In descriptions of the process it always amuses me that they talk about failure to receive Radio 4 being the test (perhaps of it also being broadcast on long wa

In descriptions of the process it always amuses me that they talk about failure to receive Radio 4 being the test (perhaps of it also being broadcast on long wave)... https://en.wikipedia.org/wiki/Letters_of_last_resort https://en.wikipedia.org/wiki/Letters_of_last_resort