A fiber optic GPS signal device and method comprising a VCSEL multimode transmitter having a gain that, together with the GPS antenna gain, is greater than the VCSEL multimode transmitter noise. The method includes the steps of determining an interhemispheric switch rate of the test subject. One or more strength rods are disposed along or within the tube. The air injection slots extend in the direction of flow through the fuel and air mixing ducts to the reduce the magnitude of the fluctuations in the fuel to air ratio of the fuel and air mixture supplied into the at least one combustion zone. In some embodiments, the objects comprise casting molds or mold parts comprising a tile structure. Then, in a step, an average voltage of the output voltage is compared with a target voltage.