HDTenEightyP/NetNews huggingface dataset:
From: rwc@ius4.ius.cs.cmu.edu (Randy Casciola)
Newsgroups: sci.electronics
Subject: High Density PCB Connectors
Date: 12 Jan 93 00:07:52 GMT
Article-I.D.: cs.C0psD4.62v.2
Organization: CMU Vision and Autonomous Systems


Folks,

I am looking for high density board stacking connectors.
All of my boards will be identical and be about 2.5 inches
square.  The idea is to pass the control, data, and address
busses from one board to the next, indefinitely (at least
from a mechanical standpoint).  Two possible ways of doing
this are:

1.  Using through-hole technology, where the pins from the
    receptacle on the top of the board go through the holes 
    in the board and are soldered to the bottom; the pins
    continue and are used to mate with the receptacle on the
    top of the next board.  And so on.  Kind of like the 
    picture below (Side View).

                           _____
    ____BOARD______________|___|_<-- HEADER 
                            | |
                            | | <-- PINS  
                           _____
    _______________________|___|_
                            | |
                            | |   

2.  Doing a similar thing, but with surface mount where an
    SMT receptacle is on the top, and an SMT header on the
    bottom, and connections are made through the board using
    vias.

                    ______
    ________________|____|_
                     |__|
                    ______
    ________________|____|_
                     |__|

The problem with the first method is that I need two rows of 
40 pins/row.  Since the connector has to be less than 2.5 inches 
wide, I need .050" pins and I haven't seen anything designed to
be stacked like this with .050" centers.

The problem with the second is that I need twice as many connectors,
and allignment problems may crop up.  I found some parts from
Samtec that I could use, but they don't provide enough space between
boards.

So, if anyone knows of a connector I can use, or a company that I
could call to get a catalog, I would appreciate hearing from you.
Or, if you have a better idea altogether of how to stack these I would
like to hear it.  It doesn't matter whether you post to this group, or
mail me at randy@cmu.edu  

I already have catalogs from:

Samtec
Aries
Mil-Max Preci Dip
Hirose
Robinson Nugent
Hypertronics


Thanks in advance,
Randy Casciola
Research Engineer
The Robotics Institute
Carnegie Mellon
Pittsburgh, Pa 15213
From: mike_d@tfsquad.mn.org (mike diack)
Newsgroups: sci.electronics
Subject: Re - audio cassette alignment tapes.
Date: Mon, 04 Jan 93 15:30:03 CST
Organization: tfsquad public access insane asylum, St Paul MN (+1 612 291 2632)

A couple of people have been asking about the availibility of these.
One supplier is TEAC corporation - the same people who make tapedecks
in the domestic to "home studio" range. the azimuth tape is a full track
6.3khz test tone @ -10dB below dolby ref level (which is, in the case of
cassette tapes, 200 nW/m i think)
TEAC also make
Dolby reference tapes (1K @ 0dB)
Wow 'n flutter tapes  (3K @ -10db)
Height alignment tapes (1K @ -10, recorded 4 track, not full track)
Freq response tapes (An assortment of useful tones)
Teac are in California , and advertise in mags like "The Mix"
Doing it :
Never make your own test tape on someones "good" deck - it will never be
right, and will cause untold greif when using your tapes on other decks.
Clean and degauss deck thoroughly BEFORE putting in your (expensive)test
tape - also ensure record protect tabs are knocked out and the protect
mechanism is functional - else you may record over your standard tape -
a ghastly experience , even more easy to do on reel/reels , but thats
another story.
Using scope in 2 channel X/Y mode, both channels set for 100mv/cm
adjust the screw with the spring under it (dont touch other one), for
a bottomleft -> topright line pattern, with minimum ovality and maximum
amplitude - if the head & electronics are perfect, you will get a 45deg
line - go for the maximum / and minimum O. There will be several false 
nodes on either side of optimum - these are multiples if one wavelength 
out. Only one maxima occurs. Expect the pattern to wobble - just go for
the best average.
cheers,
        Mike.
(ps seal screw with nail polish - green if you prefer CDs :-)

---
mike_d@tfsquad.mn.org (mike diack)
The Firing Squad BBS, public access Usenet mail and news.  +1 612 291 2632
Saint Paul, Minnesota
From: kingpin@spiff.gnu.ai.mit.edu (Joe Smooth)
Newsgroups: sci.electronics
Subject: help with Novatel cellular phone
Date: 9 Jan 93 19:33:33 GMT
Distribution: sci
Organization: None


Hi I need some help identifying the microprocessor used in a Novatel
transportable cellular phone I have.. on the microprocessor chip itself,
it says the following:

	9049AV Z90071
	VC5055-0001
	Novatel 1CPU

it also uses a 27C512 EPROM... if anyone has any information at all on this
microprocessor or any information on Novatel phones in general, please 
let me know by mailing me at kingpin@gnu.ai.mit.edu.. Thanks a lot!
From: schuch@phx.mcd.mot.com (John Schuch)
Subject: Re: PC BOARD ETCHING QUESTIO
Organization: Motorola Computer Group, Tempe, Az.
  
Date: Sun, 10 Jan 1993 22:50:53 GMT

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 --------->|
     |                             |

Then, standing in the shop with my check just out of the guys
reach ( :-) ), I measure the negative. If it's off I have him
do it again.

Works for me.
John



-- 
+--------------------------------------------------------------------------+
| John R. Schuch  -  Motorola Computer Group  -  Manufacturing Engineering |
| N7XVS - schuch@phx.mcd.mot.com - (602) 438-3008 - CompuServe: 70733.3330 |
+--------------------------------------------------------------------------+
Newsgroups: sci.electronics
From: jhallen@world.std.com (Joseph H Allen)
Subject: Re: pixel clock
Organization: The World Public Access UNIX, Brookline, MA
Date: Mon, 11 Jan 1993 17:28:26 GMT

In article <sVq7wB2w165w@sys6626.bison.mb.ca> flux@sys6626.bison.mb.ca (John Kamchen) writes:
>I am looking for a circuit that can provide me with a 14.318318Mhz
>pixel clock, derived from an incomming video source.
>I'm using an LM1881 video sync separator to obtain the needed sync 
>signals.

Well you could do it the same way TVs do:  Use a crystal oscillator
phase-locked loop.  That is, instead of using a VCO, use a crystal
oscillator with a variactor diode to adjust the crystal frequency a little.
Use some type of charge-pump circuit to get the control voltage for the
diode, and only enable the pump-up and pump-down signals during burst-gate
from the 1881.  See any color TV schematic.

Have you tried a 74S124 VCO?  That should be stable enough if you power the
analog side of it with its own 7805.  Also make sure no high-frequency noise
can get into the control signals.  Parallel the PLL filter with small disk
capacitors.

Also there is supposedly a difference between signetics and ti versions of
the 74S124.  The signetics version was supposed to be the best.

A few days ago someone posted another good method:  Use a low-distortion
transistor sine-wave oscillator for a VCO.

Tonight I'm going to attempt to build a PLL for deriving the dot-clock from
the H-sync signal of a computer-generated video source.  Its for a b/w video
capture board for obtaining data from medical imaging equipment (the
computers for CAT scanners and MRI machines unfortunately don't allow users
to download the image directly, so you have to capture it from the video
output to the monitor.  Also there's no standard video signal they use, so
you have to handle any video format).  So I'm about to have this same
problem.

BTW, what good wideband flash A/D convertors have people seen?  I'm using an
ADC-304 from DATEL, but they're expensive and the ADC-304 is speced only up to
8MHz bandwidth and 20Mhz sample rate.  Their 1988 catalogue lists better
ones, (like the ADC-301 which is 15MHz bandwidth and 30MHz sample rate) but
they're ECL, have high capacitance inputs and the salesperson says that
ADC-301 - ADC-303 are discontinued.

Also are any fast acquisition time sample & hold circuits available?  I'm
digitizing a periodic signal, so the capturing doesn't have to be real-time.
How difficult would it be to make a fast diode-switch sampler (as in a
mixer), using an LH0033 as a driver?
-- 
/*  jhallen@world.std.com (192.74.137.5) */               /* Joseph H. Allen */
int a[1817];main(z,p,q,r){for(p=80;q+p-80;p-=2*a[p])for(z=9;z--;)q=3&(r=time(0)
+r*57)/7,q=q?q-1?q-2?1-p%79?-1:0:p%79-77?1:0:p<1659?79:0:p>158?-79:0,q?!a[p+q*2
]?a[p+=a[p+=q]=q]=q:0:0;for(;q++-1817;)printf(q%79?"%c":"%c\n"," #"[!a[q-1]]);}
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 08:36:48 GMT

In article <MITCH.93Jan3164010@clsi.clsi> mitch@clsi.COM (Mitchell N. Perilstein) writes:
>I've asked in comp.sys.att, but they're silent.
>
Hmmm, I didn't see it.

>The 3b2 serial console connector is like an RJ11, but with more
>conductors.  It carries something like RS232, because I've stumbled a
>working arrangement before.  I'm less clumsy than usual: I can't get it
>this time.

This is in Appendix D of the 3b2 Owner/Operator Manual.

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.

	8-pin			25-pin			25-pin
	modular			RS232			RS232
	jack			for terminal		for automatic dial
				or printer		modem

	1 Prot Grd		1 Frame Ground		1 Frame Ground
	2 Reserved		4 Reserved		5 Reserved
	3 TXDO			3 Transmit data		2 Transmit data
	4 DTRO			8 Data terminal ready	20 DTR
	5 RXDO			2 Receive data		3 Receive data
	6 DCDO			20 Data carrier detect	8 DCD
	7 SIG GRD		7 Signal ground		7 SG
	8 Reserved		5 Reserved		4 Reserved



-- 
Dave Turner	(510) 823-2001	{att,bellcore,sun,ames,decwrl}!pacbell!dmturne
From: nsus_ss@uhura.cc.rochester.edu (Nick Susch)
Newsgroups: sci.electronics
Subject: PC VLSI Design package
Date: 5 Jan 93 17:04:28 GMT
Organization: University of Rochester - Rochester, New York

Does any one know of a VLSI design and layout package for the PC that is
either freeware or shareware? I have used Magic on Sun workstations, but was
wondering if there is anything on the net that I could try out on my PC.
Thanks for any help!

--
They say there is strangeness too dangerous | /\/ick Susch - U. of Rochester
In our theatres and bookstore shelves,      | nick@blaise.cif.rochester.edu
That those who know what's best for us      |    or
Must rise and save us from ourselves.       | nsus_ss@uhura.cc.rochester.edu
				   -RUSH   	
Newsgroups: sci.electronics
From: doug@ve7frg.ampr.org (Doug Collinge - VE7GNU)
Subject: Re: Vector wire pencils
Organization: G.M. Systems
Date: Tue, 5 Jan 1993 05:42:31 GMT
X-Newsreader: TIN [version 1.1 PL6]

James MacPhail (jmacphai@cue.bc.ca) wrote:
: You guys are aware of ScotchFlex, right? If not, check it out. It is made
: by 3M (and thus tends to be considered over-priced by some).

Yes, it *IS* overpriced.

But, you know, I've done about 3 or 4 circuits with Scotchflex,
and EVERY TIME I have gone through the same thing:

BEFORE: "This stuff is so expensive - maybe I should use wirewrap
	 this time."

AFTER:	"This stuff is so great - I'll never use wirewrap again!"

It truly is wonderful, for digital circuits anyway.  For analog
use Dead Bug (tm).

Cheers!
Newsgroups: sci.electronics
From: jgd@dixie.com (John De Armond)
Subject: Re: Microwave Oven Plasma Etcher?
Date: Wed, 06 Jan 93 09:46:39 GMT
Organization: Dixie Communications Public Access.  The Mouth of the South.

edharris@ohstpy.mps.ohio-state.edu writes:

>I'd like to use a small microwave oven ( will a small vacuum chamber inside) 
>to generate reactive plasmas ( O2 etc) for cleaning and etching in our lab. 
>The idea sort of works, but even the smallest ovens  (400 Watts or so) 
>generate so much heat that they tend to burn samples more than etch them...

>Does anyone know how to lower the power output of the magnatron, or is it
>possible at all? I'd like to cut the power to 50W or so...

Why not just put a container of water in the oven with the chamber and
experiment with the amount of water until you absorb the proper amount
of excess microwave?

John
-- 
John De Armond, WD4OQC               |Interested in high performance mobility?  
Performance Engineering Magazine(TM) | Interested in high tech and computers? 
Marietta, Ga                         | Send ur snail-mail address to 
jgd@dixie.com                        | perform@dixie.com for a free sample mag
Need Usenet public Access in Atlanta?  Write Me for info on Dixie.com.
Newsgroups: sci.electronics
From: philb@techbook.com (Phil Biehl)
Subject: NEED SOLENOID ACTUATED WATER VALVE.....
Organization: TECHbooks --- Public Access UNIX --- (503) 220-0636
Date: Wed, 6 Jan 1993 00:16:06 GMT

Hi. In examining my hydronic (hot water basboard) furnace, I find that
it is divided up into three zones. What I'd like to do is put in
electrically operated valves that controlled via a microcontroller and
three separate thermostats, one for each zone. I need to find a source
for these valves that will fit 7/8" copper piping. 12 Volt coils would
be nice but not absolutely necessary. 

Any and all help appreciated
Thanks

Phil Biehl

-- 
philb@techbook.COM  Public Access User --- Not affiliated with TECHbooks
Public Access UNIX and Internet at (503) 220-0636 (1200/2400, N81) 
Newsgroups: sci.electronics
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: RS 232 & RS-422 voltage specs wanted
Date: Tue, 5 Jan 1993 22:31:52 GMT
Organization: U of Toronto Zoology

In article <1ic8hnINNn10@uwm.edu> albrecht@csd4.csd.uwm.edu (Chad Edward Albrecht) writes:
>Standard RS-232 uses +/- 5VDC

Sigh.  WRONG.  Or at least, not very right.

Standard RS232 transmitters must produce something between +5 and +15
and something between -5 and -15.  Note that that is +5.000 and -5.000,
so you can't do it with +/-5V supplies (although some sleazy people
try anyway).  Most RS232 nowadays is done with either +/-12V or +/-9V,
the former popular with people who already have +/-12V supplies and
the latter popular with chips that generate their own supplies (because
+5, doubled, less a diode drop or two, either straight or inverted,
comes out at about +/-9).

RS232 receivers must accept anything between +3 and +25, and anything
between -3 and -25, with the threshold slightly positive so that
0 looks negative.

RS423 uses +/-5.  It is roughly RS232 compatible and can run faster.

RS422 (real RS422, not the differential RS423 that Macs use) uses
+5 and 0.  It is not RS232 compatible.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
Newsgroups: sci.electronics
From: schuster@panix.com (Michael Schuster)
Subject: Re: Who stocks DRAM NMBS AAA2800P-80?
Organization: Panix Public Access Internet & Unix, NYC
Date: Tue, 5 Jan 1993 19:43:39 GMT

In article <1993Jan5.102937.1@levy.fnal.gov> levy@levy.fnal.gov writes:
>I'm looking for a 256Kx1 DRAM chip, number NMBS AAA2800P-80.  I need 36 of these
>or a suitable substitute.  I have a number of 41256's around, but I don't have
>the data to see if they're compatible.  
>
>Anyone know of a source, or if the 41256's are indeed compatible?

If I'm not mistaken those NMB's are static column DRAM's. They sound
awfully like what came on my old Micronics memory card. If yes, then
41256's are not compatible. Microprocessors Unlimited (ads in C. Shopper,
PC, etc) or and good chip house should have them.


-- 
_______________________________Mike Schuster________________________________
NY Pub. Access UNIX/Internet: schuster@panix.com | 70346.1745@CompuServe.COM
The Portal (R) System: schuster@shell.portal.com | MCI Mail,GEnie: MSCHUSTER
Newsgroups: sci.electronics
From: "glen mead" <glen.mead@canrem.com>
Subject: audio signal switcher
Reply-To: "glen mead" <glen.mead@canrem.com>
Organization: Canada Remote Systems
Distribution: sci
Date: 10 Jan 93 17:07:40 EST

I have a quick question regarding a circuit which I believe shoould be
fairly simple.  I have two stereo line level audio sources (in my car) but
only one equalizer with one set of stereo inputs.  I want to build a
switchbox that will select one set of outputs (CD/Receiver) by default and
then select the other outputs (Cassette Deck) when a cassette is being
played back.  So, I would basically like the switchbox to select the one
input by default and then select the other input when a signal is present
on that input.  Any comments and/or suggestions on how this might be done?

Glen Mead - RZ/RD 500 Owners Group
---
 * Amiga-Reader V2.00B * 
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044
From: wcurtiss@travis.csd.harris.com (William Curtiss)
Newsgroups: sci.electronics
Subject: Re: Where to mount an outside temp probe on a car?
Date: 4 Jan 1993 13:47:35 -0500
Organization: Harris CSD, Ft. Lauderdale, FL
NNTP-Posting-Host: travis.csd.harris.com

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
>cost).
>
>Has anyone done this? Where did you mount the probe... How did you protect it?

My 86 Isuzu Impulse had an external temperature probe.  It was connected to
the A/C system, along with one inside the passenger compartment.  I'm not
quite sure what it tried to do with the two readings, but the controls were
supposed to select a given temperature, not a level of heating or cooling.

Anyway, the exterior probe was mounted underneath, inside of, and behind, the
back right wheel.  (You could lift the carpet in the hatch-back and trace the
wires going to it.  It was just pressed through a gromet.)  The manual even
mentioned that it had to temporarily removed if the car was undercoated, or
else the A/C system would malfunction.  The muffler was on the other side,
I believe.

By the way, the interior probe was near the glove compartment, slightly below
to keep it out of direct sunlight.

I don't know it the current GM style Isuzu Impluse's have this feature or not,
but I think most of the older pre-GM models do.

-- 
--
DISCLAIMER: The opinions expressed here are my own; | 
     they in no way reflect the opinion or policies | wcurtiss@csd.harris.com
     of Harris Corporation nor John Hartley.        |
Newsgroups: sci.electronics
From: siim@waterloo.hp.com (Brad Siim)
Subject: Re: 150 - 200 W. Amplifier
Date: Wed, 6 Jan 1993 22:08:05 GMT
Organization: HP Panacom Div Waterloo ON Canada
X-Newsreader: TIN [version 1.1.8 PL6]

Jack W. Weinmann (bk233@cleveland.Freenet.Edu) wrote:
: 
: A friend of mine plays the organ and wants to expand his system with
: external speaker cabinets and higher power amplifiers.  His main problem is
: to come up with 4 channels of 150 - 200 Watts each without suffering a
: financial breakdown.
: 
: My question is whether there are any plans or kits that he could use to
: build his own amps.  Are there any power amp modules that can be employed
: to make his life easier?
: 
: I have replaced a power amp module in a stereo amplifier, but I believe it
: was only around 40 Watts or so.  Are there any that will handle 150 - 200
: Watts?  If there are, how difficult is the surrounding circuitry to
: complete the driving stages?
: 
: Help will be appreciated.
: 
: Jack Weinmann  bk233@cleveland.freenet.edu

Buy it, it will be cheaper.  If you want the thrill of building an amp then
there was an article published in a number of issues of Radio Electronics
4-6 years ago by R. Metz (his name may be spelled wrong). I have seen 
the article republished at least twice in RE.  The article describes 
a 250W FET power amp with VERY nice specifications.  You can order the 
pcb's etc. from the author.

Brad Siim
Newsgroups: sci.electronics
From: Bob.Clarke%bbs@actcnews.res.utc.com (Bob Clarke)
Date: Sat, 09 Jan 93 10:11:14 EDT
Organization: United Technologies Research Center
Subject: Re: Laser gunsights (was: Info on CO2lasers wanted
Distribution: world
Reply-To: Bob.Clarke%bbs@actcnews.res.utc.com (Bob Clarke)
X-Posting-Software: UniBoard 1.10a S/N 190921

In message <6899@tuegate.tue.nl> dated 8 Jan 93 12:44:28 GMT
wouter@blade.stack.urc.tue.nl (Wouter Slegers) writes:

> jeh@cmkrnl.com wrote:




> : > [...]
> : >                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.  
> : 
> This is not quit true: a 2 mW laser is enough concentrated to damage the eye
> tissue if your looking right into it..
> 
> : 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 th
at
> Correct, but it does give some extra targetting info..
> 
> : *seeing* the dot of light from a 2 mW laser at any reasonable distance, in 

> : anything other than pitch blackness, is damned near impossible.  


True, but laser targeting systems do not use the naked human eye!!!  Most
laser targeting system do not operate in the visible range, and are used 
in conjunction with a remote viewing device such as night vision.  The army 
has a system were they bore sight a laser to a m16 rifle, the user is wearing
night vision goggles, the laser is only visible to people wearing goggles.el
Where ever the dot lands is dead!  It is good to about 50 yards, I think!















--
Bob Clarke, user of the UniBoard System @ actcnews.res.utc.com
E-Mail: Bob.Clarke%bbs@actcnews.res.utc.com
========================================================================
   United Technologies Corporation
   Opinions expressed do not necessarily represent UTC.
Newsgroups: sci.electronics
From: markz@ssc.com (Mark Zenier)
Subject: Re: Detecting Sine Wave freq
Organization: SSC, Inc.,  Seattle, WA
Date: Sun, 10 Jan 1993 05:23:36 GMT
X-Newsreader: TIN [version 1.1 PL6]

Paul Michael Wayner (pmw2c@csissun10.ee.Virginia.EDU) wrote:
: I'm interested in designing a circuit that will determine
: if a sine wave frequency is in a certain range of values,
: specifically, 45-51 MHz.  It is very important that the
: detector be as reliable a possible, so I would like to use
: only a few active components and try to stick to RC's as
: much a possible.

(At that frequency, every wire is an inductor, whether you 
want it to be or not.)

How sensitive?  And is the input an antenna or a high level
signal?  A low level signal?   What kind of noise or
interference?  More than one signal at a time?  Fixed or
Variable frequency?  Is the output an on/off digital signal, or
a amplitude, a blinking light, a spectrum display, etc. ...

[In other words, your spec. is a little vague.]

Mark Zenier  markz@ssc.wa.com  

Newsgroups: sci.electronics
From: jjj@mits.mdata.fi (Joni Jarvenkyla)
Subject: Laser cutting steel, what about glass?
Organization: Microdata Oy, Helsinki, Finland
Date: Thu, 7 Jan 1993 22:24:01 GMT


Probably everyone has heard of applications where laser beam is used to
cut steel plates. But are there similar applications to cutting glass?
Will the same setup do for glass or is it too hot?

I have a couple m^2 of raw factory mirror and would be interested in
turning it into pieces of art. Would like to hear if anyone of you has
experience in this field.

How powerful does a laser have to be in order to cut 10 mm steel?

--
jjj@mits.mdata.fi | PGP 2.0 key available | PGP 2.0 avain saatavilla
From: myers@hpfcso.FC.HP.COM (Bob Myers)
Date: Mon, 4 Jan 1993 19:36:51 GMT
Subject: Re: Digital tuning
Organization: Hewlett-Packard, Fort Collins, CO, USA