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.
These VHF/GPS combo handhelds include Digital Selective Calling (DSC), which functions as a sort of VHF-frequency emergency beacon. Just push and hold down the red DISTRESS button on your handheld VHF radio, and it sends an automated digital distress message to the Coast Guard and all other DSC radio-equipped vessels. Rescuers instantly know who you are, where you are (using GPS coordinates), the name of your boat and the phone numbers of your emergency contacts.