fellas,
the new sirio uses the longer radials with the same hoop, the new radials are 106.5" rather than 90" making the electrical length of the radials significantly longer than 1/4wave, at least that would be the case if the elements were not placed in close proximity to the central monopole,
does the close proximity reduce electrical length and raise resonant frequency enough that the longer radials are actually near 1/4wave electrical?,
could this indicate that the important dimention is the radial sleeve length and not the radials electrical length,
sirio don't claim improved gain from the longer radials they claim the same gain with a lowered radiation angle,
when i was tuning up my own antennas i posted that i felt that i was somehow manipulating the radiation angle because the improvement in signals at 60+ miles fm was more than the claimed db or so of extra gain over a 5/8wave could have provided,
i still think this is more than likely what we are doing when tuning for max signals at distance rather than effecting significant changes in absolute gain,
the way i read the patent they are saying that wider radial angles using full length 1/4waves give improved gain, obviously if you set 1/4wave radials at 30 degrees the hoop would be 9 feet in diameter and not at all practical,
avanti claim a wider bandwidth by adding the hoop and reducing radial length but they don't say what that does to gain,
note that the sirio uses 4x 90" radials where the avanti uses 3x 90" radials making them longer including the hoop
i was warned by LB.CEBIK that getting accurate results when modeling the sigma style antenna with nec ect would be very difficult.
