I am curious if there is a way to set the 520 to use the 850mhz band by default. I have read the lower frequencies tend to provide better indoor reception. I am wondering if this would help me get a better signal or not.
There's no way to select the frequency that I know of.
You are correct, the lower the frequency the better the penetration. In the Military we used ELF (Extremely Low Frequency) to communicate with submarines.