HDTenEightyP/NetNews huggingface dataset:
From: stanb@hpnmdla.sr.hp.com (Stan Bischof)
Newsgroups: sci.electronics
Subject: Re: lease/rent spectrum analyzer ?
Date: 5 Nov 92 02:31:10 GMT
Article-I.D.: hpnmdla.7380089
Organization: Hewlett-Packard, Santa Rosa, CA

In sci.electronics, urbina@novax.llnl.gov writes:

>Help!


>Does anyone know where I could possibly lease or rent an spectrum analyzer ?
>especially near or around the Bay area. With the outrageous cost of an SA,
>It's pretty damn near impossible for hardware hackers like me to be able to buy
>one.  I have access to one at work, but I want to use one at home for a part
>time business. Preferably one that sweeps from DC to around 5 GHZ and portable.

>Thanks.

>Guy Urbina  LLNL  (510) 423-6339
>Urbina@novax.llnl.gov

There are definitely companies which rent such instruments. I occasionally
get ads from one or two of them, but the names escape me right now. In any
case typical rental is not all that cheap, being ~10% of list price/month.

May make more sense to look at a used/old/obsolete but still quite
functional instrument.

Check any decent industry reference.

Stan Bischof
HPSR
From: Ted_Eugene_Viens@cup.portal.com
Newsgroups: sci.electronics
Subject: Re: Cable TV Channel Frequencies
Date: Tue, 10 Nov 92 21:38:14 PST
Organization: The Portal System (TM)
Distribution: usa

>Where's a good publication to find the center frequencies of Cable
>TV Channels?
>
>Thanks.
>
>--
>----------------------------------------------------------------------
>Scott Ferguson                        Exxon Research & Engineering Co.
>Project Engineer                      New Jersey
>----------------------------------------------------------------------
>"Always bark at a dog."
>
The Trade rag Communications Technology yearly publishes a Pull-out
poster with a great rf spectrum chart with the cable frequencies well
marked.  This years was published within the past two months.
CT Publications Corp.  (303) 355-2101.
Good Luck...  Ted..
From: aslt@acad2.alaska.edu
Newsgroups: sci.electronics
Subject: Video In on videocams?
Date: 13 Nov 92 03:20:12 GMT
Article-I.D.: acad2.1992Nov12.232012.1
Organization: University of Alaska

Hi,

This is a wierd one, but I said I'd post and ask...

Are there consumer videocameras (8mm, preferably) that can take a video 
signal from an external source and overlay it onto the image that the camera 
itself is taping?  As I understand it, this would be one of those 
lightweight all-in-one handycam units (camera and tape recording 
mechanism in single housing, like a Sony Sportcam) with a "video in" that
wouldn't switch out the camera element.

Conceptually, the syncing problems (not to mention gain, color balance, etc.)
would be, ah, interesting, but hey, who knows, MicroMiniaturization Is 
Wonderful Stuff...

Anyway, thanks in advance.  E-mail replies appreciated.

Lee
From: kingpin@mole.gnu.ai.mit.edu (Joe Smooth)
Newsgroups: sci.electronics
Subject: FOR SALE: 27512 and 27C512 EPROMs
Date: 12 Nov 92 21:33:49 GMT
Article-I.D.: mole.KINGPIN.92Nov12163349
Distribution: sci
Organization: None

I have the following for sale:

90 27512 250nS EPROMs - $2 / each

31 27C512 200nS EPROMs - $3 / each

	I will sell in quantities more than 10.. If you are interested, please
reply.. They should all work, and if any are defective, I will replace them..
Thanks..
Newsgroups: sci.electronics
From: l.gudiksen@uws.edu.au
Subject: antennas and grid dip ocillators
Organization: University of Western Sydney, Macarthur
Date: Tue, 10 Nov 1992 14:20:25 GMT

 
I just though it might try and pick some peoples brians to see if I can get any
ideas.
 
What I have is a Grid Dip Ocillator and I have known people to use these to
check antenna tunning. I would like to know how this is done. I do know they
generally used for checking tuned circuit frequencies but an antenna does not
respond the same way. I feel that most of what I am doing is looking at the
dip on the coupling coil I use to connect to the antenna.
 
Any Ideas (other than throw it out)?
|----------------------------------------------------------------------|
| Lars Gudiksen    (Senior Technical Officer - Hardware Support Group) |
|                                                                      |
|      Computing Center,  University of Western Sydney - Macarthur     |
|                Campbelltown, New South Wales, Australia              |
|                 P.O. Box 555 Campbelltown, N.S.W. 2056               |
|                                                                      |
| Email l.gudiksen@uws.edu.au   Ph (61-46) 203 259 Fax (61-46) 266 937 |
|----------------------------------------------------------------------|
Newsgroups: sci.electronics
From: tgamble@cimage.com (Rick Campbell /10000)
Subject: Re: Home alarm sensor info needed.
Organization: Cimage Corp, Ann Arbor, MI
X-Newsreader: Tin 1.1 PL5
Date: Mon, 9 Nov 92 21:18:03 GMT

Ming-Yung Lai (mylai@cs.uh.edu) wrote:
:  Hi, Can someone out there tell me how the home alarm security system's
:  sensor works. Is there any books/reference that can refer to?
:  The sensor at my house is a round (about 1/2 inch in diameter) and
:  wireless, every time I opened up the windows or door, the console will
:  have warning beep sound. Is this RF transmition? Thank you.
: 

I'm not sure what make of alarm system you are describing. I have the
remote 'Plug n Power' system from Radio Shack. The base plugs into an AC
outlet and communicates with other modules around the house. The remotes
are battery operated, and I'm not sure what freq. they run on. The performance
has been somewhat marginal. I keep having to re-install the remotes, the
system loses contact with them, and it has a limited range. The remote in
the garage seems too far away for it. I extended the antenna and raised the
height of the remote above the aluminum siding on the outside, but contact is
still intermittent.
I would be interested to hear about anyone else's experience with this system.
Perhaps if I could tell what freq. they operate on I could build a pre-amp.
Attempts to find out using my dip meter only re-programmed the fool thing.
I noticed that Radio Shack now has an updated version available. I would be
interesting to find out if any circuit improvements have been made.

RC 

-- 
 Rick Campbell  
 Internet: gamble@cimage.com
     -or-: emunix.emich.edu!rc3502
From: christos@kuhub.cc.ukans.edu
Newsgroups: sci.electronics
Subject: Connecting TV screen to computer
Date: 8 Nov 92 12:23:28 CST
Organization: University of Kansas Academic Computing Services

HEllo there,

	I am interested in connecting my TV screen to the computer and replace
it with my monitor. Is that possible? I have seen people doing it but what are
the precautions that need to be taken into account so that I won't blow up
anything and how can I really do this? Where can I get inforamtion about it?

	I would apprecoiate any relevant response.

Thanks,
Chris.
Internet Address: christos@kuhub.cc.ukans.edu
Newsgroups: sci.electronics
From: medin@catbyte.b30.ingr.com (Dave Medin)
Subject: Re: 12 V -> 3V, 0.6 A
Reply-To: medin@catbyte.b30.ingr.com
Organization: Intergraph Corporation, Huntsville AL
Date: Wed, 11 Nov 1992 16:46:49 GMT

In article <5150062@pollux.svale.hp.com>, ryoung@pollux.svale.hp.com (Roderick Young) writes:
|> Warning on using LM317 to drop 12V to 3V at 600mA...
|> 
|> You car battery could put out as much as 14-15V sometimes.  Let's say 13V.
|> That means a (13-3 = 10V) drop across this linear regulator.  At 600 mA,
|> that's 6 WATTS.  It might work, if you use the TO-3 version, and a very
|> good heat sink.  You might consider putting a 8-ohm, 10-watt resistor
|> in series with the LM317 input to disspate some of the power.
|> 
|> I actually used a (surface mount) LM317 to drop 12V to 5V, as less current
|> than you specify.  The chip got so hot, it melted its own solder!

The common TO-220 cased LM317 is good for 10+ watts on a reasonable
heat sink within the human comfort ambient temperature zone...
The 317 MUST BE HEATSINKED IN THIS APPLICATION. A 10 sq in piece
of metal mounted where there is some air movement or convection
can be set up should be a good start. Or, use the project case you're
building it in. An very CONSERVATIVE approach is to say that if the
heatsink is too hot to hold comfortably, then it needs to be increased
in size, have some air moved over it, etc. Take care that the metal tab
on the 317 is insulated from the car's frame (a mica washer, shoulder
washer, and heatsink grease from RS do this nicely). I've
used 317's before in this type of automotive application with
good results.

The resistor is a great idea, but don't mount it close to the heatsinked
part or you're back where you started (as you raise the ambient temp
close to the heat sink and decrease its effectiveness). Heat removal
still needs to be considered. I've had several power resistors
unsolder themselves without so much as smoking first.

For the poster that suggested buying commercial from Radio Shack, I
say great! You'll find in some revisions of their product they have
a transistor/zener regulator and in some others, ta-da, an LM317
(grossly under-heatsinked). I think your point on tinkering was
correct, though. Make it yourself, endure some hassle, and maybe
learn something. Or, simply pay out.

-- 
 --------------------------------------------------------------------
       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)
Newsgroups: sci.electronics
From: mcovingt@aisun3.ai.uga.edu (Michael Covington)
Subject: Re: Schematics for small audio amp needed...
Keywords: audio amp
Organization: AI Programs, University of Georgia, Athens
Date: Fri, 6 Nov 1992 22:09:55 GMT

Get an LM386 IC from Radio Shack and follow the diagram that comes
with it.

-- 
:- 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
Newsgroups: sci.electronics
From: gcouger@olesun.okstate.edu (Gordon Couger)
Subject: Re: Keypad interface to HC11
Organization: Oklahoma State University, Stillwater
Date: Wed, 11 Nov 1992 05:43:00 GMT

In article <92315.190637DI3QC@CUNYVM.BITNET> <DI3QC@CUNYVM.BITNET> writes:
>     I am planning to interface a keypad to the io lines of an hc11. Does anyon
>e have any suggestions on connecting a keypad. I was planning to scan the keypa
>d by driving one of the rows hi and testing the columns. I was planning on test
>ing this every 20ms. How would I take care of debouncing etc. Any suggestions.

I have come up with several solutions. Use a telephone key pad it fits on a 
single port and much more elegant solution is to connect resistors
across the key pad and using it for a voltage divider, saw this in Electronics
& wireless  World. Hook up the key pad with the resister and put a resistor
in series with the  key pad v+ and v-. Hook one of the pins of port 
E (watch out putting it on E0 if you are using BUFFALO it jumps to EEPROM
if E is high. and do an  A/D  and find the key board data using a single port.

A good deal of  thought is required to figure out the resistor net work. 
Diodes might be need to prevent unwanted current paths.

Hope this helps,
Gordon

AB5Dg   Agriculture Engineering Oklahoma State University
gcouger@olesun.agen.okstate.edu 405-744-6514 day 744-2794 evenings   
Newsgroups: sci.electronics
From: fdeck@lazy.helios.nd.edu (francis deck)
Subject: Source for dual audio taper pots/VCR tuner
Organization: OUC, University of Notre Dame
Date: Mon, 9 Nov 1992 19:33:51 GMT

I'm in trouble.  I need a new 250k dual audio taper pot for the
volume control on my stereo.  I've found no one in town who
sells dual pots of any kind.  Does anyone know a mail-order source
of these?  I do _not_ want to go to Radio Shack.

Second question... who sells parts via mail-order for late-model
VCRs?  Mine has a bad UHF tuner, I think.  Can a replacement
tuner be dropped right in without the need for re-alignment?

f.deck

Newsgroups: sci.electronics
From: doherty@melpar (Kevin Doherty)
Subject: Re: TEC-200 film
Organization: E-Systems, Melpar Division
Date: Tue, 10 Nov 1992 13:54:26 GMT

ajackson@ernie.Princeton.EDU (Andrew William Jackson) writes:

>TEC-200 film

>Has anyone tried this stuff?  Supposedly you photocopy your
>PCB pattern onto it with a normal photocopier and then iron
>it onto a blank copper board, peel off the plastic substrate
>leaving the pattern behind - then you etch it.  Sounds like
>a great way to make boards without the hassle of using photo
>resist.

  It's my favorite way to make PC boards, although there are a
few tricks to it.

  First, an iron doesen't do the job very well.  Uneven pressure
with the iron causes some of the lines to smear.  I sandwich the
film, the copperclad, and a piece of heat resistant foam between
two metal plates, then heat the sandwich.  This keeps the pressure
uniform over a wide area.

  Another problem is with the laser printers used to put the art on
the film.  Thin traces are fine, but large black areas tend to be
a little patchy and grainy.  If it isn't critical, I just ignore the
problem - some of the copper on the ground plane gets etched.  If I
care, I just lay down another layer of toner on top of the first.

  I've made 2 sided boards up to 6" by 9" that have come out 
beautifully.  If a circuit has more than five or six components,
these days I make a PC board as a matter of course.

  I understand, though, that this stuff has several competitors
now - particularly paper based systems.  Does anyone have data on
these?

Newsgroups: sci.electronics
From: libove@server.alf.dec.com (Jay Vassos-Libove)
Subject: wattage of fluorescent bulbs?
Organization: Digital Equipment Corporation, Atlanta Customer Support Center
Distribution: usa
Date: Wed, 11 Nov 1992 21:11:25 GMT

Please reply via e-mail.  I already read more newsgroups than I
can keep up with, or is good for my health. 8-)

I'd like to find a summary of the wattage ratings of typical
fluorescent bulbs, for example the three foot (or so) long,
one inch (or so) diameter ones; the little (six inches long?)
horse-shoe (approximately) shaped ones, etc.

I'd also like some reference about how much light they actually
give off, particularly in comparison to incandescent lights, 
and about how much fluorescent light is needed - it seems that
we always use far too much.

Thanks!!
-Jay
libove@alf.dec.com
--

Jay Vassos-Libove                  libove@alf.dec.com
Digital Equipment Corporation      decwrl!alf.dec.com!libove
Atlanta Customer Support Center    Opinions? They're mine, mine, all mine!
Alpharetta, Georgia                and D.E.C. Can't have 'em!
From: johnh@macadam.mpce.mq.edu.au (John Haddy)
Newsgroups: sci.electronics
Subject: Re: UNDERPOWERED HALOGEN LAMPS
Date: 8 Nov 92 21:49:02 GMT
Organization: Macquarie University, Sydney

In article <27806@castle.ed.ac.uk>, cam@castle.ed.ac.uk (Chris Malcolm) writes:
|> I have read that running halogen lamps on reduced voltage will shorten
|> their life, the argument being that their life depends on a cycle of
|> tungsten sublimation and redeposition which requires a certain
|> temperature to work. However, it seems to me that at lower
|> temperatures where it doesn't work (so well) it is not needed, i.e.,
|> tungsten/halogens should have the same kind of life/voltage graph as
|> ordinary vacuum tungstens.
|> 
|> Can someone who knows confirm or deny this?
|> -- 
|> Chris Malcolm    cam@uk.ac.ed.aifh          +44 (0)31 650 3085
|> Department of Artificial Intelligence,    Edinburgh University
|> 5 Forrest Hill, Edinburgh, EH1 2QL, UK                DoD #205

I have a catalogue which states that a halogen lamp's life is DOUBLED if run at
5% under voltage; and HALVED if run at 5% over.

The down side is that light output drops by 17% for a 5% undervoltage lamp.

These figures are for 12V tungsten halogen lamps - the ones with the inbuilt
dichroic reflector.

A thought:

	There's been a lot of hoo-ha recently about the high UV content of the
light output of these globes, due to the high operating temperatures. Does
anybody know how much the spectrum will differ if the globe is run 5%
undervoltage? I can't be bothered doing my own black-body radiation calculations
(its a bit difficult when you don't have all the data :-)

JohnH

----------------------------------------------------------------------------

      |  _  |_   _   |_|  _   _|  _|              Electronics Department
    |_| (_) | | | |  | | (_| (_| (_| \/           School of MPCE
    ---------------------------------/-           Macquarie University
                                                  Sydney, AUSTRALIA 2109

    Email: johnh@mpce.mq.edu.au, Ph: +61 2 805 8959, Fax: +61 2 805 8983

----------------------------------------------------------------------------
From: andyw@aspen32.cray.com (Andy Warner)
Newsgroups: sci.electronics
Subject: Re: Cable TV Rules
Date: 5 Nov 92 18:26:36 GMT
Organization: Cray Research, Inc.
Originator: andyw@aspen32


In article <720883631snx@nlbbs.UUCP>, paula@nlbbs.UUCP (Paula Stockholm) writes:
> 
> [...]
>         I'm the last one who would be considered and advocate for the
>         Cable Companies but . . . suppose you wanted to hook-up another
>         water heater - you would expect to pay for the extra juice.
> 
>           The cable signal is not as easily "meter-able" but you would
>           be using more cable signal.

Good analogy. The power company at least has the honesty to put
a meter on your feed, and charge you accordingly. They don't
snoop around checking what you've got connected (at least past
your meter). Every other utility has expended a non-trivial
amount of effort to bill you according to usage, it seems that the
cable & sat carriers would rather expend effort legislating than
developing a metering method (a gross generalisation, which I will
probably be mercilessly flamed for)..

>       I DO agree that often the extra charge seems excessive.

It seems to me any of the charges seem excessive.
-- 
andyw.	N0REN/G1XRL

andyw@aspen.cray.com	Andy Warner, Cray Research, Inc.	(612) 683-5835
Newsgroups: sci.electronics
From: dwjurkat@rodan.acs.syr.edu (Jurkat)
Subject: 65802 uP
Keywords: 6502 65802 uP 
Organization: Syracuse University, Syracuse, NY
Date: Tue, 10 Nov 92 18:11:37 EST

I'm looking for a 65802 microprocessor.  This is a direct replacement
for the 6502, has the same pins and can be substituted for the 6502.
 Any information about price and vendor would be greatly appreciated.
 You can email me at   dwjurkat@mailbox.syr.edu
 Thanks in advance!
From: Josef Moellers <mollers.pad@sni.de>
Newsgroups: sci.electronics
Subject: Re: 68000 and Cache?
Date: 10 Nov 1992 09:48:47 +0100
Organization: Siemens Nixdorf Informationssysteme AG, Paderborn, Germany
Keywords: 68000

In <1992Nov6.225506.1973@nntp.hut.fi> sakaria@vipunen.hut.fi (Sakari Aaltonen) writes:

>Several accelerator boards with cache RAM are available for Atari ST
>computers that use the 68000 processor. As the 68000 doesn't seem to
>have any provision for a cache, I've been idly wondering how the cache
>is implemented.

>Does anyone have an idea?

You don't need any provisions for a cache, i.e. none in particular.
All You need is a means to temporarily suspend operation of the CPU
while You process a cache miss.

Obviously a mechanism like this already exists, otherwise the CPU would
run a full speed and there is no need for a cache.
Usually, a special input to the CPU signals whether the CPU should
suspend operation (WAIT).
With MC68Ks it's done sort of the other way round: The CPU _will_
suspend operation _until_ a certain signal is asserted (DTACK).

The cache is placed between the CPU and main memory.

If the CPU accesses a location, the cache decides whether it holds this
information
If the information is not in the cache, the cache fetches the
information (and more, depending on the cache line size).
Now the information is in the cache and so the cache hands it to the CPU
and asserts DTACK.
-- 
| Josef Moellers		| c/o Siemens Nixdorf Informationssysteme AG  |
|  USA: mollers.pad@sni-usa.com	| Abt. STO-XS 113	   | Riemekestrasse   |
| !USA: mollers.pad@sni.de	| Phone: (+49) 5251 835124 | D-4790 Paderborn |
From: markz@ssc.com (Mark Zenier)
Newsgroups: sci.electronics
Subject: Re: ELECTRONICS LAB SOFTWARE
Date: 5 Nov 92 19:21:43 GMT
Organization: SSC, Inc.,  Seattle, WA
X-Newsreader: TIN [version 1.1 PL6]

Bartosz M. Blacha (bb2q+@andrew.cmu.edu) wrote:
: Most of us, to design and test circuits, use a breadboard, a multimeter,
: and sometimes an osciloscope.
: Some of us use software simulating those things.
: What commercial or pd software is available  for electronics lab simulation?

Addison-Wesley sells "The Student Edition of Microcap III".  This is a
MS-Dos graphic interface version of Spice II.  Limited to 30 nodes.
About $40 for the book and disks.

You'd want to run it on a system with a mouse (the keyboard interface
can best be described as mouse dung), and with a floating point chip.

Mark Zenier  markz@ssc.wa.com
From: ylo@osiris.kbfi.ee (Ylo Mets)
Newsgroups: sci.electronics
Subject: Sony CX857 chip modes?
Date: 9 Nov 1992 00:59:13 +0200
Organization: Institute of Chemical Physics and Biophysics, Estonia
NNTP-Posting-Host: osiris.kbfi.ee

Hello!
Does anybody have the description of the operating modes
of the AM stereo chip CX857 (SONY)? 
My interest is to use the quadrature detectors with the PLL
locked. Is this possible? I'd like to detect one sideband
of broadcast transmitters.
Thank you for your help.

Ylo Mets   (ylo@mango.mef.ki.se or ylo@osiris.kbfi.ee)

Karolinska Institute,
Dept. of Medical Biophysics,
Stockholm,
Sweden. 
Newsgroups: sci.electronics
From: knight@Virginia.EDU (John Knight)
Subject: Need some service info.
Organization: University of Virginia Computer Science Department
Date: Thu, 12 Nov 1992 17:44:50 GMT

Recently I lent my Sony Watchman to a friend and gave him the wrong
power supply.   The poor TV got 15 volts instead of 6 volts and the
polarity was reversed.   Apparently the TV was not protected against
this with a diode and so some serious damage was done.   The visible
effect is a surface-mounted device that is now mostly carbon.   It
would seem that the damage might be predictable and perhaps fixable
if one had a schematic.   I don't.   Does anybody out there have access
to service information such that they could help identify what might
have happened to this TV?   Thanks in advance.

-- 
___________________________________________________________
  John C. Knight
   Department of Computer Science
    University of Virginia
     Thornton Hall
      Charlottesville, VA 22903
Newsgroups: sci.electronics