https://devzone.nordicsemi.com/f/nordic-q-a/65725/measure-the-impedancePCB : thickness 1 t(1mn), 1/2oz, 2 layer The antenna was removed and the VNA was connected between L3 and C6. The impedance was about 100 ohms. The part value is shown in the picture. Question : 1. Should I connect the power and do TX modeen-USTelligent Community 13Wed, 16 Sep 2020 11:23:07 GMThttps://devzone.nordicsemi.com/thread/269845?ContentTypeID=1Wed, 16 Sep 2020 11:23:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9ad4635a-9a0a-47f5-a5a8-481edf44f8bcketiljo<p>X = 2 for all nRF24Lxx and nRF51-series radios. Note that this does not apply for nRF52 or later radios as they are completely different.&nbsp;</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/269747?ContentTypeID=1Wed, 16 Sep 2020 02:27:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d2a664ca-8cd1-4f47-8291-b2da9b8feb59JK5<p>hello.</p> <p>nwp_013 thank you;</p> <p><img alt=" " src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/lo-frequncy.PNG" /></p> <p>What is the x in nrf51822?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/268772?ContentTypeID=1Wed, 09 Sep 2020 13:24:24 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fc4509dc-0dbe-4dd7-9293-42fb208af001ketiljo<p>You shouldn&#39;t evaluate the matching network by the impedance. Instead, measure the output power and the harmonics. Take a look at this whitepaper:&nbsp;<a href="https://infocenter.nordicsemi.com/pdf/nwp_013.pdf">https://infocenter.nordicsemi.com/pdf/nwp_013.pdf</a>. The radio in the nRF51-series is the same as in the nRF24L-series.&nbsp;</p><div style="clear:both;"></div>