开云体育

Hi,

Started this new hobby setting up a RMO station and now I want to measure my DIY 4 element Yagi antenna in roder to optimize it.

Is it possible to measure the antenna leaving a Low Noise Amplifier in the circuit or do I ahve to remove it ?

Thanks in advance for any tips

regards Rainer

If I understand it correctly, you have a LNA connected to the antenna and the cable connected to the output goes to your shack and you want to measure from there, right?

In that case you will measure LNA output impedance and so, and nothing related to the antenna. You need to bypass the LNA in order to measure the antenna, and you better calibrate the nanoVNA accounting for the cable, so you have to connect the Open, Shot and Load calibration standards where the cable is connected to the antenna. Or you can calibrate with just the pigtails and then connect them directly to the antenna.

Regards,

Ignacio, EB4APL

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Hi Ignacio,

Thank you very much.

Will do. As I have build a second antenna with the same characteristics as the one which is working I can measure the one which is not installed on the roof and so know if I am on the right track.

regards Rainer