HDTenEightyP/NetNews huggingface dataset:
From: strong@tc.fluke.COM (Norm Strong)
Newsgroups: sci.electronics
Subject: Re: Hex-FET's and infinite impedance
Date: 15 Apr 92 15:28:41 GMT
Article-I.D.: tc.1992Apr15.152841.1286
Organization: John Fluke Mfg. Co., Inc., Everett, WA

In article <4764@umriscc.isc.umr.edu> dshipley@cs.umr.edu (Dan Shipley) writes:
}Hi, all!
}
}I just got a car audio amplifier from Coustic.  In the manual, it says it  
}uses hex-FET's and NOT to turn the amplifier on if there is no load on the  
}outputs.
}
}I don't know anything about hex-FET's, but it seems unusual that an infinite  
}output impedance would cause damage to a transistor.  However, I'm always  
}learning just how much I don't know, so if someone could enlighten me in the  
}ways of hex-FET's or why this might cause damage, I'd be grateful.

I have to guess:  Since it's a car amplifier, voltage swing is at a
premium.  It therefore probably has a common emitter output stage.  Such
a configuaration has a relatively high unloaded output impedance.  If
the negative feedback loop is of "questionable" stability, the extra
gain, unloaded, could throw the amplifier into instability.  In other
words it might oscillate like crazy at high frequency.  Of course,
without a load, that shouldn't hurt the amplifier.  But it certainly is
embarrassing.  :-)
-- 

Norm Strong  (strong@tc.fluke.com)
2528 31st S.   Seattle WA 98144   USA
Newsgroups: sci.electronics
From: cronin@music.Kodak.COM (Jim Cronin)
Subject: List of mail-order supply houses?
Organization: Eastman Kodak Co., Rochester, NY
Distribution: na
Date: Thu, 16 Apr 92 18:27:11 GMT


Is there a FAQ list that includes a list of mail-order
electronic supply companies?  I seem to recall seeing
such a thing some time ago, but nothing lately.  Any
info is greatly appreciated.  I will post any email replies.

Thanks...Jim

From: frankb@hpsad.sad.hp.com (Frank Ball)
Date: Fri, 10 Apr 1992 16:53:03 GMT
Subject: Re: Sony walkman antenna
Organization: HP Signal Analysis Division - Rohnert Park, CA
Newsgroups: sci.electronics

*>When I opened my walkman radio I was surprised to find that it
*>had no AM antenna.  I understand that the antenna is part of 
*>the earphone cord, but how does this work?  Also how could
*>I attach a secondary FM or AM antenna to make the reception
*>better?
*
*As I understand it, there is no provision for any additional
*antenna,  the Walkman was designed (?) as you have discovered
*to use the earphone cord as the antenna.  I do not find it
*particularly efficient except in areas of high signal
*strength, and even then the way you sit or walk can affect the reception.

Yes they are not very sensitive.  Just an interesting note:  I have noticed
that when I go shopping for headphones, most of them come with either
3 foot or 9 foot cables.  A 3 foot cable is about 1/4 wavelength for
the FM band, a 9 foot cable is about 3/4 of a wavelength.  Both of these
lengths make a good antenna.  A 6 foot cable would be 1/2 wavelength and
be a terrible antenna.  So some thought has gone into it anyway.

*I too would like to know if anyone has foung a solution to this
*problem.

I haven't tried, but I would think that if you opened up the unit and
took a look you should find TWO connections to the headphone jack:
the audio to the headphones and the antenna connection.  You could
disconnect the antenna wire and and an antenna jack to the radio.

An external antenna would restrict my moving around so I haven't tried
it.  If you don't mind being tied to one spot get some headphones with
a 9 foot cable and run the cable over the top of your desk or something.

Frank Ball   2LR-D             frankb@hpsad.sad.hp.com
Hewlett Packard                pyramid!hplabs!hpsad!frankb
1212 Valley House Drive        (707) 794-4168 work  (707) 538-3693 home
Rohnert Park CA 94928-4999     KC6WUG Seca 750 XT350 IT175 I'm the NRA.
From: hbg6@phx.mcd.mot.com (John Schuch)
Newsgroups: sci.electronics
Subject: Re: Unknown Chip AN26 (6-pin DIP)
Date: 10 Apr 92 12:27:24 GMT
Distribution: na
Organization: Motorola Computer Group, Tempe, Az.

In article <nyarko.702835588@ee.ualberta.ca> nyarko@ee.ualberta.ca (David Nyarko) writes:
>Could someone help me with specs or identifying
>the AN26 (6-pin DIP) in a telephone answering machine?
>			David

Are you sure it isn't a 4N26?

At any rate, the thing is surely an optoisolator and is probably being
used as a ring detector in the answering machine.

Pins 1 and 2 connect to the LED,
Pins 4, 5 and 6 connect to the emitter, collector and base respectivly
of the phototransistor.

John

------------------------------------------------------------------------
John Schuch           hbg6@citek.mcdphx.mot.com            (602)438-3008
------------------------------------------------------------------------
      One wonders if there would be such a pursuit of artificial
      intelligence if there were more of the natural kind around.
------------------------------------------------------------------------
Newsgroups: sci.electronics
From: raghutp@hubcap.clemson.edu (Raghu Toppur)
Subject: need help identifying component (Repost with corrections)
Organization: Clemson University
Date: Fri, 17 Apr 1992 18:35:17 GMT





The fuse on my external Hard Drive blew. I replaced the fuse, with a 5A fuse,
which is higher than the power requirement, and it blew too.

There are no schematics available, and the Technical Assistance number is
defunct. The problem is "obviously" :) in what seems to be a really fancy
power supply board. There is one part here on the 115V side,
which I have no idea what it is. 

It sort of looks like a small SilverOxide battery which has been dipped in 
tar, and has two leads emanating from it. Says CAL-R 2SS40 on it...

Can anyone help identify the part, how to find out its rating ? The leads 
are of equal length but they look like they've been snipped.


Thanks in advance.
-- 
--
Raghu Toppur                                Internet: raghutp@cs.clemson.edu
Department of Computer Science              Uucp:     !gatech!hubcap!raghutp 
Clemson University, Clemson, SC 29631       Tel:      (803) 654-3943 
Xref: sparky sci.electronics:8645 rec.radio.amateur.misc:7829
From: day@william.vancouver.wsu.edu (Steve Day)
Newsgroups: sci.electronics,rec.radio.amateur.misc
Subject: Spectrum Allocation Table
Date: 17 Apr 92 01:49:11 GMT
Article-I.D.: clark.1992Apr17.014911.21098
Distribution: na
Organization: Washington State University, Vancouver Campus

Does anyone have a table of what frequency bands are assigned to various
radio services?  I'm looking for data like 144-148 MHz is the 2-meter
amateur band, x-y Mhz is cellular, a-b Mhz is such and such service, etc..
I'm not particularly concerned with the internal structure for these services
other than something like CB is x number of AM channels y KHz wide, but I
don't need the entire band plan for something like the 2-meter ham band.

Any information will be appericiated.  Please e-mail since I won't be able
to read the news again until Monday or Tuesday and I don't have a treaded
news reader :-( :-(

Thank You

-- 

Steve Day
N7VHY
Newsgroups: sci.electronics
Subject: 46/49Mhz Cordless Phone Amp Needed
From: els@hpd.unp.ac.za (Leonard Els)
Date: Sun, 12 Apr 1992 14:23:52 GMT
Distribution: world
Organization: University of Natal (Pietermaritzburg)


Has anyone come across a 50Mhz RF Amp Schematic (about 5-10W Power output).
I intend amplifying the signal from both my base station and handset of my 
cordless phone. The handset will be used in a car, so there is no problem 
for the power input.

I do have the resources to DESIGN one myself, but this involves a lot of 
work determining the correct values for coils etc.

I someone has a design, could they get in contact with me.

Thanks
Leonard Els
University of Natal
E-mail: lels@daisy.ee.und.ac.za
    or: els@hpd.unp.ac.za
From: gloval@sage.cc.purdue.edu (Kevin)
Newsgroups: sci.electronics
Subject: Re: Dick Smith Electronics
Date: 15 Apr 92 19:11:06 GMT
Article-I.D.: mentor.45598
Distribution: usa


	Well, I am not an expert in any respect, but Dick Smith
	Electronics may be austrailian based, but there is a big
	store in my hometown of Greenwood, Indiana (little bit
	South of Indianapolis) that used to say Dick Smith Electronics
	on the outside of the building.  Over the years, it changed
	to American Electronics and whereas they have pretty much
	phased out their kits, and electronic pieceware (surplus), they
	sell A LOT of Kenwood stereo/amatuer radio stuff now and LOTS
	of old used equipment..real cheap.  It's an okay place to spend
	a few hours looking through old spare parts and surplus, but
	once you buy it, don't expect help or any more like what you 
	bought.  I guess the moral to this story is :  See also
	American Electronics.  If anyone has comments, feel free to
	post them or email me.
		P.S.  I like the place, because I like to tinker
	with electronics, but they are pretty much phasing it all
	out and going to the bigger stuff, I guess it probably
	generates more income.
From: cornhead@sutro.SFSU.EDU (Jeffrey C. Miller)
Newsgroups: sci.electronics
Subject: Intel i860's, 33 Mhz, $200 obro
Date: 13 Apr 92 21:51:15 GMT
Article-I.D.: nic.1992Apr13.145116.1750
Followup-To: sender
Distribution: na
Organization: San Francisco State University

I have some 33 Mhz i860's for sale. Asking $200, will probably take 
the best offers over $100. 

E-mail me as cornhead@sutro.sfsu.edu if you're interested.

-cornhead
From: pierson@cimill.enet.dec.com (Dave Pierson)
Newsgroups: sci.electronics
Subject: Re: Jacob's Ladder
Keywords: Tesla Coil, Gap
Date: 10 Apr 92 21:51:24 GMT
Organization: Digital Equipment Corporation

In article <kyZyiB1w164w@inqmind.bison.mb.ca>, magus@inqmind.bison.mb.ca
(James Copland) writes, in part:

>danube@dirac.physics.sunsyb.edu (Dan Koller*) writes:
> 
>>    The following works rather nicely, and can be made small.  I found an
>> old DEC monitor a year ago, stripped the CRT and threw the rest in the
>> junk box.  Recently it occurred to me the HV section probably could be
>> made to work.
>> It's sufficiently powerful to make a 3-4" high Jacob's Ladder, and if you
>> like PC board art, the extra components look kind of neat on this 
>> particular board.  If it runs in this fashion without burning up for more
>> than 20 min., 
	A wise precaution.  Some HV supplies are not designed for high load
	operation. And, as has been pointed out, such things are not quiet,
	RF wise.  The RF may well peak at a point set by the length of the
	electrodes.  Some of those frequencies are used by folk who do not take
	kindly to emi...

>Yes!  But its not "truly" a Tesla coil until you include the "rotary 
>spark gap" in the primary circuit.
	Well, a gap, anyway.  Tesla was quite happy with a variety of stationary
	gaps, until he got to truly high powers.  Likewise the early wireless
	folk...

thanks
dave pierson			|the facts, as accurately as i can manage,
Digital Equipment Corporation	|the opinions, my own.
600 Nickerson Rd
Marlboro, Mass
01752				pierson@cimnet.enet.dec.com
"He has read everything, and, to his credit, written nothing."  A J Raffles
Newsgroups: sci.electronics
From: STATRAA@YaleVM.YCC.Yale.Edu
Subject: Re: Front panel finish - related question
Organization: Yale University
Date: Fri, 10 Apr 92 10:57:31 EDT

 
I have a related question dealing with front panels - I have a steel
chassis that has a black anodized aluminum faceplace that fits over the
steel front plate, with a spacing between the two of about 1/4" -- this
allows a professional looking product becuase it allows swithces and
whatnot to be mounted on the rear (front) panel, and keeps unsightly
nuts, washers, and tightening scratches off of the front panel.  My
problem is this -- on many pro units they use this same scheme, and cut
small OVAL holes in the faceplate to accomodate the toggle switches -
this looks great, and I'd like to do something similar - but HOW can I
cut OVAL holes???
 
--
  ==================================================
  [   Travis Stansbury, Yale University - ES '94   ]
  [   statraa@yalevm.ycc.yale.edu                  ]
  ==================================================
From: pierson@cimnet.enet.dec.com (dave pierson)
Newsgroups: sci.electronics
Subject: Re: Jacob's Ladder
Date: 6 Apr 92 13:45:28 GMT
Organization: Digital Equipment Corporation

In article <1992Apr6.033914.10997@u.washington.edu>,
pollock@milton.u.washington.edu (Joe Pollock) writes, in part:

>In article <z2zt1ta@rpi.edu> richtt@aix.rpi.edu (Timothy G. Richter) writes:
>>John Robert's writes :

>>>There's one very easy way:
>>>  - Get a big old neon sign transformer.
>>[material ommitted]

>>So far, everyone has mentioned neon sign transformers.  What about fluorescent
>>ballasts, as they are high voltage step-up transformers, also?
	Not the common garden variety.  Some of the rapidstart variety have some
	fairly trick resonating circuitry that will give a high voltage until
	the tube strikes.  Dunno about the "solid state" ballasts.


>No, fluorescent ballasts do not work here.  Their operating voltage across
>the tube is only 160-500 vac or so, depending upon the length of tube 
>they are designed to operate.
	More like 60 or so, or less.  Using care & voltmeter, measure one.

>In contrast, a neon sign transformer is typically 6000 - 15000 vac,
>rated to put out 30-60 ma.  Keep in mind that these transformers are
>center-tapped, meaning the mid-point of the secondary is connected to
>the case (and to ground, if you've wired it correctly).  This means
>that THE ONE-HAND IN THE POCKET RULE WILL NOT PROTECT YOU.  Each end
>of the transformer is 7500 vac above ground.  Unless you are very
>well insulated, like on dry wood on glass insulators, you will get
>a shock in at least the "dangerous," if not "lethal," range.
	Most excellent advice.  Tesla Coils are high enough frequency that
	the HV presents little risk, at least in the usual home size.
	Neon Sign transformers, oil burner transformers, etc, are LETHAL.
	The common Jacobs Ladder uses these and is ALSO lethal.

thanks
dave pierson			|the facts, as accurately as i can manage,
Digital Equipment Corporation	|the opinions, my own.
200 Forest St			|I am the NRA.
Marlboro, Mass	
01752				pierson@cimnet.enet.dec.com
"He has read everything, and, to his credit, written nothing."  A J Raffles
Newsgroups: sci.electronics
Subject: request:source to purchase ultrasonic generators.
From: skiponeb.wimsey.bc.ca@mala.bc.ca
Date: Sat, 11 Apr 92 20:30:29 PDT
Distribution: all
Organization: The Old Frog's Almanac, Nanaimo, B.C.
Keywords: ultrasonic generators,purchase source
Summary: Please e-mail the answer if possible. Thanks

I am in need of a source to purchase small ultrasonic generators. 
The one I have at the moment is a circuit board mounted in a plastic 
container shaped like a small hockey puck.

                 skip@oneb.wimsey.bc.ca (Terry Skipper)
             The Old Frog's Almanac     Public Access UseNet    
         Vancouver Island, British Columbia    Waffle XENIX 1.64  
         (604) 758-6208 (2400 x 4)   (604) 758-9698 (v32/v32bis)
From: jonker@amc.uva.nl
Newsgroups: sci.electronics
Subject: wanted: 8bit+ frame grabber [*]
Date: 6 Apr 92 12:15:33 GMT
Organization: Central computer department

Networld,

I'm looking for a decent framegrabber which is capable of
grabbing images with _at least_ 8 bit. If
you have one, or know someone who uses this device, or a
manufacturer, please let me know. We need Macintosh or PC 
compatibility, but we can do out own programming.
$$ is less a problem than pixeldepth. I like to do 12 bit monchrome
grabbing on medical images. I already know the DT board (8bits)
used in Mac or PC, in conjunction with the Image(NIH) software,
and the rollei and kodak digital camera back. 
The rollei has a slow scanning (moving CCD array) and takes  
too long (150 sec) the kodak has many pixels (1280x1024) but
only 8 bit pixeldepth in three colors. 
Please reply by email to jonker@amc.uva.nl.
ard jonker
Xref: sparky sci.electronics:8352 rec.music.cd:3961 rec.audio:7292
From: gary@ke4zv.uucp (Gary Coffman)
Newsgroups: sci.electronics,rec.music.cd,rec.audio
Subject: Re: requesting CD player advice
Date: 11 Apr 92 17:10:59 GMT
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Gannett Technologies Group

In article <ku9ldkINNh0l@exodus.Eng.Sun.COM> nemeth@helix.Eng.Sun.COM (Les Nemeth) writes:
>In article <1992Apr8.091944.19345@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>  
>>>Some respondents have claimed that because any loudspeaker is so much 'worse'
>>>than a CD player (and I'd love to see him/her explain precisely what _that_ is
>>>supposed to mean) even if there might possibly be differences between CD
>>>players you'll never hear them.  This is arrant nonsense.
>
>>The typical loudspeaker generates between 4 and 7% distortion. A CD player
>>at .03% distortion is at least 200 times better. If you can tell differences
>>of 1/200th in distortion, you qualify as one of the golden eared.
>
>Gary,
>
>What you are missing here is the fact that distortion is of no relevance
>in this equation. There are going to be better and/or worse players than
>others regardless of price. Sound quality of the CD player has to do with
>how well the player converts the data from digital to analog. Therefore,
>it is in your best interest to buy the player with the most oversampling
>per dollar spent. It has been proven that, the more oversampling a player
>has, the better it is at reproducing the sound faithfully.

It does reduce *production* cost somewhat to use oversampling instead of
building good brickwall filters, but it's not *necessary*, however, to
use oversampling to get a faithful reproduction. Standard high quality 
14 bit A/D converters, and well designed brickwall filters are available. 
They cost more than single bit oversamplers to produce, but there's no 
theoretical reason why they should be inferior. The real culprit in
many CD players is lousy line driver amps, and that's just straight
forward analog engineering. Everybody *should* be able to get that
right, but a dime saved on capacitors is $100,000 on a million unit
production run.

>A CD player can have .0001% distortion, but if it has a tinny sound who the
>heck is gonna buy it. Probably the guy that doesn't take the time out to 
>compare one player to the other...  Conversely, if another player has .001%
>distortion but has a muddy sound, who the hecks gonna want it either. What
>we are looking for is the one that sounds the most natural, regardless of
>the distortion level, provided it's not around 10%.

My dictionary defines distortion as a deviation from the orginal signal
waveform. It doesn't define "muddy" in any useful way. When you get the
same signal out of a recording that was put into it originally, that's
no distortion. A machine with .03% total distortion is over 200 times
more faithful to the orginal recording than a system with 7% distortion.
Whatever "muddy" means, it has to show up in the total distortion figure,
or you are describing the orginal signal, and there's no helping that.

Gary
Newsgroups: sci.electronics
From: berger@atropa (Mike Berger)
Subject: Re: 46/49Mhz Cordless Phone Amp Needed
Organization: University of Illinois at Urbana
Date: Sun, 12 Apr 1992 20:17:40 GMT

els@hpd.unp.ac.za (Leonard Els) writes:
>Has anyone come across a 50Mhz RF Amp Schematic (about 5-10W Power output).
>I intend amplifying the signal from both my base station and handset of my 
>cordless phone. The handset will be used in a car, so there is no problem 
>for the power input.

>I do have the resources to DESIGN one myself, but this involves a lot of 
>work determining the correct values for coils etc.
*----
In this country, adding such an amplifier would be illegal, and
v-e-r-y impolite.  You could cause considerable interference with
other users of the band.

The worst problem with extending your range this way is that you'll
be compensating for a weak receiver by adding extra transmitter power,
so you'll be very likely to interfere with other devices, since
you'll transmit much farther than you can receive.  
--
	Mike Berger
	Department of Statistics, University of Illinois
	AT&TNET     217-244-6067
	Internet    berger@atropa.stat.uiuc.edu
Newsgroups: sci.electronics
From: koziol@void.ncsa.uiuc.edu (Quincey Koziol)
Subject: Serial Line Routines for Intel 87C51?
Organization: Nat'l Center for Supercomputing Applications
Date: Thu, 16 Apr 1992 08:50:33 GMT

Hello,	
	I'm in fairly desperate need of a working program which demostrates
how to use the serial port I/O on an Intel 87C51.  I've been trying to
use the serial port in mode 1 at 9600 baud (using Timer 1), but I can't
get the serial port to actually send _any_ data at all.
	If anyone has a working demonstration of how to do this, could
you please get in touch with me or point me to an archive site which
carries relevent information?

	Thanks very much,
		Quincey Koziol
		koziol@ncsa.uiuc.edu

Newsgroups: sci.electronics
From: twh73@isuvax.iastate.edu
Subject: Tesla coils
Reply-To: twh73@isuvax.iastate.edu
Organization: Iowa State University, Ames, Iowa
Date: Thu, 9 Apr 1992 02:32:47 GMT

Hi, aboust six monthes ago, I build a Tesla coil that, in my estimation put
out about 90,000 volts.  I have been looking for pland or information on how
to build a bigger one.  Anyone know of anywhere that I can look?.  Thankes.


                   Stiletto
Newsgroups: sci.electronics
From: franko@cco.caltech.edu (Frank Joseph Filipanits)
Subject: Re: Front panel finish
Organization: California Institute of Technology, Pasadena
Date: Wed, 8 Apr 1992 17:42:10 GMT

vestli@ifr.ethz.ch (Sjur Jonas Vestli) writes:
>Is there an easy and relaible way of writing on my Aluminium
>front panel other than using rub on letters (Letraset, which
>isn't really quick and easy anyway)?
>For instance is there any way I could print a front panel layout
>on my laser printer, and transfer it onto my aluminium plate?

I've had great success with printing a front panel on an acetate (transparency)
and then using an "art fixative" spray glue to tack it to the panel.
3M and others make this glue, it comes in aerosols <sp?> for ~$5 ea.
I did a panel this way over a year ago, and there's no peeling or yellowing.

For extra durability, you may want to print the panel mirror-imaged so that
the toner is between the acetate and the panel.  The disadvantage is some 
of the toner will stick to the panel if you want to remove the acetate.
(Doing it the other way allows you to change labeling easily)

Good Luck
-- 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Frank Filipanits         Sr EE/CS/Music, California Institute of Technology
'68 Mustang 302           '81 Kawasaki 750 LTD           Ibanez Roadstar Bass
franko@tybalt.caltech.edu   "Why should I believe what they say?..."
Newsgroups: sci.electronics
From: jsawyer@crash.cts.com (John Sawyer)
Subject: Re: Jacob's Ladder
Organization: Crash TimeSharing, El Cajon, CA
Distribution: na
Date: Sun, 12 Apr 1992 18:44:03 GMT


> 50kv @ 3000 ma Neon Sign Transformer . . .

	A 15Kv 30 Ma transformer will run approximately 50 feet of
colored/phosphored glass.  (around 40 feet for just neon).  
But 3A!!!  I've never heard of a neon transformer that will produce THAT much!
 
	John

.sig??  We don need no .sig!
From: litwack@dccs.upenn.edu (Mark Litwack)
Newsgroups: sci.electronics
Subject: Re: Jacob's Ladder
Date: 9 Apr 92 23:35:30 GMT
Distribution: na
Organization: University of Pennsylvania

In article <1992Apr7.141550.24249@cci632.cci.com>, rdi@cci632.cci.com (Rick Inzero) writes:
|> Other tidbits I've gathered enroute to building my own J. Ladder:
|> 
|> The voltage is what matters, not the current; you need big voltage
|> in order to be able to arc across an initial 1/2-3/4" air gap.  

I have found that current is also important.  It generates a hotter
spark and increases the gap size where the spark extinguishes.
Several neon sign transformers in parallel do a decent job.  I've
tried 4 of them (15,000v x 30ma each).

|> Note that there exist some big neon sign transformers.  Mine
|> is rated 15,000 volts at *3000* ma.  This most certainly would
|> do some damage if you or I were to touch it while "live".

A 45,000 watt neon sign transformer??  Must have been one big sign...

-mark