[Elecraft] wire for random wire antenna using kx3

[Fred Jensen]

My mini-dissertation strictly applies to Class A [so-called "Clear 
Channel"] stations only, who almost universally use single, 
omni-directional verticals since they are not required to protect any 
other stations at night.  There were a few Class A's on the coasts that 
did use directional phased arrays since there weren't many/any listeners 
out at sea but I don't know if any of them are left.  Non-Class A's 
generally employ 2 or sometimes 3 phased verticals to achieve 
directional patterns at night to protect co-channel stations, putting 
null(s) in the direction of their service areas.

Class A's, such as KFI, seek to maximize the coverage in their service 
area [i.e. maximize the area covered with an adequate field strength].  
Neither a 90-degree vertical ... current max at the bottom ... nor a 
180-degree ... current max half way up the tower ... will do that.  At 
640 KHz, a half-wave is ~730 ft.

The obsession with VSWR in ham radio is a bit surprising.  I can't 
really remember when the term became common, or when I first saw a VSWR 
bridge, but I do know that I never saw one in SE Asia in the mid-60's.  
These days, high VSWR seems to equate to "antenna that doesn't work."

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 12/18/2018 12:38 PM, hawley, charles j jr wrote:
> Interesting, I had an analog computer course exercise at the U of I Urbana when we had two verticals separated and phased to define the coverage pattern. I don’t remember the length of them. It’d be interesting to recall what it was.
>
> Chuck
> KE9UW
>
>