Recent Posts

1

General Technical Chat / Re: Silicone vs. PVC measuring leads

« Last post by Zero999 on Today at 05:32:06 pm »

PVC wires become very stiff at low temperatures, and can even snap when bending if it's like -30^oC

Does the LCD even work at such low temperatures?

2

Beginners / Re: FLUKE 189, 289, 789

« Last post by EJAP on Today at 05:31:37 pm »

Hello, yes I get this paper, but I speak about a real protocol implemented on fluke 289 , each frame start by 10 02 ... 10 03 crc. I have already discovered many parameters and possibilities, more than the 6 ASCII 2 bytes commands
Eric

3

Test Equipment / Re: Magnova oscilloscope

« Last post by core on Today at 05:31:35 pm »

I think that at school they should learn not an instrument, but what the purpose of that instrument is and the principle of operation, so that after graduation they can use any similar instrument.

So after graduation they will be able to use any oscilloscope, spectrum analyzer, power source from R&S, Keithley, Lecroy, Tektronix, Siglent, Rigol, etc.

In this respect, it is really useful to have instruments from different manufacturers in the school lab.

The manufacturing companies on the other hand, really need to have the same type of instruments in order to be able to standardize the test procedures. Depending on company policy they will choose a particular manufacturer.

On the other hand it is quite possible that schools will have a certain policy for the purchase of instruments, e.g. a local manufacturer if possible and available.

Fortunately, small companies have more freedom in their choice, as do hobbyists.

Otherwise there would only be 5-6 manufacturers.

4

RF, Microwave, Ham Radio / Re: Where are some good websites or videos to learn about faraday cages and basic RF

« Last post by pdenisowski on Today at 05:29:26 pm »

So where can i find good info on faraday cages and just RF stuff in general that isn't a bunch of conspiracy misinformation?

Nothing (yet!) on Faraday cages, but I've made quite a few videos on basic RF topics

https://www.youtube.com/playlist?list=PLKxVoO5jUTlvsVtDcqrVn0ybqBVlLj2z8

You might have better luck searching for "RF shielding"  I work in RF and rarely hear the expression "Faraday cage" in a "work" environment - "shield room / box" or "screen room / box" is the more common term in my experience.

5

General Technical Chat / Re: Farnell UK - web site updated, database broken?

« Last post by AndyC_772 on Today at 05:28:14 pm »

Thanks for checking.

On the page for that particular product, I see "Resistance Tolerance", "Resistor Case / Package" and "Temperature Coefficient" all have a value of 0.

https://uk.farnell.com/yageo/rc0402fr-074k99l/res-4k99-1-0-0625w-0402-thick/dp/3495638

Do you get the same?

6

Test Equipment / Re: Siglent SDS2000X HD, 12bit, 2GSa/s high definition oscilloscope serie.

« Last post by 2N3055 on Today at 05:26:38 pm »

You need to use Flattop window.
Take a note that measured signal is not in harmonic relation to bin frequency..
This measurement is at very edge.
You are measuring two signals 10HZ away, with a RBW that is almost 5Hz. There will be significant bleed between bins.
Try with 15-20 Hz spacing

ERES 3 with that low sampling frequency will act as low pass filter. Don't use it here, it has no use with FFT.
Enable split view and you will see it in time domain.

Averaging will work well with channel it is triggered on. The other channel with different frequency will not average properly.
You cannot  use it. Enable split view and you will see it in time domain.

To make sure amplitude is OK, set AWG for 50 Ω and scope inputs for 50 Ω.

7

Test Equipment / Re: ZEEWEII DSO1511G not showing square at 2mhz when other people's do.

« Last post by csuhi17 on Today at 05:26:07 pm »

Use it's own signal generator, it knows up to 2Mhz.
Why and what is the ground of your signal generator connected to??

8

Test Equipment / Re: ZEEWEII DSO1511G not showing square at 2mhz when other people's do.

« Last post by wasedadoc on Today at 05:25:23 pm »

What's you signal generator? - it could be caused by it.

The generator is probably the one in the scope but OP should confirm that.

9

Test Equipment / Re: ZEEWEII DSO1511G not showing square at 2mhz when other people's do.

« Last post by Aldo22 on Today at 05:24:09 pm »

• Switching to 2Mhz looks like the second attachment.

If you are using the internal signal generator, I can't see how that is connected.

10

Metrology / Re: HP3458A ref BD, potential fake? Ebay (photos): 03458-66509 DCV Reference

« Last post by Vertamps on Today at 05:22:58 pm »

Well they canceled the order for the hp vref board after a week, never shipped it.
Kind of a blessing as i have a two Fluke 731B's coming in the mail.
I really need to sell some gear to offset these purchases, or have a plan i stick to.
There will always be something popping up for sale, i gotta stop looking for awhile.