Because a customer is very close to the tower, I need a very low gain outdoor directional antenna for the 9000SMC. I’ve turned the power output on the SM all the way down, however the dBm received at the tower from that SM is still much too strong. Therefore I need an antenna in the 3-5 dBi range. What can you recommend?
Thanks,
Gregg Smith
Westcom
206-795-0597
dont know of anything THAT low. but i do know max rad makes a Panel that is only 7db and thats the lowest ive ever heard of
I have the MaxRad … unfortunately 7dBd translates to about 10dBi … so still too high.
Have any of you hear of the Sinclair SP441-SFXSNF? That’s suppose to be pretty low.
Thanks,
Gregg
what kind of distance and signal levels are you talking about here? we have customers that are <500’ from 900mhz Aps that are in the high 30’s low 40’s and we dont have any issues
EDIT: I should read closer…
So you have turned the power down on the SM…
What are you seeing the SM at in terms of dB on the AP?
what you could also try is if the SM is running 8.2+ you could say that the antenna is larger say 15db so it wont push as much
Did you try pointing the antenna away from the AP?
You may can just find a direction away from the AP that will give you the results your looking for.
I’ll respond to all the replys in this:
1) I was seeing 40dBm at the AP … if all the other SMs were in the low 40’s, that would be a problem, however all the other SMs are in the mid 60’s. I’ve noticed when you have one SM significantly more powerful than the others … it tends to overwhelm the AP and affect the performace of that whole sector. Best practice is to balance the AP so all the SMs are coming in at about the same dBm level.
2) I experimented and cut a Yagi Ya9-11 down to 2 elements. That actually helped. but not enough
3) What worked the best was to take the MaxRad flat panel (9.1dBi) antenna and direct it away from the AP just enough so it didn’t affect the Jitter too much, yet it droped the dBm level down at the AP so it was in-line with the other SMs.
4) The SM output level is a low as it will go … it is at 2 (it won’t go to 1).
5) If anyone knows of a flat panel that has less dBi gain that the MaxRad, please let me know.
6) Does anyone make an inline N-Type connector power reducer – something I could screw inbetween the SM and the Antenna?
Thanks,
Gregg
Take a section of LMR400 (or other 50ohm cable) and strip back the shield exposing the center conductor to make a simple whip antenna.
Start with 6" exposed which will be roughly 1/2 wave.
Put the cable into a section on PVC conduit and seal both ends. Make sure the center conductor is not touching the shield.
LOL Jerry…
I thought only us hams did stuff like that… 
We use a 6db yagi for our close shots.
pc904n is the part # and it is made by cushcraft.
Here is a 10dB pad…
http://www.tessco.com/products/displayP … ventPage=1
And here is a 20dB pad…
http://www.tessco.com/products/displayP … ventPage=1
Keep in mind that this will drop your tx AND rx signal levels…
If you are going from -40 heard at the AP you’ll move to -50 heard at the AP using a 10dB pad.
amd phreak wrote: LOL Jerry.....
I thought only us hams did stuff like that.... :P
A ham would know 468/freq...