Good afternoon everyone, I wanted to consult the following because I have some doubts about the ground plans of the antron 99 I wanted to know what the measurement of the ground plans is and if they go to 45 degrees from already thank you very much, greetings

They go to 45º if the manufacturer provides them, and the measurements are approximately 10% to 20% of 1/4 of λ of the frequencies to be used as standard media of such a reflector. If it is a BC antenna and we use the standard band of 26965-27405 the calculation would be 75 / 27,200 = 2.75m plus 20% would be approximately 3.3m each. Anyway shorter or longer or 45º or 90º what changes slightly are the angles of irradiation that become a bit closer to the ground so increase slightly and in certain propagation conditions, the range. Regards. Ric.