You are here

Sector antennas... considerations?

3 posts / 0 new
Last post
Sector antennas... considerations?

Hi All, I am attempting to pioneer a mesh for my rural area. As part of this task, I am looking at installing sector antennas and mesh nodes on the club-owned repeater tower and maybe a couple commercial towers. I will also likely have a set of sector antennas on a small tower on my hilltop.

What are some of the things/problems that I will have to consider with putting, say 3 x 120* sector antennas on the same tower? Do they play well as long as they are pointed in opposite directions or do they need extra shielding? I figure I'll run shielded cat 5/6 cable down the tower to a Ubiquiti ToughSwitch. I may also link the towers (if I can) with a 5.8 GHz link, but that's a discussion for another day.

Any tips or pointers for installing multiple nodes on one tower?

Thanks in advanced for the help and advice.

73, Matt KD2HKB

K5DLQ's picture
I would recommend the rocket

I would recommend the rocket shield for protection, or similar and DTDlink them together at the switch.

I'm going to post what I sent

I'm going to post what I sent on the side so it's in the history (and get others thinking themselves what they did but may not be thinking on at the moment)

I belive you may need to have concern about the collocates nodes and may potentially need to separate them out or find some way to provide isolation such as using a different frequency.

I'm lucky that all my personal nodes to date have been able to be on channel -2 @ 5MHz using the AREDN firmware and I haven't had to worry about collocation.  A friends node however using multiple sectors had to jump his second node to a different frequency to avoid the issues.

We have another local node using 3x NanoStations and it has serious desense due to lack of shielding.  It works it just has some issues receiving.

Another site I work with has 4 nodes each facing a different direction and has parts of the roof between it and still experiences some level of desense between nodes however not as bad as the other sites that had direct line or sight to the node

Since these will be on the same tower I think you may want to consider using different frequencies on your nodes.  One test showed 20MHz spacing provided isolation to get away but if you need 3 transmitters -2, 2, 6 @ 5MHz may be best (experiment at your leisure to try the best you can)  if you are doing vertical separation Putting -2,6 2 may provide your best isolation   (-2 and 6 can be same level. Channel 2 should be as far away from both as practical for additional isolation)

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer