Hi,
I've read a bit, but can't find anything that just address a basic setup/settings/connections to look at waveforms. I was given a used Textronix scope that supposedly works, I'm sure it does, but I'm struggling with so many controls. Would someone be willing to help me out and explain the minimum of settings/connections to get up an running? Maybe easiest would be to look at this photo of the front panel and direct me? If it's really just beyond the scope of a simple explanation, (ouch!), I'll dig in more with the books and articles.
Much appreciated.
(https://i.postimg.cc/mzHqskgp/IMG-0743.jpg) (https://postimg.cc/mzHqskgp)
Youtube might have some useful videos, e.g. https://m.youtube.com/watch?v=ueOup-XBexU
Hook up something and start by using the POSITION and VOLTS/DIV to find the signal.
Then do the horizontal SEC/DIV to zoom in and out.
I second "look up the HOW TO" vids on Youtube. And look up the manual for that specific scope, and read it!
I don't know the exact 'safety margin', but if you try to measure a signal that is too large, while you have the scope controls set for too low a range, you can and will burn up something internal and that may be 'it' for that scope. { I got mine for $99, one channel not working due to this. I had to dig inside with no schematic until I was lucky to find a burned out diode that I was able to replace }
Figure out what you're doing and you may have a fine CRO there for use for a long time to come!
Much online: https://www.youtube.com/watch?v=Lanpw4Ry8xc (https://www.youtube.com/watch?v=Lanpw4Ry8xc)
A signal generator is useful.
This one needs a cable. It is on amazon
What is shown is the power cord.
(https://i.postimg.cc/4YYGJK2C/41-P-x-D9-DDx-L-SY445-SX342-QL70-FMwebp.webp) (https://postimg.cc/4YYGJK2C)
^^ For low freq. use, one can make a cable for it out of an old RCA cable, and use an 'emptied out' pen to hold the wire probe...
Quote from: GibsonGM on March 29, 2022, 08:10:31 AM
use an 'emptied out' pen to hold the wire probe...
Mock-Tragic... :icon_biggrin: :icon_biggrin:
Yes, but very inexpensive!!
three things probably not helpful --- there is three small inner-concentric knobs across the middle, each named "CAL". turn each one clockwise until they click.
--- there is a very small terminal between intensity and position, upper left corner. this is a calibration signal for your probes, but is also a free signal for looking at. just hook your probe on and look for a trace.
--- there is just below that a button marked "BEAM FIND". pressing this will put a squashed bit of trace on the upper or lower half of the screen, indicating which direction the trace is "off" by. DON'T hold this button down, just short press it. then fiddle the vertical position knob to put a trace on screen.
but really, read the funny manual.
All replies super helpful, thanks!
The first link, YouTube video (Uncle Doug) is fantastic.
Appreciate all the good tips (ouch, another bad pun)
You're welcome, it's nice to see your graticule :)
The Uncle Doug video is so great, he is a treasure. I wonder if my used scope is malfunctioning? Though I ran all the diagnostics. The issue is that when I do the probe calibration procedure (following both Doug's and the user manual process) instead of getting a nice square wave, I get what appears to be a wave (square, I think) scanning very fast right to left. I can get it to vary in amplitude but I can't make it hold still. I'm using the inbuilt sq wave generator, tried different probes, different channels, etc..
Any ideas?
Thanks
That sound to me like maybe your time base is set too low? (SEC/DIV control) Messing with that knob won't get you in trouble. See if changing it makes a more continuous wave.
Either that or maybe something isn't set right in your trigger section. That can cause all sorts of odd junk :) If you can post a pic of how yours is set that might help - It would be faster than trying to explain how to set it.
>>>Oh, and - the 'make it bigger, make it smaller' is your voltage range adjustment...the 1st and 2nd knobs from Left...careful with those. Try not to jump the signal up HUGE (if that makes sense) by turning the knob to too low a range (turning to the right makes the range lower)...on DC, you'll see a line and it will disappear if you make the range too small. There is a limit to the input voltage allowed per range setting, if you exceed it you can blow something internally (like I mentioned above). A small voltage probably won't kill anything (I really don't know), but it's a great habit to get into. Your manual probably says more about this.
Like a voltmeter, the idea is to pre-set the input voltage range to somewhere around what you will be measuring. There are x1 and x10 probe settings to be aware of, too. Again, may not make a huge difference in small signal measurement, but putting it out there...one day you might encounter 30V or something, and if set on 10m or something, the magic smoke will come out :) Lesson: start with the range high and dial in lower scales til you get the right one for what you're measuring. Remember it's "Volts per division" of your graticule (the grid lines)...
Don't know what model that is but i am working on a 2235 today. Make sure your A+B SEC DIV are locked to each other, X10 CAL is pushed in and turn till it clicks, P-P AUTO pushed in, put all other knobs mid point. Tell me the model i can probably get you a copy of the service manual.
Finally got it, it was sec/div. Curiously, P-P Auto needs to be on for it to work. Next step is to get some of my own signal running through. I do have the user manual and service manual and will be watching a lot more videos.
Thanks to all for the counsel, appreciate this community!
J