https://devzone.nordicsemi.com/f/nordic-q-a/72702/where-can-i-find-the-antennaHi , I am leo . from China . Where can I buy an antenna???en-USTelligent Community 13Mon, 15 Mar 2021 08:21:05 GMThttps://devzone.nordicsemi.com/thread/299669?ContentTypeID=1Mon, 15 Mar 2021 08:21:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d7057c1b-98c1-4b47-aa99-9b6dd0c23088&#216;yvind<p>Yes, the connector, marked in the image with a red circle, is J1. It is used for&nbsp;<span>conducting measurements of the RF signal using a spectrum analyzer. No amplification is done on BLE signal with the J1 connector, this is handled by the radio in the device.&nbsp;</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/299607?ContentTypeID=1Sun, 14 Mar 2021 13:04:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d914f51c-8190-443e-9410-672b0cb4df9bLeonardoRoy<p>HI,yvind, nice to see you .&nbsp; as I shown in lower picture red circle ,&nbsp;Isn&#39;t it a signal interface?&nbsp;Isn&#39;t it used to amplify the Bluetooth signal?</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/_AE5FE14FFE5647725F00_20210314210017.png" alt=" " /></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/299399?ContentTypeID=1Fri, 12 Mar 2021 08:31:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:233f8d15-33c8-4604-b9b2-d67280fdccab&#216;yvind<p>Hello,&nbsp;<br /><br />Connector J1 is for&nbsp;<span>conducting measurements of the RF signal using a spectrum analyzer. See <a href="https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/hw_rf_measure.html">RF measurements chapter in nRF52840 DK User Guide</a>. The nRF52840 DK has a built-in PCB antenna</span></p> <p><span><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1615537894797v1.png" alt=" " /><br /><br />Kind regards,<br />Øyvind</span></p><div style="clear:both;"></div>