01-10-2008 4:45 PM
I live in a rural area without DSL or Cable service and I have a USB Connect 881 which I recently purchased for a residential internet connection. The device itself works very well.
Shortly after purchasing this modem I purchased an External 9dB gain antenna from CellGearUSA from their EBay Store. The problem is when I have the antenna hooked up I have issues staying connected and constant disconnects. Without the external antenna I have a signal strength of -83dBm to -86dBm and I stay connected for as long as I want (I think I had a max time of being on AIM for 4 days with no disconnect) When I connect my antenna (which I have outside and I use a USB Extension cable) I have a signal strength of -73dBm to -76dBm. I have tested the USB Extension cable and it is not causing the issue because I disconnect the modem from the USB cable and antenna and reconnect it to the USB extension cable and I once again I have the lower signal strength but I stay connected for as long as I want.
I have a WindowsXP SP2 OS and when these disconnects happen I get the sound wave (from windows) that a device has been disconnected and reconnected. This "wave spam" goes on for approx 5 to 10 seconds during which time 3G Watcher / AT&T Communication Manager cannot find a wireless device. After this event stops it re initializes the device and I can usually reconnect immediately without issue. Occasionally in order to reconnect I have to disconnect the modem and reconnect it.
This problem is frustrating me because I do not think it is caused from a faulty antenna because if the antenna itself would be faulty it shouldn't cause the device to actually "disconnect" and cause the OS to believe it was disconnected.
Any help would be greatly appreciated.
01-12-2008 2:10 AM
01-12-2008 12:46 PM
01-30-2008 1:42 PM
01-30-2008 4:24 PM
When I asked why the 881 had a battery, the salesman told me that's so you don't have to worry about the USB going Off. Is that true, or could that still be the user's problem? I'm considering getting an antenna and don't want the same problem(s).
01-30-2008 8:24 PM
I haven't had much time recently to investigate this more but I did take a few more steps to find out what is going on with the extension cable.
Thinking that my problem was due to not enough power I broke out the multi-meter and tested the voltage and amps coming directly out of my computer and out of the extension cable. They are almost identical and still both within specs of USB (5v, 500mA) I am at a complete loss as to what my problem is coming from. I tried to contact AT&T and after listening to my problem they immediately referred me to Sierra Wireless. After spending two hours on the phone with the Techs (I went through 2) they didn't know either and just ran me around in circles. They however did constantly repeat the phrase "We don't advise using extension cables".
I intend to try a powered USB hub but I don't see how that will help in any way when the voltage and amperage coming out of the extension cable are both on par. However, it will allow me to rule out that one slim possibility of a problem.
I also recently found out a neighbor of mine has this exact same PC Card and I will be borrowing his antenna to see if it causes the same connectivity problem mine does. If the powered USB hub and the different antenna fixes the problems I will be set, if not I go back to the drawing board once again.
01-30-2008 9:17 PM