>>
>> I find that it is pretty much non-directional,
>> that is, I can't seem to find a null or even a measureable drop in RX
>> levels
>> when I rotate it.
> Probably a problem with insufficient feedline choking, IMO.
>
> You should be getting 12-15 dB F/S on 7MHz and 10-12dB on 5.4MHz if
you
> don't have radiation from the tower or feedline or whatever.
> 73
> Dan
You could both be right on the figures that you are seeing / expecting.
According to 4nec-2, a 40 meter dipole at 78 feet up shows about 12 db
FS for a take off angle of 25 degrees, where it has maximum gain. For
lower angles FS increases to about 15 db. However, by 45 degrees, FS is
down to 5db and drops to zero for angles of 60 degrees and up.
In other words, for close in work, there is no need to rotate it. Also,
for close in work (highish angles), the dipole would also work much
better if it were lower than 78 feet.
--
Gerald Boutin, VE1DT
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