I have a T1 internet --->rb532a --->(5ghz link) --->rb532a (this unit is setup as AP and a Omni 10db)
I want to ad another rb5232a and the unit is in place 4 miles on another mountain a few 100 feet higher than the AP unit. I am using a directional 22db antani and I can not establish the link.
The ap with the Omni is uisng 400mw cards but a 25 foot run to the omni antani.
Should I move the radio up the tower to the antani?
Should I just install another radio and another directionall grid 22db?
And if I am to install another radio how do I bridge the unit so that it is on the same ip network as the orginal link? Ie one big smeless wan?
Thanks!
Michael
With 22 db grid you have to create link in 4 miles.
25 feet of cable is long. What kind of cable you are using? What the characteristic?
I strongly suggest to reduce the lenght to 3 feet. (60 cm?)
Also take in care that the omni has not very receive capable as the grid antenna.
I suggest a sector antenna instead of omni.
Ciao
Max
Thanks for the suggestion. The 25 foot cable is rg-400.
At the moment I plan to add another radio card and place two directional antani’s just below mid tower. One pointing to the office and one to the mountain. I can get away with 6 foot cables I belive.
What I do not know is if I can run three (Atheros AR5413) on one rb532a with 48v. Or should I lower there outpower abit?
antenna out power not depending of the POE 48 or 18 V.
As I understand it, it’s not the Voltage that is the problem. It’s the amps. 3 - 400mw Cards might be too much for a standard POE 48V Brick. Might want to look at something that puts out more amps…
Power in Watt = Voltage * Current.
mpci output power is 400mW @ 3.3 V.
means that total power is 0.4 while current is
I = P / V = 0.4 / 3.3 = 0.12 A
The power is the same in input. Means that with 48 V the current is
I = P / V
I= 0.4W / 48 V = 0.008 A or 8 mA.
48 V POE supply until 48W means 1 A.
the card will use 0.008 A … 
But pay attention instead to the power that Routerboard can supply to the mPCI slots. Total power avilable for RB is 9 Watt.
Also a card with output power of 400mW does not means that the consumption is only 400mW. in fact 400 mW is the ampli output power, while the total power of the mPCI is much more than 400 mW.
sime time ago I wrote a post with this calculations.
For example CM9 card consumption is about 400 mA during download in FTP. The maximum power is 0.4 A * 3.3 = 1.32W. As you can see the power is much more thatn 0.4W.
ciao
Thus I have a 48v supply that provides .62A I will be better off using the 12v that provides 1A if I intend to use three cards in a single unit?
From the routerboard manual the max total power consumption is 14 W comprensive of mPCI cards.
Your 48V / 0.6A provide 28W (P=V*I).
It is double of what you need.
I suggest to use 48V POE.
I planned to use it for my new network based on RB.
Massimo