Ralph Mowery wrote:
"Most likely big BS."

Also:
"---40 elements and 20.8 dbi is all that has. That is almost 3 times as
many elements as the ebay antenna."

Ralph is on the mark.

John Kraus in "Antennas", page 705, demonstrates how the gain of a
curtain antenna adds up:

"The gain of a single 1/2-wave dipole is 2.15 dBi and of 2 collinear
in-phase 1/2-wave dipoles is 3.8 dBi. The array of 8 such collinear
dipoles adds 3+3+3 =9dB. The reflectoer screen adds 3 dB more and the
ground bounce another 6 dB for a grand total of 3.8+9+3+6=21.8 dBi or a
directivity of 151 approx."

36 db is the sort of gain that one can get from a dish that is very
large in terms of wavelength and that has extremely small imperfections
in its surface. As Kraus shows, you only hope to gain 3 db more when you
double the number of elements in an array.

Best regards, Richard Harrison, KB5WZI