<story><title>The RadioInstigator: A $150 Signals Intelligence Platform</title><url>https://www.rtl-sdr.com/the-radioinstigator-a-150-signals-intelligence-platform-consisting-of-a-raspberry-pi-rpitx-2-4-ghz-crazyradio-and-an-rtl-sdr/</url></story><parent_chain><item><author>amingilani</author><text>Wait, an antenna connected to the GPIO pin on a RaspberryPi for transmissions? Correct me if I&amp;#x27;m wrong, but doesn&amp;#x27;t the Pi output square waves, that would cause harmonics if transmitted?</text></item></parent_chain><comment><author>SuperNinjaCat</author><text>There was an old RPi project released a while ago (PiRadio I think?) which simply involved attaching a jump lead to GPIO pin 4 which allowed the transmission of FM radio signals.&lt;p&gt;It worked on the principal that the Pi had a stupidly powerful clock and thus could be used as a transmitter.&lt;p&gt;I did a little experiment where I hooked it up to a yagi antenna and asked my dad to set his cars radio to the frequency I set the software to transmit on and drive around the block to test the distance.&lt;p&gt;Not only did it work well but I think I heard someone listening to the radio in their home near mine open their front door and yell out &amp;quot;who ever is doing that could you please stop it!&amp;quot; as it was interfering&amp;#x2F;jamming what they were listening to.&lt;p&gt;I&amp;#x27;m definitely checking this project out though, thanks for posting.</text></comment>
<story><title>The RadioInstigator: A $150 Signals Intelligence Platform</title><url>https://www.rtl-sdr.com/the-radioinstigator-a-150-signals-intelligence-platform-consisting-of-a-raspberry-pi-rpitx-2-4-ghz-crazyradio-and-an-rtl-sdr/</url></story><parent_chain><item><author>amingilani</author><text>Wait, an antenna connected to the GPIO pin on a RaspberryPi for transmissions? Correct me if I&amp;#x27;m wrong, but doesn&amp;#x27;t the Pi output square waves, that would cause harmonics if transmitted?</text></item></parent_chain><comment><author>drmpeg</author><text>With low cost transmit capable SDR&amp;#x27;s now available, nobody should be transmitting trash from a GPIO pin.&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.digikey.com&amp;#x2F;product-detail&amp;#x2F;en&amp;#x2F;analog-devices-inc&amp;#x2F;ADALM-PLUTO&amp;#x2F;ADALM-PLUTO-ND&amp;#x2F;6624230&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.digikey.com&amp;#x2F;product-detail&amp;#x2F;en&amp;#x2F;analog-devices-inc...&lt;/a&gt;</text></comment>