follows a straightforward logic common to many RadioShack-style scanners :
Below is a synthesized guide based on standard operating procedures for this series of 1990s-era programmable scanners. Quick Setup & Controls Power/Volume: Netset Pro-44 Scanner Manual
For those keeping a Pro-44 alive, and always carry a spare battery. This scanner was built to last 15 years – with this guide, you can get 15 more. Netset Pro-44 Scanner Manual
If a channel is constantly active with interference, press L/O while on that channel to bypass it during scanning. Troubleshooting & Maintenance Display is Dim: Check or replace the AA batteries. Netset Pro-44 Scanner Manual