[sdiy] first oscilloscope help

[Nathan M. Reeves]

I got a tektronix T922R locally from a guy who buys bulk equipment  
from military and government labs  etc etc...

This one was used at Ampex and was last calibrated in 1988 or  
something like that!

But hey it  was $20 and it works, though I did have to buy a P6006  
probe for it...and calibrate it.

By the way i have been meaning to ask if 2x 15MHz is enough bandwidth  
for most (if not all) synth DIY?

I dont have any micro pics or anything (yet?) just want basic voltage  
measurements and something with the ability to help me troubleshoot.

Also, How would one make a cable to hook up audio outs (RCA, 1/4" TS  
or TRS) to the scope channels?

Say I plug in my LEFT phono turntable to ch1 and RIGHT to ch2....and  
use dual trace, will i get neat graphs?

I am guessing the I dont even need the BNC type connector, i can use  
my probe to connect GND to SHEILD and the + pin?

My idea is to hook up audio outputs to my scope channels....for a  
SCOPE DJ SET at the local artsy fartsy venue (in atlanta this is call  
eyedrum http://www.eyedrum.org/)

I assume this would be ok as long as the impedance of the cable is ~50  
OHM, roughly the same as the probe

  though I think you can adjust compensation (is that what 1x versus  
10x is, the attenuation?

Can I hookup both and to CH1 and CH2 and get some neat graphics?  or  
lissajous curve traces?

I found this tutorial

http://www.doctronics.co.uk/scope.htm


I built the voltage divider with the cermet mic and it was neat to see  
my voice on the scope...talk about NON

sinusoidal!  OOOOOOOOOOOH,  AAAAAAAAAAAAAH, EEEEEEEEEEEEE

so much for my career as a singer 8^p

I recommend looking around locally for one, ham fest, or craigslist,  
shipping is expensive and most of these

things are tanks!

Cheers!

Nate

On Jan 13, 2009, at 6:51 AM, George Hearn wrote:

> I've got a PC USB oscilloscope from someone called Hantek I got on  
> ebay.
> It's great for portability when I'm doing stuff on my laptop like
> programming MCUs etc. but as a bench oscilloscope it's pretty naff.   
> I used
> to use a Hameg 10MHz, ubiquitous in the UK on the second hand market  
> for
> dirt cheap and a good scope, perfect for synth-diy purposes.  I now  
> use a
> Tektronix TDS3052 scope and would never look back to analogue yet it  
> was
> very expensive.  If you want a cheap scope I'd go analogue because  
> cheap
> digital scopes are often pretty cr at ppy and inferior to a good  
> analogue one
> you can get s/h for less than £50 if you're lucky.  G
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of jovius
> Sent: 13 January 2009 10:21
> To: Synth-diy at dropmix.xs4all.nl
> Subject: [sdiy] first oscilloscope help
>
>
>
> I’m looking for my first oscilloscope, it needs to be small, cheep,  
> any
> suggestions, I’ve been looking at some pc usb scopes or the are some  
> uni
> hand held on flee bay.
>
> Any recommendations suggestions much appreciated
>
> Thanks
>
> jo
>
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