UNsyncED
First Officer
Flight distance : 1083392 ft
Australia
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I apologise that I didn’t respond to the second part of you post.
The best analogy that I can use to describe the reason for 2.4ghz traveling further with reduced quality, compared to the 5.8 GHz, is to compare the 3 typical styles of radio transmission SW, AM and FM.
SW transmits at 1.7 - 30 MHz, and can be heard beyond the horizon and around the globe, as it bounces off the ionosphere (a layer in the atmosphere), but it sounds terrible and is full of static.
AM transmits at 535 kHz to 1.605 MHz, and can be transmitted about 165 km. AM is typically only transmitted in mono as the stereo separation is poor, reducing the quality of the audio.
FM transmits at 88 to 108 MHz, and at the same power (watts) as the AM can only travel a much shorter distance, however the stereo separation is possible and the audio sounds much better.
The analogy can be transferred to the DJI RF system, the lower the frequency the further the transmission can go, but the quality of signal is reduced. And the higher the frequency, the shorter the transmission will go, but the quality of the signal is improved.
DJI is saying that the 5.8 GHz can transmit 1080p to distances of 7+ km, and that 2.4 Ghz can transmit 1080p to distances of 1.25 km. There is no comment as to the total distance that the 2.4 or 5.8 GHz can transmit, just that if you want the 1080p quality the 5.8 GHz frequency can transmit up to 7+ km (I say 7+ as DJI have advertised conflicting distances that 5.8GHz can transmit the 1080p signal. They have advertised both 7 and 8 km.)
The other consideration is that the 2.4 GHz signal is noisier because the radius of signal catchment is increased, whereas the 5.8 GHz frequency isn’t as noisy as the catchment radius is reduced.
I hope that this answers your query. |
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