Hidden Info 
The VR-500 comes with two hidden Set Menu options: Narrow AM receive mode and User Port (unknown use) 
To enable these two hidden options, hold down the 0, 3, 5 and 9 keys while the radio is off and continue to press them while turning the radio on. 
Go into the Set Menu and note the addition of items 33 and 34 
The Narrow AM setting can be quite handy when surfing the crowded SW bands