I agree that Free Space figures are probably the least ambiguous; but
I'm not convinced that "averages" are very helpful!
What do we mean by "average"? What's the average of two F/B ratios, one
of 10dB and one of 20dB?
[The average of 10dBW and 20dBW is 17.4dBW]
A "not worse than" figure across the bandwidth may be more meaningful.
Steve G3TXQ
On 11/12/2014 10:30, Stan Stockton wrote:
> If every antenna were compared to every other antenna in terms of free space
> gain and all in the same unit of measure (say dBI) and if the numbers for
> gain F/B, F/R, etc were shown as average across the band then there are no
> additional questions to ask to determine which antenna is better or best. ##
> Ok, so dbd is meaningless. If dbi is used, then a graph of freq vs gain,and
> also freq vs FB, freq vs FR, freq vs swr, etc is the only thing that would
> makeany sense. Then the end user could tell at a glance what freq the peak
> gain is on,and how much it drops off on either side of the peak. You could
> easily have a yagi thathas lower peak gain, but holds a pattern better
> across the entire band. At least hecould compare 2 different yagis.
> Comparing a yagi to a dipole is a moot point anyway,since most dipoles are
> not up at 100 feet, and none of em rotate. If any of you have hada chance to
> use a rotary dipole at a decent height, its an eye opener. 15+ DB FS is
> typical.Fix
ed dipoles vs a rotary yagi is another eye opener...when the yagi is pointed
towards thenulls of the dipole. Then the differences are astounding. Jim VE7RF
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