An approach is provided for defining a 1 MHz preamble of a packet. The antenna unit includes a wire antenna element and a patch antenna element. The assembly also has a simulated fuel bed, positioned so that the simulated flames appear to arise from the simulated fuel bed. The cam is biased in a first position by a biasing mechanism, such that the recliner rod is engaged with the pawl. These freeze indicators can be small, have a low cost, and have a simple configuration.