[TowerTalk] Vertical dipole other choices?

[jimlux]

On 10/20/20 10:49 AM, Jim Brown wrote:
> On 10/20/2020 9:42 AM, k7lxc--- via TowerTalk wrote:
>>   So what other manufacturers of vertical dipoles would be worth doing 
>> business with?
> 
> Certainly those that you and N0AX tested 2o years ago. Like any 
> vertical, their performance will depend on soil conductivity, and they 
> will work a bit better if roof mounted.
> 

I think though, Steve LXC was interest in vertical dipoles (recognizing 
that some multiband verticals are quasi dipoles, albeit with very 
unequal lengths).

Isn't the GAP vertical series also a vertical dipole (off center fed)?

Except that the Greyline depends on having a tuner/matching network at 
the bottom to deal with the mismatch.

Essentially, it seems this no different conceptually than an 
electrically short horizontal dipole with a tuner at the feedpoint - 
with modern tuners, etc., I think this is pretty viable.  You make the 
dipole short enough that you don't get weird high order lobes (like you 
would with, say, a 40 foot vertical against a groundplane or radials on 
10 meter band).

Most of the commentary on the various forums seems more about the 
business practices than the actual antenna design.  Maybe it's a "you 
can't get there from here for that price" kind of scenario.

It's complicated, supply chain-wise, by the fact that the matching 
network is an integral part of the system - it's not a "go get aluminum 
tubing, cut to size, add bracketry and make the kit".

I think also, without much information, that the idea of essentially 
converting a flagpole design is a clever one. And one that could be done 
by anyone - You make a deal with a flagpole manufacturer to either build 
it with the insulators & holes in the right places, or you do that as a 
modification step.

Just browsing through the Home Depot website, for instance, you can find 
a 20 ft aluminum flag pole for $150.

But you go to commercial flagpoles and a 30 footer is a bit pricier. 
Upwards of $600.  Sectional poles (which I assume come in smaller 
lengths that you assemble, which might be better for antenna use) are in 
that bucket for a 25 footer.


https://www.united-states-flag.com/commercial-grade-sectional-25-ft-flagpole-satin.html. 
says good to 69 mi/hr without a flag.

It doesn't give any information on the lengths of the segments, but you 
could probably figure it out.