here's the thread Needle Bender is referring to .
http://www.worldwidedx.com/cb-anten...ur-favorite-citizens-band-radio-antennas.html
and heres some of the graphs from it .
maybe i'm not looking at something right , but the sigma seems to show more gain lower on the horizon than the 5/8 and .64 . the 5/8 and .64 do have more gain at a higher TOA though . FWIU a lower TOA is is better for longer distance ground wave or LOS
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"I just finished reading the old thread about eznec by ctstallion and noticed on those models that there is about 1/2 db more gain on the 64 over the 5/8 at about 5 degrees lower angle, (32 vs 27 degrees) and about the same 1/2 db gain on the 64 over the sigma4 - vector at 27 degrees. Isn't there a possibility that much gain at that higher angle could be helpful under certain conditions?"
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i would think yes . but how often do those certain conditions happen ? if its a majority of the time the the .64 would seem to be better . if its a minority of the time then no . i think the 1 db or needles worth of gain or loss is not worth arguing over . change the installation/location and another antenna may be best . try wiggling your RF gain control back-n-forth enough to move one needles worth or 1 s-unit and see how much difference it doesn't make . i think a lower TOA has more chance of making a far away contact than adding 1/2 a db of gain at a 19-22 degree higher TOA .
any idea what the increase in db gain at 10 degrees the vector has over the 5/8 or .64 ?
looking at the graph is seems to be several times the distance the 1/2 db is on the 5/8 .64 at 28-32 degree TOA .
but like i said ........ maybe i'm not looking at something right