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I made 4 "beginner" models for a 3/4 and 5/8 vertical for 28.5MHz and in these models with 30 radials. Feed point at 0.1m (I see this effectively as ground mount) it looks like the 5/8 wins in terms of peak gain at 12 degrees for both antennas and also of output/input signal at 5 degrees.

I hasten to add I am not an expert here and have a very basic ability of modelling and did not create FP matches so the SWR's are off the scale. Not sure the matches should effect the radiator length vs pattern though.

I used 300/28.5 x either 0.75 or 0.625 x 0.95 VF to get the lengths of 6.25m and 7.5m for 5/8 and 3/4 wave respectively. My red dot is at 5 degrees. I used "real ground" and values of 30 and 30 for dielectric and conductivity to best estimate what I believe my own QTH ground would be which is likely to be very good ground.

I see models as a what may or may not happen once antenna is set up in reality. A model is better than nothing to display possible responses.

Please do point out any glaring errors I am doing it just for fun. 5/8 top image and 3/4 image under edited to add a 1/4 wave for reference.. peak in/out for quarter wave at 22 degrees... and also add 1/2 wave..peak in/out at 16 degrees.

5/8 [ATTACH=full]47195[/ATTACH] 3/4 [ATTACH=full]47196[/ATTACH] 1/4 [ATTACH=full]47197[/ATTACH] 1/2 [ATTACH=full]47198[/ATTACH]

<blockquote data-quote="TheBlaster" data-source="post: 773819" data-attributes="member: 58745">I made 4 &quot;beginner&quot; models for a 3/4 and 5/8 vertical for 28.5MHz and in these models with 30 radials. Feed point at 0.1m (I see this effectively as ground mount) it looks like the 5/8 wins in terms of peak gain at 12 degrees for both antennas and also of output/input signal at 5 degrees.I hasten to add I am not an expert here and have a very basic ability of modelling and did not create FP matches so the SWR&#039;s are off the scale. Not sure the matches should effect the radiator length vs pattern though.I used 300/28.5 x either 0.75 or 0.625 x 0.95 VF to get the lengths of 6.25m and 7.5m for 5/8 and 3/4 wave respectively. My red dot is at 5 degrees. I used &quot;real ground&quot; and values of 30 and 30 for dielectric and conductivity to best estimate what I believe my own QTH ground would be which is likely to be very good ground.I see models as a what may or may not happen once antenna is set up in reality. A model is better than nothing to display possible responses.Please do point out any glaring errors I am doing it just for fun. 5/8 top image and 3/4 image under edited to add a 1/4 wave for reference.. peak in/out for quarter wave at 22 degrees... and also add 1/2 wave..peak in/out at 16 degrees.5/8 [ATTACH=full]47195[/ATTACH] 3/4 [ATTACH=full]47196[/ATTACH] 1/4 [ATTACH=full]47197[/ATTACH] 1/2 [ATTACH=full]47198[/ATTACH]</blockquote>

[QUOTE="TheBlaster, post: 773819, member: 58745"] I made 4 "beginner" models for a 3/4 and 5/8 vertical for 28.5MHz and in these models with 30 radials. Feed point at 0.1m (I see this effectively as ground mount) it looks like the 5/8 wins in terms of peak gain at 12 degrees for both antennas and also of output/input signal at 5 degrees. I hasten to add I am not an expert here and have a very basic ability of modelling and did not create FP matches so the SWR's are off the scale. Not sure the matches should effect the radiator length vs pattern though. I used 300/28.5 x either 0.75 or 0.625 x 0.95 VF to get the lengths of 6.25m and 7.5m for 5/8 and 3/4 wave respectively. My red dot is at 5 degrees. I used "real ground" and values of 30 and 30 for dielectric and conductivity to best estimate what I believe my own QTH ground would be which is likely to be very good ground. I see models as a what may or may not happen once antenna is set up in reality. A model is better than nothing to display possible responses. Please do point out any glaring errors I am doing it just for fun. 5/8 top image and 3/4 image under edited to add a 1/4 wave for reference.. peak in/out for quarter wave at 22 degrees... and also add 1/2 wave..peak in/out at 16 degrees. 5/8 [ATTACH=full]47195[/ATTACH] 3/4 [ATTACH=full]47196[/ATTACH] 1/4 [ATTACH=full]47197[/ATTACH] 1/2 [ATTACH=full]47198[/ATTACH] [/QUOTE]

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