[TowerTalk] Broadbanding 80 meter dipole

[Steve Maki]

Except Roger is envisioning sloping *dipoles*, FIVE of them. Somehow I 
can't picture five tuners hanging out there in mid-air at the 
feedpoints, begging to be tuned up and down the band. Not to mention 
that whatever pattern he's hoping for will be hopelessly compromised by 
common mode currents on the feedlines between the antenna and tuner.

-Steve K8LX

On 8/17/2017 4:16 PM, Kimberly Elmore wrote:

> Rod's idea is by far the best. Slopers are weird creatures. While you can broadband antennas by making the elements with a large diameter (as in a cage) the mechanical complexity isn't worth it. If they absolutely positively must be resonant, well...
> 
> Kim N5OP
> 
>        From: Rod Greene via TowerTalk <towertalk at contesting.com>
>   To: Roger (K8RI) on TT <K8RI-on-TowerTalk at tm.net>; "towertalk at contesting.com" <towertalk at contesting.com>
>   Sent: Thursday, August 17, 2017 2:25 PM
>   Subject: Re: [TowerTalk] Broadbanding 80 meter dipole
>     
> Or use an auto tuner at the feedpoint to match the slopers on whatever band/freq you want to use. That's what I do.
> 73, Rod/w7zrc
> 
> 
>        From: Roger (K8RI) on TT <K8RI-on-TowerTalk at tm.net>
>   To: "towertalk at contesting.com" <towertalk at contesting.com>
>   Sent: Thursday, August 17, 2017 12:33 PM
>   Subject: [TowerTalk] Broadbanding 80 meter dipole
>    
> I've seen a few possibilities in the past, but I'd like to add a dew
> slopers to come up with the 5 used for some directivity, gain and front
> to back. Switched coils at the feedpoint with frequency sensing would
> likely work.  I've had excellent results with just a couple switched
> slopers on 40.
> 
> To complicate things I'd like to do this and maintain the dual band 75 /
> 40 meter operation, which would likely require separate feedlines. The
> unused line would / could end up as a stub.  I could possibly use the
> frequency sensing to disconnect the coax for the unused band.
> 
> Thoughts?
>