Transmitter 433 MHz 10 mw range?

Question

Arduino

Is it possible with a 10 Mw transmitter at 433 MHz to break through a length of 30-40 kilometers in direct line of sight (from a height to the ground). Is there enough power? Will a directional antenna be enough to pick up the signal? or is it useless...

Answer 1

If it weren’t for the completely clogged range, one could try helixes ...
Guys on the Internet threw Wi-Fi for 30 km in direct line of sight.
But here another problem arises - how to point these antennas at each other ???

Answer 2

10 milliwatts? 30-40 kilometers? on a loaded 433? are you laughing?
Here a kilometer that achievement will be with directional ...
Here we need watts, as it were, not even tens, but hundreds with non-directional antennas.

Answer 3

Damn, but in the topic it’s 10 Mw - 10 megawatts, a lot can be broken through at 10 megawatts.

Answer 4

Oh, well, they wrote it here ... We must undoubtedly start with the fact that we want to transmit at a distance of 30-40 km with a given power and whether we have a direct line of sight. If you need to transmit data at a low speed, then this can be done without serious technical problems by narrowing the band (say, 1200 bits per second in a 2 kHz band), the receiver sensitivity with such a band will be about -130 dBm with a negligible error stream. Attenuation in space at 433 MHz at a distance of 30-40 km is 115-117 dB, the budget of our radio link (140 dB) will have a solid supply.
But if there is no visibility, then at such frequencies most likely nothing will work: the additional attenuation created by obstacles is very high. To achieve line of sight with an antenna located at ground level or at a low altitude (for example, walking with a walkie-talkie in the hands of a person) at a distance of 30-40 km, the height of the base antenna above the earth's surface should be about 100 meters.

Answer 5

10 milwatt for 30-40km will not work, except perhaps by narrowing the frequency range to tens of hertz (somewhere this topic has already slipped, it seems to be on VRTP), but other jokes begin there - quality factors of filters, the accuracy of maintaining the frequency of both filters and the signal source (what is 10Hz at a frequency of 433MHz - these are 8 orders that even such a generator as HYACINTH can hardly support) as well as a problem with the Doppler effect.
But in principle, if we take a radiated power of 0.5W, then with a directional antenna it is quite possible to achieve stable communication and for 50 km line of sight with a directional antenna in a band of up to 15 kHz.

Answer 6

You can try Pseudo Noise, on the basis of which CDMA works. Since the reception is based on the correlation of signals, there are many interesting points. But, as knowledgeable comrades say, 10 mW is very small for such distances ...

Answer 7

Would a parabolic antenna help? for this power