Author Topic: Oscilloscopes  (Read 566 times)

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Offline BDA

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Oscilloscopes
« on: Sunday,August 29, 2021, 10:33:16 AM »
Richard48Y recently brought up the topic of using an oscilloscope. In a past life, a friend of mine had a Heathkit oscilloscope and it seemed pretty interesting. Richard said they can be as inexpensive (I don't think we want to say "cheap") as about $100 (to use with your laptop. I think my wife would probably lend me her laptop so this is starting to get intriguing.

The question is what features do we need and which do we really want? They priced range from the aforementioned $100 to over a few thousand dollars. Are higher priced ones worth the extra money (speaking for myself, I would only plan on using it on my Lotus)? Are there any brands to prefer or stay away from? I see that even the least expensive Hantek model can examine CAN bus data which we certainly don't need since the only bus we're concerned about is the one that doesn't see us! Are sensors like throttle position, air flow, crank and cam shaft (I assume these give relative positions) included or are they extra cost? I notice some of them test "exhaust ignition (idle)" and "exhaust ignition (start)." I'm unfamiliar with those terms but it doesn't look like exhaust sniffers are available - which is something I would want. Did I miss something or can you hook up sensors to an O2 sensor somehow?

Ok, that's a lot of questions and that's only the beginning. If you have experience with these O'scopes or even the hand-held models, please chime in with your experience and understanding. An inexpensive diagnostic tool like this would be VERY handy for many of us. They can also be used on modern cars too!

Thanks!
« Last Edit: Sunday,August 29, 2021, 11:05:54 AM by BDA »

Offline Richard48Y

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Re: Oscilloscopes
« Reply #1 on: Sunday,August 29, 2021, 12:13:03 PM »
Here is a pic of my old Smart Engine Analyzer dinosaur and engine test stand.
Made by Allen back in the 80's for emissions certification.
The O'Scope was optional but is great for tuning as you may run primary and secondary ignition patterns.
It will also show up bad ignition wires, weak condensers, bad spark plugs and more.
Takes a while to learn to read the pattern but no time at all to spot one that differs from the others.
As a set I get to fully tune an engine before putting it back into the car, find and fix leaks, etc.

This is an OLD unit but even it has a menu to help you troubleshoot problems.
I can actually set it up for most pre-OBD cars and even antiques can be run on it in Manual mode.

I am sure the new units are capable of a lot more than anyone will use for pre-OBD cars but the basic functions of ignition, alternator, voltage analysis are nearly priceless on their own.
I need to look into these some more but may already have a small suitcase size Allen unit I had forgotten about.

EDIT to add, Most of those advanced functions such as throttle position, air flow, and camshaft will only be applicable to EFI equipped cars with OBD.
« Last Edit: Sunday,August 29, 2021, 12:21:18 PM by Richard48Y »

Offline BDA

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Re: Oscilloscopes
« Reply #2 on: Sunday,August 29, 2021, 12:25:07 PM »
That's quite a rig, Richard! Life would be a lot better if I had a place to put one like it and even better if I had one!

I figured the functions like throttle position, cam and crank shaft position would be lost on an old Lotus like ours but I was a little hopeful that air flow and exhaust ignition might be useful.
« Last Edit: Sunday,August 29, 2021, 12:29:38 PM by BDA »

Offline Richard48Y

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Re: Oscilloscopes
« Reply #3 on: Sunday,August 29, 2021, 01:26:40 PM »
"exhaust ignition" is a new one on me, I have no idea what they are referenceing.
I am sure air flow could be read on our Loti with the right acce$$ory sensor.
Standard unit should be able to read vacuum from a port.
Now I'm goiong on the hunt for my portable unit, I know it is here somewhere.

Offline BDA

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Re: Oscilloscopes
« Reply #4 on: Sunday,August 29, 2021, 02:01:31 PM »
You got me looking up engine analyzers on eBay. You can still get the old Heathkit scopes but most of them are listed for parts, some turn on at least, and most don’t have leads.  :(

Offline Clifton

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Re: Oscilloscopes
« Reply #5 on: Sunday,August 29, 2021, 02:27:47 PM »
I bought a $30 ebay hand held one to test some mag pickups I was using as wheel speed sensors. I never got to use it though, just bought an extra sensor and it worked. I know some high end scanners have the function built in. They are not cheap though. Scanner Danner on youtube https://www.youtube.com/results?search_query=scannerdanner+oscilloscope uses these as do others trouble shooting cars.

Offline Jmarkusic

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Re: Oscilloscopes
« Reply #6 on: Tuesday,September 14, 2021, 09:50:18 AM »
Nice rig.  I have a 1983 Bear one that I have managed to get 90% functional again.