Tech note
Cellular (GSM) Amplifier/Repeater/Extender

Below is a link to a cellular signal amplifier/repeater that may help improve mobile phone signal strength for HOBO RX3000 3G systems.

Note that this has not been tested or endorsed by Onset. 

http://www.amazon.com/Wireless-Extenders-Cellular-Amplifier-Repeater/dp/B000LBVEI0/ref=sr_1_1?ie=UTF8&qid=1316719940&sr=8-1