Recent Posts

1

General Technical Chat / Re: Cheapest way to get date/time from GPS

« Last post by nctnico on Today at 09:12:31 am »

In Germany we also have DCF77. The advantage with GPS is availability of cheap and easy to use receivers. To make a good DCF77 receiver with similar accuracy one probably needs a rubidium local oscillator, so it can't be competitive.

DCF77 will never get you an accurate clock like GPS as DCF77 doesn't / can't compensate for varying propagation delay through the atmosphere.

2

Beginners / Re: buying a oscilloscoop

« Last post by Aldo22 on Today at 09:09:02 am »

@scroeffie: In your price range there is only one (new) benchtop scope with 4 channels afaik. The Hanmatek
https://de.aliexpress.com/item/1005006329135606.html

I have no idea how good or bad it is.

Other than that, under €250, almost the only one worth mentioning is the Hantek.
I would take the simplest model DSO2C10 at the cheapest price.
e.g. here: https://de.aliexpress.com/item/1005006809075280.html

Seriously better benchtop scopes are only available from about 400 € upwards.

There are of course other types, such as USB scopes, handhelds, scopemeters, "toyscopes" etc.  I don't know if you are looking for something like that?
Or second hand.

3

Beginners / Re: good/cheap headphone aplifier/dac?

« Last post by radiolistener on Today at 09:02:18 am »

look for Chinese 384 kHz 32-bit DAC USB adapter like CX31993 or ALC5686.
It cost about 3-6 USD and has pretty good sound quality.

4

Repair / unknown DC-DC chip of SI-9110 differential probe

« Last post by teatime on Today at 09:00:43 am »

Hello all,

Right now I have a defective SI-9110 differential probe,
Input 6Vdc,
the problem is no -12V, +12V is normal.
I checked the waveform of Pin15, the PWM of +12v as  attachement.
But Pin 10 no any waveform.
If using external -12v instead, this differential probe works properly.
So the only problem is the DC-DC chip.
But the factory erase all chip mark.

I have draw the schematic of this part,please see the attachement.
The length of this chip is 1cm.
The bottom marked"NBK" and have a "Philippines" mark.

I hope some one can tell me the model of this chip.
Maybe this chip also used on other type differential probe.

Thanks & Best regards

5

Test Equipment / Re: SDS800X HD Bugs/Wanted Features

« Last post by tautech on Today at 09:00:00 am »

Serial decoding

I do a lot of RS485 serial decoding on an SDS2000X HD, and one of the things I miss that the older R&S RTB2004 it replaced had was the ability to show the entire "message" as a single frame/packet, and not as single bytes in a list, like the Siglents does it.

https://www.eevblog.com/forum/testgear/siglent-sds2000x-hd-12bit-(published-for-chinese-domestic-market-only)/msg5270949/#msg5270949

I've been an R&S RTB2004 user for several years but decided to buy an SDS2000X HD to use as a secondary scope.
I liked it better than the RTB2004, so the Siglent is now the main scope. And after 3D printing that VESA mount for it, it's such a convenient instrument!

However, one thing I haven't figured out is the UART bus table.
I do a lot of half-duplex RS485 decoding, and with the RTB2004 it would display each "frame" (burst of characters) on a single line in the table. The Siglent on the other hand, just places each character on a new line in the table, and I end up having to fiddle a lot to compare two received "frames".

Is there a way to have the bus table look like the RTB2004 that grouts the received data in "frames" rather than filling a list I must scroll through?

electronics hobbyist, can you add the following feature to the list as well? I have an SDS2000X HD at work, and I've ordered a 1000X HD to have at my bench at home, but this (missing) feature I'm pointing out applies for the entire Siglent lineup AFAIK, at least the 800X HD, 1000X HD, and 2000X HD. I know many other manufacturers do it exactly the way Siglent does it, but that doesn't mean it could have been done better!

Good suggestion for the entire platform range and one I believe could be accomplished quite simply by adding a menu View (type) option in the Decode List comprising of a Bytes or Frames choice, Bytes being the current list default view.

There certainly is sufficient room in the Decode Lits menu to add a View header with Bytes and Frames as the pop out choices.
In addition just the List headers would require modifying for a Frame view labels.

See screenshot and suggest where a new View (type) header should be added.....IMO directly below Display.

6

Projects, Designs, and Technical Stuff / Re: ANITA MK IX Restoration

« Last post by Haenk on Today at 08:57:39 am »

I never dared to fire up my Anitas (yes, several models, all sold now).
Essentially, almost all parts can and do go wrong in these machines, so it's almost the best choice to check every single component. The wicked semiconductors are known for their high failure rate, so prepare to "re-create" a couple.

7

Test Equipment / Re: Looking for a replacement general purpose oscilloscope for home use

« Last post by 2N3055 on Today at 08:51:07 am »

But: I would not (yet) consider their 6000 and 7000 series as a serious option.

Friendly regards

Could you elaborate why, if you are willing to?
What is making you say so?

Thanks and best regards,

Siniša

8

Other Equipment & Products / Re: CFW for KSGER/Quicko STM32 Soldering Stations

« Last post by elektryk on Today at 08:50:06 am »

Finally, I bought a KSGER v3 for my dad, replaced the stinky MM32 with a STM32, flashed the CFW, all good.
PID was a bit off, slowly oscillating back and forth.

After some tuning I got it pretty decent with the following settings:

FILTER MENU
 - Filter: 75%
 - Threshold: 60
 - Min: 40%

PID:
 - Kp: 45
 - Ki: 15
 - Kd: 6

Though the response with the Quicko tips are close to perfect compared to my old ones!

Can you recommend settings for genuine T245 (for example 931)?
In my case default ones leads to some oscillations.

9

Test Equipment / Re: ANENG goes crazy with new meters

« Last post by Aldo22 on Today at 08:49:00 am »

This list is great, but because manufacturers are more or less lying about their products. Sometimes they lie so much that it is more than obvious - like a small €6-meter I have on my bench that is labeled as CAT IV 600V.

The lying isn't ideal, but:
a) Anybody who knows what "CAT IV 600V" is wouldn't believe it, and

b) Anybody who doesn't know it's a lie isn't going to be saved by them taking it off.

My (purely empirical) observation is that Harbor Freight has been giving away millions of DT830s for decades and there's no trail of dead bodies across the country.

That's exactly it. I'd like to see statistics on how many people have died as a direct result of using an AN870 instead of a Fluke in household applications.

My guess is 0.

And if you think you should do anything above CAT II with a $20 meter, then you're in God's hands anyway.

Yes, they shouldn't lie about the specs, but let's not spread FUD.

10

Microcontrollers / Issues with LwIP Multi-Interface Switching

« Last post by tilblackout on Today at 08:45:02 am »

Hello everyone, I am implementing a program with LwIP that supports multiple network interfaces, allowing internet access via both a 4G module and Ethernet. Switching between network interfaces is simply done by calling netif_set_down/up and netif_set_default.

The 4G module is connected to the microcontroller via USB and supports RNDIS mode, which means the TCP protocol runs within the module, and the microcontroller can acquire an IP address via DHCP from the 4G module to access the internet.

However, I've encountered a peculiar issue. When switching the network to the 4G module, I cannot access the internet. Here are a few things I've tried:

1、Without using Ethernet, upon powering up, the device successfully accesses the internet through the 4G module. If I then turn off the 4G module's internet connection and turn it back on, the device can obtain an IP via DHCP but fails to access the internet again, with continuous ping failures. (This makes me suspect a problem with the USB driver reinitialization.)
2、With Ethernet connected, after powering up and accessing the internet via the 4G module, I then turn off the 4G module. The device automatically switches to Ethernet (which works fine for internet access). Then, when I turn off Ethernet and switch back to the 4G module for internet access, the 4G connection surprisingly works. (This leads me to suspect an issue with the LwIP multi-interface switching logic.)

This means that as long as the netif switches from Ethernet to the 4G module, internet access is possible, but restarting the 4G module alone does not allow internet access. This makes it difficult to determine whether the issue lies with the USB driver or the LwIP stack.


Does anyone have any insights or suggestions? Thanks for your input!