A good digital oscilloscope?

Dec 06, 2009 375 Replies

Rigol

is

This is a 4FP7 airborne radar display tube, ca WWII. It has a fast blue phosphor that excites a slow yellow one. Blasted with electrons (or a flashlight) it will glow for several minutes.

ftp://jjlarkin.lmi.net/4FP7.jpg

John

Thank you for all your great suggestions, guys! I got some brand names here, Tektronix I knew from years back, other names like Instek are new to me. Rigol still looks like a great scope for light use. Although you never know, maybe I'll like it so much that I'll use it to measure voltages :) Anyways, it might just all come down to price vs. useability. Rigol is the cheapest brand I could find (which is usually scary) but it seems to have developed some following, so it looks like a good deal. I'm going to look around some more but it does not look like there is any brand that's even remotely close to Rigol's prices so I'm most likely going to get their 2CH

50MHz model. Thanks again!

------------------------------------- /_/ ((@v@)) ():::() VV-VV

##-----------------------------------------------## Delivered via

formatting link
Electronics Enthusiasts' Community of the Net Web and RSS access to your favorite newsgroup - sci.electronics.design - 360395 messages and counting! ##-----------------------------------------------##

On a sunny day (Mon, 07 Dec 2009 20:21:56 -0800) it happened John Larkin wrote in :

Nothing special, my DVD remote does the same: ftp://panteltje.com/pub/DVD_remote_fluorescent_buttons_img_1676.jpg

On a sunny day (Mon, 07 Dec 2009 23:29:59 GMT) it happened Jan Panteltje wrote in :

Yes that was it, VR108, scope is as new again :-)

rly

Rigol

ays

??)

st

esh is

,

nes

r

ash

Not sure what sort of noise you are looking at, but I love my digital =91scope for looking at noise. The trick I use is to trigger right up at the top of the noise. Then I put the scope in average mode and you get an image that looks like the auto correlation function. My colleague has dubbed this the Quasi =96 auto- correlation function, =93Quacf=94 for short and of course pronounced quaff. (Ahh, nothing like a good beer.) If you ask for the FFT of this =91trace=92 you get a much better picture. But I=92ve become very good at reading quacf=92s.

George H.

arly

e Rigol

ways

t??)

ast

resh is

e,

ones

or

lash

Hee Hee, Yeah once they figured out to put colored 'voltage' knobs that match the color on the display I became a digital scope fan.

George H.

Try some strontium aluminate. It's something like 10x better a light storage thing than the old ZnS stuff.

John

On a sunny day (Tue, 08 Dec 2009 07:00:51 -0800) it happened John Larkin wrote in :

The DVD remote in the above link *is* strontium aluminate, I just did the 4 minute test,

formatting link
(scroll down) still clearly visible, not adapted eyes, also after 5 minutes. The color also matches tha tbird... They say the ZnS stuff is no longer used... The real 'hot' stuff I remember from my youth was 'radium', radium on watches, clocks, and even on some light switches. That was all no longer allowed at some point.

I love our TPS2024. 200 MHz, and all four channels and the trigger input are fully floating. Wanna clip the probe ground lead onto the source of a fet that's flailing 400 volts off ground? No problem.

John

Tasty.

What's C-to-ground like, is it basically a differential input (2 x 1M ||

20pF) with a BNC input?

Tim

Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms

I used to have one in round but gave it to a friend whose radio transceiver had one in there that died.

Back in those days watch dials would be readable all night, not nearly have that much decay. That is no longer the case, no matter what fancy material they use.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

A friend of mine used to take off the aluminum front panels of similar equipment and, , put it in the dishwasher. He's divorced so I guess no issues from that department :-)

Afterwards it really looked like new. I was surprised that he never had a case where the lettering came off, that's what I'd be conerned about.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

On a sunny day (Tue, 08 Dec 2009 10:58:50 -0800) it happened Joerg wrote in :

No problem, you can have it if you want: Tritium:

formatting link
Tritium watch:
formatting link
Tritium alarm clock:
formatting link

On a sunny day (Tue, 08 Dec 2009 11:01:40 -0800) it happened Joerg wrote in :

I use alcohol, 'spiritus' in Dutch.

Shame about that antediluvian CF card slot that can't write to even a

2G card. 8-(

I deal with high gain amplifiers (80 dB gain, around 256 channels per system) sitting in a sea of noise. Trying to pick out switching power supply noise, digital noise, AM & FM radio transmitters, and ground loop noise from other equipment is difficult with digital scopes since the structure of the noise is lost. I'll revert to frequency domain (usually a swept analyzer) to pick out the offending frequency if it's from a switcher, clock or radio station, but logic noise doesn't show up well in the frequency domain. The sweep rep rate of digital scopes is better than days of yore, but still not as good as a 30 year old

465 which puts digital scopes at a disadvantage when looking at noise structure. Plus, the alias factor of digital scopes is misleading - so much so, that I'll use one of my analog scopes to figure out what the real waveform looks like so I can set up the digital scope or understand why I'm seeing odd looking signals.

Not that I'm anti-digital scope, I just like using the tool that makes the task at hand easier to deal with.

Mark

The TDS220 at work has terrible noise. My Tek2230 does much better.

Failure does not prove something is impossible, failure simply indicates you are not using the right tools... "If it doesn\'t fit, use a bigger hammer!" --------------------------------------------------------------

"Tim Williams" wrote in news:hfm64q$k3h$ snipped-for-privacy@news.eternal-september.org:

it's probably just a isolated power supply and isolation from the cabinet.

differential inputs are more expensive to implement.

Did you see my earlier post about TEK moving production to China?

also,TEK has bought Sypris Test & Measurement,a third-party supplier of repair and calibration services;so it appears they're trying to re- establish the service centers they USED to have around the US,but closed the last of them back in 1999.

It only took them TEN years this time to learn they messed up closing local service centers..... Danaher really needs to "clean up" TEK T&M management.(clean OUT) Those guys never did have a clue about service. All they know is Beaverton and the factory environment.

Hmm,kinda like our politicians in DC today...

Jim Yanik jyanik at localnet dot com

Just snap a photo of the screen.

John

Something like 35 pF from the BNC outer to ground. I'd prefer less. But it's truly floating with pretty much infinite CMRR. I think it's a microwave-range FM signal link or something.

John

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required