Side Channel Attacks are a powerful instrument to break cryptographic algorithms by measuring physical quantities during the execution of these algorithms on electronic devices. In this paper, the electromagnetic emanations of smartphones and embedded devices will be used to extract secret keys of public key cryptosystems. This will be done using standard radio equipment in combination with far-field antennas. While such attacks have been shown previously, the details of how to find relevant emanations and the limits of the attack remain largely unknown. Therefore, this paper will present all the required steps to find emanations of devices, implement a side channel attack exploiting ultra high frequency emanations and discuss different test setups. The result is a test setup which enables an attacker to mount a side channel attack for less than 30 Euros.