Best oscilloscope choice?

[ayeaye]

2) the U.S. Education spares no expense on getting the good stuff.
when a school upgrades their equipment theres usually 30-50 scopes that get sold out the back door.
ive gotten a few this way over the years.

Surplus, yes, they sell old oscilloscopes in official auctions or something. These are mostly ones from 1980's, at least 20 MHz and two channels. Positive about that, is that they sell them cheaply, because they sell many of them, and thus really have no time to test whether they work or not. These scopes often end up in ebay, and the sellers also don't test them very thoroughly, as they sell many of them. So when seeing that the oscilloscope is one of such, there is a good chance to get an oscilloscope cheaply, which is better than its price may indicate. What shows that they may be some of these, is when they sell several oscilloscopes of the same type at once. I think my oscilloscope may also be one of these, as the seller in ebay sold two oscilloscopes of exactly the same type. And the other things, such oscilloscopes are sold quickly, thus they mostly are not cleaned at all, so another indication is that the oscilloscope is not made shiningly clean. Finding that it is one of these oscilloscopes, increases the trust that the seller doesn't try to cheat you with a scope that is worst than shown.

So indeed, the best option is to get some 20 MHz 2 channel oscilloscopes from 1980's. This may also be the cheapest option, because there is the biggest supply of these. I have always thought that, i told about the less powerful ones only for these who are true minimalists, and like to restore very old oscilloscopes. As this is a fun which many people cannot resist

[Paul-R]

I don't think it is worth spending a lot and buying a new scope as a first one because we learn so much with the first one bought. When we know what we NEED, by looking at blurred and indistinct scope shots, then spend the cash and get the right one.

[ayeaye]

Some warn against the Heathkit and Bell & Howell oscilloscopes. They especially warn against Heathkit and Bell & Howell school oscilloscopes, and old Heathkit oscilloscopes with vacuum tubes. But i found a video https://www.youtube.com/watch?v=hoAmzsz_bJY which shows that a Heathkit IO-4205 oscilloscope works  perfectly. This is a 5 MHz two channel oscilloscope made in 1980's, it is solid state, has triggering and modern probes fit to it, by schematics it can be used both with 120 V and 240 V mains power. Heathkit IO-4105 is a one channel version of it, but it has an external triggering. If true, this may be the cheapest reasonable option, because these oscilloscopes are the cheapest in ebay. Like there is one Heathkit IO-4105, that costs $53 with free shipping to America http://www.ebay.com/itm/Heathkit-Oscilloscope-10-4105-Working-Unit-Ships-FREE-/281908425196?hash=item41a30d31ec:g:mEsAAOSwJkJWlpeo , this one has though only a dot on the screen, but is said to be "in good overall working condition".

Some what they call school oscilloscopes, are Heathkit IO-4540, which is also named Bell & Howell I0D-4540. Heathkit and Bell & Howell oscilloscopes often seem to be completely identical, often with the exact same numbers. These look like completely identical to Heathkit IO-4105, but they are warned against and thus may not be the same inside. I found only one video in youtube about such oscilloscope, and it showed what was said to be its own calibration signal. This supposed to be sine, but it was a kind of distorted, weirdly angular. Maybe the oscilloscope's calibration signal was bad, maybe the distortion was caused by the oscilloscope, but whatever the case, it indicates a low quality of the oscilloscope. So for these reasons these oscilloscopes likely should be better avoided, in spite that they cost less in ebay than Heathkit IO-4105.

Perhaps this is all i could say about buying old oscilloscopes, from the little knowledge that i have. Hope it was anyhow useful for anyone.

[TinselKoala]

And now... RM503 and the Four Oscillators present:  Lissajous for You #2  (Best of)

http://www.youtube.com/watch?v=q55-CTCd2k4

[Nink]

And now... RM503 and the Four Oscillators present:  Lissajous for You #2  (Best of)

http://www.youtube.com/watch?v=q55-CTCd2k4

Beautiful