HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.electronics

In sci.electronics, usenet@lonex.rl.af.mil writes:

    Short of buying a pad, does anyone know a good (cheap) way of matching a
    cable tv coax (75ohms) to the input of a HP spectrum analyzer (50 ohms)?
    I'm interested in the 500MHz to 1GHz range.


    Thanks
    BRO'HERN (Electronics Engineer)

For narrow-band applications, it's possible to design impedance transformers
using trasmissions lines (e.g., a quarter wave transformer or open/shorted
stubs).  However, if you really are interested in the full 500MHz-1GHz band,
it is not easy to make a *good* impedance transformer.  The easiest way
of doing this would be to use lumped trasformers wound on ferrite cores
(TOKO makes some good relatively high frequency parts).  The problem will
be getting a good low-loss transformer with flat frequncy response.

Have you considered just tieing the 75 ohm cable directly to the 50 ohm
input?  This will give you a return loss of -14 dB , which isn't terribly
bad, depending on how accurately you're trying to measure the 75 ohm signal.
(The non-perfect match at the spectrum analyzer will create a ripple pattern
 in the response versus frequency.  Worst case ripple will be 
 +/- 20*log(1- .2 * rho) where rho is the reflection coefficient of the
 75 ohm source)

Another idea -- don't laugh -- is to tie a 25 ohm resistor in series with
the input of the spectrum analyzer.  What this does is provied a perfect
load match for the 75 ohm source but worsens the source match as seen
by the 50 ohm load.  The 50 ohm load will see a source match of -10 dB
which is poor, but this isn't a problem as long as you keep the distance
between the 50ohm input and the 25 ohm resistor very small.  The 25 ohm
resistor will give you 1.8 dB of added loss.

In short, if you really want *good* measurements without messing around
with these schemes, I'd go with the minimum loss pad.  The -5.7 dB loss is
a small price to pay for a good, flat response and good return loss.

Chris
Newsgroups: sci.electronics
From: pete_leaback@cix.compulink.co.uk (Peter Leaback)
Subject: Clipping within Delta-Sigma converters.
Reply-To: pete_leaback@cix.compulink.co.uk
Date: Mon, 7 Sep 1992 00:47:52 +0000



I would like to add a limiter to a simulated second order delta-sigma
converter so as to reduce the output to 1 bit. I have tried clipping
the signal in different places, but seems to go completely wrong 
(at least for DC inputs).

To be honest, I can't visualise how a 1 bit second order D-S converter
could work.

Thanks,
       Pete.

Newsgroups: sci.electronics
From: byrns-j@gamma.corp.mot.com (John Byrns)
Subject: What is a Tuggle circuit?
Organization: Motorola
Date: Fri, 11 Sep 1992 20:18:52 GMT

This appeared in another news group. I am hoping someone in this group knows
what a "Tuggle Circuit" is? If someone could cite any references which explain
it's operation, it would be very helpful.
 
> 
>      The very first indication of this phenomena appeared when trying
> to accurately log distant stations with a new crystal set called the
> Tuggle Circuit.  For a crystal set it has remarkable sensitivity and
> selectivity and quickly logged stations spread over half the country,
> plus Canada, Mexico and the Netherlands Antilles.
> 

 
 
 
 
Newsgroups: sci.electronics
From: pdg@math.uiuc.edu (Paul Grayson)
Subject: Lo-voltage florescent bulbs?
Organization: University of Illinois at Urbana
Date: Sun, 13 Sep 1992 23:30:16 GMT

  I've seen lots of flashlights with what looked like florescent bulbs in them.  The flashlights ran at <10Volts.  Does anyone know where I could get the bulbs??

---------
Paul
  Grayson
---------
From: collin@angelo.amd.com (Collin K. Ong)
Newsgroups: sci.electronics
Subject: looking for integrated counter/display driver/display module
Date: 10 Sep 92 21:31:43 GMT
Organization: Advanced Micro Devices, Inc.

I need a single module that integrates counters, display drivers, and
numeric displays in a single unit.  It should take a TTL level pulse 
as its clock (increment) signal, and display a decimal count on the 
displays.  A clear input would also be good.  This should display at
least 7 digits though 6 would be ok.

Right now I am using 74143 chips, which are BCD counters with onboard
7-segment display decoders/drivers, wired to discrete 7-segment LED
displays with discrete resistors.  I'd like to get all this in one
compact package.  Any suggestions as a manufacturer or part number or
catalog would be great.

Thanks
Collin

collin@brahms.amd.com
From: schuster@panix.com (Michael Schuster)
Newsgroups: sci.electronics
Subject: Re: Macrovision
Date: 15 Sep 92 13:36:33 GMT
Organization: PANIX Public Access Unix & Internet, NYC

>I work for Go-Video in Scottsdale, AZ. We make a Dual-Deck VHS VCR. Having
>both transports/electronics in ONE chassis lets you connect as many signals
>between the two transports as you want, not just CompositeVideo. And
>copying EVERYTHING on the tape, including Macrovision pulses, is one thing
>the DualDeck does well. Call Stan Brown, @ (602) 998-3400


You've repsonded to Macrovision discussions before - both by posting and
(to me) by mail.

From the reviews I've read, the picture quality produced by the Go-Video
deck is hardly something to cheer about. Considering that a VHS-to-VHS
dub produces awful results even on high-end decks, one must wonder to
what market, exactly, this product is targeted at.



-- 
_______________________________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
Subject: Re: Line hum big problem in amplifier design
From: stuartw@ccu1.aukuni.ac.nz (Stuart Woolford)
Date: Wed, 9 Sep 1992 00:59:53 GMT
Organization: University of Auckland, New Zealand.

v064mb9k@ubvmsb.cc.buffalo.edu (NEIL GANDLER) writes:


> I built an amplifier that delivers around 120 watts into 4-ohms. I
>have noticed some bad hum in my speakers when there is no or little
>music. It sometimes gets worse when I raise the volume. If definetly
>sounds like 60hz and 120hz 180hz harmonics. I increased the capacitance
>in my dual polarity unregulated +-40V Dc power supply consisting of just
>a bridge diode and 2-4400uF Capacitors. Im not sure if the
>input stage is causing this. Im using 1458 op amps as buffer and voltage
>gain amps. I would appreciate any help Thanks in advance.

If you want to give me more details, I will have a look at it for you, I
have designed a number of mid-power amp's ( 50-250W ), and have had to
cure this problem a couple of times, often the problem can be solved by
adding a seperate voltage regulator ( or even just decoupled resistors ) to
the low-level and voltage amplifier stages. It's hard to say more without
an idea of the design..
Also MAKE SURE that you have no earth-loops !!!!

---------------------------------------------------------------------------
stuartw@ccu1.aukuni.ac.nz

			>>>>In VI Where Available<<<<
---------------------------------------------------------------------------
Newsgroups: sci.electronics
From: kng@pt.com (Ken Gravenstede)
Subject: 3rd Party PADS Manuals?
Keywords: PADS schematics
Organization: Performance Technologies, Incorporated
Date: Fri, 4 Sep 1992 12:01:31 GMT

Are there any 3rd party manuals for PADS?  

The manual that comes with the 
shareware version is just too little.  I realize that if I buy the full version
I'll get the full set but what they supply is not really enough to do a small
board.

Will PADS sell a set of manuals without software?? (I really doubt it!)

Ken

-- 
__
Ken Gravenstede, Performance Technologies Incorporated	kng@pt.com
315 Science Parkway, Rochester, New York 14620            uupsi!ptsys1!kng
From: dbell@cup.portal.com (David J Bell)
Newsgroups: sci.electronics
Subject: Re: How does a UART do it...
Date: Mon,  7 Sep 92 11:21:34 PDT
Organization: The Portal System (TM)
Distribution: world

>Given a stream of 1s & 0s, how does a UART get the character framing
>established, i.e. how is the 'start' bit differentiated from all the
>others? (I want to emulate one in software)

>Steve

The 'start' bit is the first transition from the resting state. If
I remember the archaic terms correctly, the line rests in the SPACE
condition, and the start bit is *always* a MARK, and is the first
bit transmitted (obviously :{) ). Given the baud rate, the UART
counts out N/2 (N is commonly 16) clocks at N*Baud frequency, and
verifies that the current state is *still* a MARK. Subsequent reads
are then done at N clock intervals, and the 10'th read verifies that
the 'stop' bit is a SPACE. This makes it sample in the middle of
each bit cell, and checks leading and trailing framers. I believe
it then *immediately* resets to the waiting-for-start state, and
loops as above...

Auto Baud detection is sort of magic; it usually requires the
firmware to keep trying various rates until a reasonable and 
correctly framed character is received.

Dave
dbell@cup.portal.com
From: markz@ssc.wa.com (Mark Zenier)
Newsgroups: sci.electronics
Subject: Re: What Steve Wants
Date: 14 Sep 92 01:30:48 GMT
Organization: SSC, Inc.,  Seattle, WA
X-Newsreader: Tin 1.1 PL3

sakaria@vipunen.hut.fi (Sakari Aaltonen) writes:
: Steve Ciarcia wants me to subscribe to Circuit Cellar Ink - The Computer
: Applications Journal.
: 
: What do YOU think?

It's worth it.  Technically, its about on the par with
Electronics + Wireless World (but much narrower in scope).
Better than Electronics Now (also know as Radio-Electronics.)
or Elektor.  A mixture of digital hacking (in the old sense of
the word), projects, and tutorials on various subject.  From
8051 single board computers to systhesizing holograms.  Like
his old column in BYTE.  

If you can stand the two thirds of an issue worth of proto-yuppie, 
how to set up your own business sludge, "Midnight Engineering" is
also worth a look.  The technical stuff in the issues I've read is
very good, but the noise level in each issue is high, and I'm
not sure how applicable theri stuff on entrepreneurship would be outside
the country.

Are there any other good european electronics magazines?

Mark Zenier  markz@ssc.wa.com  
Newsgroups: sci.electronics
From: laird@stable.ecn.purdue.edu (Kyler Laird)
Newsgroups: sci.electronics
Subject: Re: VERY small Sony Walkman design: did this exist, any to be found?
Date: 13 Sep 92 17:18:43 GMT
Distribution: usa
Organization: Purdue University Engineering Computer Network

I'm listening to mine right now.  It's a Toshiba KT-AS10.  I bought it
when I was in middle school (~10 years ago!?).

Grr...I can't find a ruler, but yes, in one dimension it is smaller
than the cassette that it plays.  The AM/FM tuner, however, does not
protrude from the cassette cavity.

It's a neat little unit, nothing especially advanced, just different.

BTW, it is auto-reverse, has Dolby (B?), and runs on 2xAAA batteries
(or 2xC with included case!).

I don't think this unit would be worth to anyone else what it is to me.

--kyler
Newsgroups: sci.electronics
From: rodrigue@CS.Yale.Edu (Joe Rodrigue)
Subject: AC-DC transformer recommendation
Organization: Computer Science, Yale University, New Haven, CT 06520-2158
Distribution: sci
Date: Thu, 10 Sep 1992 16:15:03 GMT

Really dumb question:

I need a transformer to be able to run a tape recorder from a wall socket.
The tape recorder runs on 6V, 300 mA DC.  I am tempted to buy one from Radio
Shack but I am afraid it's a piece of junk (it's only $8).

I will obey the will of the people!  Should I go for it?  Please advise.

-- Uncertain.
Newsgroups: sci.electronics
From: kolstad@cae.wisc.edu (Joel Kolstad)
Subject: Re: Lo-voltage florescent bulbs?
Organization: U of Wisconsin-Madison College of Engineering
Date: 13 Sep 92 22:51:15 CDT

In article <BuJIMH.8Kn@news.cso.uiuc.edu> pdg@math.uiuc.edu (Paul Grayson) writes:
>  I've seen lots of flashlights with what looked like florescent bulbs in them.  The flashlights ran at <10Volts.  Does anyone know where I could get the bulbs??

If you want to run flourescents at <10V, I don't think getting ahold of the
bulbs in those flashlights is going to help -- all of the flourescent
flashlights/lanterns I've seen have cheapo inverters in them to kick to
voltage up.

Newsgroups: sci.electronics
From: gkm@cc.uow.edu.au (Glen K Moore)
Subject: Looking for company address - FILAC. Need circuit. even city will help
Summary: Faulty equipment at a science centre nee eairs but no diagrams exist
Keywords: Blood pressure heart rate
Organization: University Of Wollongong
Date: Thu, 10 Sep 92 16:11:48 GMT

Can anyone help me find FILAC ? We have a blood pressure monitor/heart rate
monitor (donated) which is faulty. I need a circuit diagram to fx it. Only info is "filac - USA". I cannot even look up tel no. without a city.

How about looking up your phone bookfr me if your in the USA?

Glen Moore
gkm@cc.uow.edu.au
Science Centre
Wollongong
AUSTRALIA
FAX 61-42-213151
Newsgroups: sci.electronics
From: bkg@ssd.kodak.com (Ben K Gibson)
Subject: Info wanted on Adac 5532DMA or 5532TTL Boards
Originator: bkg@earth
Organization: Eastman Kodak
Distribution: usa
Date: Wed, 9 Sep 92 14:51:02 GMT

I am looking for information on the Adac 5532DMA or 5532TTL boards.
I am having a problem getting the board to transfer data after an
interrupt is generated. If you have had any success integrating one of
these boards, please e-mail me your phone number. I would like to talk
with you. BTW I get the same symptoms with the ADLIB software as I get
with my own polling software. Adac insists it has to be the SW.

Thanks in Advance,


-- 
KKK  KKK  Ben K. Gibson                           E-mail: bkg@ssd.kodak.com
KK Kodak  Eastman Kodak Company                   Phone:  (716)588-4313
KKK  KKK  Rochester, NY 
----------------- Opinions Expressed are my own, Not EK Co. -----------------
From: pngai@adobe.com (Phil Ngai)
Newsgroups: sci.electronics
Subject: Re: GAL LOGIC
Date: 13 Sep 92 18:49:58 GMT
Organization: Adobe Systems Incorporated

In article <92254.103444LEEK@QUCDN.QueensU.CA> <LEEK@QUCDN.QueensU.CA> writes:
>A trademark identifies a line of products so that it won't be confused
>with something similar.  I mean is there any difference between
>
>  PAL16V8     (one-time programmable, fuse based, AMD)
>  GAL16V8     (EEPROM based, erasable, Lattice)
>  ispGAL16V8  (EEPROM based, but with 4 extra pins for in system
>               programming, Lattice)

Indeed, PAL is a trademark of Advanced Micro Devices. So if TI
sells a PAL and it's not exactly (programming and otherwise)
identical to the AMD PAL, what does that mean?

>I can't just go into a store and ask for 16V8 and expect the product

Given your expectations, no. But you can't ask for a 16R4 and get
a generic product either. You can't ask for a 4 meg EPROM and get
a generic product. You can't even ask for a 1 meg DRAM and get
a generic product.

The problem is, you don't understand what GAL means, or what 16V8
means.

>I wanted.  On the other hand I did specify GAL16V8 and got PALCE16V8.
>I could have asked my Credit Card company to cancel payment as I
>didn't get what I specified.  a Cyrus 486 is the same as an Intel 486?

Yes, you did get what you specified, you just didn't specify
what you wanted.

>GAL(TM) stands for Generic Array Logic.  Trademarked by Lattice and

But what does it MEAN? Until you understand, you are going to
keep getting in trouble like this.

-- 
My opinions are my own.
Newsgroups: sci.electronics,rec.radio.amateur.policy,alt.folklore.urban
From: pierson@empror.enet.dec.com (dave pierson)
Subject: Re: Is this legislation for real?
Organization: Digital Equipment Corporation
Distribution: usa
Date: Fri, 11 Sep 1992 17:27:47 GMT

In article <11SEP199208223835@rover.uchicago.edu>, frank@rover.uchicago.edu
(Frank - Hardware Hacker - Borger) writes...
>In article <1992Sep11.003121.13086@mole-end.matawan.nj.us>,
>mat@mole-end.matawan.nj.us writes...
>>(Flame on!)
>>Section 1706 of the 1987 (86?) Tax Reform Act was pushed through by
>>`Bedfellow' Moynihan, ...
> 
>	There is no distinctly American criminal class - except
>	Congress. - Mark Twain

	The US Congress:  The best body of men money can buy.

		Twain (?)

thanks
dave pierson			|the facts, as accurately as i can manage,
Digital Equipment Corporation	|the opinions, my own.
146 Main St			|I am the NRA.
Maynard, Mass	
01754				pierson@majsty.enet.dec.com
"He has read everything, and, to his credit, written nothing."  A J Raffles
Newsgroups: sci.electronics
From: gerry@bluemoon.rn.com (Gerard M. Foley)
Subject: Re: Question about origin of name of BNC connector
Keywords: BCN connector, name origin
Organization: Blue Moon BBS ((614) 868-998[024])
Date: Fri, 11 Sep 92 08:50:42 EDT

gmw1@cunixa.cc.columbia.edu (Gabe M Wiener) writes:

> In article <1992Sep8.205843.12516@vela.acs.oakland.edu> lmbrown@vela.acs.oakl
> >I think that the BNC stands for Bayonet Connector.  Can anyone confirm or
> >disprove this?
> 
> British Naval Connector is how I learned it...
> 
> 
> --
> Gabe Wiener - Columbia Univ.     "This 'telephone' has too many shortcomings 
> gmw1@cunixa.cc.columbia.edu       to be seriously considered as a means of 
> N2GPZ in ham radio circles        communication. The device is inherently of
> 72355,1226 on CI$                 no value to us." -Western Union memo, 1877

I have not read anything in this thread because I was sure that
the correct answer would have been given long ago. BN is the
initials of the guys who designed it.  Sorry I don't remember
the names.  Now let's quit!

gerry@bluemoon.rn whose home bbs has trouble getting the 
mail out sometimes, so it may go here instead.
Newsgroups: sci.electronics
From: johnh@macadam.mpce.mq.edu.au (John Haddy)
Subject: project design/build time (repost)
Organization: Macquarie University
Date: Thu, 10 Sep 1992 23:19:58 GMT

I suspect that the local news feed chewed up my last attempt to post this. If it
didn't then please forgive the repeat post!

If you've seen this before, I promise that this will be the last time! I truly
expected that the the topic would arouse at least _some_ interest, however I've
only had one reply (from nearby), leading me to suspect that the original post
did't get very far.

Flames to /dev/null please.

Your forbearance is appreciated.

John Haddy

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

I would like to ask for opinions on this issue:

How long, on average, would you consider a project design/construction to take?
i.e. how many man-weeks?

I refer to a project capable of being designed by one engineer and constructed by
two technical staff.

I know this is an open ended question, with not enough details to answer
precisely; but I'm after a "gut-feel", not a project plan. Projects are
non-trivial (trivial means a circuit that can be knocked up in under a week or
two with no worries) and require an engineer's skill (i.e. they're not the sort
that an experienced technician would be expected to handle), often with
background research required (e.g. magnetic properties of toroid materials, ECL
circuit design, high voltage electronics [10kV-20kV at several amps] etc).

Project design time in this case refers to:

1	Project specification
2	Design and schematic capture, with simulation and breadboarding where
		necessary
3	Printed circuit artwork design (on a CAD system)
4	Printed circuit fabrication, drilling and loading (assume in-house
		fabrication takes one day)
5	Circuit test and revision/modification
6	Chassis work (hole drilling, PC mounting, etc)
7	Front panel design and fabrication (Scotchcal or similar)
8	Final test and shipment ('out the door')

Also, how long would a repeat build take. That is, use an existing design. This
would be equivalent to steps 4..8 above, without the circuit revision or front
panel design elements.

My reason for asking is that a director here is under the impression that the
output of one engineer and two technicians here has been lower than it should.

Personally, I believe that their output has been beyond expectation. However, so
as not to bias your opinion, I'll not quote the details now.

I will summarise if there is enough interest.

John Haddy

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

      |  _  |_   _   |_|  _   _|  _|              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: magus@brewhau.bison.mb.ca (James Copland)
Newsgroups: sci.electronics
Subject: Tesla Coil? Ja!
Keywords: Tesla, Conspiricy, Money.
Date: Thu, 03 Sep 92 09:15:43 CDT
Distribution: bison
Organization: Organium Brainbending & Low Level CodeWorks of Winnipeg, Manitoba.

al@sys6626.bison.mb.ca (Haus Der Luge) writes:

>
> I am interested in making myself a TESLA COIL.
>
A good, normal, healthy interest!
>
> I have called around town here and have had a lot of trouble even finding
> anybody who knows what a TESLA COIL is.
>
What do you expect in a mid-western town?
>
> My only luck was a short conversation I had with a lab technician for the
> electrical engineering department at the University of Manitoba ... and I
> think that he thought that I was either (a) CRAZY or (b) had BAD
> intentions for this device.
>
Normal reaction for the type of person(anal retentive) in this area.
>
> Neither (a) nor (b) are really true ... although (a) is really a
> subjective concern.
>
Not to the "Concerend Citizens" of Winnipeg it's not!  After all, didn't
Tesla propose to use one to provide "free power" to the world?  Then where
would "scientific research" get its funding if the Manitoba Govt. went out
of business?
>
> I would REALLY appreciate some help if somebody could tell me where to
> find a schematic, information etc.  (I've looked through about 7 years of
> SCIENTIFIC AMERICAN "home scientist" articles to no avail.).
>
> Thanks,
> Haus Der Luge
>
Let's see, try the Centenial library.  Use the topic "Tesla" you should
come up with about two books(same as I did).  Or you could send me e-mail
for some titles and my home phone so we could discuss this.  There are
several experimenters in Winnipeg building the things(I'm one) and I'm sure
between us we have most of the litrature or can tell you where to purchase
it.

Regards,
Magus.

magus@brewhau.bison.mb.ca (James Copland)
BrewHaus -- Winnipeg, Manitoba
From: whit@milton.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: Wanlass Paraformer - does anyone remember?
Date: 10 Sep 92 01:28:52 GMT
Article-I.D.: u.1992Sep10.012852.23296
Organization: University of Washington, Seattle

In article <1992Sep4.170956.6377@javelin.sim.es.com> RSPEIRS@130.187.170.178 (RON SPEIRS) writes:

>About 10 or 15 years ago, I remember reading advertising literature from
>a company called Wanlass.  They had invented a unique kind of transformer
>and power supply (with the trademark of Paraformer or Parax?).  This
>transformer was built differently than ordinary transformers, in that
>one winding was rotated 90 degrees from another winding.  The literature
>went into the theory of how this transformer utilized a "parametric"
>term in the transformer equations

	Your memory is correct.  I have a manual here in my lap
for a Wanlass Paraformer model P1405 Parax.  Like a ferroresonant
transformer (and unlike a simple transformer), the output is 
regulated AC (circa 0.25% line regulation for 10% line variation,
and 1.5% load regulation, for load going from 0 to full rating).

        I'd call it closer to 20 years than ten; we have one,
and the instructions that came with it (the blueprint..rather,
blueline print...is dated 1967).  There's a one-page technical
summary in the manual, which gives the basic principles.

        We haven't used it in years; the power surge on startup
is excessive (it blows fuses) and possibly this indicates that the
capacitor has shorted...

        I can mail a copy of the manual to you, if you wish.

        John Whitmore

p.s. I tried E-mail, but my mailer doesn't accept the address,
nor any variant I could come up with.
Newsgroups: sci.electronics