HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.electronics

> On the same subject how much are these distribution boxes? And does
> anyone know of a supplier in the UK?

The price depends on the bandwidth needed and the number of outputs provided;
for example, we just got a couple of 200 MHz 1-to-4 amps for about $950.00
each.  NTSC or VGA-rate amps are *considerably* less (30 MHz bandwidth is
adequate for VGA).  If it's VGA you're interested in, try calling Extron
Electronics (800-633-9876) and ask for a price on their ADA 3-50 (1 in , 3 out,
50 MHz bandwidth).  They also have MUCH higher bandwidth models, as well as
those with more outputs.

(I have no connection with Extron other than having a brochure of theirs in
my video equipment file.)


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: gude@uniwa.uwa.edu.au (David J W Emrich)
Subject: Re: How do you program a EAROM
Keywords: EAROM.
Organization: University of Western Australia
Date: Wed, 26 Aug 1992 15:37:59 GMT

aaronb@suhana.analog.ingr.com (Aaron B.) writes:

>Does anybody know how to program the Mitsubishi Electrically Alterable ROM, namely
>the M58657P.

>I appreciate any help.

>Aaron B.

>aaronb@suhana.analog.ingr.com

As far as I remember, the EAROM is exactly similar to the same size
static RAM for connecting and programming  (if this is the 2k x 8 bits
EAROM, then the 6116 is the SRAM equivalent).  The only real difference
is the write time is rather longer than normal.  


[dav]    aka
David Emrich
gude@uniwa.uwa.edu.au
Newsgroups: sci.electronics
From: st1my@rosie.uh.edu (Stich, Christian E.)
Subject: Re: <<<<<FOR SALE  68030 33MHz. - $300  shipping paid by me
News-Software: VAX/VMS VNEWS 1.41    
Keywords: 68030
Organization: University of Houston
Date: Sun, 30 Aug 1992 18:04:00 GMT

In article <1992Aug30.170725.2604@cis.ohio-state.edu>, rubin@chocktaw.cis.ohio-state.edu (Daniel Rubin) writes...
>>>I have a 68030 at 33 MHz chip.  I need to sell it
>>>for $300.  I'll pay shipping.  Nothing is wrong
>>>with it, I just can't use it.  I know that the 
>>>sample price is around this figure, so it should be a steel
>>>at this price.
> 
>>Now here is an example of market forces at work.
>>Who uses the 68030?  A lot of closed-box-high-priced systems.   
>>And we're talking $300 just for the CPU.
> 
>I believe this is a terrible price for that chip.  I am sure that you can
>get it for a fraction of that cost...
> 
>If that is the going rate then what the heck is Motorola doing with that 
>chip that is so different from every other chip it makes... Geezzz...
> 
>								- Dan
>-- 
>  Daniel Joseph Rubin    |  "...A good football team for the alumni, parking
>rubin@cis.ohio-state.edu |  for the faculty and sex for the students."
>      GO        GO       |  - President E. Gordon Gee on the three things that
>    BENGALS  BUCKEYES    |  a great university president must provide.....

Software Hut (advertisement in Amiga World) sells the 68030 (with MMU) 50MHz
for $189. The combination 68030 (with MMU)/50MHz + 68882/50MHz (math co.) sells
for $269.
You can get (used, surplus, pulled from never used boards etc?) 68030/25's for
$65 from the Krueger Company.

P.S.:
Yesterday I took a look at CSN prices and I found "387-40 Math Coprocessor
CX38D8740 --- Cyrix ------ 1075.00   171.54"
		Suggested Retail^    ^CSN'S Price

Newsgroups: sci.electronics
From: gerry@bluemoon.rn.com (Gerard M. Foley)
Subject: Re: Can 220V 50 Hz Stuff be run on US 220V 60 HZ power  ?
Organization: Blue Moon BBS ((614) 868-998[024])
Date: Tue, 01 Sep 92 11:14:28 EDT

mcovingt@athena.cs.uga.edu (Michael A. Covington) writes:

> There's one BIG possible problem:  The grounding is done differently.
> 
> As I understand it, European 220V service is like American 120V service,
> in that one side of the line is at ground potential.  Right?
> 
> American 220V service is different.  Neither side of the line is grounded.
> What you have is a 240-volt center-tapped transformer with the center
> tap grounded.  120-volt service uses half of the transformer, with the
> center tap as "neutral."  240-volt service uses both sides of the transformer
> 
> It's overwhelmingly probable that the power supplies in your equipment
> will expect "neutral" to be grounded, and will fry something if it isn't.
> 
> The best way to deal with the Amstrad PC is to replace its power supply with
> an American one, or look inside for a 120v-vs-220v jumper or switch (many
> computers have them).  Ditto the low-powered audio equipment.  The huge
> audio power amplifier will be more difficult; can you replace its
> power transformer with one that has a 120v primary?
> 
> 
> -- 
> + Michael Covington - Artificial Intelligence Programs - U of Georgia - USA 
> + Unless otherwise noted, these are private opinions, not official statements
> + VOTE NO GEORGIA LOTTERY - we need not imitate mistakes of other states.

   I'll be surprised if your equipment depends on the line for 
a ground.  US 120 volt 60 hz stuff doesn't.  The frequency
difference will affect stuff that has synchronous motors, or
other things that take their frequency from the line.  Trans-
formers should do ok, since they will have more iron than a
60Hz one, and should benefit from the higher frequency. 
Good luck, and use the right size fuses.

gerry@bluemoon.rn whose home bbs has trouble getting the 
mail out sometimes, so it may go here instead.
Newsgroups: sci.electronics
From: dpalmer@mcnc.org (W. Dev Palmer)
Subject: Re: Where can I obtain EIA-232D specifications?
Keywords: EIA-232D (RS-232)
Organization: MCNC Center for Microelectronics, RTP, NC
Date: Tue, 1 Sep 1992 20:24:52 GMT

In article <1992Sep1.150258.7990@hot.com> Robert_La_Ferla@hot.com writes:
> Where can I obtain official and non-official specs on EIA-232D
> (formerly RS-232 for you old buzzards)?  I prefer an electronic copy if
> available.
> 
> Thanks,
> Robert
> 
> Robert La Ferla
> Hot Software

I don't know about electronic copies, but you can get the printed spec
(which is now called EIA/TIA-232-E) for $43.00 + shipping from:

Global Engineering Documents
2805 McGaw Avenue
Irvine, CA  92714
(800) 854-7179 ORDERS
(714) 261-1455
(714) 261-7892 FAX

We at MCNC bought several standards from them with no problems.

Just another satisfied customer,

Dev Palmer
dpalmer@mcnc.org
MCNC Room 212
P.O. Box 12889
RTP, NC  27709-2889
(919) 248-1837
(919) 248-1455 FAX

Newsgroups: sci.electronics,rec.ham-radio,rec.radio.amateur.misc,rec.radio.swap
From: wlw2286@ultb.isc.rit.edu (W.L. Lance)
Subject: Wanted: Source for K-Band (24.150 GHz) Transmitters
Followup-To: poster
Originator: wlw2286@ultb
Keywords: K-Band, Transmitters, Wanted
Organization: Rochester Institute of Technology
Date: Thu, 27 Aug 1992 02:12:47 GMT

The title basically says it all, I need some K-Band transmitters which
normally take the form of Gunn Diodes, however I am open to other
suggestions. I believe that M/A-Comm is a manufactuer but I am not
certain. If you have any suggestions on where to find these new, or
used (like from radar guns) I would really appreciate hearing from you.


Thanks,

Lance Ware

-- 
*******************************************************************************
Lance Ware			          	         Mac and IBM Reseller
Try here first:lware@wbst845e.xerox.com |  Then here:wlw2286@ultb.isc.rit.edu
                     Continually computing fractals . . .
Newsgroups: sci.electronics
From: robcruic@intacc.uucp (Robert Cruickshank)
Subject: Re: That Magic TV screen
Date: Wed, 26 Aug 1992 07:10:53 GMT
Organization: Inter/Access' Matrix BBS


The $49 plastic Fresnel lens reminds me of a similar scam that was popular in
the 1950s; for a reasonable price, they would sell you a filter that would
convert any Tv from black and white to colour. Of course, it was just a piece
of coloured plastic, but it did what it promised! I have heard that some of
these were divided into three stripes- the top was blue, for sky, the middle
was sort of flesh tone, and the bottom was green, for grass. If you were
watching the right show, it was perfect.

----rob
----
------------------------------------------------------------------------
Rob Cruickshank
robcruic@intacc.uucp
Inter/Access Artists' Center
Matrix BBS
Toronto, Canada
------------------------------------------------------------------------
Newsgroups: sci.electronics
From: frank@rover.uchicago.edu (Frank - Hardware Hacker - Borger)
Subject: Re: Data 12A6 wanted
News-Software: VAX/VMS VNEWS 1.41    
Reply-To: frank@rover.uchicago.edu
Organization: Joint Center for Radiation Therapy
Date: Mon, 31 Aug 1992 22:52:00 GMT

In article <715287220snx@black.demon.co.uk>, tchannon@black.demon.co.uk (Tim Channon) writes...
>>In article <MOTOYAMA.92Aug25101834@harlgw92.harl.hitachi> motoyama@harl.hitachi> (Hiroshi Motoyama) writes:
>>>Can anyone out there access to the data for the tube 12A6? I need the Eb-Ib 
>>>curves for that tube. The 12A6 is a GT, metal, beam pentode for audio power 
>>>amplification, developed possibly in early 40's by RCA. 
>>
>>I tried to e-mail this but it bounced.
>>

	One company I would try, they specialize in old tubes:

	United Page		Phone 201-279-7500
	481 Getty Avenue	Telex 642597 & 219026
	Paterson JH 07503

	Their last catalog, (albeit several years old,) still listed it as
	in stock.

   Frank R. Borger - Physicist    __       Internet:  Frank@rover.uchicago.edu
Michael Reese - Univ. of Chicago |___      Phone : 312-791-8075 fax : 567-7455
  Center for Radiation Therapy   | |_) _   
    2929 South Ellis Avenue        | \|_)  Dr. Livingstone I Presume
    Chicago, Illinois 60616           |_)  The full name of Dr Presume
From: hedges@pilot.njin.net (Douglas Hedges)
Newsgroups: sci.electronics
Subject: Sub'ing a 25Mhz M68030 for a 16Mhz
Date: 2 Sep 92 22:15:42 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

Naive question:  I've got the opportunity to get a 25 Mhz  M68030
and  M68882  for  a  reasonable  price.  Can I use them in my Mac
accelerator board (a TSI Gemini which allows for just  this  kind
of chip upgrade) but keeping the clock speed at 16 Mhz?  The rea-
son I don't want to change the clock speed is (a) probable incom-
patibility  with  my hard disk and floppy drive and (b) even if I
wanted to I could only boost the board to 20  Mhz  (according  to
the manual).

Thanks in advance for any advice on this.
Newsgroups: sci.electronics
From: harpe@netnews.louisville.edu (Mike Harpe)
Subject: Re: PADS software
Date: Tue, 1 Sep 1992 20:03:58 GMT
Organization: University of Louisville
Keywords: PADS schematics

If you call PADS Software, they will send you actual floppies at no cost.
I actually did this.  It's great software, I just wish I could afford the
full version....

On the same subject, does someone out there know what all the different 
ATTRIBUTE fields are?  I'd like a list of them if possible.

Mike Harpe
University of Louisville 
-- 
********************************************************************************
* "I will not barf unless i'm sick"                                            *
*                                   - A Chalkboard from "The Simpsons"         *
*                                                                              *
From: mdgoodma@CRDEC8.APGEA.ARMY.MIL (Mack Goodman Have Goals and Faith)
Newsgroups: sci.electronics
Subject: SOLDERING QUESTION -- CORROSION AND FLUX ----
Date: 1 Sep 92 14:03:04 GMT


Need some soldering advice....

I have a situation here where we are soldering a solid copper wire
into a nickel-plated cup-pin.  The pin cup is a blind hole, that is
no outlet .
 The way we are doing it is to fill the pin cup with the correct amount of
solder paste then install the copper wire and pass this under a 
propane flame for a specified amount of time ( depends on solder, etc)

This part goes into a microphone assembly and must have continuity, ofcourse.

We are using a 60/40 solder with a AC flux, however the AC flux is
organic ( non rosin ) halide.

 The question is corrosion.  In the past, everything ( literature ) has
said do not use AC flux in a electronic application due to the great
potential for corrosion, however, it appears now there are some guides
saying it's ok to use the "organic" AC fluxes.  

WE are having a problem with these connections coming loose at the
solder joint.  

IS corrosion to blame?

How can we determine it?  It seems to get worse over time but that is
very subjective right now because we can't say if the joint was done 
properly a year ago or not.  IS THERE A WAY TO CHECK THE JOINT FOR
CORROSION??

Thanks for any help you can provide.

Mack
US ARMY
ABERDEEN PROVING GROUND.
mdgoodma@crdec8.apgea.army.mil
.


         

Newsgroups: sci.electronics,misc.wanted
From: sstrong@kean.ucs.mun.ca
Subject: Project Ideas Anyone? (Repost)
Organization: Memorial University. St.John's Nfld, Canada
Date: Thu, 3 Sep 1992 16:26:01 GMT

The below is a repost of a letter I posted about 5-6 days ago.
The response was good.  Several good ideas came out of it.  I am 
reposting to see if I can get a few more.  Thanks to those who 
responded last time.
-----------------------

Good day.

I am an Electrical Engineering student about to enter my last academic term in
university.  This term we can choose all our courses (for specialization)
except for one.  This is why I am writing this letter.

The mandatory course is a project course in which we pick a project and apply
 what we have learned for the last five years.  The projects vary in
complexity and scope.  Generally there are two types of projects: a pure
research paper in which something new etc. is discussed, and one in which a 
prototype of the project is built and tested.  Examples of some projects done 
before are neural network theory, design and building of an 8088 stand-alone 
computer, remote control using MF and HF frequencies, etc.

My problem is that I can't come up with a project.  Can anyone out there 
suggest something?  I am interested in communications, and electronics 
(no power engineering).  I can program in C and assembler (80x86).  I am 
not sure what I want to do, ie. just a report or to come up with a product 
and build it.  Note, the projects are usually original and fill some gap in 
technology. 

Here are some of the things that have crossed my mind:
-Sound processing in real time (ie. effects) (digital or analog).
-Voice synthesis add on card for a single board computer (text to speech)
-Some caller id type of application

I would like to do something with telephone interfacing/computer ... but 
again, everything I come up with has either been done before, too simple, 
too complex.

Any help / ideas received would be greatly appreciated.
Sorry for the long letter.

Steve.

-- 
sstrong@kean.ucs.mun.ca
Electrical Engineering, Memorial University of Newfoundland
From: MATGBB@LURE.LATROBE.EDU.AU (BYRNES,Graham)
Newsgroups: sci.electronics
Subject: Potting toroidal transformers
Date: 26 Aug 92 04:58:29 GMT
Organization: La Trobe University
X-News-Reader: VMS NEWS 1.22

I have a couple of 300VA toroids in an audio power amp which generate
a fair bit of mechanical hum. Since their rating is very conservative
and they don't run too hot, I thought potting them might fix the hum.

Can anyone suggest a readily available, easy to use potting compound?
I've tried the obvious things like mounting them on foam of different 
types and surrounding them with sound deadening, but 50-100 Hz is pretty
long wave-length to try killing that way...
Thanks,
Graham B
Xref: sparky sci.electronics:15135 rec.video:10833
From: schuster@panix.com (Michael Schuster)
Newsgroups: sci.electronics,rec.video
Subject: Re: Macrovision
Date: 2 Sep 92 13:34:50 GMT
Organization: PANIX Public Access Unix & Internet, NYC

In article <1992Sep2.041037.347@u.washington.edu> bunky@milton.u.washington.edu (Mike) writes:
>
>     
>     Does anyone know how macrovision allows a video tape to be watched on
>     a television but not on a vcr?  I recently looked at a copy protected
>     videotape and it appeared that there were 4 white bars on the last
>     8 or 9 lines in the vertical interval that periodicly (every 15 or 20
>     sec) faded in and out.  It looks like it's changing the average level
>     of the picture to mess up the vcr.  If that's the case could this be
>     fixed with a clamping circuit or some kind of dc restorer circuit?
>     If anyone knows the technical details of how the copy protection scheme
>     works I would be very interested. 

Macrovision inserts very bright pulses in the vertical blank interval.
Most VCR's use this when setting AGC video level, and get fooled into
thinking the video levle is much brighter than the picture area really
is. Most TV's don't. Dunno why.


-- 
_______________________________Mike Schuster________________________________
NY Pub. Access UNIX/Internet: schuster@panix.com | 70346.1745@CompuServe.COM
The Portal (R) System: schuster@cup.portal.com   | MCI Mail,GEnie: MSCHUSTER
Newsgroups: sci.electronics
From: dvsg0223@uxa.cso.uiuc.edu (David Salamon)
Subject: Re: Isolated Connector for IEEE Bus?
Organization: University of Illinois at Urbana
Date: Thu, 27 Aug 1992 17:14:32 GMT
Keywords: Advices sought

fang@phy.duke.edu (Fang Zhong) writes:


>	I work on small signals of less than micro volts.  I use a computer
>to control my experiment and take data via IEEE bus.  One of the equipments
>in my setup is a digial ratio transformer made my Eaton Advanced Electronics.
>This equipment was designed so poorly that a ten-times larger noise was
>added to my circuit if I added it to my IEEE bus.  
>	I would like to find a way to add the digital ratiotran to the IEEE
>while the noise is isolated only to the ratiotran.

>	Will an optical isolation work in my case?

Yes, but it is a pain to implement all those optoisolators.

Before you try something like that, note that your problems are most likely
due to a ground loop.  The IEEE bus has two ground lines, called "shield"
and "digital ground".  They shouldn't be hooked together anywhere, and your
instrument should not be using "shield" ground as its true ground.  Digital
ground should be the only ground that is connected between machines.  The
shield should be left unconnected unless you are sure all instruments have
their cases hooked to the power line ground, in which case it is safe to hook
shield to the instrument cases.

Good luck!

David

--------------------------------------------------------------
David Salamon                Physics Graduate Student (Slave)
d-salamon@uiuc.edu           University of Illinois
--------------------------------------------------------------

Newsgroups: sci.electronics
From: magore@icr2.uwaterloo.ca (Mike Gore)
Subject: Re: Resist Pens in Plotters
Organization: University of Waterloo
Date: Thu, 3 Sep 1992 03:23:36 GMT

In article <78433@ut-emx.uucp> david@moe.ece.utexas.edu 
	(david lee) writes:
>Netfolks:
>  I have been using permanent markers in my plotter, writing directly
>onto copper pc boards, trying to circumvent the photo-lithographic steps.

	-For pens I use: Staedtler Lumocolor 313 Permanent pens.
	-For etchant I use: Ammonium Persulphate   (very clean to 
	work with and works well with the pens listed here)
	-For Tin plate I use solution from GC electronics. cat# 22-228-A
	(works great!)
	-For very fine detail I buy Micro Pigma (non water-proof) remove
	the ink filler and replace with one from a steadtler permanant
	(see above). Run the pin dry after removing the filler and before
	adding the filler from the steadtler. You have to cut the very back
	off the steadtler to remove it. Both pens use the same size fillers,
	just flip them around and punch them back into the point.
	The Micro Pigma pin come apart without damage - these pens come in 
	VERY small sizes, the 005 pens tend to clog if you leave the 
	steadtler filler in them for a long time so leave the final
	swap to just before a plot. I have been able to make surface mount 
	at .025 spacing just fine, or for example do traces between a pad 
	without problems!

	- Suggestion for those trying this - do the plot at least twice.

	- Use 0000 grade steel wool and clean the board to a polish
	just moments before the plot - wipe clean with a soft clean
	rag ( *** don't omit these steps *** )

	- Heat the Ammonium persulphate to about 60C, the easy way
	is to mix only what you need just before using - ex: I often
	use 1/4 cup AP and 3/4 cup of hot water (ratio varies, so
	check your labels) - Float the plastic tray in hot water for 
	the etch. 
	* Read the safety instructions, where gloves, use good ventilation *

	- After etch use 0000 grade steal wool and clean the board to a 
	polish just moments before the plating process but wash with clean 
	water to clean.  ( *** don't omit these steps *** ) Using a solvent to
	remove the ink will not remove the oxide that inhibits a good plate 
	so even if you do use solvent use the steel wool _after_ the board
	dries - ex: don't risk the chance of a spark - keep your solvents
	in a safe place, etc...

	(I have made a few dozen boards in this way, so far the results 
	are very very good )

	Good Luck!
	

# Mike Gore, Technical Support, Institute for Computer Research
# Internet: magore@watserv1.waterloo.edu   or   magore@watserv1.uwaterloo.ca
# UUCP:     uunet!math!watserv1!magore
# These ideas/concepts do *not* imply views held by the University of Waterloo.
From: thomasn@tekig5.pen.tek.com (Thomas M Nathe)
Newsgroups: sci.electronics
Subject: Re: coating materials for antennas
Keywords: antennas materials
Date: 30 Aug 92 06:22:06 GMT
Article-I.D.: tekig7.6790
Organization: Tektronix, Inc., Beaverton,  OR.

I've used hot dip anodizing and zinc oxide paint for aluminum with moderate
success with the zinc oxide.  The hot dip works well for salt spray and other
hostile enviroments, don't know the cost though. The zinc oxide paint was used
as a primer on the helocopters I worked on while doing time in the army.
From: mansha@ham-and-cheese.cs.wisc.edu (Rajesh Mansharamani)
Newsgroups: sci.electronics
Subject: ECA and OCR programs
Date: 30 Aug 92 18:51:34 GMT
Distribution: usa
Organization: University of Wisconsin, Madison -- Computer Sciences Dept.

I am looking for source code (preferably in C) for the following applications:

1. Electronic Circuit Analysis (ECA) Program
2. Optical Character Recognition (OCR) Program

If any one knows where to obtain source code in C or in any other language
please let me know. (mansha@cs.wisc.edu)

Thanks a lot,

Rajesh K. Mansharamani
Computer Sciences Department
University of Wisconsin-Madison
mansha@cs.wisc.edu
Newsgroups: sci.electronics
From: tmkk@uiuc.edu (Khan)
Subject: Re: Need encoding scheme for TV remote infrared controller
Organization: University of Illinois at Urbana
Date: Wed, 2 Sep 1992 13:42:19 GMT


In article <1992Sep2.003540.24065@aio.jsc.nasa.gov> mancus@roger.jsc.nasa.gov (Keith Mancus) writes:
>  We're in the process of building a small robot, and we'd like it
>to respond to a TV remote control.  Can anyone tell us:
>
>  (1) Is there a standard carrier frequency?

There isn't a standard ANYTHING. Many remotes operate on 40kHz IR carrier
frequencies, but it's far from being a standard.

>The IR sensor we're using detects 40 MHz.

Unless that was a typo and you really meant 40kHz, your sensor is
probably useless for picking up IR transmissions from TV remotes. ;-)

>  (2) Is the encoding scheme standardized?

Not by a long shot.

>  (3) Are there any other pitfalls we should know about?

Borrow/obtain an oscilloscope, hook the output of your IR receiver to
the scope's inputs, and power everything up. Then aim the remote you
intend to use at the IR receiver module, and observe the oscilloscope
screen. After playing around a bit, you should be able to determine the
encoding scheme used, or at the very least which patterns go with which
buttons, and programn your robot to respond accordingly. If the screen
remains blank, either your remote is broken or it's not using a carrier
frequency compatible with your IR receiver.

Newsgroups: sci.electronics