. QST . was not as great as with transmitting re-ports. However, in many cases it was enough tomake the difference between hearing a signal andnot hearing one. The simplicity of the antenna and the low cost,together with the improved performance over afixed antenna, make it a worth-while project foran amateur interested in 15-meter operation. Atthe time of this writing, an 0Q5 station in theBelgian Congo was heard on 15 meters workingNovice stations. Who will be the first NoviceDXCC? MEMBERSHIP CHANGES OF ADDRESS Four weeks notice is required to effectchange of address. When notifying, pleaseg
. QST . was not as great as with transmitting re-ports. However, in many cases it was enough tomake the difference between hearing a signal andnot hearing one. The simplicity of the antenna and the low cost,together with the improved performance over afixed antenna, make it a worth-while project foran amateur interested in 15-meter operation. Atthe time of this writing, an 0Q5 station in theBelgian Congo was heard on 15 meters workingNovice stations. Who will be the first NoviceDXCC? MEMBERSHIP CHANGES OF ADDRESS Four weeks notice is required to effectchange of address. When notifying, pleasegive old as well as new address. Advisepromptly so that you will receive everyissue of QST without interruption. 32 QST for Using a 304-TH as agrounded-grid amplifier, thisunit can utilize to good ad-vantage the full output of anyof a number of popular com-mercially-built transmittersfor driving power. The push-rod operated band-changingswitch can be seen projectingthrough the panel at the left-hand Grounded-Grid and the 304-TH Utilizing 200-Watt Rigs for Driving BY THOMAS P. LEARY,* W0VTP ONE thing that bothers most of us about de-signing and building a final amplifier isneutralization. This old dragon is with usin all conventional triode circuits, and a greatmany tetrodes also require it. But, with the righttube, the grounded-grid circuit will put the neu-tralizing condenser and split-stator tank ba(;k inthe junk box. Still, we cant get something for nothing andgrounded-grid operation requires four to sixtimes the driving power. If we havent alreadylost you, lets see what can be done with thisarrangement. Only the normal drive requirement of the tubeis dissipated in the grid circuit; the remainingpower passes through it and is added to the totalpower output. The filament, or input, circuit hasa very low impedance, permitting the amplifierto operate as a Class B linear without swampingresistors. Many amateurs own a Collins 32-V, a JohnsonViking or a homebrew rig with an o
Size: 1831px × 1365px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
