Phasing harness for 4-stack antenna

[JE-WV1]

It's not often I find details like these, I certainly had trouble finding anything like it when I looked some time ago... so I thought I'd share this page with you...
http://www.kr1st.com/70cmstack.htm
It shows how to stack 4 x 50 Ohm horizontally polarised loop antennas and connect it up with a phasing harness.

This kind of thing could be used to join 4 vertical antennas into a cheap DIY UHF omni like the ones used by the pros with 4 folded dipoles I guess?... although I'm puzzled by the 17" loops spacing... ... 17"/27.3" = 0.62 which doesn't appear to be any special fraction of a wavelength at 432MHz?

[5thElement]

Certaintly isn't pretty lol but seems like a nice weekend project!

[bigbloke]

although I'm puzzled by the 17" loops spacing... ... 17"/27.3" = 0.62 which doesn't appear to be any special fraction of a wavelength at 432MHz?

have you allowed for the velocity factor of the co-ax in use Andy ?

0.6 - 0.9 are fairly common

Regards

BB

[JE-WV1]

Thanks BB, but I wouldn't have expected coax VF to account for the radiating element spacings in the air?

To recap, he's designing for 432.1 MHz which is wavelength 69.4cm = 27.33" :
1/4wave = 17.4cm = 6.833"
1/2wave = 13.67"
3/4wave = 20.5"

Coax pieces
3/4wave = 20.5" x 0.66 (VF) = 13.5"
5/4wave = 34.2" x 0.66 (VF) = 22.5"

17" seems strange to me, being 62% of the wavelength, and even dividing by 0.66 doesn't match up with anything.