I heard amps are a bad idea. do i have a problem with my config

Routerboard 220 running MT 2.9.6
800mW amp
15db omni antenna
Atheros ARP5213 wireless card
and

Routerboard 220 running MT 2.9.6
800mW amp
12db NLOS omni antenna
Atheros ARP5213 wireless card

Please could someone estimate the range of this equipment for me and how it would work without the amp and which of the 4 options would work best in a radius of 5km
terrain is that of a small town
i mean should i pull out the amp

Here is a web page I use often to calculate distance and power.
It won't help you much with NLOS though.

http://www.zytrax.com/tech/wireless/calc.htm

The only way to determine NLOS connection is to do a site survey with actual equipment I've found.

You might want to make sure the power you are giving to the AMP from the Atheros card is the correct millwatt. Some amps only accept certain power to drive them (like 30mw).

Thanks for the site am still tring to understand it though. did turning off watchdog work for you.

Those are pretty high gain omni antennas in your configuration. Note that the higher gain an omni is, the flatter the rf pattern. Think of a pancake as opposed to a doughnut with lower db levels.If your antenna is two high off the ground, you have the possibility of shooting signal over your potential customers.

You say the terrain is that of a small town, but never mentioned if you were going to be shooting through dense trees. In either case I would not use an amp unless you are trying to gain back the db loss from long coax runs. If that is the case I would mount the amp at the top near the antenna so that the long run of coax will cut down on the noise that you pick up from the amp. You can purchase a two piece amp that has as dc injector that mounts at the bottom and sends the dc voltage over the coax that power the amp at the top. Look for a bi directional amp cause the long run of coax will effect both rx and tx singnals. If you can, you would be better off mounting the radio near the antenna than using an amp.

If you are going through dense trees, I would seriously look at another frequency like 900. 2.4 can work through trees, but in my experience, just isn't worth the headache.

Good Luck,
Dan

Is there any differance between trying to shoot through trees when using 802.11G instead of 802.11B ?

802.11G is still 2.4Ghz. It groups 2 adjacent channels together creating more bandwidth. G is not really meant for outdoor and won't help through trees.

D~

The difference between b ang g modes is modulation and receive sensitivity (and sometimes power levels).

G is not a good choice for folliage. It is OFDM modulation which is better for inter-city connections with possible reflections off of metal buildings.

More power might push through the trees, but trees absorb 2.4Ghz really well!

900Mhz goes a lot further through folliage.

@dwright
thanks
i tried removing the amp but what i got was improved reception for close clients and clients about 2.2Km away disconnected immediately.
then in my config; i forgot to mention i put the 800mW amp in the mikrotik box then connected it to the antenna so its high on the mast. which is about 36m, that cuts down on loss. i also think i did shot signals too high.

then i tested the so called NLOS antennas and it didnt work well enough for the 2.2km client.

i almost 4 got i dont know much about using 900hz. how do i go about it. then i think am going to have to get a license for that. apart from that can thaat carry much bandwidth

No license is needed is needed for 900Mhz. Its license exempt spectrum.

We have had good luck with Trango Broadband, and a friendly neighboring wisp has been using Motorola Canopy.

There is also Wave Rider, but don't have any experience with that.

Througput is just under 3Mbs for all.

I read a great article a while back, that compared the three. If I can find it, Ill post the link

Dan

thanks a million i would guess i would get to work and see what i can make of the info. 3mb is very coool for the throught put so

i like it