Few questions about antennas i can put on my surf 200

My town has free city wide wifi and i have a surf 200 older model im sure. Its acting kind of slow and disconnecting alot and the wifi signal just blinks. I have to unplug it and plug it back in. I dont know if its the city wifi thats doing it. I bought a cheap liehou 14 dbi antenna to put on it and it works but is there a limit on how big a dbi antenna it can power? Im thinking of getting a usb long range wifi antenna to replace it unless theres tricks to optimize this pepwave. I tried to scan in the operating menu for new firmware but it says the latest was from 2012. I dont know if thats true and theres a newer one and if that firmware would make a difference in performance. Im just curious if anyone has some advice for me. Maybe a recommendation on a good long range antenna i can use to grab the access point thats about a half block away. The neighbors have the ideaworks long range usb antenna that seems to work but i would miss the local access point i could use for my ps3 and phone. Any help would be appreciated.

Hi,

The Surf 200 has been EoL for many years and it is no longer supported. Do consider to perform hardware refreshment for the Surf 200 that supplanted by the Surf On The Go.

For more information regarding to Surf On the Go (SOTG), please refer to the URL below:

Thank You