By the way, your local soil map can be found at:
https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm
Probably not very accurate, but a good approximation.
Chuck W5PR
On Fri, Dec 2, 2022 at 8:36 PM Pete Smith N4ZR <pete.n4zr@gmail.com> wrote:
> Understood, Jim. Interestingly, I just found out that the ground
> conductivity in my area is probably very good, on the order of 2-4
> millisiemens, which may reduce the need for a huge number of radials.
> In this evening's 160 contest, I've been pleasantly surprised by how
> well the antenna works. It's past time to get my receiving K9AY loop
> back in service
>
> 73, Pete N4ZR
> Check out the new Reverse Beacon Network
> web server at<https://reversebeacon.net>.
> For spots, please use your favorite
> "retail" DX cluster.
>
> On 12/2/2022 5:51 PM, Jim Brown wrote:
> > On 12/2/2022 12:21 PM, Pete Smith N4ZR wrote:
> >> I just added 5 more radials to the 13 I had originally under my
> >> inverted L, and the R dropped from 34 to 31 ohms. Barely still worth
> >> doing, I guess.
> >
> > It all depends on the difficulty/cost of adding more. The radiation
> > resistance of a vertical, which represents radiated power, is a
> > function of the vertical height, not the total length. There's a graph
> > of this in my tutorial. The combination of radiation resistance and
> > ground loss, both in Ohms, forms a voltage divider for the transmitter
> > current, and power lost is 10 log of the divider ratio. If, for
> > example, you have 50-60 ft vertical, radiation resistance is likely to
> > be less than 8 ohms.
> >
> > 73, Jim K9YC
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