大家好
想詢問 離岸 建置ePMP1000 的可能性，距離大約2KM，有什麼推薦的作法嗎?
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Hello @Chang_Chia_Hsiang,
2km for E1K is not a distance. I saw installation up to 100km long.
But over a water body it can be challenging.
RF signals generally experience significant attenuation and reduced range when propagating through water, especially at higher frequencies, due to water’s high conductivity, leading to reflections and scattering.
I hope other community members can share their practical experience.
While I was actively involved in Radio Amateurism even before the modern internet there was an unwritten rule for centimeter band or microwave links above the water surface.
Divide the distance between radio A and radio B by 32. It would be ideal if the radios were so much or more above the surface of the water that the influence would be negligible.
In this case, the initiator of the topic is asking for something more than 60 meters.
Of course, this is often not feasible, so we tried to go as far as possible. I did not live nor had links above the surface, but many colleagues did, so I am familiar with the issue.
In the course of 24 hours, not only the thermal fading changes, but also the fading that is the result of water vapor. The two inevitable deviations in the propagation of reflexion and diflexion waves are not constant and become highly variable.
More pronounced closer to the surface.
If I needed to adjust the link with the ePMP 1 above the water surface, I would not rely on the “align tool” but would go to the optical adjustment, at 2 kilometers it is possible. This would give the best approximate average SNR in the course of 24 hours.
Regards
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There must be optical visibility.
Point the antenna of one radio as precisely as possible towards the other and so on the other side.
You start the align tool and set the maximum for one radio and do the same with the other.
That would be it.
Of course, take into account that snow falls on your devices from the roof, move away as much as possible from surfaces that can cause interference from sources of electromagnetic radiation.
Regards
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感謝您寶貴的經驗回覆，我將會上傳照片提供參考
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