Search found 562 matches

by bennog
Tue Aug 09, 2022 6:26 am
Forum: Getting Started
Topic: Possibly a newbie mistake involving x10 probes
Replies: 5
Views: 25

Re: Possibly a newbie mistake involving x10 probes

24V should be no problem with a 1:10 probe.
Probably some short spikes from cel phone or other emc related stuff.

You do use the ground clip of the probe ?

Benno
by bennog
Mon Aug 08, 2022 6:13 am
Forum: Getting Started
Topic: Possibly a newbie mistake involving x10 probes
Replies: 5
Views: 25

Re: Possibly a newbie mistake involving x10 probes

Your understanding of 1:10 probes is ok. But measuring mains voltage with 1:10 probes is not done, and can be lethal. You are probably seeing overvoltage because of some spikes that go over 200V on the input of the scope. Try setting the scope to 1:1 and the probe to 1:10 and measure the 5V again yo...
by bennog
Fri Aug 05, 2022 8:41 am
Forum: Getting Started
Topic: Common ground between 2 different USB hubs?
Replies: 10
Views: 137

Re: Common ground between 2 different USB hubs?

I have tested 2 different Pico USB3 cables and 1 cable had about 10 ohm and the other 25 ohm between the outer shielding of the USB connectors.

For me it is not a problem, will check the ground of the scope BNC and the ground of the PC and outlet later today.

Benno
by bennog
Fri Aug 05, 2022 6:07 am
Forum: Projects
Topic: Wrong ADC values in every other position of the buffer array
Replies: 17
Views: 312

Re: Wrong ADC values in every other position of the buffer array

Nice find I did nog look at it in hex values, it looks like you are right, although I would expect garbage on the 2nd wave checked about 40 of the sin wave values and they all have this pattren.

The OP can this probably confir.

Benno
by bennog
Wed Aug 03, 2022 2:52 pm
Forum: Pre-Sales Advice
Topic: Problems posting because of blacklist
Replies: 3
Views: 55

Re: Problems posting because of blacklist

I have seen this 1 time, some providers map the IP's of there customers to Spamhaus to force them to use their mail servers and not run their own mail server. So I don't think using the Spamhaus DNSBL is a good solution to prevent forum spamming. I only encountered this 1 time about 1 month ago. Benno
by bennog
Wed Aug 03, 2022 2:46 pm
Forum: Getting Started
Topic: Common ground between 2 different USB hubs?
Replies: 10
Views: 137

Re: Common ground between 2 different USB hubs?

Measured my pico cable and it was 15 ohm (variating) so I guess a capacitor also involved. High quality 5M usb3 cable was about 1.11 ohm also a bit on the high side even for 5M. It can be the original pico cable has some blowout resistor in the shielding to prevent high current if you hook up the gr...
by bennog
Wed Aug 03, 2022 12:15 pm
Forum: Getting Started
Topic: Common ground between 2 different USB hubs?
Replies: 10
Views: 137

Re: Common ground between 2 different USB hubs?

for your last question the pico GND is connected to the chassis of the PC you are using it on.
So if you use the scope on a not earthed PC then you can possibly get in a lot of trouble.

Benno
by bennog
Wed Aug 03, 2022 5:49 am
Forum: Projects
Topic: Wrong ADC values in every other position of the buffer array
Replies: 17
Views: 312

Re: Wrong ADC values in every other position of the buffer array

It looks like you are getting min-max values. 2022-08-03_07-45-36.png Ch-A from the 1st sample and every other sample Ch-B from the 2nd sample and every other sample They both show square and a sine wave only the Ch-B value is about 30% higher than the Ch-A values. So what Martyn said about MIN/MAX ...
by bennog
Tue Aug 02, 2022 8:28 pm
Forum: Getting Started
Topic: Common ground between 2 different USB hubs?
Replies: 10
Views: 137

Re: Common ground between 2 different USB hubs?

if you set the meter to AC you will probably measure 50V AC or more
that is why you always need to connect the shield of the pc to earth on de wall outlet. (unless you know exactly what you are doing and know the risks)
Not grounded power can blow up your electronics.

Benno
by bennog
Tue Aug 02, 2022 5:20 am
Forum: Projects
Topic: Wrong ADC values in every other position of the buffer array
Replies: 17
Views: 312

Re: Wrong ADC values in every other position of the buffer array

I find it hard to believe the value is exact 16488 every sample.
If you input a sin wave and post al the samples on wetransfer or here as attachment.
also for a square wave.

Benno
by bennog
Mon Aug 01, 2022 4:45 pm
Forum: Getting Started
Topic: delay through a TA057 differential probe
Replies: 2
Views: 43

Re: delay through a TA057 differential probe

I have a more or les comparable probe "Yokogawa 700925" it is only 15MHz and it shows a delay of about 21 ns
so there will be a delay but it is less than the delay I measure because the TA057 is 25 MHz.
I expect that it will give about 10-15 ns delay.

Benno
by bennog
Fri Jul 29, 2022 5:54 am
Forum: Getting Started
Topic: Trigger when transmissions start or stop
Replies: 20
Views: 718

Re: Trigger when transmissions start or stop

I think this is how far I can help you. I only have a 4444 and a 3403D over here to test. And I don't have the signal you try to trigger on (i guess I can generate it with a AWG) but then the frequency is at most 1Mhz (over 200 times slower than your data) I guess it has to do that the pulses are sh...
by bennog
Thu Jul 28, 2022 2:47 pm
Forum: Getting Started
Topic: Trigger when transmissions start or stop
Replies: 20
Views: 718

Re: Trigger when transmissions start or stop

That low timing would also trigger on the spaces in the signal. Is the signal always the same lengt (so you can trigger on the end of the signal and capture start and end) The end trigger will have the same issues as the start trigger when the time gets low then it would also trigger on the spaces i...
by bennog
Wed Jul 27, 2022 5:25 am
Forum: Projects
Topic: Wrong ADC values in every other position of the buffer array
Replies: 17
Views: 312

Re: Wrong ADC values in every other position of the buffer array

You probably have 2 channels enabled during configuration, or channel B not disabled during setup.

Benno
by bennog
Tue Jul 26, 2022 8:21 pm
Forum: Getting Started
Topic: Trigger when transmissions start or stop
Replies: 20
Views: 718

Re: Trigger when transmissions start or stop

I have found 2 options to trigger 1 for entring and 1 for exiting.
but not a option to trigger on both situations.

Benno