I know here at this shipyard when they load equipment down holes In a ship in the rain..they put the radios in a heavy duty plastic bag,sealed and taped up with duct tape.. Antenna and all.
You could probably let the antenna stick out and bag the radio ..sealing it at the antenna with duct tape.
This is how they water proof such a set up.
A waterproof radio would be considerably expensive as are the ham type weather resistant radios I have seen. So too are those computers...I think the call them tough books or such to be used in vehicles...weather etc.
Want to pick up a similar radio, the UV82HP, and be able to use it for extended periods of Backpacking. I have pretty much decided that I will use some type of Solae Cell recharging to a spare battery in a separate pouch and operating on another.
Anyone doing something like this? I want to get a cell and secure it to my present back pack.