. QST . ither forward or reflected power as selected bya front-panel switch. Two output links are pro-vided, for either low-frequency ( to Mc.)output or high-frequency (14 to 30 Mc.) \ second front-panel control is provided for theselection of various functions. The noninductive50-ohm dummy load is connected in circuit inPosition 1, while the second position switches thetransmitter to the coupler proper. Position 3switches the transmitter to a 50-ohm output con-nection which is independent of the coupler butallows the u.«e of the power-measuring devicewhen feeding directly into
. QST . ither forward or reflected power as selected bya front-panel switch. Two output links are pro-vided, for either low-frequency ( to Mc.)output or high-frequency (14 to 30 Mc.) \ second front-panel control is provided for theselection of various functions. The noninductive50-ohm dummy load is connected in circuit inPosition 1, while the second position switches thetransmitter to the coupler proper. Position 3switches the transmitter to a 50-ohm output con-nection which is independent of the coupler butallows the u.«e of the power-measuring devicewhen feeding directly into a matched 50-ohm line. The complete schematic is shown in Fig. most homebuilt projects, other parts can besubstituted. However, care should be taken in The muitihand tank circuitconsists of the split-stator ca-pacitor at the left and the twoinductors, with links, in thecenter. Coupling is controlledby the tank and the capacitorat the right. The two-terminalassemblies connect to the twolink May 1955 11 following the layout of the unit, especially theforward- and retteeted-power indicating device. Construction The Z-match shown in the photographs isbuilt on an 11% X d\i X 2i2-inch chassis, andthe panel is 12ii by 6% inches. These were usedbeeaus? they were on hand, but any number ofcommercially-available chassis and dust-covercomlMnations could be used with good results. The chassis itself is used to separate the low-impedance input circuits from the comparativelyhigh-Z output circuits, and no matter what sizechassis is used this constructional practice shouldbe followed. The coupling capacitor Clo is elec-trically above ground and is mounted on twofeed-through insulators (Johnson type 135-55),one of which is used to bring the electrical con-nection through the chassis to the rotor of capacitor is set back from the panel andcoupled to the dial by an insulated shaft, thuseliminating body capacity. Cn is mounted atthe other end of the chassis and the contro
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
