The Birmingham age-herald., 1922-05-14
Age-Herald's
 Sunday

Sloe OA OOtelQ6 Ol DullQlnKS. W nen receiving equipment ground wire is run in full compliance with rules for protective ground wire In section fd). 1t may be used as the ground con ducter for the protective device.
 For Transmitting Stations
 Antenna
 ~ (s) Antennas outside of buildings snail not cross over or under elec- trie light or power wires of any cir cult Of more than six hundred (s0o) volts or railway, trolley, or feeder wires, nor shall it be so located that failure Of either the antenna or of the above mentioned electric ligh. or power wires can result in a contact between the antenna and such cleo trict light or power wires.
 Antennas shall be constructed and installed in strong and durable manner and shall be So located as to prevent accidental contact with light and power wires by sagginE or swinging.
 Spices and joints in ths antenna span shall. unless made with ap- proved clamps or splicing devices, be soldered.
 Lead-iu Wires
 th) Lead-in wires shall be of cop per, approved copper-clad steel or other metal which will not corrode excessively and in no case shall they oo smaller than No. l4 B. & S. gage
 Ahtenna and counterpoise conduc- 1ors and wires leading therefrom to ground switch, where attached to buildings, must be firmly mounted i've e5) inches clear of the surface or the building, on -absorptive in- fu wood pins or brackets equipped with -nsulators having not less than five to) Inch creepage and air gap dis lance to inflammable or conducting material. Where desired approved suspension type insulators may be used.
 D In passing the antenna or counterpoise lead-in into the building . tubo or pushing of non a absorptive Insulating material shall be used and shall be installed so as to haye a creepase and air-gap distance of at least five t5) ip/hes to any extran- eous body. If prtcelain or other fra gile material is used it shall be in- stalled so as to be protected from mechanical injury. A drilled window provided five (5) inch creepage and
 
 Protective Grounding Switch
 C) A double-throw knife switch having a break distance of four (D Inches and blade not less than one eighth ts) inch by one-half (B) inch shall be used to join the antenna and counterpoise 1ead-ins to the ground conductor. The switch may De located inside or outside the build ing. The base of the switch shall be of non-absorptive insulating material Slate base switches are not recom- mcnded. This switch must be so mounted that its current-carrying parts will be at least five (5) inches clear of the building wall or other conductors and located preferably in the most direct line between the lead in conductors and the point where ground connection is made The con- ductor from grounding switch to ground connection must be securely supported.
 Protective Ground Wire
 tk) Antenna and counterpoise con ductors must be effectively and per- manently grounded at all times when station Is not In actual operation tun- attended) by a. conductor at least as large as the iead-in and in no case shall it be smaller than No.9l4 B. & S. gage copper or approved copper clad steel. This ground wire need not be insulated or mounted on insu- lating supports. The ground wire shall be run in as straight a line as possible to a good permanent ground. Preference shall be given to water piping. Gas piping shall not be used for the ground connection. Other permissible grounds are the grounded rt~ ~I T grounded metal work In buildings and artificial grounding devices such as driven pipes, plates, cones, etc. The ground wire shall be protected against mechanical injury. An ap- proved ground clamp shall be used wherever the ground wire is con .nected to pipes or piping.
 Operating Ground Wire
 CD The radio operating ground con- ductor shall be of copper strip not less than three eights (h) inch wide by one sixty-fourth (1-64) inch thick, or of copper of approved copper clad steel having periphery or girth iaround the outside) of at least three-ouarters (%) inch (for ex- ample No. B. & S. gage wire) and shall be firmly secured in place throughout its length. The radio operating ground conductor shall ba protected and supported similar to the lead in conductors.
 Operating Ground
 (m) The operating ground conduc- tor shall be connected to good per- nianent ground. Preference shall be given to water piping. Gas piping shall not be used for ground connec- tions. Other permissible grounds are grounded steel frames of buildings or other grounded metal work in the building and artificial grounding de- vices such as driven pipes, plates, cones. etc.
 Power From Street Mains
 (n) When the current supply is obtained directly from street main4 -he current shall be installed in ap- proved metal conduit, armored cable CT metal raceways.
 If lead covered wife is used it shall be protected throughout its length in approved metal conduit or metal race ways.
 Proteetion from surges. Etc.
 (o) In order to protect the supply system from high-potential surges and kick-backs there must be install cd in the supply line as near as pos slble to each radio o-transformer. TO- tary spark gap. motor in generator sets and other auxiliary apparatus one of the following:
 l. Two condensers leach of not less than one-half tis) microfared capa- city of withstanding six hundred (e0o) volt test) in series across the line and mid-point between condens- CTS grounded: across the line and n