Jitter, FM, residual FM, hopping, phansenoise or AM mod or what ever mess there is....
Jitter, FM, residual FM, hopping, phansenoise or AM mod or what ever mess there is....
I you check it with DSO (that can handle reasonable high frequency and has big enough memory) it'll become pretty clear that it's not a continuous signal (which I'd also prefer) but more like when it's sweeping so a bit of signal then silence for PLL to lock to the next frequency (which is just the same here) and so on (I've checked it a long time ago but if my memory serves me correct, stepping is something like 5ms).
While I did not check the code, I suspect that the same loop is used to sweep.
It's OK for VNA functionality but for CW it would be indeed better to emit real CW signal like the original Nano (even though it may eat a bit more battery etc.)
I don't think "CW mode" is intended for use as a signal generator. It is simply a zero span mode for the VNA (this is called "CW time" on Agilent VNAs as well). I agree that the name is somewhat misleading.
Adding a proper CW output in the firmware should not be particularly hard. It would still be of somewhat limited use, since it is unlevelled and there is no filtering. This is probably why no one has bothered so far. It is open-source after all.
I don't think "CW mode" is intended for use as a signal generator. It is simply a zero span mode for the VNA (this is called "CW time" on Agilent VNAs as well). I agree that the name is somewhat misleading.
Adding a proper CW output in the firmware should not be particularly hard. It would still be of somewhat limited use, since it is unlevelled and there is no filtering. This is probably why no one has bothered so far. It is open-source after all.
Yes. But there is more than just one zero span mode. For what all these need use this pulse mode for measurement. Least one can be just plain Continuous Wave. I have in my homelan workshop "trucload" of RF generators. But I think peoples who have this Nano, what is cheap, pocket size handy tiny tool. Even if its RF CW output is not good quality and without level adjustment and not even known level and or it is far away from flat, not even close, from low to high freq. Still I think it is not at all bad feature for many peoples if it have just this RF quality but without this "pulse modulation" what just make it totally useless if try use it as some kind RF generator. And because all is ready in HW for it.
In menu there can select start, stop, center, span, cw freq, and pause sweep. Is it enough that one setup can result CW without pulsing. No matter if Nano do not "listen and measure" anything in this CW output mode. Of course if need adjust level, nano do not this, but for many hobbyists there is available many cheaper and more cheap low grade attenuators and some day he or shee may check different frequencies true level and after then he can use it knowing something more about level. For things what need medium or high quality RF generator, this is not.
I am not ranting about this and that like I am if this is true commercial business model product, but it is not, this is just open source as you told.
It was wish that if developing team see it is easy to do change it is perhaps good to do. Even with all cons what it have as rf generator. Just like, better than nothing for perhaps many peoples. Least it do not shoot not down this NanoVNA value if there is this "CW only out" mode.
It also mean that in this mode it do not measure anything like it do now. In CW mode now it do measurements also. But then there is Pause Sweep selection. Now it do not update any displayed measurements in CW mode but still it continue Pulsing. For what. In this state it can send just Continuous wave out. Least I somehow think that when it do not need measure anything in CW mode then pulse modulation can also stop.
Perhaps example OwO can answer what is real reason for pulsing in state/mode when it do not any measurements.
Or is it just..."no one care" reason.
The pulsing isn't because of internal calibration, it's because the reference channel is measured by shorting port 1 to ground. The two synthesizers do not have known phase relationship (ADF4350 phase resync is not usable for the full frequency range) so the reference measurement is required. It is possible in CW mode to only measure reference once, but then you will have a lot of drift and anything that causes a ADC buffer overrun (like writing to flash) will cause it to lose sync and phase will become random.
Now here's a case. It's a wonder what you can do with Covid-19 spare time.
Angled so you can see it.
Holds SOLT, attenuators and adapters in a drawer.
Holds a standard 18650 Li cell.
Lots of air holes for cooling.
I have patched the firmware so the measurement is turned off when the sweep is paused. I am not too interested in the S-A-A2 as a signal generator, but I want to some more detailed performance characterizations and for that purpose it can be useful to have a CW output.
https://github.com/switchabl/NanoVNA-V2-firmware/tree/cw
I would really like that device with larger and higher-resolution screen, because normally I look at them from some distance (to have enough space for DUT directly in front of me). I wonder if it's possible to re-design the display part to utilize something like 7" RGB24 screen (perhaps via something like EVE controller - FT813 or BT815). Or use beefier main MCU which supports parallel RGB LCD panels directly.
That's the one I bought; look back at my posts to see how I changed it to 4" display.
I have to say that the original 3.2"? LCD was close to unreadable for my old eyes, the 4" display I fitted is really good and I have no problems using it now. I haven't got around to printing my 3D case for it yet though
So I got round to upgrading the firmware to the version that handles the 4 inch display. For those who haven't done it before:
1. Get the new .bin file ready.
2. Plug in your NanoVNA and check which port it comes up on.
3. Turn the NanoVNA on and put it into DFU mode via touch menus.
4. Plug into USB port.
5. Run up NanaVNA_QT
6. Select the port under device
7. You should now see a pop up window that says found device in DFU mode, do you want to upgrade firmware (or something close to that)
8. Click [Yes], browse to .bin file, and click [OK]
9. When it's finished unplug and power off NanoVNA
10. Fit new display and power on, it should work.
I recalibrated my touch screen after the upgrade but it was close anyway so the menus worked. I removed (carefully) an SD card reader that was fitted to my display as it interferes with the fit. I must say that the larger display and font has made this very usable for me, much easier to read now.
I found this one on Amazon https://www.amazon.com/480x320-Display-Module-ST7796S-Driver/dp/B08C5FFX9P/ref=sr_1_2?dchild=1&keywords=480x320+ST7796S&qid=1596014221&s=electronics&sr=1-2
[EDIT] I also just found this one on AliExpress, please check but I think it's the right one.
The git version has 4 inch display support but there is no binary released yet; I'll go do a release right now. https://github.com/nanovna/NanoVNA-V2-firmware
The battery is any li-ion battery (3.6V and 3.7V cells are the same thing, they are all 3.0 - 4.2V). The dimensions should be 6*40*60 mm to fit in the device, usually labeled as "604060", or use that enclosure that supports a 18650 cell (I would go this route because 18650s are generally safer).
can existing version be made faster sweep too? is it simply updating FW, or there using new IC?
Pictures of the V2 plus4 in metal enclosure, with 3200mAh battery inside
After calibration the dynamic range still reaches 70dB to 3GHz, so plus4 will come with a metal enclosure.
Pictures of the V2 plus4 in metal enclosure, with 3200mAh battery inside
After calibration the dynamic range still reaches 70dB to 3GHz, so plus4 will come with a metal enclosure.
I'm starting to loose track of the different models now.
V2 plus4 is the upgrade with better dynamic range and faster sweep with more points and 4" screen?
V2 plus is - what?