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Discussion Starter #1
This is a technical document from Rohde and Schwarz
59 pages of reading....


they start out soft, and then they dig deeper.


I have seen a few folks asking how to use a 'scope, and others asking "why is it necessary" or how is it advantageous.


this document covers all of that....
 

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Official "Cheeky Plonker"
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I just checked these things on Amazon and while $5K may be an important add on to you guys that have just bought a brand new Goldwing, and, in actual fact it's only about 25% of what I got in my GL1100 right now, the vast majority of us will just ignore it. 'Cos, we really don't need it.
 

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I just checked these things on Amazon and while $5K may be an important add on to you guys that have just bought a brand new Goldwing, and, in actual fact it's only about 25% of what I got in my GL1100 right now, the vast majority of us will just ignore it. 'Cos, we really don't need it.
I have had use for one but have gotten along without one for a long time.
 

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I've got a Tecktronix TM503 that is a great little 20lb unit with a carrying handle that I have ABSOLUTELY NO IDEA how to work!!! I had intended to use it to help diagnose tachometer problems on my 1500 but, the tach began working flawlessly all by itself.



I have no use for it but if anyone has a "need" for one, , , its yours.
 

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There are plenty of small digital scopes for cheap. Not to mention software that will let you use the audio in on a computer for some basic scope measurements. Also plenty of used CRT scopes at give away prices.
For a modern digital storage scope at a good price, have a look at the Rigol DS1054Z. A nice 4 channel scope you can find new for $300 on sale. A nice set of features and with some software mods you can find online, you can add a bunch of extra features. I've had one for a number of years and it still performs flawlessly. It seems like every electronics Youtuber and his brother have one of these on their bench, too.
 

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Still have my old reliable CRT Hitachi Dual Trace machine... Still serves me well for all I do now...
 

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I've got a Tektronix 465B 100MHz Dual-trace scope I've had since the '80s - Considered an "industry Standard" back then.

I haven't had the heart to get rid of it, but it doesn't take up that much space in the attic, and when you need it, you NEED it. Had to use it a couple times to troubleshoot fuel injection on GF's 1999 Grand Prix. Car was running bad, OBD codes said MAF sensor. Got a new one, car still running bad. Get the 'scope out of the attic - Sure enough, new sensor out of the box was bad, too!

 

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Notes on oscilloscope display measuring MAF sensor:

There's a three terminal connector to the MAF (Mass Air Flow) sensor on the '99 Pontiac, +5v, Signal and Ground. Connect scope to "Signal" and "Ground".
The MAF measures the amount of air flowing thru the intake plenum after the throttle body.
With the engine idling (air flow is minimum) the signal output from the MAF is supposed to be a nice 5v Square Wave at a relatively low frequency.
As you slowly rev up the engine the square waves smoothly increase in frequency (get closer and closer together on the 'scope display) directly corresponding to the amount of air flowing thru the plenum.
The ECU uses this information along with many other sensors to determine how much fuel to inject.
If you punch the throttle, the scope display will show the square waves tighten right up in a high frequency burst corresponding to the big inrush of air when you blip the throttle.

The bad MAF I was testing showed a very unstable square wave (random square wave pulses at random frequencies) which bore no relationship to the air flow thru the plenum.

This confused the **** out of the ECU and the car ran so bad it wouldn't idle, and spit/sputtered going down the road. We disconnected the MAF and the car ran much better - that put the ECU in a fail-safe mode and it relied on the inputs from the remaining sensors. So we were able to drive back to auto parts and exchange the bad sensor. I changed out the sensor right there in the parking lot so I'd know it was good before leaving....
 

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I've got a Tecktronix TM503 that is a great little 20lb unit with a carrying handle that I have ABSOLUTELY NO IDEA how to work!!! I had intended to use it to help diagnose tachometer problems on my 1500 but, the tach began working flawlessly all by itself.



I have no use for it but if anyone has a "need" for one, , , its yours.
I have been looking for a scope for years for odd projects, both automotive and electronic. If you want to get rid of it I would love to have it.
 

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Check this out:

[ame]https://www.amazon.com/dp/B076HD5862/[/ame]

Only 200KHz bandwidth, but it's only 32 bucks. You can do a lot with 200KHz....
 

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Discussion Starter #11
that has all the features of the little miniscope I used to have about 20 years ago.
it was a tiny 2 inch screen with a real TV tube in it.... slow to warm up, but good to a few tens of MegaHertz... I forget now.


I used it for Audio work, and it was great.
 

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The only real down side to using a scope, is you have to have a known good comparison. They are few and far between. 40 years turning wrenches and I only "needed" a scope once. For a proximity sensor.

DenverWinger.....disconnecting the MAF and running better in failsafe is a time tested diagnostic. You didn't "need" the scope for that.
 

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Most people dismiss a scope because they either don't use it enough to fully understand the capabilities or they never had one. You can change a flat tire with a tire iron or an impact wrench. Either will work. It is about working smarter. Not harder. You would be amazed the info that can be gathered from a scope if you really get in to it. Do some studying before you purchase. You probably want an automotive diagnostic sxope minimum. It needs to have the inductive pickup so you can see the complete ignition trace. Lesser scopes are OK but useful after you have a theory of where the problem is. An ignition trace is loaded with information and you need an inductive pickup to get that.
 

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We had a cartoon that was on the bulletin board above the sink we washed our hands. It was a couple of guys dressed in suits touring a mechanics shop. The one suit said to the other "if you step over here we can see our new computer system." They turned the corner and one of the mechanics was using it for a step stool! :ROFL: You only get out what you put in.
 

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It would be more helpful if the moderators told us what our opinion should be before we post. It would save a lot of embarrassment for us simpletons.
 
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