We started out with YDI amps because everyone told us they were the best with the cleanest signal. I was never able to get a stable signal past 5 miles with them. We switched to the Teletronics SmartAMP and have been very happy with it.
In using a higher db antenna you are in essence amplifying everything out there, but you are also narrowing the beam width of it's receive path. So properly aimed you are getting more of the signal you want from your AP and less of the surrounding signals. With an amp and a smaller antenna you are amplifying everything within the larger beam width of that antenna. So you are getting more of your signal, but also more of the signals you don't really want. Plus you are raising the noise floor in the area that antenna is pointing. Since it's pointing back at your AP it can have some negative effects on the rest of your customers. The ratings for amps are listed for their transmit gain. Typically receive gain (when it's mentioned in the specs) is locked in at somewhere between 12 and 16db gain. That's why amps are usually only used for APs or for Point to Point links. For CPEs it's better to just use the largest antenna required to get the RSSI you want, but not so big that you are getting to much signal. That can kill your usable signal and reduce the speed that you get. Kevin Summers KISTech Internet Services Inc. www.kistech.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Scott Damron Sent: Tuesday, July 29, 2003 11:49 AM To: [EMAIL PROTECTED] Subject: RE: [smartBridges] BEST DEAL? directional CPE antenna Wellll....If you use a good amp you will keep the same SNR. If you use something you buy off of ebay, without a name on it, you will have problems. When we first got started, we used a couple from YDI, they were really good amps, but they just did not last. We bought one from a named company who I will not mention, but they have a bird on them, and it SUCKED!!! It was pumping tons of noise into the situation. Just buy good amps and you won't have a problem. Scott The PART-15.ORG smartBridges Discussion List To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) Archives: http://archives.part-15.org
