HDTenEightyP/NetNews huggingface dataset:
From: frank@rover.uchicago.edu (Frank - Hardware Hacker - Borger)
Subject: Re: Help locate anemometer
News-Software: VAX/VMS VNEWS 1.41    
Reply-To: frank@rover.uchicago.edu
Organization: Joint Center for Radiation Therapy
Date: Tue, 26 Jan 1993 16:11:00 GMT

In article <1993Jan26.035028.21725@news.columbia.edu>, hyx1@cunixb.cc.columbia.edu (Harry Y Xu) writes...
>I've been trying to locate an anemometer with an electrical output for
>a while without much success.  The device is to be used to measure wind 
>speed on top of a residential building.
> 
>If you know of manufacturers or dealers, please help out by posting or
>e-mailing the info.
> 
>I suspect this group might not have the info, but cannot find a more 
>appropriate newsgroup.  If you know one, please let me know.
> 
	Try Edmund Scientific	
	    1-609-573-6250

   Frank R. Borger - Physicist    __       George Halas had two heirs; one
Michael Reese - Univ. of Chicago |___      carried his seed and one carried his
  Center for Radiation Therapy   | |_) _   soul. ... One can imagine the wisper
    "Birthplace of Softball"       | \|_)  of George Halas, rooting for his
Internet:  Frank@rover.uchicago.edu   |_)  soul. - Jeannie Morris
Phone : 312-791-8075 fax : 567-7455        
Newsgroups: sci.electronics
From: morteza@innovus.com (Morteza Ansari)
Subject: Opto Switch...
Keywords: optical switches
Organization: Innovus Inc., Hamilton, Ontario, Canada
Date: Fri, 22 Jan 1993 17:18:20 GMT

Can someone tell me where I could find an slotted optical switch with logic
(TTL) output?  I know motorola has a part (MOC75Tx or MOC75Ux, where x=1 or 2)
I've been looking for this device for a while now and can't find it anywhere.
Does anyone know of any other company that makes such a device?


Thanx,
_______________________________________________________________________________
                __       |
 I\    /I      /  \      |          Morteza Ansari, Computer Engineer,
 I \  / I     I____I     |                    Innovus Inc.
 I  \/  I     I    I     |              Hamilton, Ontario, CANADA
 I      I ##  I    I  ## |                   (416)529-8117
_________________________|_____________________________________________________
                             morteza@innovus.com
                                     or
                         ansari@maccs.DCSS.McMaster.ca 
_______________________________________________________________________________
Newsgroups: sci.electronics
From: jtaylor@dseg.ti.com (Jeff Taylor)
Subject: Re: Chips for wireless modem
Organization: Texas Instruments, Incorporated
Date: Thu, 21 Jan 1993 19:53:52 GMT

In article <laird.727283315@stable.ecn.purdue.edu> laird@stable.ecn.purdue.edu (Kyler Laird) writes:
>From: laird@stable.ecn.purdue.edu (Kyler Laird)
>Subject: Re: Chips for wireless modem
>Date: 17 Jan 93 15:08:35 GMT
>rwb@alexander.VI.RI.CMU.EDU (Robert Berger) writes:
>
>>In article <1993Jan13.235419.11126@ads.com> pkenny@ADS.COM (Patrick Kenny)  
>>writes:
>>> I would like to build a simple wireless modem. Are there single chips
>>> to send/recieve radio signals, and modems in a package. Or is there a
>>> kit I can buy somewhere. Any help would be appreciated.
>
>This month's Computer Craft has an ad on the first page inside the cover
>for a transmitter/receiver pair for data communications.  Crystal or
>synth. tuned.
>
>>The Motorola 3356 is a single chip receiver that's used in pagers.
>
>>For xmit, you could use a circuit used in many wireless mikes; a
>>common base Colpitts oscillator with the data fed to the base to
>>produced FSK. I have gotten this to work at 56 Kbaud.
>
>This sounds great!  Where can I pick up schematics for something like
>this?  I've been looking for ages.  (I usually find bits and pieces,
>but I want everything in one place 'cause I don't feel comfortable
>troubleshooting RF electronics.)
>
>>If you have more money than time, several companies sell spread
>>spectrum wireless modems in the 902-928 Mhz bands. These are allowed
>>1W of total power and 4W of effective radiated power; depending on
>>bandwidth they can go tens of miles.
>
>I just noticed a new version shown in 73, but I got the feeling that
>it was just for in-building use.  If I could get one to go from my
>house (elevated, but no external antenna allowed) to work (about two
>miles away in valley, but on fifth floor) reliably, I'd be thrilled.
>
>How are such modems for mobile communication?  Can I pop one in my
>car and use it around town?
>
>Note:  I don't have my ham license (but I do have a Heathkit course
>certificate from many years ago), but will get my no-code license if
>that's what it will take to get into this stuff.
>
>Thanks for the info!
>
>--kyler
>
>P.S.  I think that if someone decided to put together kits for
>complete RF modems, they'd sell like hotcakes.  (Like the FM audio
>transmitters apparently do.)  Maybe someone does already and I'm
>just out of touch...
>modems


TI makes a great chip that allows up to 1200 baud transmit and receive from
one 16-pin device. The part number is TLM3105 or its predicessor TLM3101.

JTAYLOR@LOBBY.TI.COM
From: tomb@hplsla.hp.com (Tom Bruhns)
Date: Mon, 25 Jan 1993 22:06:43 GMT
Subject: Re: Internal output resistance on op amps
Organization: HP Lake Stevens, WA
Newsgroups: sci.electronics

wout@dutentb.et.tudelft.nl (Wout Serdijn) writes:

>In most cases the output resistance of an op amp is formed by the output 
>resistance of a (bipolar) transistor in parallel with its biasing circuit.
>Depending on the type of op amp (especially its current consumption and
>the process parameters) the output resistance therefore can vary between 
>10 kilohms and 100 Megohms.

Eeek.  Sorry, I can't let this one go by.  Look up some data sheets:
Signetics/Philips lists 75 ohms typical for the old uA741 as the
_open_loop_ output impedance.  Many op amps are lower than this.
On the other hand, there are also things called operational
transconductance amplifiers (like the Harris/RCA CA3080) that have
purposly very high output impedances.  But you wouldn't normally
confuse them with normal op amps.

I wonder if the original poster had tried to look up the output 
impedance of a particular amp and not found it.  Often it's not
specified; sometimes instead, a closed-loop impedance is
specified, and other times, it's just not specified.
From: atc@waikato.ac.nz
Newsgroups: sci.electronics
Subject: Computer controlled LaserVision players?
Date: 26 Jan 93 00:07:26 GMT
Organization: University of Waikato, Hamilton, New Zealand

Hi,
I'm looking for a schematic diagram for any pioneer or philips/magnavox
Laserdisk players manufactured around 1981-83 that were computer controllable.

this control usually took the form of a serial connection(s) to the infra-red
receiver.

If anyone has information regarding how to program such a machine it would also
be useful.

Thanks in advance.

-- 
Andrew Chambers
Computer Services
University of Waikato
New Zealand

ATC@WAIKATO.AC.NZ
Xref: sparky sci.electronics:23542 rec.audio:19615 rec.audio.car:5899
From: jeh@cmkrnl.com
Newsgroups: sci.electronics,rec.audio,rec.audio.car
Subject: Re: 12V Power Amplifier Design
Date: 27 Jan 93 15:05:26 PST
Organization: Kernel Mode Systems, San Diego, CA

In article <C1It67.5E5@world.std.com>, DPierce@world.std.com (Richard D Pierce) writes:
> In article <1993Jan27.000515.19195@parc.xerox.com> tapscott@parc.xerox.com (Peter Tapscott) writes:
> 
> In demonstrating how much power you can derive from an amplifier based on
> a 12 volt rail can supply, Peter Tapscott says:
>>
>>You have to be cautious about accepting wattage ratings
>>from car amps. The manufacturers frequently exceed the laws of physics
>>with their ratings.
>>
>>P = 16/R for a 12 volt DC supply. For an 8 ohm speaker, the max
>>output is only about 2 watts. Figure 4 watts for a 4 ohm speaker.
>>
>> . . .
>>
>>I would be suspicious of claims of driving loads much below 4 ohms, except
>>for very expensive audiophile car amps, like Orion. 
>>
> 
> [...]
> It's now a trivial excercise to design and mass produce car audio
> electronics that have output amplifiers that run of supply rails that are
> much in excess of 12 volts. 
> [...]

Yes.  And it is even more trivial to build an amp that gives about 18 watts RMS
(usually claimed to be a 25W or 30W amp at an un-specified distortion level :-)
without a DC-to-DC converter.  It's called a "bridging" amp.  

Ignoring the "13.6 volts" that a car really supplies, and ignoring the voltage
drop through the output devices:  At 0 input the + and - outputs for the
channel are both at +6 volts, so no current flows through the speaker.  When
the input waveform is "all the way positive", the + output terminal goes to +12
and the other to 0; when the input waveform is "all the way negative", the +
output goes to 0 and the - to 12 volts.  This gives a 24V peak-to-peak swing
across the speaker.  This works out to about 18 watts.  Practically, these
designs usually achieve 12 or 14 watts RMS.  

> It's cheap, it's easy, it's common, and it's what you missed in your
> discussion.

What he said! :-)

	--- Jamie Hanrahan, Kernel Mode Systems, San Diego CA
Internet:  jeh@cmkrnl.com, or hanrahan@eisner.decus.org  Uucp: uunet!cmkrnl!jeh
From: kludge@grissom.larc.nasa.gov (Scott Dorsey)
Newsgroups: sci.electronics
Subject: Re: Wanted : Nicad Charger Plans
Date: 24 Jan 1993 16:11:39 GMT
Organization: NASA Langley Research Center and Reptile Farm
NNTP-Posting-Host: grissom.larc.nasa.gov
Keywords: cell battery alkaline charging duracell

In article <21152@acorn.co.uk> agodwin@acorn.co.uk (Adrian Godwin) writes:
>
>How about a charger for Alkaline cells ? I've seen one in a UK hobby magazine
>using a system of periodic charge/discharge at 50Hz, but the charge time 
>figures they presented didn't make sense.
>So I built a version that I was happier with, but performance seems poor 
>(long charge time, recharged cells don't hold their charge well).

I would bet that the charger you saw was for standard carbon-zinc cells.
The carbon-zinc batteries can be recharged somewhat, but they won't work
terribly well afterward and you can only get one or two rechargings out
of them.  Rechargers for these batteries were quite popular back before
NiCds and alkaline cells came out.

If you charge an alkaline battery, your chances of rupturing it are
pretty good.  I've never seen one literally explode, but I have seen
them split down the side and spray causic goo around.  Don't do it.  It's
not worth it.
--scott
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: Counter
Date: 27 Jan 93 23:23:00 GMT
Article-I.D.: shelley.1k75gkINNebf
Organization: University of Washington, Seattle
NNTP-Posting-Host: carson.u.washington.edu

In article <qmX1XB1w165w@sys6626.bison.mb.ca> flux@sys6626.bison.mb.ca (John Kamchen) writes:

> [I need] a counter that counts to 1818, then resets back to zero (with 
>some kinda \RCO when it hits 1818).
>I've looked through all my TTL data books, and nothing really strikes me
>as being 'right' for this application.
>The input clock pulse is 28mhz, so that rules out CMOS parts.

	This is well within 74HC series frequency capabilities;
only the old 4000 series CMOS need be ruled out.

	The number you're counting to is less than twelve binary
bits, so three four-bit counter chips will do it.  74HC163 or
equivalent would be my recommendation.  You can save a bit of
electric power by prescaling (so the high-speed clock doesn't 
clock all the stages of a synchronous counter), and your
divisor has a factor of six: you might consider using a
74LS92 for divide-by-six function, followed by a counter
set for divide by 303.

	The general scheme for a fixed-modulus counter is to use the
CARRY output connected to the LOAD input, and to strap the
JAM data input to the appropriate number (in your case,
2048 - 1818).  When 1818 counts have elapsed, the counter
CARRY gives you your pulse (and restarts the counter at
its initial value).  The synchronous LOAD function on the
74163 is ideal for this.


	John Whitmore
Newsgroups: sci.electronics
From: alan@apple.com (Alan Mimms)
Subject: Re: Pinouts for 15-pin IBM GamePort?
Date: Thu, 28 Jan 1993 00:22:14 GMT
Organization: Apple Computer, Inc.

In article <jeremym.727842907@sfu.ca>, jeremym@fraser.sfu.ca (Jeremy Thomas McDonald) writes:
> 
> Does anyone have the pinouts for the IBM-compatible 15-pin GamePort?
> What is the current rating on the +5v pin, if there is a +5v pin?
> Thanks in advance.
> 
> email to: jeremym@fraser.sfu.ca
> -------------------------------
> yes, a lowly university student
> 

I am looking at a thing called "Interfacing to the IBM Personal Computer"
(second edition -- ISBN 0-672-22722-3) which gives the following information:

An OUT instruction (any data) to port 0x201 starts four one-shot timers
whose time value is dependent on the value of four external resistors
(presumably pots attached to a joystick).  IN instructions from that
same port show the state of the one-shots and the game port switches
(there are four).

Bit     Description        Pin

 0      One shot output    n/a
 1      One shot output    n/a
 2      One shot output    n/a
 3      One shot output    n/a
 4      Switch #1 in        2
 5      Switch #2 in        7
 6      Switch #3 in       10
 7      Switch #4 in       14

The pinout is as follows

Pin #1 is +5V
Pin #2 is switch 1 (ground to turn ON, I think)
Pin #3 is the wiper of potentiometer #1 (other end should be on +5V)
Pin #4 is ground
Pin #5 is ground
Pin #6 is the wiper of potentiometer #2 (other end should be on +5V)
Pin #7 is switch 2 (ground to turn ON, I think)
Pin #8 is +5V
Pin #9 is +5V
Pin #10 is switch 3 (ground to turn ON, I think)
Pin #11 is the wiper of potentiometer #3 (other end should be on +5V)
Pin #12 is ground
Pin #13 is the wiper of potentiometer #4 (other end should be on +5V)
Pin #14 is switch 4 (ground to turn ON, I think)
Pin #15 is +5V

The potentiometers govern the (approximate) one-shot time by the formula

   time = 24.2 + 0.011 * (resistance)

Hope this helps.  By the way, this book is pretty good.

Newsgroups: sci.electronics
From: geoffrey@cosc.canterbury.ac.nz (Geoff Thomas)
Subject: Re: PIXAR
Organization: University of Canterbury, Christchurch, New Zealand
Date: Thu, 21 Jan 1993 23:59:50 GMT


NASA have been using morphing techniques in a limited way since the
year dot! When they send their satellites up for remote sensing, those
equipped with cameras needed to have the camera images 'registered',
so that the images shown on screen were indeed as they appeared and
not geometrically distorted. Consequently, as the image came in from
the camera, it was transformed in a way similar to current morphing
techniques. The NASA people weren't interested in the in-between
frames that make morphing interesting. They just wanted the final
image.

So, in my opinion, the NASA image processing gurus (or whoever it
was that came up with the technique) should be credited with the
1st application of morphing.

Just my 2 pence.
Newsgroups: sci.electronics
From: lo@pi.uleth.ca (Zachary Lo)
Subject: What is the limit of a MODEM?
Keywords: Tools of AI.
Organization: University of Lethbridge
Date: 26 Jan 93 05:45:32 GMT

Hi there

I am working in a project about AI right now.
I wonder any of you can send information about the transmit speed limit
of a electronic modem which is used in a computer.
How the EE improve the speed of the modem?
What is the factors that will affect the transmitting speed?

Thanks

Zachary Lo
Please send e-mail : lo@pi.ualberta.ca
From: bob@kc2wz.bubble.org (Bob Billson)
Newsgroups: sci.electronics
Subject: need a source for 1802 uP and 1861 video interface chip?
Summary: where can I get these chips?
Keywords: 1802 help 1861 RCA
Date: 22 Jan 93 01:10:10 GMT
Distribution: na
Organization: Color Computer 3: Tandy's 'game' machine

I have an old RCA COSMAC VIP single-board computer I would like to get running
again.  I am having trouble locating to vital chips:

     CDP1802D or CDP1802CD  - COSMAC microprocessor
     CDP1861CD              - CMOS Video Display Controller

I am sure the 1802 is still made (they are still being used in some satellites
so _someone_ must sell them).  The 1861 was made to go with 1802.

I would appreciate any pointers to a source for these chips.  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: cpuig@infoserv.com (Carlos M. Puig)
Newsgroups: sci.electronics
Subject: Re: Digital Filtering
Keywords: Digital Filter software, Matlab
Date: Mon, 25 Jan 93 16:54:21 PST
Distribution: world
Organization: Minimax Research Corp.

cmh@eng.cam.ac.uk (C.M. Hicks) writes:

> fitzpa@eeel.nist.gov (Gerry FitzPatrick) writes:
> 
> >I need to design a digital filter (either a notch filter or
> >a low-pass filter).  I will be analyzing data taken from a 
> >lecroy 7200 scope (in either ascii or binary).  I would like
> >I would like to look at the 60  Hz component of the waveform.
> 
> >Any ideas on how to write a subroutine that would perform this
> >digital filtering on stored data?  Any good books on designing
> >digital filters?
> 
> 'MatLab' from Mathsworks would be absolutely ideal, although rather expensive
> It is a data manipulation, analysis, and computational package, which has
> built-in routines for digital filtering, spectral analysis and graphical
> output (amongst many hundreds of other things). Runs on a 386 or better
> (and many other platforms such as NeXT, UN*X), but I think it requires a 
> co-processor. It will, undoubtedly, do everything you need, but maybe costs
> too much...

The Student Version of Matlab (distributed by Prentice-Hall, I believe)
is available at US $50.  Try the engineering section of a local college
bookstore.  This version will run on any PC-compatible, with or without
a math coprocessor.  However, for reasonable throughput, I recommend at
least an 8 MHz 80286 with a coprocessor.  (A Mac version is also available,
but I have not tried it.)

The student version is the same as the previous MATLAB v3.5 with some
additional m files from a couple of the toolboxes.  However, it is
limited to 1024 elements per variable, and one can print graphs only
with print screen.  For student work, these limitations are not
serious.

Although the program comes with a good manual, the manual will not
teach you how to design digitial filters.

I am an EE student and started using this program last semester.  It's
very powerful, not only for DSP, but for general purpose engineering
calculations.  A very good value if you can live with the matrix
size limitations.

There is a new newsgroup (1 or 2 weeks old) "comp.soft-sys.matlab",
that is devoted to Matlab.  It may not yet be available at all
sites.


----
Carlos Puig, KJ6ST             cpuig@infoserv.com
San Jose, CA                   (408) 289-8174
Xref: sparky sci.electronics:23177 alt.radio.pirate:795
From: dave@frackit.UUCP (Dave Ratcliffe)
Newsgroups: sci.electronics,alt.radio.pirate
Subject: Re: FM power calculations needed
Date: 21 Jan 93 00:54:28 GMT
Followup-To: alt.radio.pirate
Organization: Data Factory Services, Harrisburg, Pa.

In article <1993Jan16.223928.20802@julian.uwo.ca>, wlsmith@valve.heart.rri.uwo.ca (Wayne Smith) writes:
> In article <1993Jan16.195016.5275@netcom.com> ser@netcom.com (Steve Rubin) writes:
> >   This is still not going to keep you out of trouble... Trust me on
> >this one, Im starting to become very knowlegable in FCC rules as
> >far as what you can and can not get away with :).  Legally speaking,
> >it has to be 250uV/m at 3m from the antenna, not off the campus.  On
> 
> So even if the campus is "private property", the above rules (so much
> strength 3m from the antenna) is still applicable?

If you're in the U.S., yes. 

> What if I've got a big ranch (I wish)?  Can't I radiate as much (or
> as little) power to cover my (private) property just as long as the
> field strength is below legal levels at the boundary of the property?

No. Without a license your limitations are plainly set out in the R&R's
of the FCC and they have nothing to do with the size of your property. 

> Conversely, I know that city police here on our campus wait until a
> car that they follow is off the campus property before they give the
> driver a ticket (for something), so would FCC inspectors/technicians
> be tresspassing if they had to enter private property to make a 
> signal strength reading?

They can go where they need to take field readings subject, of course,
to the laws regarding trespassing. But I guarantee if they get an
abnormally high reading from an unlicensed site they will be knocking on
your door. First, though, they have to be there. Unless there is a
complaint or they just happen to be in the area the chances are slim
they will be. They don't have that much enforcement muscle and generally
go for the big-time violators (can you say running an RCA BTA-250L on
your back porch in illegal? I knew you could :) ). People interfering
with licensed broadcast facilities are asking for a visit. 

Speaking as a former commercial broadcast engineer BTW. The rules have
changed a bit since I was last active in the business but they haven't
changed THAT much....


-- 
 vogon1!compnect!frackit!dave@psuvax1.psu.edu            |  Dave Ratcliffe  |
 - or - ..uunet!wa3wbu!frackit!dave                      |  Sys. <*> Admin. |
                                                         | Harrisburg,  Pa. |
Newsgroups: sci.electronics
From: hougland@enuxhb.eas.asu.edu (Kriss A. Hougland)
Subject: National Semiconductor display NSM 1416 pin info wanted
Organization: Arizona State University, Tempe
Distribution: usa
Date: Fri, 22 Jan 1993 17:00:44 GMT

Thanks in advance for any help.

I tried to call up the last National Semiconductor number I had and I just
got a click.  I'm needing to get some general display info on the NSM 1416
display.  4 alpha LEDs.  If you can digitize that particular data sheet and
mail a uuencoding of it, I'd appreciate it.  Or can someone tell me who
handles the local area for Arizona.  I'm bummed out now that I gave away
all my old NS data books.

--
If were so advance, why can't people put grocery carts back where they got
them from?; Can you survive a day with out a car?
From: mdk@col.hp.com (Mark Keisling)
Newsgroups: sci.electronics
Subject: Re: UART info sought
Date: 26 Jan 1993 19:13:35 GMT
Organization: HP Colorado Springs Division
NNTP-Posting-Host: hpctdjj.col.hp.com

ar961@cleveland.Freenet.Edu (Duane Kaufman) writes:
> 
> Hello!
> 
> Just for a project I am looking to build a very simple serial to parallel
> converter. I was wondering if anyone can point me to a source (catalog etc)
> for manufacturers of UART chips?
> 
> Thanks in advance!
> 
> -- 
>                                                      TheSeeker
> Duane Kaufman
> Internet: dkaufman@vms.macc.wisc.edu
> BitNet:   dkaufman@wiscmacc.BitNet        I looked under chairs...


Check out the Harris 6402.

Mark.