HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.electronics

> BTW, I think my Sony manual says that the American stations are 9 kHz apart
> while the rest of the world uses mostly 10 kHz.  Am I wrong?
> 

You're backwards; it's the U.S. that's on 10 kHz spacing.


Bob Myers  KC0EW   Hewlett-Packard Co.      |Opinions expressed here are not
                   User Interface Tech. Div.|those of my employer or any other
myers@fc.hp.com    Fort Collins, Colorado   |sentient life-form on this planet.
Newsgroups: sci.electronics
From: schuch@phx.mcd.mot.com (John Schuch)
Subject: Re: Those Anti-Static Mats
Organization: Motorola Computer Group, Tempe, Az.
Date: Mon, 11 Jan 1993 18:11:55 GMT

In article <C0nyI5.MG2.2@cs.cmu.edu> rwc@ius4.ius.cs.cmu.edu (Randy Casciola) writes:
>
>I just bought one of those cheap anti-static mats at a computer
>......
>Well, when I held
>the leads against the mat and pressed firmly at a distance of 
>about 1 cm, the resistance was greater than the highest range on
>the DVM ( >20M ohms).  

We have a special tester to determine the conductivity of the static
mats around our plant. What you need to remember is that the mats are
"static dissipative", not conductive. Dissipative is defined as being
between 10E5 and 10E11 ohms per square inch. Most of the mats around
here are about 10E7, or 100 Mohms per sq inch. The tester has two 
conductive bars which are placed on the mat. 100 volts is applied to
one and the current between them is measured to determine resistance.
Remember, the charge your trying to get rid of is thousands of volts,
not tens of volts.

>And the resistance from one end of the
>ground cord to the other was about 1M ohm.  I assume they have
>a 1M ohm resistor in series somewhere.

Yes, there is usually a 1 meg resistor in the ground lead. That's so
there's no high-current ground path, which could be a real 'pain' if
you are working a high voltages and get across the wrong wire.

>I measured the 
>resistance of another more expensive mat (the type designed to
>be placed on the floor for you to walk on) and at 25 cm of 
>distance between the leads I measured about 20k ohms.

Floor mats are supposed to be at ground potential so they are
CONDUCTIVE, not dissipative. They are usually hard grounded,
without the 1 Mohm current limiting resistor. They should be
used with 'shoe straps'. These basically ground your ankel to 
the floor. The strap has the 1 Mohm resistor and has to be tested
often. Around here, you are supposed to test you straps every
time you enter the production area.



John

"ESD dosen't really exist. It was invented by the 3M marketing
 department as a way to move conductive plastics." :-)


-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602) 438-3008 - CompuServe: 70733.3330 |
+--------------------------------------------------------------------------+
Newsgroups: sci.electronics,comp.dsp,comp.realtime
From: Bob Zigon <bobz@truevision.com>
Subject: Need info on ultrasonics
X-Useragent: Nuntius v1.1
Date: Wed, 6 Jan 1993 14:15:31 GMT
Organization: Truevision, Inc

Hi

   I want to interface some ultrasonic transducers to a microprocessor.
As such,
I am looking for information on the transducers. If an ultrasonic 'black
box' exists
so that I don't have to do anything but hook it up to the microprocessor,
that's even
better. Can anyone help? I am also looking for any available information
on ultrasonic
based machine tool inspection systems. Any info will be appreciated.

Bob Zigon
bobz@truevision.com
From: nnw@concurrent.co.uk (Neil Watson)
Newsgroups: sci.electronics
Subject: Volume control of 100V line speaker
Date: 5 Jan 93 10:55:43 GMT
Organization: Concurrent Computer Corporation, Slough, England

Hi,

I'm SURE I had this information _somewhere_, but I can't find it when I
want it!


I need to add a separate volume control to ONE speaker in a set that is
run by a PA amplifier, driving a 100V line distribution.

I seem to recall that its not quite the "add a potential divider" type
solution (or if it is, then what sort of pot value to use).


The setup is several speakers in a large room, and one is a much smaller
room, and I need to be able to turn the volume down in the smaller room.


Any clues welcome. Please could you at least copy me with your reply via
email, as I tend to miss things in the traffic level of this group!


Thanks
Neil
-- 
Neil Watson, ESDG Product Support, Concurrent Computer Corp
G0BLD        227 Bath Road, Slough, Berks, SL1 4AX, England
             Phone: (+44) 753 513360  FAX: (+44) 753 513303 
(nnw@slough.ccur.com, nnw@concurrent.co.uk or 100021,3041 @ Compuserve)
From: advax@erich.triumf.ca (A.Daviel)
Newsgroups: sci.electronics
Subject: anyone got any 74F244DW ??
Date: 12 Jan 1993 15:24 PST
Organization: TRIUMF: Tri-University Meson Facility
Distribution: world
NNTP-Posting-Host: erich.triumf.ca
News-Software: VAX/VMS VNEWS 1.41    

I am looking for 4060 74F244DW chips (surface mount TTL buffers). Back in May 
last year when I go quotes there was no problem; when I ordered in July 
these parts had gone on allocation, so now I'm gettng desparate, with quotes 
of June 1993 (I need them next month).

So, anyone anywhere inthe world know where I might be able to get some?
I was originally quoted $0.35; I wouldn't expect to pay much over $0.60.


--
 Andrew Daviel, Vancouver, Canada
Newsgroups: sci.electronics
From: pagorm@iastate.edu (Paul A Gormley)
Subject: Re: PC BOARD ETCHING QUESTIO
Organization: Iowa State University, Ames, IA
Date: Wed, 6 Jan 1993 19:30:13 GMT

	Hi,

	A few monthes ago I responded to several people asking about
the same questions as you.  I sent out info on how to make double
sided non-plated through holed pc boards.  I can do this for anyone
interested through e-mail.  I will briefly describe my technique so
you can get an idea of what it takes.  I use negative resist
techniques, I have found them to be the best for my projects. ( I have
only made about 50 boards ranging from 2" X 3" to 26" X 15" so this is
all I can comment on).  I also use a great device for exposing called
a pmt.  I think this stands for photo mask transfer, but I'm not sure.
I get these done at a blueprint shop but you can do them anywhere that
has a large exposing lab.  Usually like a photo-lab or blueprint shop.
PMT's can be made onto many colors of film including transparent.
The PMT provides a very dark surface perfect for etching.  I have
found that I can see through almost all of the plotter pen ink and
photocopier tranparencies I have ever tried.  This leads to spotty
boards, and I don;'t like spotty boards.  I have had many pmt's made
and I would say that this is definitely the best alternative.  They
can cost upwards of $20 for a rather large one, but if you go to a
good shop with a good camera man you can get PERFECT 1 to 1 shots of
your layouts.  I always accompany the people who shoot my layouts.
They tend to understand the importance of perfection when you explain
to them what you are doing. The guy that does my PMT's is pretty cool 
so we can talk about music and stuff while he works anyway.
Well there you go, I am interested in helping people get started in
this area so give me a yell at pagorm@iastate.edu I'll try to help you
with any problems or questions you might have.  
					See ya later,
							Paul Gormley
							[@:{)
Newsgroups: sci.electronics
From: stettbac@isi.ethz.ch (Daniel Mueller)
Subject: Re: EPROM programming info.
Organization: Swiss Federal Institute of Technology (ETH), Zurich, CH
X-Newsreader: TIN [version 1.1 PL8]
Date: Mon, 11 Jan 1993 16:51:57 GMT

Tom. Adams 529-7860 (tadams@sbctri.sbc.com) wrote:
:
: Are all, say, 2764's programmed the same or do different manufacturers
: use different times and voltages?  Where can I find out more about this?
: -- 

Hi Tom

You should expect different programming voltages; the optimal timing
may also be different. But don't worry about that too much with your
programmer. The programming may take a little longer (if puls prog.
mode is used) but you'll get your EPROM ..

Anyway, you will find all details in the data books.


juerg at ethz switzerland
From: etxjvo@eos.ericsson.se (Jari Vuorio)
Newsgroups: sci.electronics
Subject: ST-506 HD Interface card to atari ST
Date: 4 Jan 93 09:18:11 GMT
Organization: Ericsson Telecom AB

I have a friend who has a harddisk with ST-506 interface and he want's to connect 
it to his ATARI 520 ST. But since ATARI only sells SCSI interface cards (here in 
sweden) he cannot use it with his ATARI.
Now the question is has someone got a scematic of a ST-506 interface card for ATARI ST 
(hopefully without PAL's or ROM's)?

Please send me a mail so we can discuss how I can get the scematic.

Thanks
From: FELSON_ADJ@CCSUA.CTSTATEU.EDU
Newsgroups: sci.electronics
Subject: Re: Where to mount an outside temp probe on a car?
Date: 4 Jan 1993 21:32:45 -0600
Organization: UTexas Mail-to-News Gateway
NNTP-Posting-Host: cs.utexas.edu

! From: schuch@phx.mcd.mot.com (John Schuch)
! 
! In article <86134@ut-emx.uucp> lihan@ccwf.cc.utexas.edu (Bruce G. Bostwick) writes:
! >In article <1993Jan4.134028.27684@phx.mcd.mot.com>,
! >schuch@phx.mcd.mot.com (John Schuch) writes:
! >|>In article <1993Jan4.002944.6494@sequent.com> washer@sequent.com (Jim
! >"Throw it over the wall" Washer) writes:
! >|>>I'd like to mount a temp probe on my car to sample the air temp. I'd like
! >|>>to get as accurate a reading as possible (without exceeding some reasonable
! >|>
! >|>I think I'd try either in the trunk, or inside one of the tail-light
! >|>assemblies first. At sixty miles per hour, the airstream hitting the
! >|>sensor will cool it nearly as much as being wet. You need to find
! >
! >BZZZT!   He _wanted_ the air temperature -- which means he _wants_ _maximum_
! >"cooling" of the sensor.
! >
! 
! Excuse me but if you cool the sensor by placing it in an airstream, your
! not reading the actual temperature of the air. Reading a sensor cooled
! by an airstream, by itself, tells you nothing. If you measure one sensor
! in an airstream and another one nearby but shielded from the air stream,
! you can determine the speed of the airstream. Other than that, I don't
! know why you would want to cool the sensor.
! 
! You will note that weather stations keep the thermometer in a little
! louvered box to break-up the wind. Even high-end indoor/outdoor
! thermometers include a little shell to place over the external
! sensor.
! 
! John
! 
! 


Being "cooled" by the air stream is exactly what is desired.  This will cause
the sensor's temperature to be the same as the air's temperature.

Unless the sensor hapens to be a warm blooded organism, there is no wind-chill
effect. The only error you can get is evaporative cooling, and if you keep it
dry, that will not occur. 


__a__d__a__m__
Newsgroups: sci.electronics
From: uchrgrh@Msu.oscs.montana.edu
Subject: Re: Printed Circuit generating Software?
Reply-To: uchrgrh@Msu.oscs.montana.edu
Organization: Montana State University
Date: Fri, 8 Jan 1993 18:18:05 GMT

In article <1993Jan4.173951.7346@organpipe.uug.arizona.edu>, dlatimer@iris4.chem.arizona.edu (Darin Latimer) writes:
>In article <00966196.5B59D140@Msu.oscs.montana.edu>, uchrgrh@Msu.oscs.montana.edu writes:
>|> In article <bhertz.3285@terapin.com>, bhertz@terapin.com (Ben Hertz) writes:
>|> >        Hi everyone.  I'm a high school student who's interested in
>|> >electronics.  I enjoy building little circuits and reading all the stuff in
>|> >this conference that I know absolutely nothing about.  
>|> >        After seeing some new "iron-on" sheets for making P.C. boards
>|> >advertised in several catalogs I began considering generating my own boards. 
>|> >What I'm looking for is a Shareware, or relatively cheap program that will
>|> >generate patterns for me.  There is a review of such a program in the May
>|> >edition of Computer Craft, but after reading it over I'm not so sure if it does
>|> >what I originally thought it did.  I am hoping for a program which I tell what
>|> >I need connected to what other things, and it spits out a pattern. Maybe that's
>|> >too much too ask, I don't know.
>|> >        Anyway, if someone out there knows of a shareware program that creates
>|> >Printed Circuit patterns, or where I could get one, I'd like to hear from them.
>|> > Thanks.
>|> >
>|> >P.S.  Anyone know how many people are connected to this conference?
>|> >
>|> >                         Ben Hertz (bhertz.terapin.com)
>|> >                         Richmond, California
>|> Ben,
>|> I just recently read something on this network concerning PCB software and 
>|> called the company, Protel technology, with great success.
>|> Their number is 1-800-544-4186.  Just tell the person on the other end
>|> who you are and tell them you are interested in Easytrax.  It is shareware
>|> and really does quite a lot.  I am not well versed in it but I am pretty sure
>|> it will at least get you started.  I would send you a copy of what they sent
>|> me but if you call them you will get all of the information on their other
>|> software also. 
>|> 
>|> good luck
>|> 
>|> Richard 
>
>I too have tried the Easytrax --- I much prefer PADS-PCB.  The Easytrax is 
>quite simple to use but the router uses a TON of vias which is painful if you 
>are building your own boards.  Additionally, the PADS-SCHEMATIC is a great 
>tool for building schematics; the output is easily imported to the PADS-PCB.
>If you have $300 to spare then you can buy the newer version from Protel (which
>is supposed to be nmuch better).  My $0.02, Darin.


Hey Darin,
Where do you get PADS-PCB and PADS-SCHEMATIC?  How much does it cost?
From: slmdj@cc.usu.edu
Newsgroups: sci.electronics
Subject: Re: NINTENDO: How do ya clean'um
Date: 11 Jan 93 11:51:33 MDT
Distribution: usa
Organization: Utah State University

In article <1993Jan7.170714.14089@phx.mcd.mot.com>, schuch@phx.mcd.mot.com (John Schuch) writes:
> The game carts for my kids Nintendo are really getting flakey. I'v
> found that if I clean the contacts with Q-tips and alcahol, they
> work for a couple of days but quickly crap-out again. Anybody
> know the proper ( or at least a better ) way to solve this problem?
> 
> Thanks,
> John
> 
> -- 
> +--------------------------------------------------------------------------+
> | John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
> | N7XVS - schuch@phx.mcd.mot.com - (602) 438-3008 - CompuServe: 70733.3330 |
> +--------------------------------------------------------------------------+

I know this isn't exactly an orthodox method, but it works _really_ well!

I had much the same problem.  (I assume... :-) [you almost couldn't play the 
Nintendo because it took several frustrating minutes to finally get the 
cartridge to make a good connection])  My solution was to take the Nintendo
apart *gasp* (it wasn't under warranty or anything, and I have some
troubleshooting experience) and take a look around.  What I found was that the
large connector (spring-type connections, not sure how many pins) that is to
connect directly to the cartridge had been used so much that it wasn't really
reliable anymore.  My solution (I'm cheap if I have to... :-)) was to use a
thin, narrow pen knife to _GENTLY_ bend each individual spring contact towards
the one opposite it.  (ie: make the space between the two rows of contacts 
smaller)  After this was completed, I re-assembled the machine and Voila!... It
works like a charm again.  One note, however, after this is done-- It is
somewhat harder to remove some cartridges, so just pull a little harder to get
it out :-)

Hope this helps!

-- 
********************************************************************************
      Paul Cowley      *             "If you tell the truth,
   ==EE Undergrad==    *                  you don't have to remember anything."
 Utah State University *                       --Mark Twain
  C/A1C  CAP Utah Wing *
   slmdj@cc.usu.edu    *
********************************************************************************
From: jeh@cmkrnl.com
Newsgroups: sci.electronics
Subject: Re: Laser gunsights (was: Info on CO2lasers wanted
Date: 7 Jan 93 03:19:34 GMT
Organization: Kernel Mode Consulting, San Diego, CA

In article <6802@tuegate.tue.nl>, wouter@blade.stack.urc.tue.nl (Wouter Slegers) writes:
> I'd like to get some info CO2-lasers... I read the following on a BBS..
> If anyone has a sequel on this, please email it to me..
> [...]
>                LASER WEAPONRY / PART 1 / LASER SIGHTS
> [...]

I don't know about the circuitry provided... but the stuff in there about a 
2 mW HeNe laser being dangerous to human eyes is complete bunk.  

I would also point out that the claim of "perfect targetting" for a laser 
gunsight just isn't so -- elevation and windage still are factors -- and that
*seeing* the dot of light from a 2 mW laser at any reasonable distance, in 
anything other than pitch blackness, is damned near impossible.  

	--- 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
From: dhi00@ccc.amdahl.com (mofo )
Newsgroups: sci.electronics
Subject: re: xilinx destruction
Date: 12 Jan 93 17:07:26 GMT
Reply-To: dhi00@juts.ccc.amdahl.com (mofo )
Organization: Amdahl Corporation, Sunnyvale CA

someone wrote about the xilinx parts not loading its info correctly during
a production run and possibly blowing up on powerup.  i want to inquire 
doesnt your programmer to a verify cycle to assure the fpga didnt drop
anything during loading?  this is how most PAL programmers work;  is
a verify not possible with this type of part?


d
Newsgroups: sci.electronics
From: dmturne@ptsfa.PacBell.COM (Dave Turner)
Subject: Re: ATT 3b2 console pinouts ... please?
Reply-To: dmturne@PacBell.COM (Dave Turner)
Organization: Pacific * Bell, San Ramon, CA
Distribution: sci
Date: Mon, 4 Jan 1993 08:39:52 GMT

In article <1993Jan4.083648.20297@ptsfa.PacBell.COM> dmturne@PacBell.COM (Dave Turner) writes:
>
>Looking at the console modular jack on the rear of the 3b2 (the locking tab
>should be down) the pins are numbered right-to-left 1 to 8.
>
In case this isn't clear, it is trying to say:

		8 7 6 5 4 3 2 1


		     tab


-- 
Dave Turner	(510) 823-2001	{att,bellcore,sun,ames,decwrl}!pacbell!dmturne
From: sysrick@starbase.spd.louisville.edu (Rick McTeague)
Newsgroups: sci.electronics
Subject: PADS PCB help needed: Creating an edge card connector
Date: 7 Jan 93 04:51:27 GMT
Organization: University of Louisville

I have been trying to use PADS PCB to create a small card which has an
card-edge connector, and I'm having a devil of a time trying to get it
to do what I want.

I want to create a part which has pads on both sides of a two layer
board, but which are not connected. I've created a decal with 64 pins,
and messed with the pad stacks so that pins 1-32 on the bottom layer
and 33-64 are on the top. Then I create a part with the decal.  When I place
the part, it only seems to put it on one layer, and I can't get at the
pins which are on the other one.

Where am I going wrong here? Any gurus care to offer some help?

Oh. Instead of creating a "part" using the decal, I've tried creating a
"connector", but with worse results. There, it complains about an
invalid pin or something like that. Help!

Rick
-- 

Rick McTeague
Electrical Engineering Department, Speed Scientific School
University of Louisville, Louisville, KY 40292
(502) 588-7020

Internet: sysrick@starbase.spd.louisville.edu

Disclaimer: I'm a stand-up comedian; if anyone takes me seriously, I'm
            doing something wrong!
Newsgroups: sci.electronics
From: wlsmith@valve.heart.rri.uwo.ca (Wayne Smith)
Subject: Re: Re: How can I align a cassette tape head?
Organization: The John P. Robarts Research Institute, London, Ontario
Date: Wed, 13 Jan 1993 01:39:56 GMT

I take an old tape, or a good commercial tape, and, with head phones on,
turn the treble all the way up and the bass all the way down, and turn
off the noise reduction, turn the volume up, and adjust for maximum
hiss (noise), ie adjust so you can hear the high frequencies the best.

I end up braketing a 1/4 turn segment (rotating the screw quickly) that
contains the best segment, and set it for the center of that range.
From: apn@Apple.COM (Alex Novickis)
Newsgroups: sci.electronics
Subject: Re: PC BOARD ETCHING QUESTIO
Date: 11 Jan 93 03:04:32 GMT
Organization: Apple Computer Inc, Cupertino, CA

In article <1993Jan10.225053.28590@phx.mcd.mot.com> schuch@phx.mcd.mot.com (John Schuch) writes:
>I, to, have had this problem once in a while but have found most 
>cameramen pretty darn accurate. Another thing I ALWAYS do is include
>a rule in the artwork. Something like this:
>
>     |----|----|----|----|----|----|
>     |                             |
>     |<-------- 3 INCHES --------->|
>     |                             |
>
>


With current laser photoplotting technology, WHY ?? whould you want to 
do reductions ?? LP's can generate things much finer than you can
ever hope to etch.... I think that's about 4 mil traces with 4 mil
seperations. And it usually costs me under 10$ for a 10x10" film (OK, 
well I do need several of them... but still)






-- 
Alex P. Novickis, Real Time systems demi-guru.  (W)   408-862-4541
ALINK:alex.n                                    (H)   415-691-0657
UUCP:{amdahl,claris,pyramid,sun,decwrl,well,ubvax,ames}!apn@apple.com,apn@nonvon
"I think... I think it's in my basement. Let me go upstairs and check"-Escher.
From: nagle@netcom.com (John Nagle)
Subject: Re: 9600 baud Modem design?
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Date: Mon, 11 Jan 1993 04:06:24 GMT

scottcr@wkuvx1.bitnet writes:
>I am designing a custom 9600 baud link using a voice channel
>with the following specs: BW: 100-5Khz  S/N = 35+ dB.
>Are there any "rules of thumb" about choice of carrier
>freq 2K ?  3k ?  What about FSK deviation?  With this
>type of system how does modulation index affect performance?

        I'd suggest getting the current Rockwell modem data products
book.  There's probably an off-the-shelf single-chip solution to your problem.
Try Rockwell Semiconductor Products at 1-714-833-4655.  Other
manufacturers offer similar solutions.  Using a 9600 baud FAX modem
part is probably the simplest way to go.  The channel you have is
good enough.  FAX modems are half-duplex (one way at a time), so
assuming you want a simplex channel (one way), this is the way to go.
You avoid the complex bidirectional cancelling schemes used to push
data in both directions simultaneously over two wires that are used to
make 9600 baud data modems work.  Those modems won't work over a one-way
link.

					John Nagle
Newsgroups: sci.electronics
From: ahmadz@newton.ccs.tuns.ca (Zakaria Ahmad)
Subject: simulation of gate oscillator start-up
Date: Mon, 4 Jan 1993 07:05:41 GMT
Distribution: electronics
Organization: Technical University of Nova Scotia, Halifax, N.S.

hello netters. I am doing my senior-year -engineering project under aboved title.Does anybody know about how to get the materials regarding that matter? I tried to look at some engoneering journals but I could not find much. S o if anybody knows or has the materials could you please tell me. I really appreciate it because it will be helpful for my project.
Thank you