The project takes advantage of the odd harmonics of square waves ... [Manzel] points out that this method does put out a lot of RF energy in the surrounding bands, but for direct hookup to ...

60 cycle AC and its harmonics - secure connections to ground. - use shielded, balanced lines. - avoid ground loops. this may mean not grounding a particular device or connecting the cable shield at ...

We generally don’t highlight commercial products in FotW, but in the case of this substandard RF signal generator ... the forest of spikes indicating harmonics across the band.