[TowerTalk] Vertical Antenna Question

[Richard Bell]

Looks like I’m a little late for this party. Thought I’d share my experience with my very recent vertical project. 

The backyard is on a slope. Soil conditions are pathetic, rock and clay (think it may have been a model for the Flinstones movie set).  Numerous  trees, about 70 total. 

The project was further complicated by the fact I live in antenna restricted HOA. 

I opted for a Mosley RV-7C, which I ordered from the company. 

There was ample experimentation with the physical placement to ensure the antenna would not be readily observable, somewhat away from the surrounding trees, in a place where I could run radials that did not involve being diverted around the surrounding trees and as far as possible from my inverted V.

Mosley documentation suggested a single above ground radial for each band. They provided the length of each but the recommendation did not correspond to any calculation I could come up with. Nor did they they recommend a height above ground level for the radials (I’m still a bit disappointed with the doc provided by the manufacturer). 

With all of that said, I did the following:

Antenna is mounted on a 5 ft 4 inch galvanized 2 inch pole buried approximately 3.5 ft in depth.  That was as deep as I could get using an auger and a post hole digger. 

There are 4 radials each for 40, 30, 17 and 15 meters. I used the accepted calculation for quarter wave radials.  All radials are run perpendicular to the base and are not parallel to any other radial. 

Each radial is supported by 1/2 inch PVC approximately 12” above ground level. Yes, I used a fair amount of PVC in order to prevent sagging radials from touching the ground. 

The antenna is fed with about 150ft of Times Microwave LMR-400. I might add, I did use their connectors. 

So far I have no complaints about performance. I am able to use the antenna on all bands with a tuner.  It seems to perform as desired. Don’t think it’s as omnidirectional as I would like but it does accomplish getting me on the air. 

I would like to model the antenna using a reputable antenna analyzer (read what you like into that statement). But finances dictate that will have to wait. 

OK, I’ve sucked up enough band with.  Good luck!

W5BXE Richard 
> 
> Message: 4
> Date: Thu, 9 Apr 2020 02:23:01 +0000
> From: Gary <gary_mayfield at hotmail.com>
> To: "'towertalk at contesting.com'" <towertalk at contesting.com>
> Subject: [TowerTalk] Vertical Antenna Question
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> 
> I used my DX Engineering gift certificate to buy a copy of the "Champion Radio HF Vertical Performance - Test Methods & Results". I really enjoyed the book and learned a lot.
> 
> It looks like a vertical is the only antenna I am going to get in my terraced back yard. Has anyone done a similar look at verticals where they looked at radials vs no radials? There are a lot of claims out there about verticals that work without radials. The above test looked at some of those antennas but they were mounted over a radial field...
> 
> I am still wondering how I am going to run the radials up the brick terraces, and they are going to have to be pretty short.
> 
> I am ready to listen and learn.
> 
> Thanks and 73,
> Gary "Joe" Mayfield, kk0sd
>