Y-adapter for external antennas

This thread does also apply to MOX, but one cannot choose more than one forum category :wink:


did anyone from you already use a adapter like this one to maximize the antennas’ coverage?

I believe this can only work with directional/sector-anntenas which are pointing in completely different directions, where there is no possibility of overlapping areas.
My goal would be to attach two external sector-antennas to it.


I’m not good at physics but wouldn’t it halve the output/gain nearly to the level of one good omnidirectional or dipole antenna?

Good point - didn’t really calculate that until now.

first calculation

I also have to take into account attenuation for the long cables:

  • AW7915-NP1 TX power per chain: 20 dBi/2=10 dBi per antenna
  • gain sector/directional antenna: +13/+8 dBi
  • attenuation cables RF240: 10m*(-0,41 dBi/m)=-4,1 dBi
  • totalled = 19/14 dBi per antenna

While this still makes sense for the sector antennas (keep in mind mobile devices only reach a TX of ~16-17 dBi), it is semi-optimal for laptops (Intel cards have a TX of 20 dBi) and not acceptable for the the directional antennas.

First calculation didn’t take into account, that as an emitting party one has to take care about the output of the antennas and not only about what is parametrized in router software.
Therefore I checked what driver is accepting as maximum power for 2,4GHz: 29dBi (setting up in software as country “US”).

  • TX power per chain: 29 dBi/2=14,5 dBi per antenna
  • gain sector antenna/directional antenna/omnidirectional antenna: +13/+8/+4 dBi
  • attenuation for cables RF240: assuming 10/2/0m*(-0,41 dBi/m)=-4,1/-0,8/-0 dBi
    → totalled maximum radiation power for sector antenna/directional antenna/omnidirectional antenna: 23,4/21,7/18,5 dBi.

So in my case one can set the TX-power to 22 dBi and will have in the end totalled 19,9/18,2/16 dBi.
Which is adhering to German/European law and completely satisfying my needs/covering the needed area of the allotment :slight_smile: