. An elementary manual of radiotelegraphy and radiotelephony for students and operators . Fig. 3. In eases in which bent or directive antennae of Marconisform are employed, then two or more masts have to be erectedto sustain the horizontal portion of the antenna in the requireddirection (see Fig. 3). A very common form of antenna is thatcalled an umbrella antenna. In this case a single mast ortower is erected, and from the top insulated wires extend outwards. Fig. 4. and downwards like ribs of an umbrella (Fig. 4). The tower issometimes insulated at the base and forms part of the ot
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . Fig. 3. In eases in which bent or directive antennae of Marconisform are employed, then two or more masts have to be erectedto sustain the horizontal portion of the antenna in the requireddirection (see Fig. 3). A very common form of antenna is thatcalled an umbrella antenna. In this case a single mast ortower is erected, and from the top insulated wires extend outwards. Fig. 4. and downwards like ribs of an umbrella (Fig. 4). The tower issometimes insulated at the base and forms part of the other times the wires are insulated at the top from the tower. Unless the mast or masts are erected in contiguity to somealready existing building or lighthouse, it is then necessary to RADlOTELEGRAPHtC STATIONS 339 «erect luar ilio biiso of tho mast or inasU in 8<mim *i<iivcnieutpositiiiu a Imiklui^ which serves lis u nulititilej^; stutiou,which may be of wiuui, brick, or iron, u« most con-veuient. Into this buihlin<{ the antenna is tliun led, and animportant detail of construction is tho means necessary to securethe necessary insulation and yet weather tij^htness. (Jne methodis to cut a hole in a pane of glass in a window, or \Ai make awindow glazed with a sin^de sheet of thick plate ghiss. In thisa hole is bored, throu<,di whicli passes a thick-wallcd ebonitetube made ti^dit with indiarubber washere. It is advanta;,eo
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
