[TowerTalk] 1/4 wave vertical with counterpoise

[Jim Brown]

On 1/17/2026 12:56 PM, Brian Beezley wrote:
> I never worry about takeoff angle, which I take to mean the angle of the 
> maximum lobe in the elevation plane. Communication takes place at angles 
> determined by path distance, ionospheric height, ionospheric tilt, and 
> probably more. It does not necessarily occur where any particular lobe 
> is located. I generally pick what I think is a representative low angle, 
> usually 5 degrees, and compare gain for all antennas I'm considering there.

YES!  Takeoff angle is a stupid concept. For those reading the mail, 
look at the link I posted about antenna planning, which contains plots 
of multiple conditions on the same scale, and compare the dB difference 
between those conditions at the same vertical angle. While propagation 
takes place at all angles, for the most part, low angles are most 
important, especially on the lower bands.

All of these plots look similar, so looking only at the field strength 
at max misses a lot. And both NEC and ARRL plots automatically scale 
plots to that maximum value. When using NEC for designs, it's helpful to 
save a plot for one condition, then import it into the screen for 
variations we make. The cursor on the imported design will read out the 
difference from the current design. VERY instructive.

Doing this can often point out that curves that look very similar and 
have little difference in "takeoff angle" can have differences of 3-6 dB 
at low angles! And look at the differences in how the height of HF 
verticals changes both their vertical pattern and ground loss!

73, Jim K9YC