On 2/5/2021 6:12 PM, Mel Farrer via groups.io wrote:
And then, all 3 have varying degrees of sensitivity to RFI - you're
measuring an antenna that's outdoors.
This is definitely something to keep in mind when you are testing an antenna at a tower site, like at a repeater site. Other transmitters at the site can affect the readings.
I do antenna testing and certification with an Anritsu Sitemaster analyzer. The Sitemaster has the ability to send a coded signal that it can recognize as a valid test signal. This can eliminate some of the interference (but not always all) at a site during testing. This does affect some testing accuracy. The Sitemaster also has the ability to turn off this coded signal and go into the "CW" mode for greater accuracy.
Just something to keep in mind when using the NanoVNA or other device around other live transmitters.
Joe
