I have a UML290 and I am on the fringe of the closest 4G cell tower. I'm looking for people that use an external antenna with their UML290 and how well their antenna performs for them, and what model is their antenna. Thanks in advance!
I use the MiFi 4510L and a external antenna from Sierra Wireless:
You can look into more powerful antennas such as those provided by Wilson Electronics:
External Antenna's vary in size and power so you should purchase one that fits your needs. Most external 3G/4G antennas that have a matching plug will be compatible with your device, even if it does not specifically say so. The antenna that I use is fairly small, lightweight and unpowered which works well for me. If you need better reception and do not need your antenna to be mobile then the Wilson Electronic boosters are a good solution for home or car installations.
You can see some pics of my setup and speed test results here.
Be sure to get the proper cables. LMR-400 is supposed to be really good for long runs.
Best of luck,