Your RadioShack DX-399 Shortwave Receiver brings the voices of the world to you. You can hear news broadcasts and other pro-. View online or download Radio shack DX-399 Owner's Manual. We have 2 Radio Shack DX-399 manuals available for free PDF download: Owner's Manual I picked up a new Radioshack DX-399 over the weekend. These are on The manual says the indicator should flash when the battery strength is 3 or lower.Great deals on RadioShack Radio Communication Manuals & Magazines. RADIO SHACK DX-399 VINTAGE FM STEREO MW/LW/SW RADIO AC/DC FREE SHIPPING USA.