Hello All,
And good Monday morning!
Sorry for my delay but I do not work every week end.
The reason for the 8 DBd on the flag pole support is as most of us know they compress
the pattern the higher the gain and flag pole supports are not that high. If you go to high in gain your coverage will suffer.
Like a height above average  terrain (HAAT) of just 100' out say 40 miles a 8 DBd will work far better then say 10 DBd.
So more real gain is not all ways a good idea. Some times less is more. As they say around the office "WHY PUT ALL THAT GOOD RF IN THE DIRT. The flag pole support folks recommend that at 450 MHz you not exceed 8 DBd when mounting a 450 MHz in side the support. Just the physics of the animals!
The 440 Ham band would work close to the 450 MHz band would when mounted inside the support. Good luck with your project we have mounted many antennas inside flag poles for public safety users with very good luck. Your project on the Ham 440 MHz band should serve you very well.
Dean Westbrook, EE, PE.
 








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