then an "E" shows up on the LCD display
and the unit stops.  Any ideas of what's going on here?

I can see red light coming from inside the unit - so I believe the laser is
operating, but it doesn't want to stay running.  No audio comes from the
unit while it is doing this.

Any help would be appreciated (my son is 15 years old and is upset that his
high-tech dad can't just tweak something and make it work again)

Jack Weinmann  bk233@cleveland.freenet.edu
From: pevzner@ceg.uiuc.edu (Vadim Pevzner)
Newsgroups: sci.electronics
Subject: 128K MAC, What to do, what to do?
Keywords: 128k mac
Date: 5 Oct 92 16:10:16 GMT
Article-I.D.: ceg.pevzner.718301416
Organization: University of Illinois at Urbana

I've got 128k MAC, one of the chips burnout.
To fix it may cost upto $100. I also own
a dotmatr. printer and a modem. What should
I do with the MAC? Fix it? Upgrade it? Trash it?

I would I appriciate your advice.
Send me your mail at pevzner@hp720.ceg.uiuc.edu

Many-many thanks.

Vadim
Newsgroups: sci.electronics
From: medin@catbyte.NoSubdomain.NoDomain (Dave Medin)
Subject: Re: Russian tubes
Reply-To: medin@catbyte.b30.ingr.com
Organization: Intergraph Corporation, Huntsville AL
Date: Fri, 2 Oct 1992 15:10:28 GMT

In article <1992Oct1.165047.3239@cs.ucf.edu>, crochet@next3.acme.ucf.edu (Larry Crochet) writes:
|> Can anyone recommend importers of Russian made tubes?  I'm particularly  
|> interested in type 6550 tubes.Someone had told me that the former Soviets  
|> can export and sell tubes at a very low price.
|> 
|> Thanks,
|> 
|> Larry 

I don't have the issue here, but the most recent Radio Electronics
mag I received had a one page ad for a tube importer in the middle
ad section... Soviet tubes were included.

-- 
 --------------------------------------------------------------------
       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: kzyx@vax5.cit.cornell.edu
Newsgroups: sci.electronics
Subject: FPGA/VHDL/PLD
Date: 30 Sep 92 10:58:50 EDT
Distribution: sci
Organization: Cornell University

	Howdy,

	Where can I get info/databooks on FPGA/VHDL/PLD?

	Any good books? Suggestions are welcome.

	Reply to esantos@ee.cornell.edu

	Thanks,
	Edval J. P. Santos
esantos@ee.cornell.edu
From: bob@kc2wz.bubble.org (Bob Billson)
Newsgroups: sci.electronics
Subject: composite->RGB and sync circuit?
Summary: need to split composite video to RGB and sync
Date: 3 Oct 92 02:27:31 GMT
Distribution: na
Organization: Color Computer 3: Tandy's 'game' machine

I am posting this for a friend.  PLEASE EMAIL HIM DIRECTLY.

My friend, Rich, is in search of a circuit to take composite video (NTSC) from
his computer and split it into R, G, and B signals.  He also needs to recover
separate horizontal and vertical sync.  

If you have any circuits, pointers to circuits, suggestions, etc.  PLEASE
EMAIL HIM AT: rich@cecg.com.

Thanks...Bob
-- 
  Bob Billson, KC2WZ                          | internet: bob@kc2wz.bubble.org
  $nail:  21 Bates Way,  Westfield, NJ 07090  | uucp:     ...!uunet!kc2wz!bob

  "Professional ear piercing--while you wait!"  --sign in local jewelry store
From: DEIL.CLAYTON.BLAND@mailbox.bison.mb.ca (DEIL CLAYTON BLAND)
Newsgroups: sci.electronics
Subject: Re: How does stereo FM radio work?
Date: 25 Sep 92 00:08:55 CST

Organization: The Portal System (TM)

In article 125938 Mark Lee asked:


>I don't know if this is a FAQ, but I have never seen this question asked
>here and I want to know.  How do they broadcast and receive the two
>channels of information needed for stereo on FM radio?  More
>specifically, how is the modulation and demodulation of the two sets of
>audio done on a single carrier frequency?  Do they use asymmetric side
>bands or what? And if so, how is this done?  And why was FM stereo in
>common use long before anyone broadcast AM stereo?

>I have asked several people who know high-frequency electronics about
>this and never gotten an intelligible answer.  I'd appreciate it if
>someone could point out to me a decent text or article, appropriate for
>someone like me who already understands basic mono AM and FM.

>I'm just curious.

>--Mark
>markl@research.nj.nec.com

The baseband output of the discriminator is 0 to 100 khz. In the 
normal audio range (60hz to 15khz) is a combined left plus right 
channel signal. This is for compatibility with monaural receivers. 
At 19 khz there is a pilot used to synchronize a 38khz oscillator 
used for demodulating a left minus right double sideband channel 
transmitted at 38 khz. In the receiver the L+R and L-R are 
combined in phase in a resistive network to produce left channel 
audio and 180 degrees out of phase to produce the right channel 
audio. Many FM stations also broadcast SCA at 67khz.

Deil Bland

dbland@cup.portal.com

 * Origin: The Electronic Mailbox (1:348/7.0)
From: icarus!ag@fokus.gmd.de (A. Gavras)
Newsgroups: sci.electronics
Subject: Need info on CAM chips
Keywords: CAM content addressable memory
Date: 2 Oct 92 15:00:27 GMT
Organization: GMD-Fokus (Berlin)

Hi,
I need all the information I can get on available CAM IC's.
CAM stands for content addressable memory.
Thank's in advance
-- 
_____________________________________________________________________________
Anastassios Gavras, GMD-FOKUS, Hardenbergplatz 2, 1000 Berlin 12, Germany
Tel:+49 30 25499263 FAX:+49 30 25499202 e-mail:gavras@fokus.berlin.gmd.dbp.de
_____________________________________________________________________________
Newsgroups: sci.electronics
From: mtarrant@snuffy.wa.atk.com (Mike Tarrant)
Subject: Re: Electronics magazines & Mail order brides
Organization: Alliant TechSystems Inc.
Date: Mon, 5 Oct 1992 18:22:50 GMT

In article <kennehra.718236463@craft.camp.clarkson.edu> kennehra@craft.camp.clarkson.edu (Rich"TheMan"Kennehan) writes:
>
>
>Hi.  I was flipping through the back sections of one of my electronics
>magazines when I saw these ads advertising "attractive asian ladies
>who seek friendship, marriage..."  Could someone PLEASE tell me why
>a company like that would advertise in an Electronics magazine?!?!
>Has anyone ever answered these ads?!?!  This is something "consumer
>reports" should definitely check out!!!
>
>- Rich
>  kennehra@logic.camp.clarkson.edu
>
>
They wouldn't advertise if they didn't get business.  Maybe
the sterotype of the nerdy electronics guy has a ring of
truth to it...


Newsgroups: sci.electronics
From: jeremym@fraser.sfu.ca (Jeremy Thomas McDonald)
Subject: Pullups needed for high-impedence TTL inputs?
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Sat, 3 Oct 1992 07:19:59 GMT

I know pullups are required for CMOS inputs if the inputs can go into
high-impedence.  Does the same hold true for TTL?  What about HCT?
From: dino@inqmind.bison.mb.ca (Tony stewart)
Newsgroups: sci.electronics
Subject: Re: DC to AC help
Date: Tue, 29 Sep 92 19:47:56 CDT
Organization: The Inquiring Mind BBS  1 204 488-1607

princecr@mala.bc.ca writes:

> 	If I have a DC current how can I go back to an AC current???  This has
> confused me greatly.  Can anyone help?
> 						chris.
> 

Sorry once you've gone to DC you're stuck... for life.

Just kidding..THis basic problem can be addressed by understand what you 
want to generate. If by AC you mean AC power 60 Hz sine wave, this is 
done by things called INVERTERS. But small signals are easier to generate 
with Signal generators, oscillators, choppers or anything that ALTERNATES 
THE DIRECT CURRENT.

dino@inqmind.bison.mb.ca
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607
From: laird@stable.ecn.purdue.edu (Kyler Laird)
Newsgroups: sci.electronics
Subject: Help needed with RTI on M68HC11EVBU
Summary: can't get RTI to call subroutine
Keywords: 68HC11EVBU
Date: 30 Sep 92 16:45:52 GMT
Organization: Purdue University Engineering Computer Network

I've had fairly good success with using the OCx pins on the EVB (for
infrared remote faking), but on my current project I'd like to save
them for other functions and use the real time interrupt (RTI) to
periodically call a subroutine.

So far, no luck.  I set the vector up (finish the jmp instruction in
the pseudo vector table of the EVBU ROM), set the MSK and FLGS values,
and clear interrupts, but my routine doesn't seem to get called.

Help! 

BTW, the project I'm working on is a soil moisture sensor that uses
the reflectance of three wavelengths of light.  I'm pulsing the three
lasers and reading the value of the photodiode into three locations.
I'd like to do this (and someday the moisture calculation) in the
background, while the user interface is running in the foreground.

Thanks!

--kyler
From: mcovingt@athena.cs.uga.edu (Michael A. Covington)
Newsgroups: sci.electronics
Subject: MISCONFIGURED NET SITE!!! was: Re: multimeters
Date: 29 Sep 92 02:28:21 GMT
Organization: University of Georgia, Athens

In article <717712154.108@mailbox.bison.mb> Michael.A..Covington@mailbox.bison.mb.ca (Michael A. Covington) writes:

^^^ Whoa there!  That's not my email address!
    A lot of mail from lots of other people has suddenly been duplicated
    in this newsgroup, with the author's address changed from
    whatever it was, to mailbox.bison.mb.ca.

-- 
+ Michael Covington - Artificial Intelligence Programs - U of Georgia - USA 
+ Unless otherwise noted, these are private opinions, not official statements.
Xref: sparky sci.electronics:16512 sci.astro:10384 rec.radio.amateur.misc:16437
From: IFF212@DJUKFA11.BITNET
Newsgroups: sci.electronics,sci.astro,rec.radio.amateur.misc
Subject: looking for dc-motor driver diagrams
Date: 3 Oct 92 23:45:37 GMT
Organization: Forschungszentrum Juelich


Hello everybody,

I am going to build a telescope which axes should be driven by dc-motors.

In order to achieve a high accuracy and also to control the motors by a

computer I want to use quartz controlled servo motors.

Now I am looking for circuits which provide such a driver (with current

regulation, PLL etc.). It would be very nice if there is someone who can

send me such circuit diagrams by e-mail or tell me some good references.


Thank you in advance.


                             Markus Wollgarten


My addresses:

iff212@djukfa11.bitnet
iff212@zam001.zam.kfa-juelich.de
wollo@iffh01.dnet.kfa-juelich.de
From: miked@syscon.rn.com (Mike DeMetz)
Newsgroups: sci.electronics
Subject: Re: Flyback transformers...
Date: 6 Oct 92 13:59:34 GMT
Distribution: sci.electronics
Organization: Syscon Corporate Headquarters - South Bend, IN USA

If the picture is OK you may just have loose yoke windings and are
hearing the Horiz sweep. If you you may be able to fix it by spraying
the windings with clear lacquer to stick them together. If the picture
is breaking up you probably have a bad cap in the horiz circuit or
possibly the switching power supply(if it uses one.). Be careful
around that flyback >10KV!