https://devzone.nordicsemi.com/f/nordic-q-a/124556/unexpected-2-4-ghz-emissions-during-emc-testing-radio-supposed-to-be-disabled-nrf52840Hi, I&#39;m working on a product that uses nRF52840 (The custom board actually has the Ebyte module E73-2G4M08S1C). nRF5 SDK 17.1.0. The firmware consists of: 1. Bootloader - Derived from pca10056_usb example bootloader (minimal changes, in sdk_config.h onlyen-USTelligent Community 13Sat, 27 Sep 2025 16:06:51 GMThttps://devzone.nordicsemi.com/thread/549940?ContentTypeID=1Sat, 27 Sep 2025 16:06:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bc115781-5cd3-4ed1-ac97-30a7132d6ea1enukic<p><a href="https://devzone.nordicsemi.com/members/asfo">Asbjørn</a>&nbsp;<br />Thank you for your response.<br />As it turns out the lab made an error, and as the result of this error spectrum analyzer pricked up some environment signals (probably WiFi).<br /><br />This ticket can be closed.</p> <p>Thank you<br />Kind regards<br />Emir</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/549652?ContentTypeID=1Wed, 24 Sep 2025 10:07:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0e35a220-a997-4ccf-b2c6-a95599c37d42Asbj&#248;rn<div>Hello Emir,</div> <div></div> <div>Q1: Just to be sure, these emissions disappear if you remove battery or voltage to the board? So you are sure it is coming from your board?</div> <div>Q2: If you unplug the USB, does it stop then?</div> <div></div> <div>You have switched off the radio with your configuration, so there shouldn&#39;t be anything from the nRF52840 unless you somewhere else enable it again unintentionally?&nbsp;</div> <div></div> <div><img src="https://devzone.nordicsemi.com/resized-image/__size/2080x480/__key/communityserver-discussions-components-files/4/pastedimage1758708429112v1.png" alt=" " /></div> <div>This screen shot doesn&#39;t really look like nRF/BLE activity. It looks a bit more like WiFi channels, but it is difficult to say for sure. If you do not enable the radio, there won&#39;t be any transmit or activity in the band.&nbsp;</div> <div></div> <div>In the E73-2G4M08S1C, does it come with some BLE features enabled? Is there a built in bootloader in the module or is it completely empty flash?</div> <div></div> <div></div> <div>Best regards</div> <div>Asbjørn</div><div style="clear:both;"></div>