HDTenEightyP/NetNews huggingface dataset:
From: jk@panix.com (Jim Kalb)
Subject: Test
Organization: Institute for the Human Sciences
Distribution: nyc
Date: Wed, 6 Jan 1993 10:32:38 GMT


Just a test.
-- 
Jim Kalb (jk@panix.com)
"We are, I know not how, double in ourselves, so that what we believe we
disbelieve, and cannot rid ourselves of what we condemn."  (Montaigne)
Newsgroups: sci.electronics
From: gantzm@gantz.bowlgreen.oh.us (Michael L. Gantz)
Subject: Why etch? Is copper deposition possible?
Organization: GantzNet - Bowling Green, Ohio.
Date: Sun, 10 Jan 1993 21:27:46 GMT

I have been reading all the articles concerning the etching of circuit
boards, something I have a great need to do.  And they all assume that
one would be etching the copper off of the board.  Is it possible for
the home hobbyist to devise a system to deposit copper onto blank
boards?

I would picture a system where the hobbyist would pre-drill a blank
board, then treat it with a photo-sensitive material.  After the
photo-sensitive material has been applied both sides of the board
would be exposed.  The exposed images would then be developed most
likely in a chemical process.

After the circuit images have been developed the board would then be
treated either chemically or electrically to bond copper to the traces
developed on the board.  The might solve the problem of plated through
holes as they might get coated also.

I remember years ago someone describing a system similiar to this.
But I do not remeber if it dealt with circuit boards.  It may very
well have been used on something totally different not even related to
electronics.

If anyone knows of a process similiar to this I would sure like to
hear about it.  I picture the process would be much more precise then
etching, one would not have to worry about the etchant cutting under
the traces, etc.

I'm trying to do digital circuits and am getting ready to purchase
some TEC-200 paper to experiment with.  But I don't think it's gonna
be easy to do double sided boards or keep the traces as small as I
need them.

Thanks for any info.

-- 
------------------------------------------------------------------------------
Michael L. Gantz        ! gantzm@gantz.bowlgreen.oh.us ! I know JCL and also
213 Napoleon Rd.        ! osu-cis!bgsuvax!gantz!gantzm ! use Unix.  No wonder
Bowling Green, Oh 43402 ! (419) 353-5029               ! I have problems.
From: rosa@sci.ccny.cuny.edu (Cheryl-Ann De La Rosa)
Subject: info. on wireless mic needed 
Reply-To: rosa@sci.ccny.cuny.edu (Cheryl-Ann De La Rosa)
Organization: City College of New York - Science Computing Facility
Date: Mon, 11 Jan 1993 23:45:23 GMT


Hi, I am trying to build a wireless mic (IR or RF media).
Is there any information available on detailed implementaion
(maybe a similar project in INK)?
Thanks in advance.
From: miller@hmsp04.wg3.waii.com (Griff Miller X7114)
Newsgroups: sci.electronics
Subject: STK-3076
Date: 4 Jan 93 16:44:27 GMT
Organization: Western Geo. - Div of Western Atlas Intn'l Inc., Houston, TX
Originator: miller@hmsp04.wg3.waii.com

Hi. I'm looking for this chip. It's the driver IC from a Yamaha R900
receiver, circa 1983 or so. Any suggestions on where I might could
get it? I've exhausted all my local sources.

Please email to below address. Thanks!
--
Griff Miller > miller@monarch.wg3.waii.com < use this for email.

          *** My opinions are mine, not Western's. ***

   "The fear of the Lord is the beginning of knowledge, but 
    fools despise wisdom and discipline."   - Proverbs 1:7
From: miller@hmsp04.wg3.waii.com (Griff Miller X7114)
Newsgroups: sci.electronics
Subject: O2 Sensors - Automotive
Date: 12 Jan 93 15:40:33 GMT
Distribution: usa
Organization: Western Geo. - Div of Western Atlas Intn'l Inc., Houston, TX
Originator: miller@hmsp04.wg3.waii.com

Can anyone tell me how these work? Also, would excessive heat damage one
(as in a car running very lean and getting the exhaust pipe cherry red)?
Naturally, I'm not talking about obvious damage like melting.

Yeah, I know - I hate to think what shape the exhaust valves are in, too.
--
Griff Miller > miller@monarch.wg3.waii.com < use this for email.

          *** My opinions are mine, not Western's. ***

   "The fear of the Lord is the beginning of knowledge, but 
    fools despise wisdom and discipline."   - Proverbs 1:7 
Newsgroups: sci.electronics
From: wizard@athena.mit.edu (Tony C. Le)
Subject: In search of DRAM
Keywords: Memory
Organization: Massachusetts Institute of Technology
Date: Tue, 12 Jan 1993 23:33:12 GMT

I am looking for 20-pin DIP 4Mbit (1Mx4) 80ns DRAMs.  I don't know whether
they're rare or whether I'm looking in the wrong places, but only one catalog
I've looked in lists it and that supplier doesn't even have it in stock.

Does anyone know of a supplier that has this chip with 90%+ certainty?

Thanks,

Tony Le
wizard@athena.mit.edu

O-----------------------------------------------------------------------------O
|                                                                             |
| "I will love you," she told me, "until the mountain crumbles into the sea." |
|                                                                             |
| The next day, Krakatoa erupted.                                             |
|                                                                             |
O-----------------------------------------------------------------------------O
Newsgroups: sci.electronics
From: fhn@oclc.org (James Feehan)
Subject: Battery Gell cell or Lead acid?
Organization: OCLC, Dublin Ohio.
X-Newsreader: Tin 1.1 PL3
Date: Tue, 5 Jan 1993 14:56:18 GMT

I am in the process of making a rechargeable bicycle light and wanted to know 
which type of battery would be better Gell Cell or a Lead Acid. What are the 
pros and cons of each? I have heard that it's not a good idea to fully 
discharge a Lead Acid is this true?  Also how would the cold effect each of 
these types of batteries?


Thanks in advance.
Newsgroups: sci.electronics
From: msd8065@ultb.isc.rit.edu (M.S. Diamond)
Subject: Self-Timed Controller Technology
Originator: msd8065@ultb
Reply-To: msd8065@ultb.rit.edu ()
Organization: Rochester Institute of Technology
Date: Fri, 8 Jan 1993 17:52:44 GMT

HI I am looking for any information about Self-Timed Controler technology.

Please if you have any tech papers, or your own info on this subject can you
please send me the info.

thanks

THE MITCH MAN

mitch@blaise.cif.rochester.edu
From: gkwan@balboa.eng.uci.edu (Greg Kwan)
Subject: Re: Basic bench equipment query
Newsgroups: sci.electronics
Organization: University of California, Irvine
Date: 4 Jan 93 06:10:55 GMT

In article <1992Dec27.030536.1024@cmkrnl.com> jeh@cmkrnl.com writes:
>In article <BzwHA7.6y@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer)
> writes:
>> In article <2B3582F9.18867@news.service.uci.edu> gkwan@balboa.eng.uci.edu
>> (Greg Kwan) writes:
>>>1. Get the best DMM you can--it's the most important test instrument.
>>>I have a Fluke 77 and have been very happy with it, but would probably
>>>go for an 87 or 79 now. You'll probably use the freq. counter since
>>>it's a pain to fire up the scope just to measure a frequency...
>> 
>> Note, though, that any frequency measurement using something other than
>> a scope relies heavily on assumptions about waveform.  When I first got
>> my current scope, I hoked up a little audio-frequency square-wave generator
>> with a 555 as an independent test signal.  I was a bit surprised to find
>> that my frequency counter read twice what the scope showed me.  
>> [...] There is no substitute for seeing exactly what's happening.
>
>I'll second this, and LOUDLY, too.  

I guess I was remembering my Hitachi V-1150 w/ its built-in frequency
counter and ``interpolated'' to the Fluke DMMs. Not quite the same, I
admit. I just hate counting hash marks or moving cursors (I'm REALLY
lazy :-). Definitely fire up the scope if there's any doubt.

>It appalls me to see frequency counters (and instruments like DMMs that include
>counters) that have no trigger level control, no input coupling selector (AC or
>DC), no edge selector (rising or falling).  You wouldn't buy a triggered-sweep
>scope without such controls; of what possible use is a counter without them? 

(I'm talking about scopes here.)
Even better, why not show the trigger level? If I'm remembering right,
the higher end Tek's (e.g. 2445, 2465, ...) show the trigger level, al-
though it's just a number (the voltage). The new Fluke 97 actually has
the trigger voltage superimposed (i.e. a line) on the signal. It doesn't
seem too difficult to add that feature and yet would help quite a bit.

One reason I don't use auto-setup buttons on scopes is that the scope
always has a different idea of what I want to see; they'll trigger on
the noise riding on a signal or something equally bizarre and leave
the volts and time scales at extremes.

>Anyone who trusts one of these counters without checking the waveform on a
>scope, if only to get in the right ballpark, is being as foolish as the person
>who thinks that a digital watch must be accurate simply because it isn't
>analog.  

I don't agree 100% here. I think counters are useful to get an idea of
what is going on in well behaved circuits. E.g. I'd use it to check AC
line frequency (60Hz [USA] is not fun to measure with analog scopes--
too much flicker) or to measure the frequency out of a signal generator
to make sure you're getting what you expect. Of course, I don't accept
as gospel every counter reading--just as I don't believe every volt
meter reading.

IMHO
greg

gkwan@balboa.eng.uci.edu
From: sasrer@unx.sas.com (Rodney Radford)
Newsgroups: sci.electronics
Subject: Caller-ID chip group purchase....?
Date: 5 Jan 93 19:05:42 GMT
Organization: SAS Institute Inc.

A few weeks ago, Mark Keisling, posted to sci.electronics about some caller-id
chips forsale. Unfortunately, he sold all of his chips before I saw the post.
Then someone else (name forgotten) was getting together another group order, 
but I have not heard anything about the status of this new order.

So, is anyone currently working on a group purchase? If so, I am interested
in purchasing some (about 4) of the SC11211CN chips.

Also, does anyone know the name (and email address) of the 'other' group
purchase order - thanx.
--
---
Rodney Radford          || Computer Graphics/Imaging
sasrer@unx.sas.com      || SAS Institute, Inc.
(919) 677-8000 x7703    || Cary, NC  27513
From: kludge@grissom.larc.nasa.gov (Scott Dorsey)
Newsgroups: sci.electronics
Subject: Re: HDTV Question
Date: 9 Jan 1993 20:12:59 GMT
Organization: NASA Langley Research Center and Reptile Farm
NNTP-Posting-Host: grissom.larc.nasa.gov

In article <1993Jan9.192008.1528@mtu.edu> cmwolf@mtu.edu (christopher m. wolf) writes:
>kludge@grissom.larc.nasa.gov (Scott Dorsey) writes:
>>In article <1993Jan8.055618.24902@mtu.edu> cmwolf@mtu.edu (christopher m. wolf) writes:
>>>If HDTV will be digital, what will be the number of available colors for
>>>display?
>>
>>Depends on the format that is decided on.
>>
>>>Instead of the "infinite" we have with NTSC now, this will have to be reduced,
>>>depending on the digitalization, but what are we talking about numbers-wise?
>>
>>Infinite colors?  With NTSC?  You have to be joking... the linearity of the
>>chrominance signal is terrible on any NTSC systems.  The number of discrete,
>>distinguisable colors is far fewer than those that can be seen by the eye,
>>or even recorded on a good film.
>>--scott
>
>I looked at it as an analog signal have an infinite number of divisions, every
>one just slightly different.  I wasn't commenting about how it IS being
>used, but rather how it COULD.

Well, first of all an analogue signal doesn't really have an infinite number
of divisions if it's represented as a voltage or a current, because they are
both quantized.  You can't get any unit of charge less than an electron.  It's
just that the number of divisions is extremely large.

In addition, the linearity of the encoding comes into play here.  With the 
NTSC encoding scheme, not very many colors are possible.  But, the number of
colors is going to be a function of the dynamic range of the system and is
therefore dependant on the bandwidth you want to allocate.

In a digital system, it's the same way.  If you allocate more bandwidth, you
can get more of a color range, or you can get more resolution.  The nifty
thing about digital systems is that it permits much easier allocation of
bandwidth (even on the fly!), and although digital encoding generally uses
more bandwidth than the theoretical minimum of an analogue system, because
the baseband signal can be better packed into the available space, it can
be more efficient.
--scott

Disclaimer: NTSC is one of the least efficient color encoding schemes around.
Plus the number of colors is limited, the grey scale isn't very long, and
the resolution is poor.  As far as I can tell, the programming quality isn't
so hot either.

allocate.
From: paula@nlbbs.UUCP (Paula Stockholm)
Newsgroups: sci.electronics
Subject: How to prevent feedback in a intercom ckt ???
Date: Wed, 06 Jan 93 04:23:07 GMT
Reply-To: paula@nlbbs.uucp
Distribution: world
Organization: The Electronics Workbench - Cumberland Maine

        Look in a telecommunications IC book for a hybrid circuit. These
        are basic telephone circuits which convert 2-wire (the phone or
        Intercom line) to 4-wire (the headset and the mic).
Newsgroups: sci.electronics,misc.consumers.house
From: sasbge@unx.sas.com (Gantt Edmiston)
Subject: SmartHouse - anybody have one?
Date: Sun, 10 Jan 1993 04:39:14 GMT
Organization: SAS Institute Inc.
Keywords: SmartHouse,X10,automation

I'm in the early planning stages of a new house and I am considering
having the house wired with Home Automation (HA) in mind.  One of the 
latest things in HA is SmartHouse technology.  I just received a book
by H. Brooke Stauffer and Ray C. Mullin, titled _Smart House Wiring_.

It is quite complete and details the concepts.  What I really want
to know, is there anyone out there who has a SmartHouse home or have
knowledge of costs associated with it?  I know that X10 stuff has
been around for quite some time.  Since I have the option of using
SmartHouse, I thought I would get any feedback from the net.

Based on what I have seen so far, it looks quite expensive.  One of the
big problems right now is the limited amount of SmartHouse products
available.  This drives the price very high.  I could wire
the house as Smart-Remi and wait for the components to drop in price.
Of course this depends on whether or not the market accepts this
technology and more products and vendors appear.

You may respond via Email or post here.  Thanks.


--
-----------------------------------------------------------------------------
Gantt Edmiston - SysAdmin     o |If you always do  what you've always done,
SAS Institute Inc.          <(  |you'll always get what you've always got.
Quality Assurance - V416     [\.+--------------------------------------------
Cary NC 27513 919-677-8000 x6091|            sasbge@unx.sas.com
-----------------------------------------------------------------------------
Newsgroups: sci.electronics
From: cthomas@athena.mit.edu (Michael T Ford)
Subject: Re: Telephone "in use" light
Organization: Massachusetts Institute of Technology
Date: Sun, 10 Jan 1993 06:38:30 GMT

In article <1io3i5INNnat@MINERVA.CIS.YALE.EDU> shaffer-wendy@MINERVA.CIS.YALE.EDU (Wendy Shaffer) writes:
>Regarding the telephone in use light, the Feb issue of Popular Electronics has
>a schematic.  Unfortunately, I'm completely unfamiliar with how the telephone lines
>work.
>The schematic shows two wires going to the telephone line.  One of them is marked with the word "Tip" and a + sign.  The other is marked with "Ring" and 
>a minus sign.  Could somebody fill me in on what these mean and how to identify
>one from the other.  Thanks

Telephones nowadays run off of only two conductors.  The red and green
wires are the most common.  And if I remember correctly, red is tip, and
green is ring.  (Someone correct me if this is backwards.)
Don't worry about hooking the circuit up backwards; the worst that will
happen, if anything, is that it won't work.

Good luck,
Mike WZ0C
From: flux@sys6626.bison.mb.ca (John Kamchen)
Newsgroups: sci.electronics
Subject: Still at it?
Date: Tue, 12 Jan 93 02:26:39 CST
Organization: System 6626 BBS, Winnipeg Manitoba Canada

Ahh..  this is a simple one.. Run the 7Mhz clock through a delay gate
(yikes.. maybe a few!), and then XOR the output from this delayand the 
original 7Mhz clock.  Fiddle with the delay range (you need about 55ns of 
delay time).  The output won't be a perfect 50/50 duty cycle, but it 
should be close.
Ya know..  you could always use on of them CDAC clocks (they run at 
14mhz) .. this IS for a new 14mhz hack, right?
How about an '030 hack?
-John
SSE BBS (204)589-1078 v32bis AmiTronics- MEGS of 'em
Newsgroups: sci.electronics,rec.audio.pro
From: tome@cs.umr.edu (Tom Erb)
Subject: Question: What to lubricate plastic pots with?
Date: Thu, 7 Jan 1993 19:34:39 GMT
Distribution: usa
Organization: University of Missouri - Rolla
Originator: tome@mcs213h.cs.umr.edu

I know, it's really a clause in the subject line, but I think it gets the
point across. 

I maintain a small FM radio station, and we have many conductive plastic 
potentiometers in our mixing boards. These things are fairly expensive.
They get noisy after a while, but if I take them apart and clean/lubricate
them, they never feel nearly as smooth as they did before. I've tried using
"Big Bath" from ECG, and some other chemical from ECG that said "Cleans and
lubricates potentiometers." I haven't taken apart any of the expensive slide
pots yet as they haven't caused any problems, but the rotary pots have.

Reply by posting or email, I'll post a summary of any emailed responses.

Thanks,

Tom Erb (tome@cs.umr.edu)
Chief Engineer: KMNR 89.7fm, Rolla, MO
around the place. 
Newsgroups: sci.electronics
From: u009@csx.cciw.ca (G. Stewart Beal)
Subject: Wanted: FTP site for IR remote control info
Organization: Canada Centre for Inland Waters
Distribution: na
Date: Wed, 6 Jan 1993 19:18:30 GMT
Summary: IR receiver/transmitter info wanted 
Keywords: Infrared remote control 

Some months ago someone posted the name of an FTP site where (apparently)
lots of information on design, building and use of IR devices in remote
control etc. applications was posted. It was info for some undergraduate
programme, I believe. Now that I require the information, I can't find the
FTP address I squirrelled away somewhere. If you know the site, I'd be
happy to get Email from you with the name.
Thanks in advance for your help.

 
Regards, Stu Beal, VE3MWM, U009@CSX.CCIW.CA,
National Water Research Institute, Burlington, Ontario, Canada.
From: chris.guli@factory.com (Chris Guli) 
Newsgroups: sci.electronics
Subject: PC BOARD ETCHING QUESTIO
Date: 5 Jan 93 16:34:00 GMT
Distribution: world
Organization: Invention Factory's BBS - New York City, NY - 212-274-8298v.32bis
Reply-To: chris.guli@factory.com (Chris Guli) 

TO: news@synapse.bms.com

Rich,

-> 1) Can I realistically make double sided PC boards?  My first board
-> will be single-sided, but I would like to try more complicated boards
-> later.
->
-> 2) What are the best photo-resist methods and chemicals?  I have seen
-> ads for both positive and negative photo resist.  Is there any
-> difference other than
-> the need for negative vs. positive artwork?

Double-sided boards (homebrew) can be a pain since it is almost
impossible to produce plated through holes (PTH). There is a vendor
which has a PTH kit, but it is expensive and time-consuming. Also,
alignment of the component and solder sides is critical. With patience,
a non-PTH DS board is feasible, however.

I've heard (on this newsgroup and in Don Lancaster's column in Nuts&
Volts) that negative photo resist works much better - more forgiving of
exposure variables and it is more stable in the development phase.

I'm moderately experienced with home fabrication of PCBs, but the more I
look at it, the more attractive a PCB house looks. I've come across a
Canadian vendor (AP circuits) that will produce two 4x5" board, DS/PTH,
for about $79 total. The per board price goes down as total area
increases. You have to consider your time, so outsourcing may be worth
it.

My main problem with home fabrication is getting the negative - does
anyone have a fast/cheap way of getting a high quality negative on film
? (SMT features)

Chris
From: wellison@kuhub.cc.ukans.edu
Newsgroups: sci.electronics
Subject: Re: Ancient Scope Info Required
Date: 6 Jan 93 08:22:11 CST
Organization: University of Kansas Academic Computing Services

I'll zip out a snail mail to you with the manuals and you can re-imburse me
after the manuals arrive. I only have one copy of each, but I think I can get
extras. If not, I'll xerox mine (three manuals or about 180 pages ! ! !). Give
me about a week.....

-=-= Wes =-=-
From: whit@carson.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: RF noise generator circuit wanted
Date: 7 Jan 1993 08:04:24 GMT
Organization: University of Washington, Seattle
NNTP-Posting-Host: carson.u.washington.edu

In article <C0EnDp.FEB@newsflash.concordia.ca> davec@ECE.Concordia.CA (Dave Chu) writes:
>
>I'm looking for a simple circuit that will generate RF noise from
>25-75Mhz.  I was thinking of using a series of 2N222's as class C amps,
>and tune each of the amp at 10 or 15Mhz apart to cover the 25-75Mhz
>range.  I am planning to use this circuit to jam RC or any types of
>remote controlled cars. 

	Firstly, jamming is illegal.  Don't get caught.

	Secondly, you want to overwhelm a transmitter that has perhaps
100 mW of output power, all in a narrow band (10 kHz or so); to do
so for the whole 50 MHz you describe, all at once, will require
about 500W of transmitter... doing this with 2N2222's is gonna
be lots of not much fun.  

	Doing it for one frequency band at a time, IS practical; check
out _The ARRL Handbook for the Radio Amateur_, any of its dozens
of editions, for grid dip meter plans.  A grid dip meter is a
unmodulated test oscillator, which will easily do the kind of
task you describe.

	And, by reading out the calibrated scale, you can 
know roughly what the RC signal frequency is... it's a 
genuine, legitimate reason to have the gizmo.  In case
anyone asks.

Newsgroups: sci.electronics
From: thomasd@tps.COM (Thomas W. Day)
Subject: Re: Tube Amplifier Design Questions
Organization: TPS
Date: Tue, 12 Jan 1993 18:37:43 GMT

In article <5170257@hplsla.hp.com> tomb@hplsla.hp.com (Tom Bruhns) writes:
>A pair of the 4CX250's
>would give you 500 watts of plate dissipation and if you can't get
>200 watts of audio out of that, even class A, you're probably doing
>something wrong!  

Really?  It has been a while since I've messed with tube designs and even 
longer since I played with tubes and Class A, but I don't remember getting 
better than 20% efficiency out of that kind of design.  I'd love to talk (
write, E-Mail, whatever) with you about your design tricks.

Tom Day
Newsgroups: sci.electronics