If you use those plastic insulation troughs and overlap the top one of the lower ones even if rain should sneak up past the shingles, past the builders felt it will fall on the plastic trough and be carried out past the building envelope.. 1  Reply. 2  Reply to Original. 3  Print this page. 4  Email this Message.
Double-sideband suppressed-carrier transmission. Double-sideband suppressed-carrier transmission (DSB-SC) is transmission in which frequencies produced by amplitude modulation (AM) are symmetrically spaced above and below the carrier frequency and the carrier level is reduced to the lowest practical level, ideally being completely suppressed.
Digital Selective Calling (DSC) radio is the latest in marine radio technology. Digital Selective Calling is part of a global upgrade in maritime distress communications. Satellite and digital technology used for several years on commercial ships is now available to the recreational boater. DSC radios allow boaters to make ship-to-ship private calls and the DSC distress channel is currently being monitored by commercial ships. Since 1996 recreational boaters were no longer required to have a ship's station license issued by the FCC in order to operate a VHF radio.