Does anyone know why the 433 Mhz Telemetry kit comes with two "Air" modules unlike the 915 Mhz kit which has the "Ground" module with the built in USB.
Is there some advantage to two air modules vs the ground? At first I wanted to use the 433 because I am using a 900mhz video TX but that does not seem to be an issue (per other posts). Are there advantages of one over the other (in the USA)?
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I am using the 433MHz telemetry kit. This version came with two identical modules, and either can be "air" or "ground", depending on whether they are connected to APM 2.5 via the short adapter cable or to the PC's USB port via the FTDI cable (both supplied). Telemetry is working flawlessly. I wonder what range should be expected with the 20dBm (100mW) setting and standard antennas (both vertically polarized)? The ground module & antenna are mounted to a clamp that is magnetically attached to the car rooftop, which hopefully acts as a ground plane.
It's because testing revealed noise problems on the USB "ground" module (only on 433, not 915), so it was not released, and instead two air modules are used. In the US, we recommend the 915 modules, which have the longest range and come in the regular ground/air combo.
There is a version of the 433 USB board that seems to have resolved the noise issues, but it will have to be tested more before it is released.