Post by thread:[EE]:Oscilloscope

I am just a home hobbyist (no corporate $$ to help out). I have a background in software and have just started to experiment with microcontroller application development. Do people consider an oscilloscope a "must-have"? A logic probe just doesn't cut-it for rapidly changing pins. Does simulation using MPLAB completley eliminate the need for real circuit checking? (I'd be surprised). I have read very interesting .pdf from Tektronix which really pushes $$$ DPOs, but I do not have a multi $k budget for my (new) hobby. Can anyone recommend an entry-level 'scope for use in developing PIC circuits/applications. My budget is not without limits, but I want to get something that will be useful. Is spending, say, < $500 a fruitless exercise? TIA. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Sun, 3 Feb 2002, Gary Russell wrote: > I am just a home hobbyist (no corporate $$ to help out). > > I have a background in software and have just started to experiment with > microcontroller application development. > > Do people consider an oscilloscope a "must-have"? A logic probe just doesn't > cut-it for rapidly changing pins. Does simulation using MPLAB completley > eliminate the need for real circuit checking? (I'd be surprised). A 'scope is really nice to have, but I personally very rarely have to drag it out. > I have read very interesting .pdf from Tektronix which really pushes $$$ > DPOs, but I do not have a multi $k budget for my (new) hobby. Of course -- they make a LOT of money pushing new, super-whizbang scopes. If you're designing new 2GHz motherboards or UHF transceivers, you need a high end scope. If you're playing with 10 or 20MHz PICs, you don't need anywhere near that kind of hardware. > Can anyone recommend an entry-level 'scope for use in developing PIC > circuits/applications. > > My budget is not without limits, but I want to get something that will be > useful. Is spending, say, < $500 a fruitless exercise? Not at all. I have an old low-end Hitachi V-212 20MHz 'scope you could probably pick up used for well under a hundred bucks, it's quite sufficient for anything I've worked on lately. You don't need a lot, but at least a dual-channel with triggered sweep is good. For a lot of years I worked as a mainframe field engineer working on IBM gear. We always carried Tektronix 475 'scopes, which I have seen selling at under $200 on eBay... this floors me, these things are super nice. If you can find one with a DM44, so much the better - it's a piggyback digital multimeter. Dale -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Sun, 3 Feb 2002 22:41:29 -0500 Gary Russell <spam_OUTgary-russellTakeThisOuTPSUALUM.COM> wrote: > I am just a home hobbyist (no corporate $$ to help out). > > I have a background in software and have just started to experiment with > microcontroller application development. > > Do people consider an oscilloscope a "must-have"? A logic probe just doesn't > cut-it for rapidly changing pins. Does simulation using MPLAB completley > eliminate the need for real circuit checking? (I'd be surprised). For a hobby, maybe it is not necessary to have a 'scope. But I can think of a times when a storage scope was worth its weight in gold. Debugging I2C and SPI drivers, finding compiler interrupt handler bugs, and presenting an oscillograph to a memory manfuacterer showing their product is not to spec are a few. > I have read very interesting .pdf from Tektronix which really pushes $$$ > DPOs, but I do not have a multi $k budget for my (new) hobby. > > Can anyone recommend an entry-level 'scope for use in developing PIC > circuits/applications. For a low cost storage 'scope see: http://www.linkinstruments.com/oscilloscope21.htm I think you can get a 100MSa/s for 525USD. > My budget is not without limits, but I want to get something that will be > useful. Is spending, say, < $500 a fruitless exercise? > > TIA. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body

Gary, About a month ago I bought a Tektronix 475A Oscilloscope that Dale is talking about, on eBay. It cost me $252.45 including shipping. That thing is heavy and kind of beat up, but works very well - it's a 200Mhz scope with two channels and a multimeter. Once you compare it to RadioShack's 50Mhz scope for $800, I think you would agree that it is an awesome deal. I think you can get by without an oscilloscope, but when your circuit doesn't work, it simplifies troubleshooting by letting you "see" what's going on. Logic probe can't do it for you. Bottom line is, if you spend a lot of time dealing with circuits and don't care about the instrument's appearance, I would go ahead and buy a used scope. Works just as good (perhaps even better) as a new one, but doesn't cost as much. Sincerely, Vitaliy <SNIP> >We always > carried Tektronix 475 'scopes, which I have seen selling at under $200 on > eBay... this floors me, these things are super nice. If you can find one > with a DM44, so much the better - it's a piggyback digital multimeter. > > Dale -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

Gary Russell wrote... >Do people consider an oscilloscope a "must-have"? My own personal opinion, yes. It's one of those things which you don't really "need" that frequently, but when you do need it, it has this magical ability to transform the deeply mysterious into the blatantly obvious. An oscilloscope can save a **LOT** of time and frustration. Unless you're doing a lot of high-speed digital work, though, I don't think getting a scope with wide bandwidth gets you much added troubleshooting power. I'm still using the 20 MHz B&K two-channel scope I bought for hobby use ten years ago, and am completely satisfied with it. Dave -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam.....mitvma.mit.edu with SET PICList DIGEST in the body

> I am just a home hobbyist (no corporate $$ to help out). > > I have a background in software and have just started to experiment with > microcontroller application development. > > Do people consider an oscilloscope a "must-have"? A logic probe just doesn't > cut-it for rapidly changing pins. Does simulation using MPLAB completley > eliminate the need for real circuit checking? (I'd be surprised). As lots of people are about to tell you, an oscilloscope is the most indispensable iinstrument in the world. By dint of converting time domain signals into eye-domain :-) signales it lets your brain input vast quantities of otherwise unavailable information. If you are going to deal with analog signals Even if you are going to deal almost only with purely digital signals the scope will be very useful. If you deal with multiple digital channels the scope will be less useful mainly because it is less than adequate for the task which is better suited to a logic analyser BUT will still be far far better than alternatives. Ideally you want dual trace and delayed timebase and as many MHz as possible BUT a miniumum of a single channel with a good triggered sweep will be very very useful. At the very very bottom lvele you get old nasty single beam scopes without proper triggering. These are extremely frustrating and will put you off scopes. Even a 5 MHz scope is useful for many things but 10 MHz is better, and higher still better again. A scope will display signals above its rated bandwidth at rapidly decreasing amplitude but ideally you want a bandwidth at least as high as the maximum pulse speed you want to observe. Thus you will still see a 20 MHz / 50 nS single pulse on a 20 MHz scope even though you are at (or theoretically beyond) the limits of its ability. If you can afford digital storage you will not regret having it but it is not an essential to start with. An oscilloscope is liable to be your most useful tool. regards Russell McMahon {Quote hidden}> > I have read very interesting .pdf from Tektronix which really pushes $$$ > DPOs, but I do not have a multi $k budget for my (new) hobby. > > Can anyone recommend an entry-level 'scope for use in developing PIC > circuits/applications. > > My budget is not without limits, but I want to get something that will be > useful. Is spending, say, < $500 a fruitless exercise? > > TIA. > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

You may look in to http://xoscope.sourceforge.net/ and http://www.bitscope.com/ Francisco Russell McMahon wrote: {Quote hidden}>>I am just a home hobbyist (no corporate $$ to help out). >> >>I have a background in software and have just started to experiment with >>microcontroller application development. >> >>Do people consider an oscilloscope a "must-have"? A logic probe just >> >doesn't > >>cut-it for rapidly changing pins. Does simulation using MPLAB completley >>eliminate the need for real circuit checking? (I'd be surprised). >> > >As lots of people are about to tell you, an oscilloscope is the most >indispensable iinstrument in the world. By dint of converting time domain >signals into eye-domain :-) signales it lets your brain input vast >quantities of otherwise unavailable information. > >If you are going to deal with analog signals > >Even if you are going to deal almost only with purely digital signals the >scope will be very useful. > >If you deal with multiple digital channels the scope will be less useful >mainly because it is less than adequate for the task which is better suited >to a logic analyser BUT will still be far far better than alternatives. > >Ideally you want dual trace and delayed timebase and as many MHz as possible >BUT a miniumum of a single channel with a good triggered sweep will be very >very useful. >At the very very bottom lvele you get old nasty single beam scopes without >proper triggering. These are extremely frustrating and will put you off >scopes. > >Even a 5 MHz scope is useful for many things but 10 MHz is better, and >higher still better again. >A scope will display signals above its rated bandwidth at rapidly decreasing >amplitude but ideally you want a bandwidth at least as high as the maximum >pulse speed you want to observe. Thus you will still see a 20 MHz / 50 nS >single pulse on a 20 MHz scope even though you are at (or theoretically >beyond) the limits of its ability. > >If you can afford digital storage you will not regret having it but it is >not an essential to start with. > >An oscilloscope is liable to be your most useful tool. > > > >regards > > > > Russell McMahon > > > > > > > > > > > > >>I have read very interesting .pdf from Tektronix which really pushes $$$ >>DPOs, but I do not have a multi $k budget for my (new) hobby. >> >>Can anyone recommend an entry-level 'scope for use in developing PIC >>circuits/applications. >> >>My budget is not without limits, but I want to get something that will be >>useful. Is spending, say, < $500 a fruitless exercise? >> >>TIA. >> >>-- >>http://www.piclist.com hint: The PICList is archived three different >>ways. See http://www.piclist.com/#archives for details. >> >> >> > >-- >http://www.piclist.com#nomail Going offline? Don't AutoReply us! >email listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body > > > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email @spam@listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

A number of years ago I bought a used 15 MHz analog dual trace scope at the Dayton Hamvention for $80. A better $80 has never been spent. This has saved hours and hours of debugging time by allowing me to figure out exactly what is going on rather than making educated guesses. The MPLAB simulator is not a complete substitute because it moves rather slowly through timing loops when the stopwatch is enabled. When you are dealing with the timing of signals, the scope is a much more useful tool. Given that I was working with PIC's... mostly at 4 MHz... the 15 MHz bandwidth limitation was never much of a problem Recently my employer purchased a really nice Agilent mixed signal scope. Of course it does a lot that my old $80 scope won't do. But I survived quite nicely for several years with a cheap scope... it was well worth the money. John Hansen At 10:41 PM 2/3/2002 -0500, Gary Russell wrote: {Quote hidden}>I am just a home hobbyist (no corporate $$ to help out). > >I have a background in software and have just started to experiment with >microcontroller application development. > >Do people consider an oscilloscope a "must-have"? A logic probe just doesn't >cut-it for rapidly changing pins. Does simulation using MPLAB completley >eliminate the need for real circuit checking? (I'd be surprised). > >I have read very interesting .pdf from Tektronix which really pushes $$$ >DPOs, but I do not have a multi $k budget for my (new) hobby. > >Can anyone recommend an entry-level 'scope for use in developing PIC >circuits/applications. > >My budget is not without limits, but I want to get something that will be >useful. Is spending, say, < $500 a fruitless exercise? > >TIA. > >-- >http://www.piclist.com hint: The PICList is archived three different >ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email KILLspamlistservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

Dave Dilatush wrote: > > Gary Russell wrote... > > >Do people consider an oscilloscope a "must-have"? > > My own personal opinion, yes. It's one of those things which you don't > really "need" that frequently, but when you do need it, it has this > magical ability to transform the deeply mysterious into the blatantly > obvious. An oscilloscope can save a **LOT** of time and frustration. > > Unless you're doing a lot of high-speed digital work, though, I don't > think getting a scope with wide bandwidth gets you much added > troubleshooting power. I'm still using the 20 MHz B&K two-channel scope > I bought for hobby use ten years ago, and am completely satisfied with > it. I think a decent dual trace cro is very important, especially for a beginner who will gain a lot from "seeing" what the electricity is doing. Even 50MHz duals are cheap secondhand. -Roman -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

At 10:41 PM 2/3/02 -0500, Gary Russell wrote: >Do people consider an oscilloscope a "must-have"? A logic probe just doesn't >cut-it for rapidly changing pins. Does simulation using MPLAB completley >eliminate the need for real circuit checking? (I'd be surprised). You have a question about something that I feel *VERY* strongly about! I consider a scope to be *essential* if you are going to be doing any serious electronics work. I use a dual trace analog scope (Tek 465) as my main tool - I use more it than I use any other instrument. Even more than a multi-meter or DMM. I reach for the scope probe whenever I need to measure a voltage or see just the circuit is doing. Most of the time, voltage measurements are qualitative and do not need a lot of accuracy. Is the supply sitting at about 5V? The scope tells you: yes - about 5V - nice and clean - no ripple or noise. What about that pin on the processor? Touch the probe and see. Spend some money on a used (but working!) analog scope and spend as much or more money on a couple of used (but working!) Tek X10 scope probes. Good scope probes are essential - you will waste much time and frustration working with cheap probes. X10 probes are MUCH more useful than X1 but switchable X1 - X10 Tek probes tend to be expensive - even used. So stick with X10 probes if you are on a budget. eBay or a local hamfest are great places to buy both scopes and probes. If you have any budget left after buying the analog scope and probes, head over to Oricom's site <http://www.oricomtech.com/indexa.htm> and take a close look at Dan's pocket test bench. Its a nice little add-on for a PC or laptop that gives you digital scope capability, as well as logic analyser, pulse generator, etc. Dan has done a nice job on the package and software and sells it for a very reasonable price. But you won't use it anywhere near as often as the analog scope. dwayne Dwayne Reid <spamBeGonedwaynerspamBeGoneplanet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email TakeThisOuTlistservEraseMEspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

Hi! I Used the RS232 output from my DMM (Voltkraft, true RMS autorange) it's a nice feature, specially because this model has an Optocoupler, so the measured source is isolated from the computer, I use this one with a computer program in visual basic to plot the curve discharge/charge of a battery, very useful when you design a battery charge :-) But keep in mind that the readout speed is SLOOOOOW, about 1 read every 2 seconds, but for my requirements are far enough!. thisone sends a decimal value ever 2 seconds in 2400 baud N81 Oh another thing: Thinking about buy an Oscilloscope???, My humble opinion is that if you are a Pic programmer (or any processor) there is nothing more usefull that a DSO (Digital storage oscilloscope) I have the Tektronik TDS-220 dual trace 100 mhz 1 Gigasample, great machine, It's a little expensive but it worth every cent. Sometimes when I can't get a pic program works, and I have no idea of what is going on, just program one pin in the PIC so that in a given moment a UP or DOWN signal ocurrs and connect this to the TRIGGER input, and set the Scope for single shot. After that event, the oscilloscope will record all the information from the triger moment to ahead (depends on the timebase) later you can simply navigate the signals to see what hapened in this moment, this is an amazing capability that is impossible in any analog scope!. hope be helpfull with my comments. see you. byby Some hours ago you wrote: >Date: Mon, 4 Feb 2002 13:05:04 -0800 >From: Colin Constant <EraseMEColin_Constant-NRRAYTHEON.COM> >Subject: Re: [EE]:Oscilloscope >MIME-Version: 1.0 >Content-Type: text/plain; charset=us-ascii > >Has anyone tried one of those multimeters that have a PC interface? Worth >having? > >Thanks, >Colin _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservEraseMEEraseMEmitvma.mit.edu with SET PICList DIGEST in the body

----- Original Message ----- From: "Colin Constant" <RemoveMEColin_Constant-NRspam_OUTKILLspamRAYTHEON.COM> To: <RemoveMEPICLISTTakeThisOuTspamMITVMA.MIT.EDU> Sent: Monday, February 04, 2002 3:05 PM Subject: Re: [EE]:Oscilloscope > Has anyone tried one of those multimeters that have a PC interface? Worth > having? I have a metek with a PC interface, and I used it a lot. Didn't like the software that came with it, so I hacked my own interface with visual basic. One time I used it to calibrate a wind veloicity meter. We hacked the wind velocity meter to a tall pole on top of my pickup truck, tossed a generator in the back, and my friend rode shotgun with a desktop PC in his lap (having no laptop) taking data from the wind sensor. I drove the rig. We got it all together about midnight one Saturday night, and rode out into the flats on a long straight road to do the calibration run. I started out driving down this highway at 5mph for a few minutes, then 10 mph for a few minutes, and so on whilst he operated the datalog program I wrote, jotting down the speeds and making sure the data was being logged. It was quite a sight, creeping along at 5mph in the night, with this crazy sensor pole sticking up 15' high out of the truck bed whizzing away, Well pretty soon some bright lights come up behind us. It was a cop. He stopped us, and asked if we were drinking, then started examining the crazy rig, the PC in the lap, and the running 120V generator on the back of the truck, all inching down the road at a fast walk, with these two guys telling this cockamamie story. He was not convinced by our excuses for a long time. When we finally talked our way out of jail, we resumed our slow test, 5mph at a time. The sensor blew up when we hit 50MPH, exploding in a flash of plastic, metal, and duct tape. It was the most fun I'd had in years. --Lawrence -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservspamspamBeGonemitvma.mit.edu with SET PICList DIGEST in the body

> At 10:41 PM 2/3/02 -0500, Gary Russell wrote: > > >Do people consider an oscilloscope a "must-have"? A logic probe just doesn't > >cut-it for rapidly changing pins. Does simulation using MPLAB completley > >eliminate the need for real circuit checking? (I'd be surprised). Scopes are like libraries: ANY scope is better than no scope. Any library is better than no library. A fast scope is better than a slow scope A two channel (or more) scope is better than a single channel scope a DSO is better than an enalog scope, in most cases but if you don't have any scope at all, and have no money, a really cheap used student model from 1960 will be a great addition to your lab, and won't set you back much more than a week's worth of big macs. 90% of what you use a scope for will be will under 1 mHz, single trace, repetitive waveforms that won't require DSO. Another guy in the lab gave his old scope to his kids, who built it into part of their "submarine control room" consisting of blamkets over cardboard boxes, a cheap student model scope, some relays and wires and a burned out audio board. --Lawrence -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestSTOPspamspam_OUTmitvma.mit.edu

Also don't discount the (really) cheap approach. There is a program called DigiTrace out there. Basically it turns your parallel port into a logic analyzer. You just have to build a cable that hooks your port up to your project. No circuitry involved...just a cable. It's a great program, and you get some pretty good results considering the price. It has saved my butt a couple of times at least. The one thing I'm not exstatic about is that when you exit the program, I think it turns the port back to outputs, and if your cable is still connected, you can get some wierd results. That one freaked me out once :) I tried to contact the author of the program about adding a small buffer that could be tristated when the program exits, but I have yet to see a response (~1-2 months). Eventually when I find time, I will try to figure out if when the program is loaded, it happens to toggle some other bit on the parallel port, which I could then hook to a buffer. If anyone else has time to do this first, please share :) This program is windows based. I've only ever run it on win98. The timing seems to be fairly accurate, it runs through a self calibration when you start it. If you play with the value you lose timing accuracy, but you can see more than one iteration of the waveform. Here is a link for the page: http://www.xs4all.nl/~jwasys/old/diy2.html . I hope someone else finds this as useful as I do! Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams > > I am just a home hobbyist (no corporate $$ to help out). > > > > I have a background in software and have just started to experiment with > > microcontroller application development. > > > > Do people consider an oscilloscope a "must-have"? A logic probe just doesn't > > cut-it for rapidly changing pins. Does simulation using MPLAB completley > > eliminate the need for real circuit checking? (I'd be surprised). > -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestSTOPspamEraseMEmitvma.mit.edu

My most common use for a scope is for RS232 or RS485 connections that won't work. The scope makes it obvious if the baud rate is wrong, if the signal is inverted, if the signal really goes negative when it should, how many data bit are there, etc. For that a 5MHz single channel would do, but I recommend at least two channels. If money is short, (as usual) buy used gear locally so you can play with it before buying. If you buy used gear by mail you should know the gear and/or the dealer well. Don't worry about age as long as it is at least transistorized. The age of gear may become a factor in the future. I have some analog stuff built in the 60's that I use reguarly. But if EPROMS are only good for 10 to 25 years some of the digital stuff built in the 70's and 80's may start crapping out soon! Sherpa Doug P.S. If anybody knows of a modern replacement for a HP4800A Vector Impedance Meter for under US$5000 please let me know. > {Original Message removed}

> ANY scope is better than no scope. > but if you don't have any scope at all, and have no money, a really cheap > used student model from 1960 will be a great addition to your lab, and won't > set you back much more than a week's worth of big macs. I agree with the above BUT !!! There really is a minimum level below which you have to work hard to make your tool help you. The really cheap 60's model student type instruments (eg some bottom end Heathkit scopes etc) didn't have a triggered sweep that understood the meaning of the word trigger, had no time base calibration, no vertical amplitude calibration and more (or, rather, less). While such scopes DO have a useful place when there is absolutely nothing else you really really really should try and rise above this level if you can. I would venture to suggest that an old valve scope with a decent timebase and y amplifier with calibration would be more useful than a newer bottom end largely solid state scope. (I've used both). I suspect you could often do this for only tens of dollars in the US. As noted before - more is always better but useful entry level is one beam/trace, proper triggered sweep, calibrated sweep speeds, multi range calibrated voltage input, 5 MHz bandwidth. After that a second trace is pretty useful, more bandwidth is always nice, various sync modes, beam add/subtract etc. Delayed sweep is very useful but usually comes after quite a jump in other specs. Storage is nice but dearer. Old analog storage scopes tend to be very dim, very dead, hard to use and cranky. The tube is a very very major part of the system and they degrade terminally with age and are cost far more than the scope is worth to replace. (Note that most scopes have a single beam which is chopped or alternated to make two traces. True dual beam scopes are rare - the feature is useful to have but only if everything else meets your spec). Probably un-useful thought - a modern PC would make an interesting high speed scope using eg a Sigma Delta A2D if you could burrow under the operating system and timers etc. You might be able to get many 10's of MHz of analog bandwidth using a now entry level Celeron/AMD/xxx 850/1000 MHz cpu and a parallel port. Russell McMahon -- http://www.piclist.com hint: To leave the PICList KILLspampiclist-unsubscribe-requestspamBeGonemitvma.mit.edu

On Mon, Feb 04, 2002 at 01:37:59PM -0700, Dwayne Reid wrote: > I consider a scope to be *essential* if you are going to be doing any > serious electronics work. I use a dual trace analog scope (Tek 465) as my > main tool - I use more it than I use any other instrument. Even more than > a multi-meter or DMM. I reach for the scope probe whenever I need to > measure a voltage or see just the circuit is doing. Would an analog scope, like the Tek 465, be useful for a serial digital signal, like the PS/2 port on a PC? I guess I'm asking, would a used Tek 465 or a used TDS 210 be a better buy for a beginner/hobbyist doing some PC integration projects? From the looks of it, a used TDS 210 goes for about 3 times a used Tek 465, but if it's 3 times as useful, I may consider it. -Dave -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Hi Dave, I bought my first 'scope when 13 years old, a Hameg 307, 10 MHz, one channel, cost me more than half a year of my pocket money, and still my father added abt 75% of the cost. Last April it celebrated its 20 th anniversary, and I still use it some, it is still as good as it was 20 years ago. Of course, I have progressed along the line, and my most recent buy was a TEK 485 (350 MHz) for 700 Deutschmarks (abt. 300 $US), and I consider this one among the best 'scopes for any hobbyist - IF we are talking analog 'scopes, that is. I have worked several years as developer at a well-known 'scope manufacturer in Frankfurt, Germany, they are called HAMEG, in the US IIRC they are called B+C, this gave me a lot of insights also for preferring analog 'scopes to digital ones for ALMOST any work. I have used the TEK TDS220 and the big 300 series, and "I was not amused"! Cumbersome menus, knobs responding a lot after "realtime", and - hear, hear - some nasty software errors, if you knew where to look for them... My "I wish I had it" instrument is the TEK 2467, a 400 MHz unit with a super optical amplification unit in front of the CRT. Price for this one - albeit used - is absolutely prohibitive! But for the lucky guys who have used it sometime, it is abolutely the best. Greets Jochen Feldhaar DH6FAZ (BTW: I always use my analog 'scopes for looking at serial signals, to check for baud rates and voltage levels. I even use the 'scope instead of a multimeter in most instances where I am looking for a fault in some circuitry) Dave Dribin schrieb: {Quote hidden}> > On Mon, Feb 04, 2002 at 01:37:59PM -0700, Dwayne Reid wrote: > > I consider a scope to be *essential* if you are going to be doing any > > serious electronics work. I use a dual trace analog scope (Tek 465) as my > > main tool - I use more it than I use any other instrument. Even more than > > a multi-meter or DMM. I reach for the scope probe whenever I need to > > measure a voltage or see just the circuit is doing. > > Would an analog scope, like the Tek 465, be useful for a serial > digital signal, like the PS/2 port on a PC? I guess I'm asking, would > a used Tek 465 or a used TDS 210 be a better buy for a > beginner/hobbyist doing some PC integration projects? From the looks > of it, a used TDS 210 goes for about 3 times a used Tek 465, but if > it's 3 times as useful, I may consider it. > > -Dave > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Absolutely, an analog scope is fine for digital signals. IMHO a low end analog scope would be far more useful than a low end digital scope, but that's my opinion. I have not used digital scopes extensively, but from what I understand a cheaper DSO might nt have a hgh enough sample rate to catch very short glitches. You won't see a one-time glitch on an analog scope either, but you won't miss any detail. Dale -- "Curiosity is the very basis of education and if you tell me that curiosity killed the cat, I say only the cat died nobly." - Arnold Edinborough On Wed, 6 Feb 2002, Dave Dribin wrote: {Quote hidden}> On Mon, Feb 04, 2002 at 01:37:59PM -0700, Dwayne Reid wrote: > > I consider a scope to be *essential* if you are going to be doing any > > serious electronics work. I use a dual trace analog scope (Tek 465) as my > > main tool - I use more it than I use any other instrument. Even more than > > a multi-meter or DMM. I reach for the scope probe whenever I need to > > measure a voltage or see just the circuit is doing. > > Would an analog scope, like the Tek 465, be useful for a serial > digital signal, like the PS/2 port on a PC? I guess I'm asking, would > a used Tek 465 or a used TDS 210 be a better buy for a > beginner/hobbyist doing some PC integration projects? From the looks > of it, a used TDS 210 goes for about 3 times a used Tek 465, but if > it's 3 times as useful, I may consider it. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

part 1 3057 bytes content-type:text/plain; charset=us-ascii Hi, Dale wrote: Absolutely, an analog scope is fine for digital signals. IMHO a low end analog scope would be far more useful than a low end digital scope, but that's my opinion. I have not used digital scopes extensively, but from what I understand a cheaper DSO might nt have a hgh enough sample rate to catch very short glitches. You won't see a one-time glitch on an analog scope either, but you won't miss any detail. I agree with what Dale says especially with respect to digital signals; this is where the low-end digital scopes are very useful. We have several TDS-220s and we find them invaluable especially when debugging serial comms/bit bash protocols; it is very easy to capture I2C sequences, for example, which is very difficult using an analog scope. In the end, it boils down to what you imagine you will use it for most. I will say that when we introduced one of our contractors to the TDS-220, he went and purchased his own almost the next day and he uses it day in-day out. Dan (Embedded Dale Botkin <EraseMEdaleEraseMEBOTKIN.ORG>EraseMEMITVMA.MIT.EDU image moved 06/02/2002 13:34 to file: pic22413.pcx) Please respond to pic microcontroller discussion list <@spam@PICLIST@spam@spam_OUTMITVMA.MIT.EDU> Sent by: pic microcontroller discussion list <spamBeGonePICLISTKILLspamMITVMA.MIT.EDU> To: .....PICLISTspam_OUTMITVMA.MIT.EDU cc: Subject: Re: [EE]:Oscilloscope Security Level:? Internal Absolutely, an analog scope is fine for digital signals. IMHO a low end analog scope would be far more useful than a low end digital scope, but that's my opinion. I have not used digital scopes extensively, but from what I understand a cheaper DSO might nt have a hgh enough sample rate to catch very short glitches. You won't see a one-time glitch on an analog scope either, but you won't miss any detail. Dale -- "Curiosity is the very basis of education and if you tell me that curiosity killed the cat, I say only the cat died nobly." - Arnold Edinborough On Wed, 6 Feb 2002, Dave Dribin wrote: > On Mon, Feb 04, 2002 at 01:37:59PM -0700, Dwayne Reid wrote: > > I consider a scope to be *essential* if you are going to be doing any > > serious electronics work. I use a dual trace analog scope (Tek 465) as my > > main tool - I use more it than I use any other instrument. Even more than > > a multi-meter or DMM. I reach for the scope probe whenever I need to > > measure a voltage or see just the circuit is doing. > > Would an analog scope, like the Tek 465, be useful for a serial > digital signal, like the PS/2 port on a PC? I guess I'm asking, would > a used Tek 465 or a used TDS 210 be a better buy for a > beginner/hobbyist doing some PC integration projects? From the looks > of it, a used TDS 210 goes for about 3 times a used Tek 465, but if > it's 3 times as useful, I may consider it. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads part 2 165 bytes content-type:application/octet-stream; (decode) part 3 154 bytes -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> Would an analog scope, like the Tek 465, be useful for a serial > digital signal, like the PS/2 port on a PC? I guess I'm asking, would > a used Tek 465 or a used TDS 210 be a better buy for a > beginner/hobbyist doing some PC integration projects? From the looks > of it, a used TDS 210 goes for about 3 times a used Tek 465, but if > it's 3 times as useful, I may consider it. > > -Dave I've never used an analog scope (well, not technically true, but not for anything practical!), but do have a TDS-210. I absolutely love it! As a hobbyist, I found it difficult to determine whether a resonator was resonating, and if my project was not working because of a logic bug, or because the micro had no clock! As I moved into IIC communications, and serial comms., the scope became complete indispensable ... it's amazing how you can (with the right sweep rate) actually display and read the digital data of an RS-232 connection running at 115,200 (or such). I do mostly digital stuff and the digital scope has done me well. For someone with a broader analog requirements, an analog scope might be a better choice. -- Mitch -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

----- Original Message ----- From: "Mitch Miller" <TakeThisOuTmitch.....TakeThisOuTMDMILLER.COM> > I've never used an analog scope (well, not technically true, but not for > anything practical!), but do have a TDS-210. I absolutely love it! As a > hobbyist, I found it difficult to determine whether a resonator was > resonating, and if my project was not working because of a logic bug, or > because the micro had no clock! As I moved into IIC communications, and > serial comms., the scope became complete indispensable ... it's amazing > how you can (with the right sweep rate) actually display and read the > digital data of an RS-232 connection running at 115,200 (or such). > I would like to add, I have a TDS 220, and I would sell body parts to rasie money to pay bills before parting with the scope. I design equipment for DMX 512 stage lighting. The serial RS 485 stream runs at 250Kbps, and I can get a good trigger and then move to any byte I wish to observe and watch the bits toggle. (the data stream has 513 bytes (one start byte and 512 data bytes)) I used to own a Kenwood cs 5165 IIRC triple channel 6 trace analogue scope (the third channel was useless as it was a fix amplitude) and I would have a hard job to keep it triggered while trying to watch a byte. Another partially satisfied tek customer (not satisfied as the supplied probes keep loosing tips, and the wave star software they give with the fft comms module is next to useless, the new version costs a bit to upgrade to :o() Regards, Kat. ____________________________________________________________________________ /"\ ASCII Ribbon Campaign | K.A.Q. Electronics \ / - NO HTML/RTF in e-mail | Software and Electronic Engineering X - NO Word docs in e-mail | Perth Western Australia / \ | Ph +61 419 923 731 ____________________________________________________________________________ -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Hello everyone, Love the talk about the scopes, it's been on my mind too. I think all of you have just modivated me to LUG my huge Tek 45A from storage to my shop my grandpa gave it to me a long time ago, but I never did anything with it. For those of you unfamilar with the Tek 45A..... it's HUGE!!! I'm not sure how old it is, but I'm pretty sure it's a tube scope. I have a "little" cart that it sits on and I think you can rack mount it.... but I don't have a rack for it. Hopefully it's good enough for what I need it for...... pic6F877 stuff.... 20MHz I'm not sure how fast the scope is..... ------ I'm looking into the OsziFOX (ProbeScope).... it looks neat....small and portable I just got an email back from a sales person checkout: www.testequipmentdepot.com/Wittig/ozsifox.htm they have the OsciFox for $69 it comes with the Windows Software...... and the cables for $10 you can get software that will work on the PalmPilot!!!!!! which is what I was REALLY looking for.......so I think I'm gonna shell out the bucks for that now. --you can also find some software on sourceforge.net that will work with it too.... for linux and other OS's g {Original Message removed}

Maybe un-useful, but one I have thought of often. Here's my thinking: Forget trying to get high speed analog signals into your PC. Have an external box that captures the waveform, scales it, isolates it from your precious PC's ground and power supply, and also scales it in the time dinemsion, and wraps a nice ground plane around it.. Jam a bitstream into whatever port is easy - RS232, parrallel, or USB (if it were a commercial product USB would be the way to go) and use the PC's megabytes of memory for the digital storage, use the PC's powqerful graphics for the display, and use the brain for things like displaying the RMS value as a digital voltmeter, counting the frequency, counting the pulse width, all the things that take a lot of squinting or guessing on an old analog scope. At least 4 channels, plus a few logic channels like an HP mixed signal scope. Now if we are going to measure signals in the megahertz range, we are out of the PIC's league. How do TEK and the other big boys achieve A/D conversion in a 100 mHz scope? keep in mind this is just an interesting mental excercise - I'm not planning on building this anytime soon. Besides, they already make them. --Lawrence > Probably un-useful thought - a modern PC would make an interesting high > speed scope using eg a Sigma Delta A2D if you could burrow under the > operating system and timers etc. You might be able to get many 10's of MHz > of analog bandwidth using a now entry level Celeron/AMD/xxx 850/1000 MHz cpu > and a parallel port. > > > > > Russell McMahon > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

----- Original Message ----- From: Dave Dribin <TakeThisOuTdave-mlKILLspamspamDRIBIN.ORG> > Would an analog scope, like the Tek 465, be useful for a serial > digital signal, like the PS/2 port on a PC? I guess I'm asking, would > a used Tek 465 or a used TDS 210 be a better buy for a > beginner/hobbyist doing some PC integration projects? From the looks > of it, a used TDS 210 goes for about 3 times a used Tek 465, but if > it's 3 times as useful, I may consider it. Well, I'd say yes. For doing embedded work digital scopes are a huge help. I got a used TDS 320 off of Ebay a while back for $350; it's in rough shape, but very usable --nice to have a "real" digital scope at home. We've got TDS-420's at work that we use all the time. We also have a TEK 465, but use the TDS's more often, however there are times when you can't see whats really going on with older digital scopes like we have. The digital phosphor scopes are nicer, but are still going for $$$. These seem to do the trick for now. Before that, at home I used a RadioShack Probescope (aka OzziFox) that I got when RS was closing them out ~$28. --Its a little cumbersome, but you could use it when a proper scope wasen't available. Also, the thing is darn portable. These are offered up all the time on Ebay. Anyway, if you're just tinkering at home, and can wait, maybe you could shop around and see whats available. If you get paid to tinker, I doubt you'd go wrong going for the TDS210. My old instructor used to say something like "You never regret having the proper tools, but you can often regret not having them." :') -Dal -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Wed, Feb 06, 2002 at 07:34:19AM -0600, Dale Botkin wrote: > Absolutely, an analog scope is fine for digital signals. IMHO a low end > analog scope would be far more useful than a low end digital scope, but > that's my opinion. Well, I like that opinion (probably because it's cheaper :). As long as an analog scope is "good enough" for my limited home use, I'd rather save the few hundred dollars on PCB manufacturing or something. BTW, are there any "buyer beware" questions I should ask and signs I should look out for while buying a used analog scope? Are there certain parts that always break? How important is calibration for non-critical measurements? Are there certain models that should be avoided due to notriously poor quality? Are there certain models that are notriously high quality? Thanks again for all the good input so far, guys! -Dave -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Wed, Feb 06, 2002 at 10:42:03AM -0700, Dal Wheeler wrote: > ----- Original Message ----- > From: Dave Dribin <.....dave-mlRemoveMEDRIBIN.ORG> > > > Would an analog scope, like the Tek 465, be useful for a serial > > digital signal, like the PS/2 port on a PC? I guess I'm asking, would > > a used Tek 465 or a used TDS 210 be a better buy for a > > beginner/hobbyist doing some PC integration projects? > > Anyway, if you're just tinkering at home, and can wait, maybe you could shop > around and see whats available. If you get paid to tinker, I doubt you'd go > wrong going for the TDS210. My old instructor used to say something like > "You never regret having the proper tools, but you can often regret not > having them." :') Yeah, I totally agree about having the proper tools. I'm just trying to find the minimum I can skirt by with. If I got paid to tinker (i.e. price really wasn't a limiting factor), I'd definitely go with a new DSO. But if I can monitor signals like I2C and PS/2 with a used analog scope, I'll probably go that direction. -Dave -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

The commonest gotcha with a digital scope is aliasing caused by the sampling frequency being too slow. If you want to look at a 20MHz square wave you need to sample at >100MHz to have even an idea of what it looks like. I was snagged for a while looking at what was supposed to be a 4MHz PIC oscillator (using a Tek THS720) and seeing a perfect sine wave of several kHz, thinking something was very wrong but finally just changing the timebase clarified the situation. I would not have had the problem using my ancient Heathkit 20MHz single-trace scope that I had to throw out after a filter cap broke down and burned out a transformer winding: impossible to get parts. /\/\/\/*=Martin {Original Message removed}

> Yeah, I totally agree about having the proper tools. I'm just trying > to find the minimum I can skirt by with. If I got paid to tinker > (i.e. price really wasn't a limiting factor), I'd definitely go with > a new DSO. But if I can monitor signals like I2C and PS/2 with a used > analog scope, I'll probably go that direction. There is always a market for working, used test equipment. You can probably grow your capability pretty painlessly as your needs and budget grow. If you purchase a used scope (analog or digital) at a fair price and take care of it you'll get a lot of your money back when you trade up some day. My first scope at home was a 20MHz Dual Trace Hitachi. I bought it at a Hamfest for $90USD, used it for about 5 years and sold it for $75USD. Pretty low cost of ownership considering all of the projects it worked on. Tim -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 11:55 AM 2/6/02 -0600, Dave Dribin wrote: >On Wed, Feb 06, 2002 at 07:34:19AM -0600, Dale Botkin wrote: > > Absolutely, an analog scope is fine for digital signals. IMHO a low end > > analog scope would be far more useful than a low end digital scope, but > > that's my opinion. > >Well, I like that opinion (probably because it's cheaper :). As long >as an analog scope is "good enough" for my limited home use, I'd >rather save the few hundred dollars on PCB manufacturing or something. I use both analog (Tek 465) and digital (Tek THS-720P) scopes and find I use the analog scope FAR more often than the digital. I agree with Dale - if you have a limited budget, spend it on an analog scope. But like I mentioned earlier, buy decent scope probes too. If you buy a used scope off eBay, expect to spend as much on probes as you paid for the scope. I really can't emphasize enough just how important good probes are. Stick with Tek X10 probes unless you get a great deal on Tek X1-X10 probes. Avoid the cheap import X1-X10 probes - they break easily and just don't work well. >BTW, are there any "buyer beware" questions I should ask and signs I >should look out for while buying a used analog scope? Are there >certain parts that always break? How important is calibration for >non-critical measurements? Make sure the trace is bright and focused over the entire screen. Wiggle (side to side as well as up & down) all the controls and rotate them over the whole range - you are looking for noise or bad connections. Feed a variable frequency square wave signal into the vertical inputs (DC coupled) and see just how square it looks. >Are there certain models that should be avoided due to notriously poor >quality? No idea. > Are there certain models that are notriously high quality? Tektronix! Just excellent! dwayne Dwayne Reid <RemoveMEdwaynerspamBeGoneplanet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

----- Original Message ----- From: Lawrence Lile <spamBeGonellile@spam@spam_OUTTOASTMASTER.COM> To: <TakeThisOuTPICLISTspamMITVMA.MIT.EDU> Sent: Wednesday, February 06, 2002 12:51 PM Subject: Re: [EE]:Oscilloscope > I knew somebody had done it. > > BTW, the link you sent was really interesting, but didn't seem to have much > to do with a scope. > --Lawrence Well, no, but the fundamental components are there. You mentioned that a pic probably wasen't up to it previously, but it really doesn't need to be part of the actual aquisition circuit using the techniques shown in the video digitizer. Fill up the FIFO using a HS clock, use the pic to poll the ram and send it serially; like the bitscope... Actually he does have a 20MHz generic sampler somewhere on that site... PS sorry responding directly to you, I hit reply and didn't send to the list... > > ----- Original Message ----- > From: "Dal Wheeler" <dwheelerEraseMEinsightek.net> > > Doesn't this sound like the Bitoscope project? > > > > I thought about rolling my own someday too though... > > Something roughly like this: (only faster) > > http://www.techmind.org/vd/mk1/vdescrpt.html > > Slap a different trigger on it; higher clock and smaller buffer, multiple > > similtaneous channels, 8 fast comparitors into an extra FIFO,No fpga on > > it...? -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> >BTW, are there any "buyer beware" questions I should ask and signs I > >should look out for while buying a used analog scope? Are there > >certain parts that always break? How important is calibration for > >non-critical measurements? Calibration is normally good on more "modern" cros, generally anything 20MHz dual trace or 50MHz dual trace will have ok calibration, even the cheap asian brands. I've owned a few. As they age the electro caps can get ESR faults, these change performance over time and heat. Most typically the symptoms are that the timebase or vertical amp will change over time, so a 10v dc input may start ok reading 10v than read 10.5v when the cro is hot. (or freq change) This only takes 10 mins to test. Also check with a hard to trigger signal and adjust the triggering so it JUST triggers, then wait for it to get hot and see if the triggering circuit goes iffy. A good signal for this is a composite video from an AV plug on a VCR etc. The MOST COMMON fault is "scratchy" pots, like an audio pot they "crackle" when moved and will cause movement or jumping of the trace. Watch the trace while you wiggle and slowly turn the pots. Sometimes that can be fixed by spraying with pot cleaner, but likely they will never be perfect again. Also look for any burnt-in lines across the screen showing the cro has seen long hours of use. :o) -Roman -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

I really want one of these: http://www.jwardell.com/about/seniorproj/ . Seems ideal for me for so many applications. Also begging to be open sourced...a $25 scope would help so many people out (ok, ok I know you gotta pay for the Palm too). Unfortunately every time I check with one of the guys who designed it, he tells me that Syracuse University is still pulling an intellectual property thing, and that he can't give me any more information bout it. Now since all the guys have graduated, he says the project is pretty much dead. Does anyone know how to get around intellectual property crap like this? Seems like the university is limiting education, not helping it along. Any ideas? Did I mention I really really want one? :) Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Hi Dave The 465 is a nice Scope! however, not a DSO at all, and I think that Digital storage is a requirement for capture data from Rs232, It would be useful to see if the voltage changes are right, but to see what data is going on, how many bits, and stuff like that, you need a digital storage. You need Digital Storage for that, I have at home the TDS 220 and is a amazing machine, I can see almost everything, and I think that it worth every cent I spend on it, but , I buy it because I work at home. if you intend to use it for hobby maybe it's a little expensive for that :-) I think that If you want an Oscilloscope for digital use, and hobby only, you can use a computer based scope, they are far more cheaper (yet not as good as a TDS-210) and is good for digital signals. an even cheaper way for digital analisys are parallel port "software" logic analyzer. There is one at: http://www.xs4all.nl/~jwasys/old/diy2.html the program is called : digitrace_win95.zip I downloaded the software (the only necessary thing), but don't tested yet, it uses the parallel port directly as digital inputs directly. Does not have too much storage 32K samples only, but It can be enough for Rs232 capture. see you Leandro At 01:18 06/02/2002 -0600, you wrote: >Would an analog scope, like the Tek 465, be useful for a serial >digital signal, like the PS/2 port on a PC? I guess I'm asking, would >a used Tek 465 or a used TDS 210 be a better buy for a >beginner/hobbyist doing some PC integration projects? From the looks >of it, a used TDS 210 goes for about 3 times a used Tek 465, but if >it's 3 times as useful, I may consider it. > >-Dave _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Wed, 6 Feb 2002 18:58:30 -0300, leandro wrote: >Hi Dave > >The 465 is a nice Scope! however, not a DSO at all, and I think that >Digital storage is a requirement for capture data from Rs232, It would be >useful to see if the voltage changes are right, but to see >what data is going on, how many bits, and stuff like that, you need a >digital storage. > Sorry to disagree but a DSO is not really a *requirement* to scope RS232 data. Folks were scoping RS232 data long before DSO's came into existence (or at least commonly available). With proper triggering, sweep rate, and a repeating data pattern, RS232 data can be quite easily seen on an analog scope. The ability to 'de-calibrate' also allows you to set the sweep for one division per bit time. Very handy. This isn't to say that DSO's aren't very good tools; they are. Analog scopes, though, are a good alternative in many cases. Regards, Bob <snip> -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Wed, 6 Feb 2002, Bob Barr wrote: > Sorry to disagree but a DSO is not really a *requirement* to scope > RS232 data. Folks were scoping RS232 data long before DSO's came into > existence (or at least commonly available). Amen! I'm one of them. Of course the last time I did it, 19200 was considered pretty fast ;) but of course the speed doesn't matter, until you get really sloooow, when phosphor starts to fade between bits... I've occasionally wished for a DSO when looking at hard to reproduce one-shot events, but since I already have a CRO I seriously doubt I'll ever need one badly enough to actually shell out cash for one. Dale -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 11:55 AM 2/6/02 -0600, you wrote: >Are there certain models that should be avoided due to notriously poor >quality? Are there certain models that are notriously high quality? Some of the Tek models use hybrids in the deflection circuits. They are not repairable except by cannibalizing another 'scope as the hybrids were proprietary/in-house and Tek has gotten rid of their hybrid facility but kept the design secret. "U401" ;-) Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" RemoveMEspeffEraseMEspam_OUTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com 9/11 United we Stand -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Spehro, or anyone else for that matter: any chance you can share the "models"? > At 11:55 AM 2/6/02 -0600, you wrote: > >> Are there certain models that should be avoided due to notriously poor >> quality? Are there certain models that are notriously high quality? > > > Some of the Tek models use hybrids in the deflection circuits. They > are not repairable except by cannibalizing another 'scope as the > hybrids were proprietary/in-house and Tek has gotten rid of their > hybrid facility but kept the design secret. "U401" ;-) -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>> Some of the Tek models use hybrids in the deflection circuits. They >> are not repairable except by cannibalizing another 'scope as the >> hybrids were proprietary/in-house and Tek has gotten rid of their >> hybrid facility but kept the design secret. "U401" ;-) >Spehro, or anyone else for that matter: any chance you can share the >"models"? I've got a 7934 with hard-to-get hybrids in it; the same devices are also used in some of the 7104, 7103, and maybe 7904A units as well. The 2465 series is notorious for parts made of unobtanium. newell -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 07:22 PM 2/6/02 -0800, you wrote: >Spehro, or anyone else for that matter: any chance you can share the >"models"? The 2445/65, according to the info I have. Tek sold off their hybrid division to Maxim, who decided Tek wasn't buying enough and they'd discontinue the chips (Horizontal output), so Tek did a last time buy. The parts from the last time buy had an abnormally high failure rate. This, from a Tek insider at the time (not me). Tek also has closed their repair department and subs it to 3rd party cal/repair, BTW. I have no way of verifying it, but it seems plausible. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" @spam@speffRemoveMEEraseMEinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com 9/11 United we Stand -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>Are there certain parts that always break? Yes, probes. Always have some cheap probes available that you normally use, and keep the expensive wide band/high quality ones in a draw for when you need them. Probe leads always manage to get tangled where you least need them and get pulled so that the inner core of the coax breaks or goes intermittent. If you can find cheap probes with a replaceable lead, they may be worth investigating. You will find that cheap probes will generally be designed for 50 or 100Mhz bandwidth, so with most scopes will not be too limiting. It is only when you go to a 200+MHz scope that the differences really become apparent. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

>> Are there certain models that are notriously high quality? >Tektronix! Just excellent! Or Hewlett Packard/Agilent. Either Tek or HP are really the best when it comes to 'scopes. The biggest problem you will have with trying to look at serial transmission (I2C, SPI, RS232) with an analogue scope is that it is hard to "read" the data unless you have a reliable trigger point and a repetitive wave form (identical data going across each time). This is where the digital scope scores because you can do single shot displays. If it is more a case of looking for marginal levels, then an analogue unit will be OK. However there is always the possibility of building a digital storage unit to use with an analogue scope if you need to look at serial data. This may be useful as you can then set the amount of storage available :) -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

At 09:08 AM 2/7/02 +0000, you wrote: > >> Are there certain models that are notriously high quality? > > >Tektronix! Just excellent! > >Or Hewlett Packard/Agilent. Either Tek or HP are really the best when it >comes to 'scopes. Everyone seems to believe that, with the consequence that other brands can be cheaper to buy for the same functions. I have a compact 20MHz one that I keep on my office mini-bench that does 90% of what is needed and leaves room for everything else. Cost? Maybe $140 US including the 'scope, reprinted service manual, and two nice new generic probes. The Tek gets used when its needed, but often most of the work is in the software, the analog stuff just needs a quick test or two). I picked up a cute little Tenma (Taiwan made) 3" scope (needs a new cap in the power supply) for $10 that will live in a semi-permanent test fixture for one product line. The only ones I'd absolutely avoid are the old vacuum tube Eico and Heathkit ones unless you absolutely can't afford anything more than $15-$25- even a 1MHz scope is sometimes better than nothing! There are still even a few Tek vacuum tube scopes that are still worth having if you have more room than money. Also, take care on ebay, there are stories of known bad stuff being sold, so do watch feedback ratings and so on. Watch out when there is no return policy and the seller claims not to know anything. For example, there is a problem on the 4xx series with attenuator contacts, IIRC, and those can be hard to fix, I understand. But, used test equipment dealers are so expensive that you could buy a couple from ebay and still come out ahead. P.S. I've heard Frys (SW USofA) sometimes has good prices on some of the little Tek TDS portable digital LCD scopes. http://www.tek.com/Measurement/cgi-bin/framed.pl?Document=/Measurement/scopes/index/prodindex_handheld.html&FrameSet=oscilloscopes (of course they are more than $500, but $900+tax might be within reach). Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" EraseMEspeff@spam@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com 9/11 United we Stand -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Somehow I wound up replying directly on this, so here it is again... (Sorry Lawrence) The bitscope project is nice. Velleman has some assembled PC scopes at about the same price point (with plusses and minuses over bitscope). I've been spoiled to have Tek and HP analog and storage scopes over my entire career, but I've often thought that for the hobbyist, a scope is a big investment. The PC soundcards scopes are probably better than nothing but not accurate for quantitative measurements. I've often wondered what you could do to make a cheap hobby scope. I've thought about an A/D, a counter, a memory system, and a CPU, but then you have bitscope and you probably can't do it for much less money. $200-$300 will buy a pretty nice used scope so there isn't as much incentive. Some of my wilder ideas: It sure seems like you could make a multisync monitor into a bizzare scope with just a little hassle. 15" monitors are cheap as can be these days. Drive the horizontal at the sweep frequency. You can convert the signal to 8 bits using an A/D and feed the green (mono) input. Count lines to skip a little bit between "traces" and use a counter to generate a vertical sync. So you wind up with a 3D scope where the amplitude is the brightness of the "trace" and you get a bunch of traces on the screen at once. Probably not very practical. We've all see the propeller clocks and the little LED "metronomes" that display messages in the air. Wouldn't a scope like that be cool? An LM3909 (bar graph driver, right?), and LED bar, and a motor spinning at the horizontal sweep frequency. Blank it between pi and 2pi. I wonder if you could have one blade of the propeller do channel 1 and the other blade channel 2? While one is blank, you drive the other one (chop only, no alt). I remember seeing plans years ago for driving an old TV's sweep circuits to make a scope. That's always been an interesting idea to me but it seems too hard to go find the right spots. Easier to display on a PC. A while back I did a "stamp project of the month" where we took our APP-II (basically a PIC16F873) converted analog samples and drove a VB program to make a kind of scope. Not especially fast but sort of cool. Anyway, just random musings.... Al Williams AWC * Floating point A/D http://www.al-williams.com/awce/pak9.htm > {Original Message removed}

The other thing I heard is that the magazine isn't going to be supplying ROMs for much longer (they might have stopped already), which means that again, the information is out there, but you can't get access to it. The author can't distribute it, and the magazine won't. Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams Michael Rigby-Jones wrote: {Quote hidden}> > Not really what the OP was after, but a couple of us at work built the > GameBoy DSO and I have found it very usefull for relatively low frequency > jobs where power is a problem e.g. checking igntion/injector waveforms on > car enignes. Only real downer is the author signed a deal with Elektor so > he can't open the source code. > > http://www.semis.demon.co.uk/Gameboy/DsoDemo/DsoDemo.htm > > Regards > > Mike -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> -----Original Message----- > From: Josh Koffman [SMTP:spamBeGonelistsjoshEraseME3MTMP.COM] > Sent: Thursday, February 07, 2002 5:17 PM > To: PICLISTspamBeGoneMITVMA.MIT.EDU > Subject: Re: [EE]:Oscilloscope > > The other thing I heard is that the magazine isn't going to be supplying > ROMs for much longer (they might have stopped already), which means that > again, the information is out there, but you can't get access to it. The > author can't distribute it, and the magazine won't. > > Josh > Just checked on the Elektor web site, and they have 30 complete (ready built) cartridges left at the 'special' sale price of $135 (76.50ukp). That doesn't seem very special compared to the Oszifox which has a 20MS/s sample rate, and has a built in LCD. The gameboy cartridge is two channel though, and I have found it usefull. But then, a couple of us in work built them and we only had a buy a few components (ROM, PCB and a couple of op-amps), the rest we "found" in our lab :o) The site is also showing the PCB for $16.50 and the EPROM for $28.00. If it ever gets to the state when neither Elektor nor the author will supply the EPROM/hex file then I may be able to help (but not until/if that situation arises). Mike -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads