www.youtube.com/b3yFxg2LwXI
mnem
![Popcorn :popcorn:](https://www.eevblog.com/forum/Smileys/default/EatingPopcorn.jpg)
Look like output impedance is fix at 50
. On the Rigol you can set that manually and it will automatically adjust amplitude based on selected output impedance. I often use that feature.
Mmmhmmm... that's not a feature available on every Sig gen tho. I wonder if that tradeoff was necessary to get the improved output level linearity? ![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
@tautech - what do you have that's comparable, and what gotchas do you know about on this unit?
EDIT: Manual is here: http://68.168.132.244/PSG9080_EN_manual.pdf
mnem
![Popcorn :popcorn:](https://www.eevblog.com/forum/Smileys/default/EatingPopcorn.jpg)
who says linearity is better on the Juntek than Rigol ? you found a comparison somewhere ?
To get the BW this one advertises on the bottom-of-the-line Rigols and Siglents, you have to hack them. Then output linearity goes totally out to lunch when you get up in those frequencies; its a constant topic of conversation in the hack/mod threads. Of course, since they aren't meant to operate up there, not the MFR's fault.
Don’t do the junktek. It’s a piece of trash. Check the tear downs. I know it’s slightly more expensive but the ass end Rigol and Siglent units are better value for money.
The first thing I noticed in Scott's (Defpom) teardown was the SMPS powering it. ![Shocked :o](https://www.eevblog.com/forum/Smileys/default/shocked.gif)
Really, who wants one of those powering your signal source ? ![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif)
To clarify the impedance and amplitude thing it’s pretty lame implementation usually. There is no ALC feedback or anything like that which you’d expect in a decent signal generator. Basically source is 50 ohms. Into a high Z load that’s insignificant so amplitude is set against a peak reading voltmeter for a bunch of frequencies and the cal curve is build out if that to control the amplitude. 50 ohms, well you just half the amplitude from the cal curve. Job done! 50 ohms source and load is a 50% voltage divider. Then if you know the load impedance you can calibrate it in dBm doing a simple calculation.
When the output is set to 50 ohms impedance dBm units can be selected in Siglent AWG's.
Enter the value required and the unit selection pops up, select dBm !
@tautech - Oh, come on... SMPS are in everything. I suppose I should chunk all my 2465s because of that too.
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/facepalm.gif)
Now if it's a bad implementation, sure. But that's true of every bit of test gear ever made.
@bd - Thanks, that's the kind of insight I was looking for. I DID look at the teardowns. This looked like a lot of bang/buck; I was asking for constructive response, not
just "It's junk".
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/wink.gif)
I expect it to be cheaply made; it's like the next generation of the FeelTech ARB for duck's sake. I'm not seeing anything here that I didn't see there, and the FeelTech costs only a few $$ less for much lower resolution and again, really horrible output level linearity.
![Shocked :o](https://www.eevblog.com/forum/Smileys/default/shocked.gif)
Bottom line is I'm not going to spend $300-400 on a SG anytime soon. I expected it to be slightly better than the FeelTech; which really is all I need for my ESC tinkery. I figured a few bux more for a little better wasn't too bad.
For better absolute quality like bd139 was saying, I can get a WaveTek 145 for $50 from AllTest.
![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
mnem
![Popcorn :popcorn:](https://www.eevblog.com/forum/Smileys/default/EatingPopcorn.jpg)