Recent Posts

1

FPGA / Re: Help on translate schematics to Verilog.

« Last post by Wiljan on Today at 09:23:58 am »

(well, I use Quartus schematics for now...)?

If you use Quartus and have made a schematic, then while the schematic are selected you can click "File"/"Create/Update"/"Create HDL Design File from current file" (the schematic)  select verilog, give it a name, quartus will then make a verilog version of your schematic.

2

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by Fungus on Today at 09:22:14 am »

In reply #465, 2N3055 showed stable reconstruction of a 220 MHz sine which was sampled at 500 MSa/s. So the SDS800X HD can still resonstruct properly at a sampling rate of less than 2.5x of the signal frequency, while the Rigol started to show wobbles at 3x or so.

I'd like to see a frequency sweep.

The Rigol is applying the theory correctly and the Siglent can't possibly be doing an infinitely wide reconstruction, so... 

3

Beginners / Re: What function generator, that does a bit more than just a simple signal

« Last post by Doctorandus_P on Today at 09:15:14 am »

I read about the FY6900, that there are a few issues (hardware/software) and it seems a bit pricey to me. Is it really that much worth?

So what do you think it costs or is worth?

I bought the JDS6600 myself, which is quite similar to the FY6900, but I bought the "low frequency" variant ("Only" up to 15MHz). It's plenty for my needs and paid around EUR80 for it.

And these things use DDS, and can do much more then sine waves. In the end the limitations are with memory depth and the software to generate a waveform. But I agree with johansen. It may be better to combine the outputs from multiple devices. From your description, it looks like you want to do some signal modification mostly based on logic levels, and that is probably best done with a microcontroller.

4

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by Fungus on Today at 09:14:12 am »

Nowadays jellybean logic has edge rates of 1ns, and faster. That translates to 350MHz, and higher.

Yep. If you're really into "logic" then a Rigol MSO5000 is the way to go.

5

Test Equipment / Re: New 2ch pocket DSO+SG - Zeeweii DSO2512G

« Last post by Aldo22 on Today at 09:13:17 am »

But you shouldn't exaggerate, it's not a high precision device. 

Do you mean FY3224s... or DSO2512G?

Both of course. 
Both are pretty much the cheapest usable representatives of their kind.
FY3224s has quite good precision (frequency response) up to 10MHz, but is not very accurate, i.e. the multimeter shows slightly different values in certain voltage ranges from what is set on the FY3224s.
Normal oscilloscopes are rarely very accurate. 2%-5% is normal.
That's OK, just don't overdo the calibration, it won't be like a multimeter.

https://en.wikipedia.org/wiki/Accuracy_and_precision

6

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by Fungus on Today at 09:12:25 am »

Screen capture over network still works even on an unsigned app.

not everybody like to connect to network for a mere screen capture, i do it with usb stick. my ethernet cable is super long and its quite a mess trying to run it to my dso, at my lab setup, connecting to usb cable is much easier. and that luckily i have ethernet cable at all so i can do some adb hack albeit a bit inconvenience. ymmv.

Cable? My WiFi adapter cost me $7...

7

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by 2N3055 on Today at 09:11:42 am »

that lead to proper Sinc reconstruction reveals siglent DHO800X can do it properly unlike Rigol, this can also can help user make decision whether this is important or not.

When was THAT proven?

In reply #465, 2N3055 showed stable reconstruction of a 220 MHz sine which was sampled at 500 MSa/s. So the SDS800X HD can still resonstruct properly at a sampling rate of less than 2.5x of the signal frequency, while the Rigol started to show wobbles at 3x or so.

Let's call it a demonstration, not a "proof", since this was just a quick one-off test.

Loot at the post :

********************
When was THAT proven?

Siglent has a higher sample rate.

Rigols aren't forced to work at 312.5MS/sec.
********************

So :
He knows it was proven and when.
He knows Siglent has higher, sufficient sampling as opposed to Rigol.
He knows Rigol does not do it right but "Rigols are not forced to at 312.5MS/sec.", which is absolutely lie for a 4ch version.

All of that mean he knows the truth. He is trying to bend it..

8

Security / Re: Microsoft repackages apps with a telemetry .NET wrapper

« Last post by bd139 on Today at 09:08:14 am »

Some developers use telemetry to figure out how people use their software

Shouldn't that be done in-house, or at minimum with users that agree to be monitored? Are you happy with your car telling the manufacturer where you went, what speeds you did where, how you used the brakes, your acceleration, where you were looking, how you flash the lights, etc? What time you go to work, the shops, hey - is that the place where Ms Periwinkle's car is parked and it's always 8pm to 10pm?

That's a bad straw man. You can't draw similarities between different topical studies.

Most operational telemetry in the IT space is classified as "VALE" - Volume, Availability, Latency, Errors. That does not apply well to cars as you can probably imagine 

9

RF, Microwave, Ham Radio / Re: High bandwidth FM signal generation

« Last post by pdenisowski on Today at 09:05:43 am »

A hardware that can do phone jammer might work for me but phone jammers do not require a large bandwidth like I do.

As someone who has (professionally) hunted down and analyzed illegal jammers:  most phone jammers are not precision devices where the jamming energy is strictly constrained to the band(s) of interest.  Many "multi-band" jammers may have multiple antennas (one per band) but actually just put out continuous noise.

In fact, what caused most of the people operating jammers to be caught was that they thought they were only jamming one narrow part of the spectrum but ended up jamming spectrum that "belongs" to someone with the resources to find them.

With regards to jamming cellular networks (LTE, 5GNR), it's often sufficient to simply jam the resource blocks / BWPs of the control channels (e.g. PUCCH).  I've even seen this happen unintentionally on some occasions - narrowband, non-malicious signal fell directly on the control channel and the eNB could no longer "hear" the UEs' control channels.  I did a presentation on this at a conference once, but I think it was one of those conferences where the papers aren't available on the web

*Cellular network operators do have the personnel and resources to find people jamming their networks - I worked with them for years - but most of the time this jamming is unintentional

10

Projects, Designs, and Technical Stuff / Re: role of optocoupler for biasing drain of amplifiers

« Last post by john23 on Today at 09:04:43 am »

Hello , There is a logical problem
The source of the mosfet is connected to the drain of the amplifier.
The source of the mosfet is something floating :-)
I need the source to be 20V because its the drain of the amplifier.
So either my schemtics is wrong  and source of the mosfet is not connected to drain of the amplifier?
How do i make sure i get 20V to the drain of the amplifier?