Chasing down interferance

[wa2ise]

Originally Posted by old_tv_nut

Zenith had a device they called "the growler" for testing analog TV sync circuits. It was a metal box with RF input and output ports that contained a vacuum cleaner motor coupled to the signal. ...

When the ATSC high def digital over the air systems were tested, one of the tests was a vacuum cleaner motor that made RFI. To see how well the transmission methods handled it.