The generation of entanglement by a dual-frequency Hahn-echo sequence can be implemented in NMR using standard methods, both in hetero-and homo-nuclear systems. In the hetero-nuclear case standard rectangular pulses can be used to excite each nucleus separately, as their Larmor frequencies will be significantly different. The use of multiple simultaneous pulses at different frequencies is a key part of many common NMR experiments, such as the closely related Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) technique. In homo-spin systems the two spins can be excited selectively, either by long low-powered pulses or using shaped pulses. The use of simultaneous pulses is generally avoided in EPR as overlap of pulses in time tends to lead to distortions in data. For example the 3P-DEER sequence (Figure ) has a 'dead-time' at short 𝑡, where the initial detection and pump pulses overlap in time. The 4P-DEER sequence (Figure ) circumvents the dead-time and so has almost completely superseded 3P-DEER. The principle cause of pulse distortion is the non-linear amplitude response of microwave components involved in pulse generation, which tend to saturate at a maximum outputted power. To characterise the amplitude response of our spectrometer, we recorded the attainable nutation frequency of pulses as a function of their amplitude prior to amplification. In our apparatus, multiple components in the pulse generation chain exhibit nonlinearities; rather than characterising each individual component, we calibrate the whole chain at once by measuring the effect on the nutation frequency of the spin system directly.