HAYSTAC’s search for dark matter axions involves a detector that is in essence a very sophisticated radio. Axions can resonantly convert to a weak RF signal in a high-Q cavity permeated by a strong magnetic field. The condition for resonant conversion is that the frequency of the microwave cavity equals the mass of the axion. In our experiment, optimistically the signal could be a billionth of a trillionth of a watt, and likely much smaller. Furthermore as the mass of the axion is unknown, and thus the experiment must be tuned very slowly in very small frequency steps, just as one tunes for a very weak station on a car radio. To cover the open frequency range will take many years.