Oscilloscope for home duty

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I've always wanted to learn how to use one. Can some give advice on a cheap model that would suffice for most work I'd encounter in simple troubleshooting of stereo equipment? I see there are a number quite cheap <$50 on Ebay such as the Hitachi V-212. What about some of those Leader branded? Any must have accessories?

Here is a local craigslist post, prices look high, don't they?

Leader LBO-514A, 15MHz, works fine, excellent condition, with manual and RSR AK-220 x1/x10 high-impedance probe. $100.

Hitachi V-212, 20MHz, looks very good, works fine, with manual and Hitachi AT-10AJ x1/x10 high-impedance probe. $115
 
thats not to bad Ive got 2 tektronix scopes and 1 hp I've used a hitachi scope but never a leader.
I now there both good brands as for the price it depends how old they are and what condtion there in. So when it comes down to it all thay matters is do you want to spend that much.

If $100 is ok then I say go for it but my choice would be the hitachi as for using the it's pretty straigh forward.

1 knob is vertcal deflection or y axis this is your voltage and your horizontal ie frequency like 1micrometer per microsecond or anything like that.
But you set the horizontal to the frequency you want to display and the vertical for how tall you want it to look .

The screen has a grid on it that corresponds the the increments on the horizontal and vertical knob.

Hope this helps you alittle if you have any other question please ask away.
 
Are the ranges and features on that Hitachi appropriate for audio equipment troubleshooting and messing around? I think the price is a little on the high side, some of these go for under $50 on the 'Bay, but the seller is a HAM hobbyist, so it hasn't been abused like some you see that appear to be from a workplace.
 
Really theres no real ones for just audio the 10mhz bandwith means that the higest frequency that it can display 1 single cycle on the crt is. Ya you can go on ebay but for fifty buck I won't expect much.

And I bet the one that the HAM is selling could be calibrated if you wanted to pay for the service as for the fifty dollar one I DON'T KNOW.

Just remember an oscillascope is a precision piece of equipment and when you buy from the owner 9 time out of ten you can belive them as for some ebay seller how knows.

I'LL just leave you with this you get what you pay for.

Nick
 
DreadPirate said:
I've always wanted to learn how to use one. Can some give advice on a cheap model that would suffice for most work I'd encounter in simple troubleshooting of stereo equipment? I see there are a number quite cheap <$50 on Ebay such as the Hitachi V-212. What about some of those Leader branded? Any must have accessories?

Here is a local craigslist post, prices look high, don't they?

Leader LBO-514A, 15MHz, works fine, excellent condition, with manual and RSR AK-220 x1/x10 high-impedance probe. $100.

Hitachi V-212, 20MHz, looks very good, works fine, with manual and Hitachi AT-10AJ x1/x10 high-impedance probe. $115


It's a GREAT idea to have an oscilloscope, if you like to play with electronic signals or circuits. After a multimeter, it's probably the next piece of test equipment to buy.

I used to buy lots of surplus oscilloscopes and refurbish and sell them (I'm talking well over a hundred scopes, over two or three years). And I don't think you can go too far wrong by getting an older Tektronix analog model. I wouldn't even consider any other type. Anything from a 453 to a 475 will be pretty cheap, fairly repairable should the need arise, and will be extremely-well-known by much of the tech community if you need help, and will have dirt-cheap parts-units available for quite a long time. But, mainly, they were by FAR the best scopes available, when they were made, and are still far better than most or all newer non-Tektronix analog scopes. They were definitely built to last, too.

If you can afford the space for a larger, heavier scope, the most value can probably be had by getting a Tektronix 7000-series mainframe scope and some amplifier and timebase plug-ins. The 7704 and 7704A (200 MHz), and the 7904 and 7904A (500 MHz), are regarded by many as some of the best analog oscilloscopes ever made. A couple of decades ago, a loaded 7904A would set you back about $30,000. Now they're about $300! And if you go for a 100 MHz 7603, the price might be less than half of that, or even lower. And there are all kinds of other plug-ins available, for them (e.g. 7L5 spectrum analyzer plug-in). (Shipping costs would be quite high, for the 7000-series. So see farther below.)

Slightly less reliable (and with more "unavailable" Tek-custom ICs), but newer, lighter, and "better" in many ways, would be something like a 300 MHz Tek 2465 (or the A or B versions; 350MHz and 400 MHz). The 2465's are regarded by many as the best portable analog oscilloscopes ever made. The rest of the 2200-series are decent, too. Something like a 2235 (100 Mhz) is very common, and very nice to use, as well as very small and light. And they are fairly easy to work on. The 2213A or 2215A (and others) would be OK, too (although I would stay away from the non-A versions of those two, since they had an older type of power supply).

I like them all!

And, if you happen to be lucky-enough to be anywhere near one of the main warehouse sites, keep an eye on http://www.govliquidation.com . They are the sole-source private contractor that sells the military's surplus equipment. I used to buy my equipment there, to resell, before they went to an on-line auction format, and cut the lot sizes down to onesies and twosies. Just keep in mind that nothing from there is guaranteed to work, or even be complete. And don't necessarily trust the photos, descriptions, or conditions codes. So don't bid as high as you might on eBay. And it's a very good idea to GO to the site, before the auction, to inspect everything. (At a larger site, for a large test equipment sale, it's REALLY, really(!) interesting, anyway!) And, if you're lucky, you'll be able to buy THREE scopes, there, for the price of what one would have been, on ebay (or maybe even for the $45 minimum bid!), and maybe at least one or two of them will work perfectly, and you'll have one or more parts units already, or be able to sell one or more of them. (Note, too, that you normally have to GO to the actual warehouse site, to pick up any items that you have won the auctions for. They don't ship anything.)

You will need some good probes, too. You should try to get probes that have a higher bandwidth than the scope (as long as their compensation range is still compatible with your scope's inputs), in case you ever want to use the scope's full bandwidth. There are usually quite a few good used Tek probes, on eBay. And the Tektronix site (http://www.tek.com) has a page that lists the probes that are meant to be used with each of their older model scopes. (They also have a great scope tutorial, called something like "The XYZ's of Oscilloscopes".) There are probably some links, for those pages, on my links page, at http://www.fullnet.com/~tomg/links.htm .

Sorry to blather-on, for so long, about all of that. That was the short version! I could probably drone on, about scopes, for many pages.

Good luck!

- Tom Gootee

http://www.fullnet.com/~tomg/index.html

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Re: Re: Oscilloscope for home duty

gootee said:



It's a GREAT idea to have an oscilloscope, if you like to play with electronic signals or circuits. After a multimeter, it's probably the next piece of test equipment to buy.

I used to buy lots of surplus oscilloscopes and refurbish and sell them (I'm talking well over a hundred scopes, over two or three years). And I don't think you can go too far wrong by getting an older Tektronix analog model. I wouldn't even consider any other type. Anything from a 453 to a 475 will be pretty cheap, fairly repairable should the need arise, and will be extremely-well-known by much of the tech community if you need help, and will have dirt-cheap parts-units available for quite a long time. But, mainly, they were by FAR the best scopes available, when they were made, and are still far better than most or all newer non-Tektronix analog scopes. They were definitely built to last, too.


http://www.fullnet.com/~tomg/index.html

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I forgot to mention that I think I'd stay away from the Tek 455. I think they were mainly sold to the military. At any rate, they're "dogs". I haven't owned quite ALL of the later Tek models, but, I think that almost any other Tek general-purpose scope model, from, say, the 422 on up, should be fine for most purposes, except that I wouldn't want any model with "455" in the model designation.

There are always trade-offs, when considering used equipment. But you can't go too far wrong with any of the Tektronix 400-series, 2200-series. or 7000-series oscilloscopes.

- Tom Gootee

http://www.fullnet.com/~tomg/index.html

"He who lives in a glass house" should not invite "he who is without sin".

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nhuwar said:
Really theres no real ones for just audio the 10mhz bandwith means that the higest frequency that it can display 1 single cycle on the crt is. Ya you can go on ebay but for fifty buck I won't expect much.

And I bet the one that the HAM is selling could be calibrated if you wanted to pay for the service as for the fifty dollar one I DON'T KNOW.

Just remember an oscillascope is a precision piece of equipment and when you buy from the owner 9 time out of ten you can belive them as for some ebay seller how knows.

I'LL just leave you with this you get what you pay for.

Nick


Nick,

Maybe you were thinking about something in the timebase specs. The BANDWIDTH specification of an oscilloscope is simply the frequency at which the displayed amplitude is 3dB down from what it should be (based on the input's amplitude).

And, IIRC, most of the Tek scope models I've calibrated would display less than one cycle, for the whole CRT width, at higher frequencies than their bandwidth rating. At any rate, most scopes can at least _display_ signals that are higher than their bandwidth rating. But for input frequencies higher than their BW, the displayed amplitude is incorrect (usually on the low side by more than 3dB, with more error the higher the freq goes).

Some scopes also won't _trigger_ at frequencies that are much above their rated bandwidth. Some of the Tek 475 "200 MHz BW" scopes that I cal'd would trigger at over 300 Mhz. But some of them would only go to 220 MHz or less before the trigger just wouldn't "lock-on" to the signal, any more.


- Tom Gootee

http://www.fullnet.com/~tomg/index.html

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nhuwar said:
Really theres no real ones for just audio the 10mhz bandwith means that the higest frequency that it can display 1 single cycle on the crt is.

We might want to clarify what is meant by bandwidth on a scope, it is the bandwidth of the vertical amplifiers, basically the highest frequency the scope is capable of accurately displaying.

The highest frequency that a scope can display one single cycle of would be determined by the horizontal sweep rate.

I've got a couple of old Tektronix scopes in the basement, a 555 (couple of pics of one here ) and a 551 (pic here )
They've got some really cool plugins, and inside the construction is a thing of beauty. I just wished the #&$*# things worked.

You could probably pick one of those models up on Ebay for about $10, but the shipping would be around $23,968 (just the power supply is enough to give you a hernia) ;)
 
m8o said:
Tom, Thank You!

And thanx for the link to govliquidation.com and annotation. Yep, wish there was a location on LI. But I don't understand, can one bid and purchase completely online? I don't understant how it's done.

edit: oh, never mind. Bidding isn't open on any of them. I get it now. ;)

Thanx again,
Steve


Steve,

Usually, there's one good test equipment sale each month, at http://www.govliquidation.com . But it happens simultaneously at many of their warehouse locations. So just "keep an eye on" their site. And if you register, there, you should be able to "save your favorites", so you're (more) ready when bidding opens, on them.

Intelligent searching can save you a lot of time. For example, looking for FSC codes (e.g. "electronic test equipment" is "6625") can help. But looking for specific keywords is usually great, e.g. "tektronix", or "packard" (or maybe "hewl" instead), or, of course, "scope", although looking for common mis-spellings can pay off, too. Also, once you are familiar with which warehouse sites/bases are (fairly) nearby, you can use the Advanced Search to narrow things down, considerably.

You CAN "bid and buy completely on line", as you put it. But, you normally DO still have to physically go to the warehouse site that you bought the stuff from, to pick up the item(s), for the cost to be reasonable ([Hint:] unless you can form a network of friends near the various sites, who can ship to each other; BUT, some of the stuff is so "odd" that you just have to see it for yourself, to know... You could spend a lifetime looking at all the cool stuff they have... You'll see!), and, you have to pick it up within the allotted timeframe or you forfeit your stuff and get no refund!

Have fun! (I sure did!)

Once you get into the nitty-gritty, feel free to email me before committing, at tomg at fullnet dot com.

- Tom Gootee

http://www.fullnet.com/~tomg/index.html

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Sounds like I've tapped the right well here. I'll go with Tek if that is the industry standard. Same reason I went with the Fluke 77 for a meter. This surplus site is great. I'm in the DC area, probably lots to look into. I'm going to have to get rid of some stuff first, I'm on a "one in" "one out" rule now.
 
gootee said:



Nick,

Maybe you were thinking about something in the timebase specs. The BANDWIDTH specification of an oscilloscope is simply the frequency at which the displayed amplitude is 3dB down from what it should be (based on the input's amplitude).

And, IIRC, most of the Tek scope models I've calibrated would display less than one cycle, for the whole CRT width, at higher frequencies than their bandwidth rating. At any rate, most scopes can at least _display_ signals that are higher than their bandwidth rating. But for input frequencies higher than their BW, the displayed amplitude is incorrect (usually on the low side by more than 3dB, with more error the higher the freq goes).

Some scopes also won't _trigger_ at frequencies that are much above their rated bandwidth. Some of the Tek 475 "200 MHz BW" scopes that I cal'd would trigger at over 300 Mhz. But some of them would only go to 220 MHz or less before the trigger just wouldn't "lock-on" to the signal, any more.


- Tom Gootee

http://www.fullnet.com/~tomg/index.html

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My mistake Inever said I know everything I just thought I did
:headbash:
 
Our electronics lab at university is furbished with about 100 tektronix scopes, the budget TDS model or whatever it is. There are significantly better scopes available if you have money spare, but the TDS is pretty easy to use. The manual actually makes sense and it's all kind of easy.

I used to have a Fluke 123 Scopemeter, very, very easy to use, well made and useful to have to hand. But also not cheap.
 
Somewhat OT, but related...

Question for those in the know, for the non-electronics-diy-newbz like me ...

If I want to check that my opamp-based amp does not ocillate, what MHz should I "check up to" ?

I ask, as this will define the ocilliscope bandwidth I should be looking for (and partially, how much $$$ I will need to spend). I have a -OLD- Heathkit scope my dad made when he took their self-study at-home courses. I'd like something better tho... :eek:

If that is too broad of a question to answer given all the variables that may go into it, is there a "frame of reference" that can be made based on the open loop gain frequency response of a opamp/device then? something like "check up to 1/2 the bandwidth" or "check up to twice the bandwidth", etc.?

thanx all
 
Re: Re: Oscilloscope for home duty

gootee said:


Slightly less reliable (and with more "unavailable" Tek-custom ICs), but newer, lighter, and "better" in many ways, would be something like a 300 MHz Tek 2465 (or the A or B versions; 350MHz and 400 MHz).
------------------

Yes, the 24xx are well known to blow up their input amplifier hybrids.
You cannot repair them and you cannot get new hybrids from Tek.
Best to stay away or to check them carefully at least.

Gerhard

ps
I really liked the Iwatsu SS-5712, 4 ch 200 MHz, very bright,
excellent trigger, circuit is in the handbook, mostly standard parts,
one bad transistor in X-deflection in 20 years of service,
was easy to repair.
 
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