Recent Posts

1

RF, Microwave, Ham Radio / Re: Unexpected Smith chart behavior

« Last post by Randy222 on Today at 12:43:10 am »

1) you don't have a cable in the test, you have a transmission line.
2) on that TL you have some uncharacterized adapters on the front side. Each insertion changes effective VF of the TL.

I suggest you calibrate the nano using BNC open,short,load, leave all the S11 adapters there, calibrate with those attached to S11.

And finally, as stated, the cable in pic is not a "cable", it's a TL (cable + connectors), aka cable assembly.

2

General Technical Chat / Re: Some YouTube videos glitching for no reason.

« Last post by Postal2 on Today at 12:30:38 am »

Thanks. I might try that, but it would be interesting to know if you have the pausing issue with a current(ish) Firefox.

If your Firefox is 32-bit and there are files with the same name in its folder - change it and everything will work. I don't have any stops, because advertising is completely disabled in Russia, but there is a jump back for a couple of seconds every 23 minutes because of these dlls, it doesn't bother me.

3

General Technical Chat / Re: Possible to trigger at battery explosions in pagers ?

« Last post by ataradov on Today at 12:23:18 am »

will never again trust a cell phone, pager, walkie talkie or any other electronics device from now

Why? You just place in place screening procedures and may be proactively replace the batteries before use.

It would be really stupid to limit your communication options because of one incident. Imagine if US banned airplanes after 9/11.

In fact, I expect this to just push them to take a second look at the communications infrastructure and explore more secure communication option, may be using custom apps with encryption. At least that's what I would do.

4

General Technical Chat / Re: Some YouTube videos glitching for no reason.

« Last post by PlainName on Today at 12:22:37 am »

To make youtube work on the version of firefox that is on my screenshot, you need to replace the firefox files with the files from the archive below

Thanks. I might try that, but it would be interesting to know if you have the pausing issue with a current(ish) Firefox.

5

General Technical Chat / Re: Possible to trigger at battery explosions in pagers ?

« Last post by Stray Electron on Today at 12:20:07 am »

It would be so interesting to get the hands on some unexploded samples.

It is also worth noting that this is essentially one time attack. Once it is used, the cover is blown. The decision to activate it must not be an easy one.

  No, it's not a one time attack. If they're even half intelligent the Palestinians (and many others!) will never again trust a cell phone, pager, walkie talkie or any other electronics device from now and until doomsday so in reality this means they will never again be able use any form of electronic communications so this will have to fundamentally change how they plan and coordinate their attacks. So even if another attack like this one never happens again, everyone will have to change the way that they operate.

   What this really means is that ANY electronic device that is capable or receiving a signal in any form can now potentially be used to create a remote control bomb.  Think of all of your wi-fi, internet or radio connected devices such as your Atomic Clocks, routers, computers, solar system micro inverters, wi-fi connected refrigerators, GPSs, laptops, security cameras, etc etc etc and then think of the potential for any of them to be made into a bomb. Even large devices such as your automobile computers could potentially made into a remote control bomb and potentially very massive ones. The implications of these attacks are HUGE and not just for the Palestinians.  Just imagine that the Palestinian terrorists decide to convert a bunch of Wi-Fi routers into bombs and to sell to households in say France and then simultaneously detonate 10,000 of them at some point to make a political statement.

6

Beginners / Re: Direction of Current?

« Last post by wasedadoc on Today at 12:17:29 am »

Positive and negative whether applied to voltages, charges, numbers or anything else are only conventions.  There is no absolute truth that electrons carry a negative charge. Just an agreement that it is the one of the two possible words ("positive" or "negative") everyone will use.  The world would function equally well if the words "positive and "negative" were swapped everywhere.

7

Test Equipment / Re: What does "Average Type" Refer To in Siglent SVA1032X "BW" Menu ???

« Last post by starlite4321 on Today at 12:16:25 am »

Thanks for another response tautech,

Yup, that's the one I've got.  As I mentioned, I just bought it therefore I just downloaded the manual so it's the latest version.

Again, newbrain whose post you quoted here didn't understand the question.  Of course the manual describes what the averaging types are.  And the posts with external references like the one from Keysight just explain the same thing all over again and don't help at all. 

Once again, the question is, what averaging is the "Average Type" setting controlling ?  Where is it happening and how do you TURN IT OFF !!   NOT WHAT AVERAGE TYPES CAN BE SELECTED - which is clearly shown in the manual as keeps being pointed out over and over again.  Because as has been made clear here many times, it's not the "Trace Type" in the Trace menu, and it is not the "Average" settings in the Detect menu.  Because you can turn those off and the "Average Type" setting still affects the trace in the display.  And the type that has been selected is ALWAYS listed on the left side of the display. No setting that I can find turns it off despite what the manual says !

8

General Technical Chat / Re: Some YouTube videos glitching for no reason.

« Last post by Postal2 on Today at 12:12:30 am »

... Mine is 32.0 so actually really ancient

No problem. To make youtube work on the version of firefox that is on my screenshot, you need to replace the firefox files with the files from the archive below. Also, file substitution works on computers with a version of firefox without sse2 (43?).

9

Projects, Designs, and Technical Stuff / Re: Isolated gate drivers for series MOSFET configurations in HV applications

« Last post by Benta on Today at 12:10:41 am »

I think you'll find out why gate transformers are used in this kind of application:
They can supply the needed energy to the gates directly, and can be designed for almost any isolation distance you need.
Optocoupler or level-shifter drivers need elaborate floating power supplies, which is super-difficult and complex in a circuit like this.

10

Beginners / Re: Direction of Current?

« Last post by IanB on Today at 12:08:59 am »

I am neither a troll nor an "AI something".  I was watching a presentation last night that showed current flows from positive to negative.  It was the opposite of what I remembered being taught in high school (almost  60) years ago when we were taught that whoever named positive and negative got it backwards.  I checked it on Google where I found that current and electrons move in opposite directions.

If electrons happen to move in the opposite direction to electric current, this is all relative. If you are sitting still in a train, and look out the window, you may see the scenery moving past the window. So are you moving forwards, or is the world outside the window moving backwards? How could you tell the difference?

As for the ice cube touching question, " Heat energy always flows from the warmer object to the cooler object.".

Maybe, but now, what is energy? And why can't we say that cold energy flows from the cooler object to the warmer object?