More on Oscilloscopes

[Gandledorf]

Seems like I sparked a lot of conversation on scopes. Here is an update on my hunt, and a request for some opinions.

I have found an offer for a scope that seems pretty good, however, I'd have to buy it as is, without having seen it work, with no probes. The owner claims it is in good working order, and says she'll offer a DOA warrenty on it, but being a home user, I suppose I have no guarentees.

It's a Tektronix 5403, with three plug ins. Two of them are 5A38's, which are evidently 35MHz dual trace amplifier plug ins.

https://sphere.bc.ca/test/tek-plugins/tek-5a38.jpg Photo of a 5A38

The other is a 5B42 time delay plug in (what is this, to adjust the time scale? I've never heard of scopes with plug ins)

https://sphere.bc.ca/test/tek-plugins/tek-5b42.jpg Photo of a 5B42

The owner is asking $100 for the unit. Is this a good price? Is this a good scope? How worried should I be that it is broken? How hard should it be to find probes (it comes with no probes, and no manual).

On another, related note, how hard would it be to build a scope, using ADC's, uC's and an LCD graphics display (crystalfontz.com sells a 128x64 LCD for only $25). This doesn't seem like a terribly involved project... any comments on this idea?

 

[plot]

i'd say a 100$ on any scope is a killer deal, but i know nothing about the particular one you listed. Tektronix are popular from what i've seen, so finding scope probes should be no big deal.

One thing that makes me iffy, when googling for it.. i found a bunch of stuff about that scopes "mainframe", not sure what that means... heh.

as for building one, i've seen do it yourself PC scope kits, and just those (no LCD, runs through your computer), cost around 400$.

 

[Russlk]

A scope is not a simple device. If audio frequencies are good enuf, you can build one yourself, but for 35 mHz it is best to buy one. Scope probes are available from DigiKey or Mouser, $25 to $30 each. Mainframe probably means no plug-in.

 

[Gandledorf]

It is a main frame but comes with the plug ins I've listed above.

Why are scope probes so expensive? Aren't they just passive shielded connectors?

 

[Russlk]

Good probes have adjustable compensating capacitors in them.