http://cgi.ebay.com/ws/eBayISAPI.dll...m=220340273153
Is that o-scope any good for simple sound card dac tuning
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http://cgi.ebay.com/ws/eBayISAPI.dll...m=220340273153
Is that o-scope any good for simple sound card dac tuning
Just about any oscilloscope will be fine. We're dealing with signals in the Khx range, not Mhz, so even a 1Mhz scope is overkill.
Having said that, the one you linked to is rather old. If it still works, then the price is certainly right. (6 bucks!) Of course, shipping will probably run you $40 on it.
I paid around $100 (including shipping) for my 100 Mhz Techtronics 'scope when I bought it on E-bay a few years ago, but it was much newer than the one you linked to. It's got true X/Y plotting though, which is nice. You can see the scanner output on the 'scope's screen.
Eh - if you don't mind driving up there to get it, and assuming you can get it for $6, it's probably worth it.
Adam
well shipping is 12.95 do that not a big deal..
after talking to you i decided i need to get one..
i got a 13 pound plate of aluminum in the mail and that only cost 13 bucks..
For $13 shipping I'd say go for it. You'd burn more than that in gas money driving up there to pick it up.
An oscilloscope for $19? Yeah, that's a deal even if it is ancient.
Adam
ok.. i made my bid (top bid) 25.
keeperx, I'd make sure the scope can do X and Y. I did a quick google search for that model and couldn't find much about it. If you get a decent scope, not only will it do X and Y, but it will handle blanking as well.
Here's a decent scope that handles X and Y, not sure about intensity though. But it probably has alot more features than the PDC scope. http://cgi.ebay.com/Heath-40-MHz-Osc...QQcmdZViewItem
well my id is in.. if its not useful ill give it to someone that can use it..
If thats the case ill have you find me another one when the time comes.
Anyone here use software-based scopes, and have any recommendations / pros / cons they would be willing to share?
i would say its cheaper to find a used oscope the deal with the software..
I had cause to explore this, and went with advice Steve (Roberts) and others gave. Go for the best used analog scope you can afford. Minimum of 100 MHz. You never know what you might want to do with one once you have it and how many do you really want? The moment you want to test diode driver overshoot you want FAST response, never mind the fact that the mod wave might only be 25 KHz or so.
Software scopes are a pain unless you have heaps of loot and need storage of waveforms and digital image presentation. And for similar performance their cost is extreme compared to a decent old analog scope.
When I researched scope choices, I learned that two scopes were highly recommended, Tektronix 265B (I think it was that), and HP Agilent 1740A. I bought one of each, second hand. The Tek was horrible. (Actually it was so decrepit that I argued for and got a refund). While both makes are recommended because field repair keeps them going way longer than their intended life, and is apparently eassy enough for many techs, I see no contest between them. HP Agilent scope 1740A has no fan, the case is sealed so dustproof, the graticule illumination is a backwash of electrons instead of feeble incandescent lamps that dull and blow and are awkward to replace and look just plain terrible in comparison. The HP Agilent controls are better, period. They handle hard use much better.
So, if you can get a good cheap HP Agilent 1740A scope, grab it and don't let go. It even does X/Y and Z (intensity), so you can test a galvo drive and laser mod all at same time. It only has one drawback, it's a bit big. But don't let that stop you, the Tektronix is too. If you really must have small, go with something like the Vellemann LCD scope.
I've tested the velleman. The 8 bit resolution is actually 6 bit, useless for laser.
problem with sound card scopes is they are sampling at the same rate laserboy is displaying at, so you'll get aliasing.
it costs beaucoup bux, but go with a picoscope if you must have software scope.
Parallax tech has one for 110$ , but its max rate is 100 khz, so on a 48 Ksamp second waveform, your pushing it, and on a 96 khz sound card, your toast.
This is one case where even a 1 mhz CRT based scope is really cost effective.
Nyquist's rule says you need to sample at a minimum of just over two times the max frequency of your waveform, and people who do this in practice will tell you 4-6 times for a digital scope, as many anti-aliasing filters in the scopes are poor at best.
Make sure whatever you buy has triggered sweep, or you will watch your laser waveforms "march" left or right across the screen. This is very annoying.
It will show up on the scopes control panel as a "Sweep Level" control. Or a "trigger" knob in the timebase.
Steve
Ok. That's no good then. Maybe eOscope is worth a look though, for small handheld LCD type. It's DIY though. I only mentioned this because they're small and portable. My earlier post covered what I think is the right way to go.Quote:
Originally Posted by mixedgas
Don't forget you can use my 'max.wav' I posted earlier for sound card DAC tuning without a scope, only a multimeter.
the software scopes I have seen don't let you do X/Y mode :( but then again I haven't looked in some time
I picked up a BK scope for $60 shipped, and found another one for parts for $10 local, does display the dac images pretty nicely.
FYI, there is a following of people making scopes out of soundcards :D I thought about doing that to mess with James...Picture it, sound card DAC hooked to soundcard scope displaying laser boy image on computer screen :eek: hmmmmm, hope I started something here lol
Only reason I stayed away from that was the input voltage was rated far too low for what I needed it for originally.
Does anyone know anything about these:
http://cgi.ebay.com/OWON-portable-7-...3A1%7C294%3A50
It's affordable, small, and has some nice features. The main drawback is it only goes up to 25MHz but that is good enough for most applications. I like that it can work off of a battery and has a USB port for PC data acquisition.
It has fair to good recommendations on sci.electronics.design, but according to those who have bought them, the serial/usb module costs extra, the backlight is dim,its best used in bright light, and the voltmeter function has its own inputs, ie its signal doesn't come in on the scope probes.
Also no FFT.
most buyers reccomend their next model up, which supposedly has a much better lcd.
Steve
Thanks. I wouldn't mind trading in my Tex 7603 for something like that. I love the 7603 but it's so BIG!
ok i lost that auction
can someone who know about this stuff find me a good o-scope deal?
im looking for the cheapest thing that will do what i need it to do..
I found mine on craigslist. I see them there from time to time. Try looking locally because there will be less people fighting to get them. Any deal on Ebay gets looked over by thousands. Also, oscopes (that you can afford) are big and heavy so you don't really want to have to ship one anyway.
Quote:
Originally Posted by carmangary
If your a craigslist junkie like me...check out craigshelper.com Lets you search many citys at once, instead of having to go to each one individually :)
My friend bought one of these a couple of months ago, I have had a chance to play with it a bit. Overall for the price I like it. The display could be better and it will not tell you pwm duty cycle. But you can measure the duty manually. Other than that everything is pretty ok.
Not sure what mixed is talking about. You can measure a voltage and see it on the screen with the probes. Maybe there is an even cheaper model.
If you are doing just electronic work it is a good little cheap scope. If you want x-y vector stuff, like a scanner output than you would be better off with an analog one.
Chad
Quote:
Originally Posted by carmangary
i could get this one
http://washingtondc.craigslist.org/m...985990390.html
Get it now!
chad
there are 8 of them
RIGHT NOW, GRAB ONE!Quote:
Originally Posted by keeperx
when you pick it up, cycle through the controls a bit and make sure the switch contacts are good. then take it home and put it where the puppy cant pee on it.
if you want to destroy a instrument, pee is better then acid, and mouse pee is the best at it.
quick test:
take a paper clip with you set it to a 10 or hundreds of millivolts scale,bleed off the static charge on your body, stick the paper clip into the center conductor of the BNC and grab the paperclip, assumes your wearing sneekers and NOT grounded, you should see a dirty 60 hz sine wave pickup when you have the sweep set to integer multiples of 16.7 milliseconds.
http://www.tek.com/Measurement/App_Notes/XYZs/
Steve
well i can pick it up tomorrow or thursday at lunch. so i hope there is one left.. there are 8 of them so,.....
anyone else want one?
read the manual tonight. I prefer to read manuals while doing #2, as do most engineers. makes it worth heating the bathroom.
http://bama.edebris.com/manuals/goldstar/os7020a
what the heck a dejavu file is, I have no idea.
Steve
its like PDF
http://sourceforge.net/projects/windjview
wow if this thing is in good condition, its a steal...
thats a much better scope then what you were going to get from da bay.. I just read the manual and looked at the schematics. nice one.
dont burn the crt by leaving a bright static dot on it, and READ the manual. Its also servicable to a certain extent, and the manual has the schematics,.
That is a excellent beginner's to intermediate oscilloscope. If it wasnt that I already have two scopes and 3 xy displays, I'd have you grab me one.
500 khz bandwidth in xy mode, not bad. blanking is inverted which is normal.
enjoy.
Steve
does that me i can draw laserboy waves on the screen?
that unit is overkill for laserboy, which is good. Its also good enough to measure DPSS risetimes and fall times.
Steve
And you found this how? >:)Quote:
Originally Posted by mixedgas
lost a 450$ (used) PTS-160 with the one hertz step option to 1 pregnant mouse and her offspring. She climbed in a open D sub hole on the back of the unit while I was away for a week to give birth.
I tried and tried and tried to stop the corrosion, to the tune of several gallons of solvent and adjusting the Ph, but it was not ment to be.
I had to settle for a ebay PTS250 without the front panel knobs (OEM) as a replacement.
Any one who works on used tech , especially that stored in old warehouses, will tell you "Death to Mickey", you hit a mouse once, you'll hate em.
http://www.programmedtest.com/pts160.html RIP, my beloved. Do note the 6,850 USD baseline price.
Steve
Ouch. I had it easy when I learned about mice and machines, it was only a microwave, and it wasn't mine either. Was inspiring though, I managed to half-rewrite the Mouse in a Windmill in Old Amsterdam on the strength of it. It was a horrible piece of doggerel, all I can remember offhand is "A little house with wires in, there on the stair, going buzz fizzle and zap in the air"..
ok im picking up 1 of these tomorrow. there are 7 left as of right now so i think im good (only sold 1 so far)
they are 60 bucks.. im not profiteering but i will gladly pick one up for someone.
they weigh just under 20 pounds each.
i have to drive to get them..
i will pick one up for someone else (if they are in good condition) for 110$ shipped in the US.
ok so now im picking up 2.. any other takers
whats the best way to ship an o-scope??..
i guess i should insure it..
Lots of bubble wrap and yes, I'd insure something of that natureQuote:
Originally Posted by keeperx
No reason to insure it since by default UPS insures up to $100 on all packages.
Definitely pack it well with lots of bubble wrap or styrofoam to protect the CRT.
yeah ill finger it out.. i have shipped plenty stuff.. i was just wondering about the internal components
call me and I'll walk you through it.
I have skype working.
Steve
steve, these leads will work right?
http://cgi.ebay.com/Two-x1-x10-100MH...|39:1|240:1318
yeah, those are nice, and they have compensation adjustments, which lets you match the response of the probe to the scope for fast work.
You pump a fast square wave into the probe and tune the little screw adjustment back at the connector for best looking edges.
very nice.
Steve
cool thnx, ill buy them (no probes included with scope)
One reason I went with the HP Agilent 1740A was that it had a source of fast square wave built in. It had just about everything I knew might be important. These new LCD scopes look nice though, I'd have one, if I had money for it.Quote:
Originally Posted by mixedgas
well i got the scopes..
they came in original packaging, are bareley used, and work perfectly...
don't mind the thick looking wave form.... thats just my finger...
Suh - weet! Send me a tracking number when you have one. :)
Good score that looks like a nice little scope.
chad
It will hopefully be the replacement for my big honking 7603. It isn't as good as my 7603 but should clear out some space. If anyone is interested in a 7603 (tektronix) and cart let me know. It's big so it might be better if you are local to austin or willing to travel. PM me if interested. (I am not holding my breath.)