CommScope DB408 vs. DB411

[Cowley639]

Hello all,

I am looking at purchasing a DB-408 or DB-411 for a repeater site. I was able to find a DB-411 for much cheaper than the DB-408. Are there any advantages over one or the other? This is for a 100W analog conventional repeater on a building about 70 foot in the air.

The DB-411 has better gain, but I know more gain isn't always better.

Thoughts?

 

[prcguy]

The DB-408 is an omni with about 6dBd gain. The DB-411 is sold as a cardioid directional pattern antenna with about 9dBd gain when all elements are lined up on one side. If you mount each element on a different compass heading it will give you a mostly omni pattern with about 6dBd gain.

 

[Cowley639]

Is their any advantage to the DB411 in terms of directionality? I’d like to have a little bit better “range” to the north of my site.

Would the DB411, with the radials pointed to the north give more power in that direction?

Sorry the ignorance on this… I know the antenna will have better performance than my current Comet CA-712EFC.

 

[prcguy]

I have a couple of DB-411s and they are not a beam antenna but have some very useable gain off the sides and some of the rear. Here is a radiation pattern showing what to expect. Mine are mounted up against a tower leg giving a little more gain out to the sides and a bigger null to the rear. I did some testing on a repeater that had a Comet GP-9 and the DB-411 works much better. https://www.commscope.com/globalassets/digizuite/40742-095025-000-06-21-2016-pdf.pdf

Is their any advantage to the DB411 in terms of directionality? I’d like to have a little bit better “range” to the north of my site.

Would the DB411, with the radials pointed to the north give more power in that direction?

Sorry the ignorance on this… I know the antenna will have better performance than my current Comet CA-712EFC.

 

[kk9h]

We have a DB411 on our club’s 440 repeater located on the north side of Chicago. The elements are aimed west away from Lake Michigan and it works beautifully for our desired coverage area.