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Re: Mobile antenna question



Bob, I looked at your experiment on your webpage regarding mobile antennas. I have a couple of questions...

The chart says it includes "range gain". Is this basically a plot of the average signal strengths or have you adjusted the chart to compensate for the distance from the signal source?

Also it looks to me like the 1/4 and 3/4 wave plots cross at about 35 degrees, not 25 degrees. Am I misreading this?

Quite a novel idea on how to model antenna gain BTW....

73, Drew KO4MA
 
>
>Yes, it gives worse gain below 20 deg, about equal at 25 and is
>3 dB better above 30 on up to 80 deg.  See plot about 80% down
>my page:
>
>http://www.ew.usna.edu/~bruninga/astars.html
>
>So if you drive back east and are always in trees except for
>everything around you above 25 deg, then use the same 2m
>19.5" whip as a 1/4 on 2m and as a 3/4 on 70 cm for better
>performance.  BUT of all the times that a satellite is in view, it 
>is only above 25 deg less than 30% of the time..
>
>But when it is, you'll be 3 dB better off.
>
>But previous mode J birds had such low pwoer that
>the 1/4 couldnt hear it reliably at the horizon anyway
>(its 6dB further away) so having better 1/4 performance
>down below 20 deg where you can't hear the bird anyway
>is a moot point.
----
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