so....i got an oscilloscope ....

[pinkjimiphoton]

it's an older model, a tektronix 310 a from the late 50's...i found the manual for it online, which surprised me!!

it's clean, and seems to work...i've messed around sticking a piece of wire in the input jack and looking at things...

but am a total newbe and have no idea how the hell to hook it up.

i need a probe, right? is that something i should buy, or should i build one?

i looked around trying to find a cheap one, all electronice has one for 19 bucks to 500mhz, or 29 bucks for 1000 mhz...

but i really don't know what i need. can someone please advise me as to what may be a good probe, and how to proceed? i don't have a lot of cash to work with
that's for sure.

also, can anyone point me at some good resources for a newbe to learn about how to use these things?

probably asking for an awful lot, but i really appreciate the help and advice folks, thanks so much!!

[earthtonesaudio]

This is a DIY forum, right?


Step 1: find/buy a BNC-BNC cable (assuming your scope has BNC inputs)

Step 2: cut the cable in half

Step 3: strip the outer insulation, peel back and solder the ground braid to a short length of wire terminated with an alligator clip

Step 4: strip the inner insulation to expose the center conductor.  If it's a solid wire, congrats!  That is your probe tip and you're done.  If it's stranded wire, attach a bit of solid wire and that's your probe tip.  Done.

Step 5 (optional): repeat for the other half of the cable.  Now you have two probes!

Step 6 (super optional): solder a 10M resistor in series with the probe tip to make a 10x probe.

[earthtonesaudio]

Bah, dang.  I googled your scope and it does NOT have BNC inputs.  No bother, in fact the probe-job becomes easier.

Replace step 1 with:

Step 1 (for super old scopes): find/buy a length of coax cable

...

All other steps still valid.

[pinkjimiphoton]

no way....it's really THAT easy? don't i need a cap or something in line with it? far out!! thanks ETA!!!

[Earthscum]

This is a DIY forum, right?


Step 1: find/buy a BNC-BNC cable (assuming your scope has BNC inputs)

Step 2: cut the cable in half

Step 3: strip the outer insulation, peel back and solder the ground braid to a short length of wire terminated with an alligator clip

Step 4: strip the inner insulation to expose the center conductor.  If it's a solid wire, congrats!  That is your probe tip and you're done.  If it's stranded wire, attach a bit of solid wire and that's your probe tip.  Done.

Step 5 (optional): repeat for the other half of the cable.  Now you have two probes!

Step 6 (super optional): solder a 10M resistor in series with the probe tip to make a 10x probe.

I wish I would've known that a long time ago. I've been staring at this damed B-K Precision 1500, 100MHz Dual Channel o-scope since spring!!! I can't afford probes, and when I can, I usually end up getting something else because I space it.

[defaced]

Tek makes a primer called the XYZ of Oscilloscopes.  There are old ones and new ones floating around online.  Definitely worth checking out.  Here's one of the first ones to pop up on Google:
http://ecee.colorado.edu/~mcclurel/txyzscopes.pdf
These are written as a general overview of scopes and their functions.  The advanced functions won't apply to your scope, but the basics never change.   

As for probes, it depends on what you want to look at and how accurate your measurements need to be.  If you're just going to use your scope for signal tracing, ETA's advice will do you just fine.  If you want to play in tube amps, you'll probably want 10x or 100x probes.  And if you're making any measurements you actually really truly care about, you'll want to calibrate your scope and probe.  Alot of probe advice I've read form service guys who play in tube amps say the cheapies work just fine.  My experience has been similar.  I think the set of probes I bought were 15-20 bucks shipped.  These are what mine look like, they're pretty common, just different names on the stickers depending on who's selling them. http://www.partsforhdtv.com/images/tools/probe.gif

[PRR]

310A seems to be found with either BNC or "UHF" (big round) input.

Radio Shed no longer stocks those big coax connectors.

Find a sheet-metal screw which is a light force fit in the center of the connector.

Go to the Shed and get a pack of alligator clip-leads (for many uses beyond just 'scope kludging).

If you want to trust your gator leads: bite the clip on a screw, slide the cover back, solder the wire GOOD. Maybe take it apart, solder, then try to crimp the ears on the wire insulation. Or if you have better wire (preferably in colors), use that.

Use a green lead from the bare binding post to your circuit chassis ground.

Use a red lead from the connector center hole to the point you want to measure.

As a total newbie, you should clip to a guitar cord (green to plug body, red to plug tip), plug that to gitar, strum, and try to get some wobbly waves. Guitar never stands-still, but you should glimpse fragments of waves in the blur.

For something like probing pin 2 of a chip, the gator lead is too blunt and liable to short to something bad. Glue-up a plastic pen and a nail or stout copper wire to make a poker.



> don't i need a cap or something in line with it?

The cap is IN there... the AC/DC (no, not the band) switch next to the input.

You need a Real Probe for high voltage (over 100V) or for high frequency (far past the audio band). IMHO any 'scope that "needs" a probe is "too good" for most audio dinkerings.

[Skruffyhound]

http://www.diystompboxes.com/smfforum/index.php?topic=82173.0

Some resources Brymus was kind enough to put together.

[amptramp]

Just to add some information, if you want manuals for pretty much any piece of test equipment, this site has a lot of them for free download, but you need the (free) deja vu reader from LizardTech.  Deja Vu files are like pdf files but generally more compact.  Just go to:

www.edebris.com

and you will find a choice of four options.  Choose BAMA (which stands for Boat Anchor Manual Archive, boat anchor being a term used to describe amateur radio receivers.  My heaviest is only about 28 pounds, so it barely qualifies.)  You will find manuals for a lot of test equipment there, including over half of my large collection of test equipment.

[pinkjimiphoton]

hey guys, thanks so much for all the great info, i've been surfing it all morning and learning what i can, even found some of the
"vanished" apps thanks to the net archive...got it all in a folder for later perusal!

[arawn]

one other hint jimi we work with signals that run from 20hz to 20khz roughly so if for some reason you buy a probe it only needs to be like 100khz at most.

[amptramp]

one other hint jimi we work with signals that run from 20hz to 20khz roughly so if for some reason you buy a probe it only needs to be like 100khz at most.

I would recommend having response out to a few megahertz because one of the things you are looking at is the possibility of high-frequency oscillation at some point during the cycle of a waveform.  This is especially true of old solid-state amplifiers  (including a few guitar amplifiers) and feedback amplifiers using older op amps.  Oscillation is also the bane of many current limiting circuits, whether used in a power supply or an amplifier.  The typical current limiter will switch on and remove all bias from the protected transistor.  With no bias, it carries no current.  So the current limit switches off and the current ramps up again.  Then the current limited switches on... well you get the idea, it oscillates.  If you are protecting bipolar transistors, this can be slow enough to see with a 100 KHz scope.  If you are protecting power MOSFET's, this can go into the low MHz.

[pinkjimiphoton]

thanks for the info guys....for right now i have a piece of shielded cable with a bnc on one end and a couple roachclips on the other end. i haven't had a chance yet to even try it out again, my work space kinda got moved from the dining room table to my kid's room since she moved out. so i'm at a premium for space, cuz all her stuff is still in there while she's in school, and i'm forced to work on one of them little maybe 15 inch around end table things at the moment.

i was wondering how good of  a  probe i'd need eventually...i can get a 100mhz (maybe a thousand? i forget) probe at all electronics for about 30 bucks.

thanks for the info guys, i really appreciate it!!

[wavley]

I know that you don't want to hear this, but I ended up with an old 547 scope from NASA surplus that was hosed beyond reasonable repair so I pulled all of it's tubes and made it the coffee table in my studio lounge.  That thing was full of super great Telefunken and Amperex Bugle Boys SCORE!!!

Of course, you have a working scope, so you probably shouldn't go pulling the tubes out of it.

[pinkjimiphoton]

yah, this one works, and was well-maintained...i like plugging my guitar into it with various stuff between them and watching the squiggly lines. 

[Ronan]

For most pedals a multimeter probe is fine. I have measured over 600kHz with just straight DMM (multimeter) probes. The guitar signal range only goes up to less than say 10kHz. For hobby use, you don't need anything fancy. +1 for post #2. Great tool to learn and understand electronics, when the going gets tough, get the scope out.

[wavley]

It's true, I have several scopes in varying levels of portability, they really do help out a lot for both troubleshooting and understanding exactly how something is mangling your signal.