Expanding the capture area of the directors by using a spearhead shape lowers the inductance without changing capacitance; thereby providing a broader band circuit.
Mounting the spearhead directors side by side (in co-linear fashion) creates a broad aperture resulting in an extremely narrow beam width that produces exceptionally high gain. The net effect is that of two yagi antennas mounted side by side with a common feed.
|The original Channel Master Quantum 1162 used a unique adjustable bandsaw element (shown above) for the UHF directors that could be tuned to the UHF channels desired. The second generation, labeled the Quantum 1162A, replaced the bandsaw UHF section with the spearhead design shown on the 1162A above. Lab tests demonstrated an additional average gain of 1.5 dB, and as high as 2.9 dB gain, depending on the channel, over the bandsaw design.|