Topband: Using 4 - 6 elevated radials in lieu of 120 buried wires

[Joe Subich, W4TV]

On 1/5/2024 12:53 AM, Robin wrote:

> One thing to bear in mind throughout any analysis of such designs
> for 160M is that the total focus of the Broadcast designs and
> measurements and proofs is energy at zero degrees elevation.  Our
> needs benefit from low angle radiation, for certain,  but,  little
> attention is paid by the broadcasters and by the modeling programs to
> position and shape of elevated lobes, or for that matter, the shape
> of the main lobe above zero elevation
Not exactly true.  Many "modern" broadcast facilities are designed to
minimize high angle lobes that cause destructive *self-interference*
at the outer edges of the [night time] ground wave coverage.

73,

    ... Joe, W4TV

On 1/5/2024 12:53 AM, Robin wrote:
> Milt Jensen, N5IA (SK) constructed his original (circa 1990s) 160M 
> station TX antenna based on a similar design I encouraged him use.  He 
> built a 180 ft tower with an insulator at 50 ft,  Four elevated quarter 
> wave radials, each  made of a box of four pieces of # 12.  This was on 
> his "city" lot where buried radials were impossible
> 
> It worked very well,  We did not have the tools to make real field 
> strength measurements to compare to a model, but on air performance was 
> excellent
> 
> It worked well enough for him to use the concept in several similar 
> installations and to make his 8 circle array
> 
> The radial height above ground clearly did not need to be 50 feet,.  It 
> did need to be high enough to easily be well above a tall truck, or more 
> commonly, a horseback rider.
> 
> We used a single element elevated radial 160M TX antenna, and for the 
> 80M 4 square at XZ0A with considerable success.
> 
> The concept of exciting a tower from the inside is very interesting.  
> The reposting this article a has me thinking about one situation I have 
> available to me that can not have a complex installation outside the 
> general dimensions of the tower (large but not tall)
> 
> One thing to bear in mind throughout any analysis of such designs for 
> 160M is that the total focus of the Broadcast designs and measurements 
> and proofs is energy at zero degrees elevation.  Our needs benefit from 
> low angle radiation, for certain,  but,  little attention is paid by the 
> broadcasters and by the modeling programs to position and shape of 
> elevated lobes, or for that matter, the shape of the main lobe above 
> zero elevation
> 
> Robin Critchell, WA6CDR
> 
>