My new SAA2N worked fine sweeping HF antennas until yesterday when the Logmag graph values are at the top of the graph and the Smith Chart values are clustered to the left and outside of the outer circle, even with CH0 terminated with the 50 Ohm load. This happened after I had been measuring a large HF Discone antenna. I suspect that wind static voltage from the antenna damaged the CH0 input. Using a NanoVNA-H to measure impedance looking into the SAA2 CH0, I see about 16 Ohms with the SAA2 Off. When the SAA2 is on, I see the same 16 Ohms but it has pulses when the SAA2 is sweeping. Anything else I should check? Does anyone offer repair service?

Hi, we recommend contacting the store you bought it from for warranty service or return.
Please note the only official stores are listed on https://nanorfe.com/nanovna-v2.html#buying, anything else are not our products and we can not guarantee anything about performance or quality.
If you are looking for a lower cost option, we advise to avoid V2/S-A-A-2 based VNA (any version advertising >3GHz capability), as they may use non new parts.
Thanks,
NanoRFE Support

Ken,

I hope you have luck getting it repaired.

I have static dissipation resistors installed on my antennas. I would recommend using them. AD5X has an excellent writeup on the subject:

<http://www.ad5x.com/images/Articles/Static%20Bleed.pdf>

Mike N2MS

> On 10/04/2023 11:49 PM EDT Ken <ko6no@comcast.net> wrote:
>
>
> My new SAA2N worked fine sweeping HF antennas until yesterday when the Logmag graph values are at the top of the graph and the Smith Chart values are clustered to the left and outside of the outer circle, even with CH0 terminated with the 50 Ohm load. This happened after I had been measuring a large HF Discone antenna. I suspect that wind static voltage from the antenna damaged the CH0 input. Using a NanoVNA-H to measure impedance looking into the SAA2 CH0, I see about 16 Ohms with the SAA2 Off. When the SAA2 is on, I see the same 16 Ohms but it has pulses when the SAA2 is sweeping. Anything else I should check? Does anyone offer repair service?

You can not measure a vna'output impedance with another vna.. That does
not work!!!

Dg9bfc sigi

>
> You can not measure a vna'output impedance with another vna.. That does
> not work!!

>
> Dg9bfc sigi

Thanks. I know that you can't measure its output impedance. But the impedance seen by another device looking into the connector can indicate damage when compared to a good unit.

>
> Ken,I hope you have luck getting it repaired.I have static dissipation
> resistors installed on my antennas. I would recommend using them. AD5X has
> an excellent writeup on the subject:< http://www.ad5x.com/images/Articles/Static%20Bleed.pdf
> >Mike N2MS

Thanks. Wasn't my antenna in this case. I'm familiar with static drains as we used them on shipboard receiving antennas to protect the receivers. I've devised a drain resistor to add to the antenna. I should also build a resistor into a tee-connector for use when measuring unknown antennas and cables. The schematic of the 'H4 doesn't show any DC path at the input to discharge the cable. The input is cap coupled to the first device so the cable discharges into that cap and the IC. -ken-

I got it from Aursync/Amazon. They are not on your list but I don't think the failure had anything to do with authenticity. I'll check to see it they cover it with warranty.