Thursday, December 29, 2016

5ft (1.5m) Satellite Dish

A few days ago I constructed a crude 5-foot satellite dish and it got decent signal strength from Inmarsat 4F3 (98W) while indoors. Today I took it outside to finish testing it.

Inmarsat Aero from 98W using my 80cm DirecTV dish:

Same LO frequency, 5ft dish
Admittedly, the SDRplay's oscillator drifted a bit.

Using the bigger dish, you can clearly see how the wide signals are redder and how the narrow ones are appearing.

I was also, using my big dish, able to receive the Inmarsat satellite at 54W, which I have never been able to receive previously when I was using the 80cm dish.

Inmarsat 54W Aero reception, 5ft dish

Finally, I noticed that some of the Aero signals seem to be almost mutually exclusive. As I moved the helix in front of the dish, some would fade out while others faded in.

Except for the bottom, they do appear to be mutually exclusive, as if there was some kind of polarization difference or something.