Best oscilloscope choice?

[ayeaye]

I think i should exactify what i said about buying old analog oscilloscopes. As anyway i have responsibility. From the companies i said, it is said Trio and Kenwood oscilloscopes are not good, so avoid these. Others said not to be good, are Heathkit and Bell & Howell, so avoid these, in spite they often are the cheapest. What this guy from eevblog said to be good other than Tektronix, are Hitachi, GoldStar, Kikusui and Hameg. Also HP, but some say HP oscilloscopes are not so good. This guy knows what he says. He especially said that Hitachi is good, so prefer that, it's like the next best after Tektronix.

Some others who can be trusted, said that Iwatsu is good, also Leader. There is not so good information about the others, so see the reviews and learn more. BK Precision also seems to be appreciated, also some serious people seem to use Beckman and Philips. There was an excellent demonstration of a Tenma oscilloscope, and this oscilloscope performed just wonderfully, better than any other i have seen. But it was said, that such oscilloscopes, different from Tektronix, are not based on military standards. So when if buy Tektronix, you get a good thing, but then you pay twice more.

About the very old oscilloscopes, like these with vacuum tubes, the only ones they say can be used, are Eico and Telequipment. Like one can get an Eico 460 worth to buy from ebay in America, for $50 with shipping. These are only 4.5 MHz one channel, but one may find a use for them. One should consider with so old oscilloscopes though, that you most likely should replace just everything there, other than the crt tube and power supply transformer, so make sure these work. At that vacuum tubes don't seem to be a problem at all, as they seemingly can always be bought from ebay, so in spite of how it may seem, vacuum tubes are not really things to avoid. It is possible to get service manuals online, for almost all these. But it may cost to you more than buying a good 1980's 20 MHz two channel oscilloscope, so it is not exactly minimalism what concerns money, it may be minimalism just for the sake of it, or when you love restoring old oscilloscopes.

My oscilloscope still works fine. Except when i don't use it for some time, the potentiometers and switches somewhat play, until i move them back and forth a bit, then they work fine again. But that's normal.

Why some oscilloscopes are not so good, like some analog oscilloscopes or pocket or usb oscilloscopes. Because their circuits, such as amplifies and triggering, are so primitive. Things become more complicated when measuring changing things, Like the amplifies themselves contain capacitances and whatever, which cause distortion and interference. So what can be wrong. Everything can be wrong you can imagine. The can be unstable, like show different values at different times, with no way to fix it. They may distort the signal. The may cause interference, like additional oscillations in your signal. They may make the signal to be unstable and change fast, when it really doesn't. Because of instability of the signal or a primitive triggering system, they often may not be able to trigger. At that things may be fine, when you just measure a 60 Hz sine signal, but you see problems when you go to any higher frequency or hae a more complex signal. At that, it may not be fine even then. Like some Heathkit oscilloscopes show some sharp angle at the bottom of the most perfect sine signal. More than that, some even show you always a sine signal, no matter what the shape of your signal is.

So consider, this need for quality, is not for having a very high precision measuring equipment. So one should consider these requirements, just to have an instrument which you really can use for measurements. Not a thing which shows funny things on a screen, which may also look like nice, but that really cannot be used for anything useful. Especially when you are using it for things like overunity, one should be especially careful, as measurement is everything there.

When buying an oscilloscope, as i said, the best when on its picture there is a signal on the screen, especially when you don't feel being able to repair an oscilloscope. But this eevblog guy said, it's enough when they say that it is working. Then the very minimum is, that it's said that it powers on, and something appears on the screen, like a dot. Less than that, don't even consider buying, unless you need some spare parts from that particular scope. Because when the power supply transformer or the crt tube doesn't work, then this scope cannot be even repaired. Don't rely on sellers saying that this scope was just not tested, or they cannot or have no means to test it, this doesn't assure you anything, and it's also often questionable, that they pretend to be so stupid that they cannot test an oscilloscope anyhow. Don't rely on statements like, the oscilloscope is in good condition, this may mean anything, like it looks nice, but its crt tube doesn't work. Look for clearly saying that it works, because when it works, there is no reason that prevents the seller from clearly saying so.

About auctions, it is better to buy items from ebay, that you can buy at once. Because auctions are often a anipulation in ebay. Consider most of the bids mostly come in the very end of the auction. The buyer can also in some cases choose not to sell to the highest bid, so he can use his sock puppet or a good friend or business partner, just to pump the price up. What concerns old oscilloscopes though, auctions can sometimes be considered. Like there are auctions where they couldn't sell the oscilloscope at all, and sometimes it's an oscilloscope worth to buy, which one can get cheaply. It is possible to see in ebay, what items were actually sold, and with what price. So when you see an oscilloscope in an auction worth to buy, and before the very end of the auction there were no bids at all, you may consider buying it, you may get a bargain. But avoid the hazard, that is, maybe i can get it cheaply, think seriously about the reasons before going for anything.

I also found a new method of using oscilloscope. Like, often you have to calculate a power, and all you have are oscilloscope images, like of the voltage and current. Then what you can do, is to draw these graphs in gschem. Gschem has a very simple output file, just a text file for vector graphics. And from that file, like use python to calculate the bower based on two graphs of the oscilloscope signals.

What concerns my oscilloscope, i didn't have to do any repair. All i did, was a minimal calibration based on the oscilloscope's calibration signal, and even that was almost correct. The biggest problem was the cleaning. I used a strong cleaning agent for painted surfaces, no it doesn't damage plastic parts neither make them less shining, but you may first try out at some less visible place. Plus some graffiti removal pads maybe. I got it nicely clean, even the yellow on the light plastic parts, goes away with this. The only problem, the paint seems to be somewhat oxidized, as it is darker than it originally was. Some paint polisher may improve that, but i did not risk that, to damage the paint anyhow. It is also no problem to paint the metal case, it can be easily taken apart so that only the sheet metal remains. But this is not necessarily a good thing to do, as the original paint is a great value.

The metal parts i cleaned only with a tooth paste, maybe a lack of my imagination, but it was enough, makes them nicely shining, removing dirt and also oxide. The moving parts of the handler needed oiling, for which i used vaseline. The knobs are sometimes somewhat bent, as they hit them with heavy objects or then like to put the oscilloscope to stand on its knobs, doing that carelessly. A knob has a long rod, that is fixed at one end with a screw or something. It can be taken out and bent straight. I have one knob bent slightly, which is almost not noticeable, and causes no problems. But i did not risk to make it straight because this is a somewhat risky, as the rod has to be perfectly straight. I could make my scope nice and decent looking, all i think is necessary. I wrote this just to give you some idea of what it takes. Nothing much, it's mostly just cleaning. Unless there is some knob missing or such, and you have to replace it with some 3D printed one, or something. But in this selfless overunity effort, using an oscilloscope with some knobs missing, is i think a sign of pride.

Oscilloscopes, these things show us the nature. Not what we used to see nature is, but nevertheless it's nature, the ways we may not used to think about it. Beautiful as it always is.

Hope this was useful for some. And hope that it makes you not to hesitate to buy an old oscilloscope. The risk is not so great as you think, if you think everything well through, i think in 90% of the cases you will get a good working oscilloscope. And you will discover what a fun dealing with such old oscilloscopes, really gives you.

[FatBird]

Ebay has some good values for the money.
Here is a Sinometer brand for under $200 with free shipping.

                                                                                                                               .

[AlienGrey]

Ebay has some good values for the money.
Here is a Sinometer brand for under $200 with free shipping.                                                                                                                             .

Your having a larff it's got nothing on it, i wouldn't wast your money! you can get a Regol DS 1054z for £250 and look at the diffidence !

https://www.rigol-uk.co.uk/Rigol-DS1054Z-Digital-Oscilloscope-p/ds1054z.htm#.VpbSBlIVvcshttps://www.rigol-uk.co.uk/Rigol-DS1054Z-Digital-Oscilloscope-p/ds1054z.htm#.VpbSBlIVvcs

[ayeaye]

Ebay has some good values for the money.
Here is a Sinometer brand for under $200 with free shipping.                                                                                                                             

$200 with shipping, good value for money? I'm talking about old oscilloscopes one can buy from $50 with shipping, to $100. Good, completely working oscilloscopes, one can use for anything.

But you have $200 to spend? Great, then buy this one http://www.ebay.com/itm/Tektronix-Tek-465-Oscilloscope-with-Factory-Installed-DM43-Multimeter-/281903775425?hash=item41a2c63ec1:g:wQIAAOSwZG9Wjx2s  Tektronix 465, 2 channel 100 MHz, refurbished, calibrated, tested, has probes, excellent scope. The same TinselKoala had, if i'm not mistaken, ask him, he can tell you plenty of things about it. And all for $186 with shipping if you are in America. That is, it depends on where you are in America, but if you are in America, you can certainly get it for less than $200 with shipping. If you are in Europe, you should find scopes sold in Europe, as these things are heavy and their shipping costs a lot. But i don't know where you are, so i brought that as an example. Now compare that to this 10 MHz single channel Sinometer, these things cannot be compared, simply cannot be. This Tektronix is so good that i cannot even dream to have a so good scope, yet i'm satisfied with the one i have, it is a good scope and works well.

But this Sinometer. 10 MHz, one channel. Ok, you don't need more than 10 MHz, Ok, you can do with one channel, as it has an external sync. But this frequency is not only about range, it is about quality. These scopes are known to give different readings at different times, they are also likely unstable, and have plenty of interferences. Some people say, they can only be used to see wave forms, and it it is a question how reliably they do even that. So you want to buy that for $200, just to find that this is true? And nothing can be done about it, this is caused by its primitive circuit. You will find that it's just useless for anything. And after a year ago it will make a buff of smoke, and seizes to work beyond repair, as some people have said. They make many similar scopes, but they are all the same, likely made in the same factory in China, only the case differs a bit. They are known to be the most primitive, and made carelessly. They are low quality not only what concerns the electronics, but their physical parts often break as well.

Yes they are small, and resemble some old oscilloscopes with vacuum tubes, though they have no vacuum tubes. This also includes a tiny screen, which is not good at all, but overall yes, they look lovely. But all the negative about them still makes that worthless. And small, an oscilloscope doesn't take so much room, you can manage to put one at the corner of your desk. And, like having a Tektronix oscilloscope on your desk, this looks great, impressive for everyone who sees it. Everyone has computers, but not many have oscilloscopes.

But this thing, it is minimal, right. But i don't understand such minimalism. If you are minimalist in that way, you should rather buy an old Eico 460, you can get one for $50 with shipping http://www.ebay.com/itm/Vintage-Eico-Model-460-Wide-Band-Oscilloscope-Electronics-Repair-Tester-/231807804023?hash=item35f8d26277:g:aUwAAOSwJkJWkCDs  It is 4.5 MHz, one channel, and has triggering and external sync. And make it to serve you well. That one you can actually use, in spite old, it is a usable oscilloscope. Different from that Sinometer, do all you can to keep away from that scope.

[ayeaye]

I'm sorry for this Tektronix 465 i referred to. I selected "buy it now" in ebay, and also only looked at oscilloscopes with "buy it now". So it had to be "buy it now" when i found it, it is very unlikely that i didn't notice the auction. I don't know what it is, but something is wrong there. That oscilloscope is most likely good, but the seller may screw up the price, using weird tricks. So, sorry again and be careful.