. QST . ndicator, and either of the two systems shown abovecan be used. In A, a single dial lamp with one-foot leadsis clipped onto the feedline. As the transmitter and cou-pler are tuned to maximum output, the dial lamp willlight up. It may be necessary to move the clip leads upthe line to find a point where sufficient coupling isobtained. At B, the dial lamps in parallel are connectedin one of the feeders. To start out, all three bulbs shouldbe connected to prevent possible burn-out. They canbe disconnected one at a time until the best indication isobtained. shown in Fig. 3. An absorption-ty
. QST . ndicator, and either of the two systems shown abovecan be used. In A, a single dial lamp with one-foot leadsis clipped onto the feedline. As the transmitter and cou-pler are tuned to maximum output, the dial lamp willlight up. It may be necessary to move the clip leads upthe line to find a point where sufficient coupling isobtained. At B, the dial lamps in parallel are connectedin one of the feeders. To start out, all three bulbs shouldbe connected to prevent possible burn-out. They canbe disconnected one at a time until the best indication isobtained. shown in Fig. 3. An absorption-type wavemeterloosehj coupled to the feedline can be used. Center-Fed Antennas A center-fed antenna doesnt have to be aspecific length to work well. If you can make theantenna a half wavelength long at the lowestband, fine and dandy. But if your (JTH is suchthat putting u[) a half-wave antenna would meantying the far end to your neighbors TV antenna, * McCoy, The Baking-Pan Wavemeter, QST, Febru-ary, In this view the link capacitor is shown at thebottom and the tuning capacitor at the top. The lineconnected to the coaxial socket is a short piece of 52-ohmcable. use a little discretion and compromise with theideal. A slightly shorter antenna wont show anappreciable difference in performance. The im-portant thing about a center-fed antenna is to besure that the feedline is connected at the exactcenter of the antenna and, if possible, that thefeedline runs away from the antenna at rightangles for a considerable distance. Some ama-teurs do this by bringing the feedline straightdown from the horizontal antenna to a mast orpole and then running the feedline into theshack. The horizontal section of the feedlineshould, of course, be high enough to clear theheads of any pedestrians. It is a good idea to make the length of thefeedline plus one-half the antenna length amultiple of a quarter wavelength at the lowestoperating frequency. A quarter wavelength isfound by dividing 246 by t
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
