Adding Gain to an Existing Vertical
- Alternative concepts: WW2Y, K3LR, K4ERO, KB8I, K8UR, ON4UN, others
Assume you already have a tower already being fed as a single vertical on 160. How do you get more gain? Most peoples dream is the 4-square which yields an additional 5.5 dB of gain over one vertical. However, as you can see in the figure, the 4-square uses a lot of real estate--remember to consider the space needed for radials! It also requires four towers, or the at least the ability to support four verticals. A number of hams, some of whose calls are indicated in the chart, have devised alternative concepts, using tower supported wire verticals, parasitic arrays of some kind, inverted L elements, or slopers, all of which are simpler to erect than a full-size 4-square. We present another alternative--the FVR Spitifire array--which comes close to the performance of the 4-square, but is much more compact and can be erected in essentially the same space already occupied by the single vertical and its radials. Furthermore, the incremental cost of upgrading your tower to a Spitfire array is quite small.