vhf quarter wave ground plane antenna radial shape?

[wqzw301]

Does the shape of a ground plane radial matter?
Modeling software deals with lengths maybe even diameter... Ham, commercial, marine antennas - dyi or purchase have tubular or wire radials....
I have a vhf antenna that has (and is the only fault in design) 3 radials maybe 3/8th in diameter.
My plan was to add more radials.. But because of set screws, where I would drill and tap 3 more radials, my plan changed to just widening the existing radials.
I eventually came to the conclusion I could get more width out of aluminum flat stock than wider aluminum tube.
1.25" width x .25" thickness on all three radials. And I could use the original tapped sockets with aluminum bolts to secure them.
I know it won't change the decoupling from the mast,,, but will it change anything, I'm not thinking of?
It's unity gain, so I don't think it will effect take off angle?
It's not that crucial but now the thought is in my head... and now I'm curios .
Any thought's Please and Thank you

 

[KEWB-N1EXA]

The ground plane angle sets the feed point impedance - 120degrees' between vertical to horizonal makes it between 50-75 ohms.

If you made them say both vertical like a dipole the impedance would be over 300+ Ohms and at than point you need to
put A transformer on it say like A tv antenna one 300-75 ohm antenna transformer.

Pete N1EXA

 

[jhooten]

More is not always better. What are you trying to accomplish?

 

[KEWB-N1EXA]

The ground plane angle sets the feed point impedance - 120degrees' between vertical to horizonal makes it between 50-75 ohms.

If you made them say both vertical like a dipole the impedance would be over 300+ Ohms and at than point you need to
put A transformer on it say like A tv antenna one 300-75 ohm antenna transformer.

234/freguency x 12 = the antenna in inches as where the ground plane would be 5% larger

The thickness has to deal with surface area and would be more important in transmitting An AC field vs surface area.

Pete N1EXA

 

[prcguy]

A 1/2 wave dipole or coaxial dipole is around 72 ohms so that would be the highest impedance you should see with radials pointing straight down. The ground radials can be perfectly horizontal or 90 degrees to the vertical element and you can achieve a perfect 50 ohm match. A 1/4 wave vertical monopole over a perfect flat infinite ground plane of copper is around 35 ohms impedance. Reduce that to three or four 1/4 wave wire ground radials and the impedance is around 50 ohms.

Also, the 5% longer thing is not correct and from a long time ago, the radials should be 1/4 wavelength so the RF makes a 1/2 wave round trip back to the feedpoint. Changing the radial length will require changing the vertical length to keep a 50 ohm match.

The ground plane angle sets the feed point impedance - 120degrees' between vertical to horizonal makes it between 50-75 ohms.

If you made them say both vertical like a dipole the impedance would be over 300+ Ohms and at than point you need to
put A transformer on it say like A tv antenna one 300-75 ohm antenna transformer.

Pete N1EXA

 

[wqzw301]

I would keep them at 45 degrees..... And defiantly a quarter wave length.. Just change the shape

 

[prcguy]

If you look at a Kreco ground plane with 6 radials, they use a roughly 25 degree angle from horizontal. Fewer ground radials like four or three would be closer to 90 degree to the vertical element. Kreco could have used 90 degrees and it would work fine.

I would keep them at 45 degrees..... And defiantly a quarter wave length.. Just change the shape

 

[ka3aaa]

flat stock will be fine for radials and it is used by several manufactures on commercial antennas.