waashk/20ng huggingface dataset:
I have a new scope and I thought I'd save a few bucks by buying one with a function generator built in. After having it awhile I noticed two things about the function generator. For one, there seems to be a bias even when the 'pull-offset' is pushed in. That is, I have to pull that know and adjust it to get a signal sans some random 50mV bias. 	The other _really_ annoying thing is that the damn output won't go below about 1V p-p. I am a student ( you may have guessed from my previous posts ), and I often have to measure the input impedances of various circuits I build.Many of the circuits have maximum input signals of way less than 500mV amplitude and most have input impedances in the 10's of Kohm range. The thing is, in order to use my function generator I have to divide the voltage to some thing reasonable. Then, of course, to measurethe input impedance of my circuit I am going to have to throw in another resistor in series. With the 50ohm output of the generator I could just ignore it, but now with this little divider there I have to figure that in. It's kind of a pain in  the ass. 	Is there any way I could make myself a little box that could solve this little problem. The box would tkae the function generator input, lower the voltage and give an output impedance that is some low, unchanging number. I would want to lower the voltage by a factor of one hundred or so. I could just build a little buffer amp, but I'd like to have this box not be active. 	Any quick ideas. The scope's not broken. For other reasons I had sent it to the shop to get repaired and they replaced it. The function generator was the same way on that one, too.  			please help as I am feeling very stupid  			today,
>In <3889@ncr-mpd.FtCollinsCO.NCR.COM> Brad Wright writes: > >>	If you know much about PC's (IBM comp) you might try the joystick >>port.  Though I haven't tried this myself, I've been told that the port >>has built in A-D converters.  This would allow the joystick to be a couple of  >>pots.  If you could find the specs this might just work for you...  I believe that the "A-D converters" found on a joystick port are really timers that tick off how long it takes an R-C circuit (the R being your paddle) to charge up to something like 1/2 Vcc.  For games this works pretty well, but you certainly wouldn't want to try to take lab measurements off something as non-linear as that.  Hmm... I suppose you could linearize it in software, but the real problem is that the precision of your measurement is no longer constant (higher voltages would be more precise).  On the other hand, I could be wrong and perhaps the game card designers splurged for the extra $.50 to make a cheap constant current source out of an op amp.  But I wouldn't expect that...
Bill Willis (willisw@willisw.ENG.CLEMSON.edu) wrote: : I have notice a lot of electronics questions by people who are obviously not  : "tuned-in" to electronics.  Many of them have rather simple answers, and  : many of them require a circuit diagram.  : Rather than muck up the network, why don't you write to me, send a self- : addressed, stamped envelop, and I'll answer your questions, if I can.  : W. L. Willis, P. E. : 114 Fern Circle : Clemson, SC 29631  Because the network is quicker, easier, and free (at least to me).  --  ------------------------------------------------------------------------------ Christopher Wolf             Electrical Engineer                cmwolf@mtu.edu
At 50 miles, a conventional set of TV antennas on a pole (one aimed at each transmitter location) should work well.  "Rabbit ears" inside the house are probably not adequate.  Gadgets to plug into your house wiring are even worse. At VHF, you don't want a _big_ antenna, you want a _resonant_ antenna.
Can somebody please help me with information about an American Magnetics Corporation Magstripe Card Reader that I recently bought locally from a surplus dealer.  On the rear it has the following information:  	American Magnetics Corporation 	Carson, CA, USA 	Magstripe Card Reader 	Model 41, 	P/N 507500 - 2300112311  It is fitted with a cable with a RS232 Cannon 25-pin connector on the end and has a separate power connector like the once used with wall chargers.  Frode
donrm@sr.hp.com (Don Montgomery) writes:   >Radio Shack has canceled their "Battery of the Month" Club.  Does  >anyone know why?    >They say they'll honor existing cards in customer hands, but no new >cards will be issued.  I was told that this is an environmental based move.  I was also told that there will be 'somthing' else to replace the battery club.  Like maybe the 360K floppy club ;-).  We'll see ....
I have an Adcom GFA-555 that I got in 1985.  There certainly isn't anything magic about it.  The components used are decent, but nothing uncommon with respect to consumer grade components.  The GFA-555 is a nice piece of equipment.  I'm glad that Adcom had the guts to not over-do the packaging.  It irks me when I see audiophile oriented equipment whose case and heat sinks probably cost much more and receive more attention than the electronics they are supposed to serve.  I don't see any big deal about the geographic region in which something is assembled.  This is especially true for something as low-technology as a GFA-555.  I'd hope that a GFA-545 would still work well after several years. Except under conditions of extreme abuse, there isn't much there to go wrong.
I built a little project using the radio shack 5vdc relays to switch audio.  I got pretty bad 'clicks' when the thing switched.  I was doing most of the common things one is supposed to do when using relays and nothing seemed to get rid of the clicks.   My question is:  	Is there a good relay/relay circuit that I can use for switching audio, so that there will be *NO* noise of any kind on the audio lines.   I will appreciate any advice or references to advice.  Also, exact part numbers/company names etc. for the relays will help!  Thanks!
In article <1d.11083.3287.0NAC6CC5@synapse.org>, martin.vuille@synapse.org (Martin Vuille) writes...  >Does anyone know who to contact to obtain a copy of the PCMCIA standard?  	PCMCIA 	1030G East Duane St 	Sunnyvale, CA 94086 USA 	408-720-0107  	See also: 	alt.periphs.pcmcia
Fellow Info-junkies,   I have an extra CCI #27 (Real Time Programming/Embedded Sensors & Storage) and an extra CCI #32 (Voice control of telescope, among other articles). No labels. No torn, cut-up, or missing pages.  Would like to trade for CCI # 26, or CCI # 23, or CCI # 19 in same condition (Labels OK).  I mail mine you mail yours mutual trust kinda thang OK? You don't actually throw them away, do you?
In article <C5uLqn.Gpw@fc.hp.com> cfb@fc.hp.com (Charlie Brett) writes: >: While driving through the middle of nowhere, I picked up [KNX], AM 1070, >: a clear-channel station based in Los Angeles. They had an ad  >: claiming that they were able to get traffic flow information from  >: all of the thousands of traffic sensors that CalTrans has placed >: under the pavement. Does CalTrans sell this info? Does [KNX] have >: an exclusive? What's the deal?  Well, they claim they are the only radio broadcaster with this information.  But the city's cable channel (35 in CableVision areas) shows this information map during travel times (6-9am and 4-7pm, I believe).  Most of the major LA freeways are covered.  The computer-generated map shows green, yellow, red, or flashing red (respectively: <40mph, 25-40mph, >25mph, and "incident"--I might be off a little on the speeds, since this is from memory).  I often look at this display in the morning to see if I really want to fight the traffic on the Sepulveda Pass or work from home for a little while to wait for it to clear.  Another poster explained the origin of the information: sensors (embedded wire loops) in the pavement near ramps and every half mile or so.  CalTrans has had a "big board" driven from this data in their traffic control center for some time.  I don't know if they are selling the data or if anyone with the equipment necessary for its transmission and display can have it.
cyborg@kauri.vuw.ac.nz (-xivo-Alex Ivopol) writes:  >I believe that persistence overcomes even the very best copy protection >schemes.  I would expect that CD-ROM software would not even need copy protection. As the program on a CD-ROM would not fit onto a hard-drive, and it is impossible for the average (and even not-so-average) user to write to a CD-ROM, copies of the software (that still work) could never be made.  Hmmm.. now that I think about it.. with a creative TSR, maybe disk-swapping could be used to simulate files on a single disk. You would need a tonne of disks though.  >--  >Alex T. Ivopol                           cyborg@kauri.vuw.ac.nz >External User - Victoria University of Wellington - New Zealand >************* I speak for myself and no one else. *************
>There are devices you can buy and/or make.  Look in Radio & Popular  >Electronics mags for the devices.  If all else fails, you can build one  >using the curcuit design from the Dec. '87 issue of Radio Electronics.  My very favorite ad for such a device is on the back of the latest Damark catalog.  Quoting from memory:  [Big flashy type] "Dual deck VCR copies any tape -- Even those that are copy protected!*"  (And underneath the ad in very small print: *This device is not intended for making illegal copies of copyrighted material.)  :-)  --
Hi there,  I am looking for a wide band analog time delay (not phase delay) variable from 200 microseconds to 2 milliseconds.
This has been an interesting thread to follow... and obviously this group wasn't intended as a forum for the discussion of piracy... Has anyone seen any estimates of the lost revenue due to pirates?  I was wondering if piracy is more rampant in Home or Corporate computing environments.  I would tend to think that business environment "piracy" is the major contributor to this form of lost revenue.  So many companies will purchase a few copies of a software package and then employees will internally distribute them as if they owned a site-license!  What do you guys think?
> noeler@xanth.CS.ORST.EDU (Eric Richard Noel) writes: > > [Discussion on Piracy Deleted] >  > Off deeper end-> Why does everyone think they need to be able to make a  > backup copy? Almost all new software must be installed to the hard disk, > so you are left with the originals as your backups. I think its a waste > of time, space, and money, as well as it makes it to tempting to "lend" > out the backups.  >  My own practice with new software :  make a copy of the original floppies to a second set of floppies.  install to hard drive from second set of floppies.  put originals in a box in room number one.  put copies in box in room number two.  1) Accidents DO happen to original floppies. 2) Accidents CAN happen to the installation floppy. 3) Sometimes software goes out on floppies that are JUST marginally good.  Or    gets too close to a magnet in shipping or storage.  I've had experience with SOMETHING like the last.  I purchased a compiler from a reputable vendor.  THe debugger in the package just would NOT install to the hard drive. NO WAY.  Repeated floppy-to-floppy copies FINALLY got a clean read of the disk.  I DON'T recall if I used "diskcopy", "copy/b", or "xcopy".  I made a second copy of the marginal floppy and installed from that.  No problenms ( except with my typing :-)  ) since.  I regard backup floppies as CHEAP insurance.  Just my side of the question...
ptorre@hardy.u.washington.edu (Phil Torre) writes:  >I have a project in mind that requires an array of LEDs that can be addressed >individually by a microprocessor (say, 16x16 or so).  Is there an LSI that >is designed to drive an LED array (including RAM to hold the array state), >or failing that, some way of multiplexing the display so I don't have to >latch a bit for each LED using a discrete latch?  (I want to avoid having >a huge board covered with 373s if possible!)  Thanks in advance...  Maxim makes a chip that does exactly what you want. The MAX7219 drives 8 7 segment LED displays with full decode or drives 64 discrete LED's with a 3 wire serial interface.  The chips can also be cascaded to allow very large arrays.  I am working on a sign display using this part.  I'll have to post the contact info for Maxim later, it's at home.  There was a series of articles on this chip in the last couple of Circuit Cellar Ink's.  Mike Harpe
Help !! - I'm looking for a ISA driver card and driver software for a Logical Devices Husky programmer (It aint mush good without these) can anyone help with either of these items ? cheers Mike.
dnewman@lynx.dac.northeastern.edu (David F. Newman) writes:  > Hi there, > Can anyone tell me where it is possible to purchase controls found > on most arcade style games.  Many projects I am working on would > be greatly augmented if I could implement them.  Thanx in advance. >  > -Dave > dnewman@lynx.dac.northeastern.edu >   Contact Chris Arthur at Chris_Arthur@pennies.stratus.com He restores lots of old video and arcade games and knows where to get parts.  Tony  ----------------------------------------------------------------------- -- Anthony S. Pelliccio, kd1nr/ae    // Yes, you read it right, the  // -- system @ garlic.sbs.com          // man who went from No-Code    // -----------------------------------// (Thhhppptt!) to Extra in     // -- Flame Retardent Sysadmin       // exactly one year!            // ------------------------------------------------------------------- -- This is a calm .sig! --
You can get a *little* UV by putting a heavy UV filter (deep purple) in front of an ordinary flashlight bulb (the brightest you can get). My father used a setup like this in law enforcement work circa 1964.  Good UV ("blacklight") bulbs work like fluorescent bulbs.  I'd proceed by getting a cheap battery-powered _fluorescent_ light, then going to an electrical supply house and finding a UV bulb that would fit it.
In article <sgberg.23xu@charon.bloomington.in.us> sgberg@charon.bloomington.in.us (Stefan Berg) writes: >... I don't know why my FPU has an XC (my original 33MHz FPU >was label MC68882-33), but it seems to work fine on my system... >P.S. Or does it mean eXperimental Chip instead of Motorola Chip? .-)  The rule for the designations is that if it says MC, that means it works *exactly* the way the datasheet/book specifies.  If it says XC, that means there is at least one known bug.  Often these bugs are small and obscure; you might never run into them in practice.  At least Motorola admits it, unlike certain other companies...
The subject line says it all. I'm working on a project that will use a car battery. I need to pull off 3V and possibly 48V at 3A.  I have several ideas, but I'd prefer to benefit from all you brilliant people :-)
In article <1993Apr16.142715.12613@sol.ctr.columbia.edu> seema@madvlsi.columbia.edu (Seema Varma) writes: >Hi, >	I am looking for some help in choosing a package >for a high-speed silicon ADC (100Mhz) currently being  >fabricated. This is a PhD research project and I have to test >the chip at speed on a PCB. I expect to have roughly 100 >packaged circuits and will do DC, low-speed and high-speed >testing using 3 different set-ups for the test chip. > 	 >	I know for sure that a DIP will not work >(the long lead lines have too high an inductance). >Getting a custom-made package is too expensive, so >I am trying to choose between a flatpak and a >leadless chip carrier. The flatpack would be hard >to test since it has to be soldered on to the test >setup and I would spend loads of time soldering  >as I kept changing the test chip. The leadless chip >carrier sockets also have long lead lines and may >not work at high speeds. >  >	Does anyone out there have experience/knowledge >of this field ? I would greatly appreciate help! Any ideas/ >names of companies manufacturing holders/sockets/packages >would help.  >  >P.S. The multi-layer fancy GaAs packages seem like a bit >of overkill(?) >	 > --- Seema Varma   You didn't mention whether or not cost is an issue.  Where exactly are you running 100MHz??  THe digital side?  TTL? ECL?  We run 200MHz and 100MHz all over our IC test equipment  all day long in the ECL domain, and we use DIP's along with PLCC's, 25mil and 20mil pitch 256pin QFP's to name a few.  I don't see a problem in packaging as long as you adhere to sound engineering practices.    A good source of information is Motorola's MECL System Design Handbook. The latest ed. is dated 2/88.  That is considered to be one of the *bibles* in high-speed design.  The very fact that you need to build a test fixture means you're most likely going to need a socket.  It in itself has far more inductance per pin than the package you are testing, not to mention any impedance discontinuities.  I don't see the big concern over the packaging because it probably isn't going to make that much difference  If you're trying to get TTL to run at 100MHz, have fun... TTL was never designed to run in a 100MHz environment. :-(  aaron
jeh@cmkrnl.com writes: > >Hmmm.  How are those orange "isolated ground" outlets (often used in >computer rooms) wired?    They require two separate grounds.  One ground goes to the ground pin of the outlet, and the other ground wire is connected to the outlet's mounting tabs (and thus grounds the box and faceplate screw and metal faceplate, if any).  The box/faceplate ground goes to the normal distribution panel ground. The outlet ground-pin wire is generally connected to an insulated busbar in the distribution panel which is, in turn, connected to the building-entrance main ground by its own wire.
In article <sehari.735962071@du139-201.cc.iastate.edu> sehari@iastate.edu (Babak Sehari) writes: >From: sehari@iastate.edu (Babak Sehari) >Subject: How to make the disks copy protected (continued) >Date: Wed, 28 Apr 1993 01:54:31 GMT >--- > >The discussion under the old topic went in the wrong direction.  Some people, >instead of discussing the issue itself, they decided to discuss the >non-technical part of the issue.  So, Here I go with my limited knowledge >about this issue.  Hoping you guys cut the crap and talk about the real >technical ways to do this.  The methods that I am aware that are effective >are: > >1- Laser hole burning.  This would leave the disk damaged, so if you format >   that particular sector of the disk you can not write to it.  It is very                                             ^^^^^^^^^^^^^^^^^^^ Laser holes are (or were) used to prevent someone from making exact copies  of a disk. You do not want to write to the damaged disk, only read and use  the programs.  >   hard for crackers to damage the disk exactly the same way. >  I remember a program called Copywrite that could copy a disk with a laser  hole in it. I think it simulates the laser hole. After copying the disk the  program is, if necessary, used in conjunction with a program called Nokey or  something. (The program tells you which program to use)  No solution.
Does anyone know what causes the ever-growing black border around the edges of my computer screen?  The growth has been gradual so I don't know how long it's taken to get this bad.  I have a 19" DEC (?) color monitor, maybe five years old, and the black border is about 1.1 inches on the left and right sides, about 1.75 inches on the bottom and negligible at the top of the screen.  The only controls are brightness knob, contrast knob, deGauss switch, and power switch.  Is there anything to be done, or are the monitor's days numbered?
I'm trying to figure out how to operate a Pioneer Laserdisc LD-1000 that I bought at a surplus store. It is reputedly from some kind of computerised viewing and/or ordering system. THere is what may be an HPIB connector on the back. When I power it up, the front panel power light comes on, but no activity, and the door doesn't open. Anyone have any experience with this unit or any ideas on how to obtain documentation?
In article <1993Mar31.204036.4359@ssc.com>, markz@ssc.com (Mark Zenier) writes: |> Zack Lau (zlau@arrl.org) wrote: |> : In sci.electronics, xhan@uceng.uc.edu (Xiaoping Han) writes: |> : >In article <1993Mar24.163510.158@hubcap.clemson.edu> michaet@hubcap.clemson.edu (Michael D. Townsend) writes: |> : >>brendan@macadam.mpce.mq.edu.au (Brendan Jones) writes: |> : >> |> : >>My mom's 25" Magnavox does this as well.  I put chewing gum all around |> : >>the horizontal sync transformer so it wouldn't resonate the board as |> : >>much.  Don't flame, it worked.  I realize that there is a more suitable |> : >>substance available for this purpose, but I don't remember what and |> : >>where it is. |> :  |> : >Adhesive silicon, from hardware store. |> :  |> : If it smells like vinegar, it may damage metal surfaces by |> : promoting corrosion.   |>  |> Anybody tried Superglue (cyanoacrylate ?).  This should sneak |> into the cracks better, and is stiffer than silicone.    I've found this works pretty well on noisy laminated power transformer cores and windings (the 60Hz kind). Likewise, if anybody has tried this on a flyback I'd like to hear about it.  I would suspect it would not be as effective as it was on power transformers as the material wouldn't damp as well--something I suspect would be critical at the frequencies involved (in other words, you want absorption rather than prevention which would be real difficult at 15 KHz).  --  --------------------------------------------------------------------        Dave Medin			Phone:	(205) 730-3169 (w)     SSD--Networking				(205) 837-1174 (h)     Intergraph Corp.        M/S GD3004 		Internet: dtmedin@catbyte.b30.ingr.com   Huntsville, AL 35894		UUCP:  ...uunet!ingr!b30!catbyte!dtmedin     ******* Everywhere You Look (at least around my office) *******
When constructing active filters,  odd values of resistor are often required  (i.e. something like a 3.14 K Ohm resistor).(It seems best to choose common  capacitor values and cope with the strange resistances then demanded).  Is there a PD program out there that will work out how best to make up such a resistance, given fixed resistors of the standard 12 values per decade?.(1, 1.2,1.5,1.8,2.2,3.3 etc ).  It is a common enough problem,  yet I cant  recall seing a program that tells that Rx+Ry//Rz gives Rq,  starting with  q and finding prefered values x,y and z.
In article <oxenreid.734127163@chaos.cs.umn.edu> oxenreid@chaos.cs.umn.edu () writes: >In <1993Apr06.173031.9793@vdoe386.vak12ed.edu> ragee@vdoe386.vak12ed.edu (Randy Agee) writes: > >>So, the questions are -  >>  Are any brands "quieter" than others?  Yes some radar detectors are less detectable by radar detector detectors. ;-)
Hi, 	I am looking for some help in choosing a package for a high-speed silicon ADC (100Mhz) currently being  fabricated. This is a PhD research project and I have to test the chip at speed on a PCB. I expect to have roughly 100 packaged circuits and will do DC, low-speed and high-speed testing using 3 different set-ups for the test chip.  	 	I know for sure that a DIP will not work (the long lead lines have too high an inductance). Getting a custom-made package is too expensive, so I am trying to choose between a flatpak and a leadless chip carrier. The flatpack would be hard to test since it has to be soldered on to the test setup and I would spend loads of time soldering  as I kept changing the test chip. The leadless chip carrier sockets also have long lead lines and may not work at high speeds.   	Does anyone out there have experience/knowledge of this field ? I would greatly appreciate help! Any ideas/ names of companies manufacturing holders/sockets/packages would help.    P.S. The multi-layer fancy GaAs packages seem like a bit of overkill(?)
In article <C52EGz.27t3@austin.ibm.com> $LOGIN@austin.ibm.com writes: > >Does anyone out there have the toll-free (catalog request and order line) for >Heathkit/Zenith?  Please post the number if you've got it!  Thanks.