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Message started by Tricky Dicky on Dec 3rd, 2022 at 5:25pm

Title: BNC+ attenuators
Post by Tricky Dicky on Dec 3rd, 2022 at 5:25pm
Hi, first post.

Looking at the new style kits they don't appear to have an attenuator but have a regular electrics type x10 oscilloscope probe supplied, has this item replaced the old type attenuators because of BNC+??

Can I still use my old attenuator?

Do I even need one with the new models?

I read it says the new scopes are backwards compatible with older probes, anything else I need to be aware of?

I have a fair bit of older pico stuff like current clamps/attenuators/5m long scope leads etc.

Thanks in advance

Title: Re: BNC+ attenuators
Post by Dave Thomas on Dec 4th, 2022 at 3:37pm
Yes you can use your old stuff on the new scope. The new scope has a limit of 200 volts. Use attenuators on this one the same as you did with your older scope.

Title: Re: BNC+ attenuators
Post by Tricky Dicky on Dec 5th, 2022 at 7:52am
Thanks Dave 👍

Title: Re: BNC+ attenuators
Post by Joel C on Dec 30th, 2022 at 3:21pm
want to visit this post,  was checking for a misfire on a 19' honda accord 1.5l. using the bnc + cable, followed guided functions and set-up. I used the 20:1 ant(all I have) and I got no reading at any pin(supposed to be coil ground). I used an old style bnc with same 20:1 and a very poor display, had to go to 2 volts then got a ringing instead of a spark event, i did get an ok event using my cop wand but i wanted to see it more clearly, could this be a vehicle that it's best to use the secondary adapters?
Joel

Title: Re: BNC+ attenuators
Post by Sam M. on Dec 31st, 2022 at 11:37am
Hey Joel,

My understanding is on 3 and 4 wire coils (basically coils where the transistor to do the work of turning on and off the ignition primary circuit is located within the coil itself), you may not be able to see a traditional coil primary waveform as witnessed on a two wire coil. Lets see if there are other opinions on this to be on the safe side.

In my experience  on 3 and 4 wire COPs you see usually battery voltage on the positive wire and a somewhat consistent ground on the negative wire, and during the coil saturation period you may see the circuit dip on the voltage side a bit and rise on the negative a bit. If you used the Pico configuration I do not know why you did not see at least that unless the voltage scale was just so large it was difficult to make out as the voltage rise will be small, it will be millivolts.

My understanding on these 3 and 4 wire coils is you can monitor PWR and GND as you would any component, and I will use a current clamp and my secondary COP wand.

Question on your set up, so you were using your BNC + lead (TA404 thru TA407) with a 20:1 attenuator adapter? I just have not done this before and am curious.

Also, do you have the trace by chance?
Honda_1_5L.png (45 KB | 53 )

Title: Re: BNC+ attenuators
Post by Dave Thomas on Dec 31st, 2022 at 5:53pm
Yes Sam that's exactly how 3 wire coils work. You will not see a primary waveform.

Title: Re: BNC+ attenuators
Post by Joel C on Dec 31st, 2022 at 6:29pm
well Dave, you answered my question. and Sam thanks for taking the time to research and show why.
Joel

Title: Re: BNC+ attenuators
Post by Joel C on Jan 5th, 2023 at 12:50pm
also to add, Sam you got it 100%, I got an easy explain from a ATG book i was reviewing(ford drivability & code diagnostics) , simple answer to using the scope.  3 wire has internal control and will not see a pattern, 2 wire you will see it in primary because the pcm is control.
Joel

Title: Re: BNC+ attenuators
Post by Sam M. on Jan 7th, 2023 at 3:21am

Joel C wrote on Jan 5th, 2023 at 12:50pm:
3 wire has internal control and will not see a pattern, 2 wire you will see it in primary because the pcm is control


Thank you Joel for the follow-up and Thank you Dave for the confirmation. [smiley=thumbup.gif]

I am always hesitant to speak in "absolutes" but now feel more comfortable especially if there is some ATG material confirming the operation.

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