Creating A 4 Element 440 Yagi
A recent addition to the repeater list had given me a reason to make up a 440 antenna...the typical 1/4 wouldnt cut it as I am in the blind spot of the repeater. So I made up a 4 element yagi.
Its a direct connect antenna...easy and simple.
Dimentions are as follows:
Reflector length: 13"
Driven Element: 13" (trim to optimize SWR)
Director 1 length: 12"
Director 2 length: 11.75
Reflector spacing: 0 (what to measure all the others off)
Driven Element spacing: 2.5" from reflector
Director 1 Spacing: 5.5" from reflector
Director 2 Spacing: 11" from reflector
The driven element is 3/4 of a folded dipole. The top is a 13" -ish in length (trimmed to lowest swr reading). Then folded back on itself until it meets the boom. The center of the coax gets soldered on the short portion of the driven element, the shield soldered onto the top long portion of the driven element. Both soldering points are as close to the boom as possible.
I havent done any solid testing but I get less than 1.3 SWR and am able to get 40 over signals from the repeater that I could not get into on a 1/4 wave.