802.11 Testing

Saturday, March 20th


John's comments

 Range testing against the NT5NT access point was held last saturday night, with 7 hams in attendance.  The access point is a located on the roof of the 16 story Nortel building at 2221 Lakeside Parkway (NNW of Campbell and 75).  The AP is a Linksys WAP11 repackaged in a somewhat weatherproof Toro sprinkler controller box and is connected to a 16db Andrew QD-2400(?) Microceptor antenna.

 Pics of the AP in its' case at:


 Antenna information:


 Antennas tested included:

 a 24dB Andrew 26T-2400 "MagGrid" antenna


 a 14dB Enterasys CSIES-AB-Y-14 Yagi Antenna


 and a 3ft parabolic reflector with a custom patch feed constructed by N5PYK.

 The antenna is currently pointed in the direction of Wiley, TX, where it will be used to support the May 8 "Wild Ride" bike rally.  We were able to locate ground locations where we able to get signal back from the tower.  One location was a Home Depot parking lot at 544 and state hwy 78.  This location was visually observed with Binoculars from the roof of the building. We were not able to visually identify the tower from the parking lot, since testing was done in the dark and appeared to be behind bright stadium lights.  The other was an area just south of Lavonia Park (a park at Lake Lavon) which had a good view of the horizon.

 Joe's comments.


  1. We need to troubleshoot the access point to determine why it would not allow us to associate on Saturday.  We know that the station was responding to ping requests for the SSID.
  2. An external antenna is absolutely critical for work >1 mile.  There are a few PCMCIA cards out there that have this capability and pigtail connectors to mate the card with an N-connector.  If you have plans to purchase a card, the external antenna connector is more important than power out alone.
  3. For events, one should really plan to have a tripod and mast at least 6' tall to hold the antenna in position. 
  4. For planning purposes, 10' of coax is 1.2dB loss with RG-8 and 0.7dB loss with LMR-400.  Yes, in many applications, 50' of this stuff will still allow a usable signal if you are not in a border situation....but try to keep lengths at a minimum for best throughput.  Connector losses, if done correctly can be ignored.
  5. Patch antennas are a reasonable means of feeding a dish.  They are simple to make and actually work!  A 6x6 piece of aluminum sheet, a 3x3" piece of sheet hobby brass (with some trimming) with an N-connector puts you in business.
  6. Participants should learn how to configure their wireless card with a fixed-IP Address (e.g. 47.254.254.XXX) as well as become familiar with the configuration and setup of their 802.11 card.  Read up and become familiar with your equipment....just like a radio.  It is really helpful for each person to know their stuff.  I encourage everyone to experiment with their equipment and get comfortable.

I've posted a listing of participating users, their MAC address, and each of your assigned IP addresses on the NTMS-HSMM yahoo group files section.  Please note that the temporary number I provided to you on Saturday is NOT your permanent allocation.  Check the file for the IP address that you should be using.  http://groups.yahoo.com/group/ntms-hsmm under FILES section.

Here is a map of the paths.