As of 2022 there are many badly performing clones on the market. V2/3GHz NanoVNA uses parts like ADF4350 and AD8342 which are costly and clones have been cutting costs by using salvaged or reject parts.
See official store and look for V2 Plus4/V2 Plus4 Pro versions only to avoid getting a bad clone. We have stopped selling V2.2 versions since October 2020, so all V2 hardware that are not Plus or Plus4 are not made by us and we can not guarantee performance.
I would like to use V2 to measure the 4 S parameters of a low noise amplifier. To measure S11 the applied power must be <-10dBm and to measure S21 the applied power must be <-30dBm. What is the RF power applied to the device under test by V2? I realize i can add an attenuator to reduce the applied power but this reduces the dynamic range.
What if you match the attenuation with the Gain of your LNA? I measured
S21 for a 60dB LNA with a 60dB attenuator using the NanoVNA without any
problems.
Am 2021-06-05 um 08:13 schrieb sweinreb@caltech.edu:
I think the power is adjustable. Here’s a link to the manual. Check the section entitled “setting sweep range and parameters”
https://nanorfe.com/nanovna-v2-user-manual.html#__RefHeading___Toc2287_3894313802
Think we’ve met before. I was in grad school at UVA in the early 80s.
Lyn,
The manual describes a power level setting of the source but then says v2 ignores those settings. I do know whether this means the calibration software ignore the power setting or whether the power control is not passed on to the signal source. I think the best step for me may be to buy the v2, measure the power output, and see what accuracy I can achieve through an S11 measurement that includes an attenuator.
Sandy Weinreb
Sandy,
You’re right I missed that. So my V2 plus4 generates ~250 mV pk-pk into a 50 ohm load at 1 MHz. I can probably measure it at a few hundred MHz if desired but I suspect you may be looking well beyond what I can measure.
Lynn Mears
For my Nano VNA V2.2 (Black and Gold) in Zero Span (CW mode) and ADF4350 TX Power 3, I get:
MHz dBm
10 -8.9
100 -10.2
500 -8.9
1000 -9.5
2000 -10.5
3000 -11.9
4000 -11.8
Changing the ADF4350 TX Power in zero span mode does not have any effect immediately. Instead it takes effect *only when and if* you change the CW central freq (maybe this is a little bug). Outup levels are reduced with respect to TX Level 3 of about 3 dB (TX level 2), 6 dB (TX Level 1), 8 dB (TX level 0). In scan mode (no zero span), the TX power configuration takes effect immediately.
So, above 140 MHZ, the out level is configurable between -10 dBm and -18 dBm. Below 140 MHz, the level is fixed at about -10 dBm.
Attached some SA figures.
Best Regards, Marco.
Marco – Thanks, this is very helpful. - Sandy
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