Automatic fire suppression health effects. From the mid-1960s Halon 1301 was the industry standard for protecting high-value assets from the threat of fire. Halon 1301 had many benefits as a fire suppression agent; it is fast-acting, safe for assets and required minimal storage space. Halon 1301's major drawbacks are that it depletes atmospheric ozone and is potentially harmful to humans. Since 1987, some 191 nations have signed The Montreal Protocol on Substances That Deplete the Ozone Layer. The Protocol is an international treaty designed to protect the ozone layer by phasing out the production of a number of substances believed to be responsible
QSK operation (full break-in) QSK operation must ensure that their radio equipment includes the hardware capability for radio frequency antenna switching that operates rapidly enough to allow listening between signals at the appropriate Morse code sending speeds with appropriate lifetimes and reliability. QSK operation (full break-in) "Turning over" a communications channel is the change in communications protocol transmission status that occurs when a transmitting station releases transmitting control of a communications channel thus turning it over to allow another station to transmit. QSK or full break-in operation is one of several techniques and protocols for turning over control of a Morse code radiotelegraph communications