[TowerTalk] 43 feet pole for vertical

[K8RI]

On 11/1/2012 6:02 PM, Rick Karlquist wrote:
> Kelly Taylor wrote:
>
>> The model I seem to recall, either by K9YC or W8JI, involved the feedline
>> running to the base of the tower to a choke and then up the tower to
>> another
>> choke at the feedpoint.
>
> And after all that, the elevation pattern would be considerably
> inferior to a dipole, as documented in the ARRL Antenna Handbook
> in a graph illustrating the pseudo Brewster angle effects for
> horizontal vs vertical polarization.  There is a reason why
> you rarely see vertically polarized antennas on a tower, unless
> ground wave propagation is involved.

In actual use, I've mounted a multi-band 40-6 meters (AV640) and some 
years ago a 1/4 wave on 40 on top of 40 foot towers. This is only two 
instances but about half the time the vertical out did the sloping 
dipole and half the time the dipole won.

In the case of the 1/4 wave I only had 4 radials that also served as 
guys at the top of the tower. They drooped at about 45 degrees. I used a 
current balun at the base of the vertical.  In both cases the coax was 
taped to the tower with no choke at the base.

The AV640 appeared to work better on a 32' tower rather than the 40 
footer. That's very close to a 1/4 wave on 40.
I did not have two of them up at once so I couldn't do an A/B comparison 
as I could with the vertical and dipole.

73

Roger (K8RI)

>
> Rick N6RK
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>