Helical-wound radials for vertical antenna
#1
I am trying to fit a 4 band HF vertical into a very tight space. It is mounted on top of a 5m high pole. I was going to use 4 elevated radials but there is no room to fan them out. My thought is to helically wind them on to a pieces of PVC pipe attached to the base of the antenna.  I think there are some commercially-built verticals that have similar radials (CP6?).

What say ye!

73

Wayne VK4WDM
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#2
Wayne

Expect narrow SWR bandwidth with helical radials : the Diamond CP6 does have them but have a look at the freq  response width at http://www.diamondantenna.net/pdfdocs/CP6A.pdf

To homebrew, try this calculator with the same values for min and max former diameters for straight wall PVC tube (non-shrinking) - it will at least get you into the 'frequency ballpark' :  

http://www.vk4adc.com/web/hf-projects/45...-whip-calc

Doug
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com

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#3
(20-02-2018, 09:16 PM)VK4ADC Wrote: Wayne

Expect narrow SWR bandwidth with helical radials : the Diamond CP6 does have them but have a look at the freq  response width at http://www.diamondantenna.net/pdfdocs/CP6A.pdf

To homebrew, try this calculator with the same values for min and max former diameters for straight wall PVC tube (non-shrinking) - it will at least get you into the 'frequency ballpark' :  

http://www.vk4adc.com/web/hf-projects/45...-whip-calc

Doug

Hello Doug

The narrow frequency response won't really be a problem because the station is almost all CW and digimodes. Now that the wet weather has gone, at least for now, I will wind the radials and see what happens.

73

Wayne VK4WDM
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