Oscilloscope ~General~

[stprue]

ok so I have good news and bad news!  My wife let me open my Christmas gift early yesterday (RIGOL scope) and low and behold it came with a AUS power cord and I live in the US lol!!! Now maybe one of you can help me out.  The end that goes into the scope looks like a standard computer monitor power cord and also looks to be rated very close to the AUS power cord that comes with the device.  My question is can I use a US computer monitor power cord on my scope or should I wait for the adapter to arrive?

[poynt99]

Stew,

The most important thing of course is if the scope can accept 120VAC @ 60Hz. If it can, then yes you should be able to use any "instrument cord" that fits your power outlet.

So in short, yes. I'm not sure what kind of adapter they would be sending you?

Congrats on the new scope, what model?

.99

[stprue]

Thanks Poynt,

Model:
RIGOL DS1052E Digital Oscilloscope 50MHz, 2ch 1Gsa/S

Power requirements:
AC:100 ~ 240 VACRMS, 45 ~ 440 Hz, CAT II, 50 VA Max

So it looks like I can use a standard computer monitor cord!

I'm so excited, it will take me a while to learn how to use it but I don't mind going over basics 

[Grumpy]

how do you permit a scope to "see" something that would noramlly be too fast for it to see?  Is there some sort of "delay probe" available?

[poynt99]

You're welcome Stew. Looks like you're good to go!


Grumps, that's a tough one. It may be possible to use a heterodyning front end to bring down the frequency, but that has it's own problems. Seems to me the only way is to obtain a faster data acquisition board or scope.

What frequency are you trying or expecting to measure?

.99

[Grumpy]

pulses that rise in a few ns

[poynt99]

If you are interested in knowing that something is there, it would be possible to design a circuit that could detect a fast rising or falling edge and even give you an indication of the slope. The output of this circuit could drive your scope if desired.

My advice to anyone wanting to do some serious research, is to invest in a decent scope. Even though I have a 1GHz DSO, I bought a Tektronix 2465B 400MHz analog scope for $300. These are excellent scopes at a reasonable price, and with the proper probes, should do well for 99% of the testing anyone here is doing.

.99

[Grumpy]

I have a 2465, but my probes may only go to 250mHz (can't recall)

put these somewhere for everyone to use:

ABCs of Probes
http://aries.ucsd.edu/najmabadi/CLASS/COMMON/ABC-probe.pdf

XYZ's of Oscilloscopes
http://www.tek.com/Measurement/App_Notes/XYZs/03W_8605_2.pdf

[stprue]

Thanks for the links Grumpy!  I will read through them after finishing the 180pgs users manuel of my scope.

[stprue]

Ok so here's my new toy in action after the first chapter on the most basics self tests!

   

I'm so happy!!!!

[CompuTutor]

how do you permit a scope to "see" something that would noramlly be too fast for it to see?  Is there some sort of "delay probe" available?

Wow, that brings back memories of bucket-brigade delay lines for VOX recorders to catch stuff...

When using at least a two channel scope,
and a signal with which your already familier/anticipating.

Using channel one to basicly be the trigger port,
and using a delay line from channel one to channel two works.

Most good scopes already have at least one in them.

You can buy a retrofit delay lots of places,
they are meant for older units:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=380158749065
But you need to be careful as all of them distort the trace.

Still, for just doing relative measurements, not literal ones.
And for just tweaking projects in a draconian way their fine.

[Peterae]

Wow a delay line using what looks like flat wire 

[CompuTutor]

Yeah, skin effect at work.
most are flat strap, not round wire.

Thats a dual channel set.
(Two shielded flat straps)

But remember guys,
these are real nice wire...

But they are still non the less
coaxial capacitors still.

They are installed with a set of precision value
passive components as a  network at each end.

Look at a typical shop maintenance manual.

But they can be used bare if all you want is to see something,
without much concern for what your doing to the signal.

As channel one would still be fairly real
except for the capacitive effect of the delay line also attached
going to channel two.

You can compare all but the very first part of the capture on Ch-1,
then compare it to Ch-2 to judge distortion.

The capacitance, the waveguide effect (Standing wave), etc.
all adds up on some degradation of the signal.

Still, this is pure hillbilly, even though it works good...

[bte]

Sorry for resurrecting this old thread. I love analog scopes, IMO, they kick the crap out of digital ones for TPU/pulse work. I've been hooked on mine, so much nicer than the digital one I had, then again, it was cheap.