Downtilt

Products ePMP
1

Hi,

How to properly measure downtilt of a sector, there is some specific tool!? Usually how many degrees downtilt use?

2

Typically we use a downtilt calculator along with the antenna specifications to get a rough idea. More recently however we've started using LinkPlanner to give us a better idea of exactly what downtilt to use along with estimated bandwidth in a given sector/area. Both tools are available for free.

2 Likes
3

If you're talking about measuring the downtilt of the sector at installation time in order to get the correct alignment, that's almost as hard as trying to align a dish with a compass.

For me it's always:

  1. Simulate the future AP (ie, with LinkPlanner).
  2. Put a client on every interest area.
  3. Test several tilts/azimuts on simulation to get an idea of the best numbers I could get.
  4. Get the AP working and grossly pointed (as per simulation).
  5. Get the first clients working.
  6. Realign the AP tilt to resemble the expected signal figures for clients (you will be looking for signal differences patterns between them, not absolute levels; sims are not perfect!).
  7. Ready to go! You're getting the most of it.

Regards!

1 Like
4

We did the non scientific method. We took a CPE on a pole to the furtest reaches that we wanted to go, the person with the pole pointed to the CEP and watched the eAlign and I was up on the tower tilting till it degraded and moved it slightly back. Have not had an issue with signal in the 9 or so months its been up.

1 Like
5

I mean the mechanical downtilt if specification is 3 degrees, how to measure it correctly, the tower can be with 1 degree of slope and sector support may be over 1 degree in the case are already two degrees, if u are guided by the angles marked on sector support will no longer be necessary. I bought this tool but do not know if it works the way it should, she put behind the sector and scored 2 degrees, but signal on the client got worse. I do not know if I could well express my doubts.

Tool.

6

Wise men trust practical results. So, you measure 2 degrees with your tool and got worse performance? Try 3! Or 1. Just keep into mind: if you're thinking your microwaves travel in an ideal straigh-line you're plain wrong.

So, don't trust mechanical measured tilt because even getting you exact value, the performance won't by as calculated: your microwaves are pretty alive and move all the way!