Info = Solar, Equipment

Hi Could someone from South Africa comment please

I’m planning 2 high sites for a PtP link between offices
Distance between HQ and Tower1 is 6.7 Km and Tower1 to Tower2 is 2.1 km and Tower2 to Remote Office is 7.1 km

On both the HQ and Remote Offcie i’m planning MT 911G 5Ghz utilising 30dbi Dual Feed Parabolic dishes

On each Tower MT RB-433GL with 2 R52Hn radio cards with a 30dbi Dual Feed Parabolic dishe (to bases) and a 23dbi Dual Feed Parabolic dishes (tower)

I don not have power at the tower site so ill have to make use of solar the plan is to run 24V on 4 X 105ah deep cycle batteries and the charge will be from 2 X 80W solar pannels

I’m looking for as much bandwith through put as possible

Could anyone please comment on where and why I should make changes ?

change the 4xx to 9xx. (to to it really nice, 800)

If a unit have more than one wlan card, make sure you have enough power. Or make/buy a “power to pci” card to get enough power to wlan cards.

I’d go with completely separate parts for the mid tower. Two RB911 5HnD, each in their own case, shielded, and as far apart from each other as feasible for the link.

You could still run a single cable up the tower into a decent case with an RB750UP inside, then split from there to each AP.

I’ve had better luck with the MMCX cards over UFL sharing space on a single board, but I’m getting away from that entirely. Self interference is a pain in the neck.

Tx for the replies

What I don’t understand is why would you get a routerboard with multiple wifi card slots if self interference is such a problem ?

Should I also be worried about antenna iterference as these to dishes would sit back to back on the tower ?

If I understand correctly I shoud not use the same freq for HQ - Tower1 - Tower2 - Remote site ?
Rather something like

HQ - Tower1 5200
Tower1 - Tower2 5650
Tower2 - Remote 5200

Would you also keep the 24V option or would 12V be better and why ?

24v would probably be better for the equipment, low voltage would still be within its operating limits, but plenty of people use 12v on here without issue.

The antennas will interfere with each other back to back, you want as much vertical separation as you can afford to use without causing problems with your link.

As for the slots on a single board, there are several different cards, you can run different bands, have redundancy built in, etc. Lower power cards don’t cause as much of a problem, below 19dB tx power doesn’t cause as much of an issue. A 24dB tx at 5825 will interfere with a 5745 broadcast on the same board.

So if I understand correctly would it be better to do option 1 or option 2

option 1

HQ - Tower1 5Ghz 6.4km
Tower1 - Tower2 2.4Ghz 2.1km
Tower2 - Remote 5Ghz 7.4km

Thus a tower will have a 433GL board with 1 X 5GHz and 1 X 2.4GHz , will this have less interference ?

option 2

change the quipment to 2 X 433GL boards each with it’s own radio card with a shield between dishes and each in an aluminium enclosure