Recent Posts

1

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by ebastler on Today at 12:25:51 pm »

I do not agree at all with this "practice", if planned, as in your case, it is unfair and is to the detriment of others, seller and customers that eventually will receive your "tested" device later.

Please re-read my post. Where did you pick up the message that I planned to return it from the start? I would have loved to find it convincing and keep it, since I bought it at the very favorable Black Friday price.

2

RF, Microwave, Ham Radio / Re: RF 2.4GHZ through Via

« Last post by ConKbot on Today at 12:19:07 pm »

The via with the grounds right there is good enough that it shouldn't significantly impede the signal. Perfect swr? Probably not. Still signal? Yep. Is there a ground plane immediately on the bottom layer of the module? Running under the module with it loading down the transmission line would reflect way more power than the via mismatch.

3

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by markone on Today at 12:19:06 pm »

-snip

Seems fair to me for a mail-order purchase which you can't check out hands-on before buying. Also, I used my existing probes and mains cable for testing, not even unpacking the ones shipped with the scope, so the returned unit was "as new".

I do not agree at all with this "practice", if planned, as in your case, it is unfair and is to the detriment of others, seller and customers that eventually will receive your "tested" device later.

I also bet you too hate receiving opened used boxes and tested equipment...

4

Test Equipment / Re: Siglent SDS800X HD 12 bit DSO's

« Last post by gf on Today at 12:17:16 pm »

Something interesting about the SDS800x HD is that the Time Base is in the time domain is separate from the Frequency Domain Time Base (FFT). This is only seen in the top models of class "A" manufacturers. Siglent has "arrived there"...
This is very interesting for the analysis of low amplitude RF signals.
I have verified, through articles and images, that the SDS1204X the two time bases are linked. To "see" the FFT, you need to multiply the time base in time domais by 1000, to be able to see the well-defined FTT ranges. In the SDS800X HD, it is separate. Including numerically marking the FFT peaks, and being able to edit which ones should appear in the "Peak Table" is exceptional.

If anyone can, please clarify whether other models od Siglent above the SDS800X HD have this possibility of having separate time bases.

The only "separate timebase" which comes into my mind is the timbase of a zoom window, because a zoom window has its own time/div. Can you explain where else you see "separate time bases"? The main time base (and the derived sample rate and record length) applies to both, time and frequency domain. You cannot set these parameters separately for time and frequency domain.

Note that the time/div value is irrelevant for the FFT anyway. What matters for the FFT are sample rate and number of points. However, with automatic memory management, you cannot set time/div, sample rate and record length independently, but they are linked. IOW, if you want to set a sample rate and record length suitable for a "nice" FFT, then you can only do that by adjusting time/div.

5

Thermal Imaging / Re: My new Hikmicro Pocket 2

« Last post by An0v0meo~ on Today at 12:14:34 pm »

you can try "admin" "abcd1234", hikvision use this user name and password, maybe it can works in hikmicro too

6

Test Equipment / Re: SDS800X HD Bug Reports + Firmware

« Last post by ebastler on Today at 12:12:44 pm »

Still, something is wrong in the screenshot eTobey shared. Mask details aside, the zoomed view does not show the time window indicated in the upper window. What happened there?

7

Projects, Designs, and Technical Stuff / Re: Coulomb counter IC for coin cell products.

« Last post by Psi on Today at 12:11:39 pm »

hm.. I wonder how small one could build a circuit that reads the voltage difference across a current sense resistor and translates that to rate of charge into a capacitor. The more current through resistor the faster the cap charges. Then have it trigger an interrupt on the MCU when it reaches a maximum cap voltage. MCU wakes up, increments a counter and discharges the cap back to zero then goes back to sleep.  An advantage doing it this way would be that it's all done as analog circuity so it should handle pulsed loads like BLE very well.

Just a thought, probably not very practical, accurate or low power.

8

DIPtrace / Re: DipTrace 5.0 Beta

« Last post by MarkF on Today at 12:09:35 pm »

It's good to have someone from the team on the forum.

I do have a minor bug in version 4.3.0.5.
In the 3D view, the zoom value is not always correct.
If you zoom in and then 'Reset View', the zoom is not reset to 100%.
Also when you zoom in, exit the 3D view and reopen the 3D view, the zoom is not reset.

9

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by ebastler on Today at 12:08:19 pm »

Even though Dave doesn't always go into as much detail as we'd like, the work he does is VERY time consuming and the equipment he has access to for reviews is not available to all of us.

And the style he has covers a wide range of users. From beginners to advanced anyone can find useful and very useful information.

Maybe I have not found the right EEVblog videos then -- I certainly don't claim to know them all. Would you have an example of an EEVblog T&M review which goes into enough detail to base a 5000€ purchase decision on it?

I don't like to order and then return the equipment. I prefer to have as much information as possible from the start.

And I wouldn't like to receive equipment already used as new.
If I don't like it, I'll sell it as second hand afterwards.

I mostly agree, and don't use that return option lightly. E.g. I have never ordered two or three products (in any price class) in parallel with the clear intent to keep only one and return the other(s). But with the DHO1074 which I ordered after quite a bit of online "research", I ended up returning it after finding too many glitches.

Seems fair to me for a mail-order purchase which you can't check out hands-on before buying. Also, I used my existing probes and mains cable for testing, not even unpacking the ones shipped with the scope, so the returned unit was "as new".

10

Beginners / Re: Strange noise/signal on scope

« Last post by radiolistener on Today at 12:07:57 pm »

However, If I remove the 10 Ohm resistor, the FFT signal looks completely different and the prominent 1 - 2 MHz signal is not observable any more.

There are two possible reasons for that (in practice you will have both of them in combination):
1) adding resistor affects noise power transferred from the source
2) adding resistor affects noise figure of RF frontend input (it can decrease or increase noise figure depends on exact type of LNA)

So, adding resistor affects both - your signal source and your oscilloscope input noise performance.

There is also third reason for the noise level change (which I think is dominant in your case) - adding resistor turns your installation into magnetic loop antenna which is very sensitive for near field magnetic interference. It's the same as adding short circuit, but adding resistor decrease Q factor of such magnetic loop antenna in comparison with short circuit and it makes it more wide bandwidth.

So far I could not yet detect the source of this radiation.

it can be display of your oscilloscope or any other digital circuit near your installation. You can try to find it by moving your "probe" around room and find location where noise level is increased.