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Author Topic: Reception based on East coast/West coast  (Read 3050 times)

Offline NJQA

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Re: Reception based on East coast/West coast
« Reply #15 on: January 17, 2020, 1317 UTC »
An alternative to ground mounted/buried radials is to use elevated radials. The common lore is that 4 elevated radials will provide performance equivalent to 60 buried radials.

Things are usually not that easy though.  N6LF has researched this in detail, and his recommendation is for 12 elevated radials.  Still, you will need a boatload more buried radials for comparable performance to a vertical with elevated radials.  You can read his extremely detailed analysis here:

https://rudys.typepad.com/files/elevated-ground-systems-article-final-version.pdf

If you are using a vertical with elevated radials for transmitting, you also have to be aware that there will be high voltages at the ends of the radials.  You should also think about how you will address lightning protection for the elevated radial installation.

 
« Last Edit: January 17, 2020, 1319 UTC by NJQA »

Offline ChrisSmolinski

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Re: Reception based on East coast/West coast
« Reply #16 on: January 17, 2020, 1328 UTC »
Things are usually not that easy though.  N6LF has researched this in detail, and his recommendation is for 12 elevated radials.  Still, you will need a boatload more buried radials for comparable performance to a vertical with elevated radials.

This is what has stopped me from adding a vertical to my antenna farm. You need a lot of radials to get a good performing antenna (good performing relative to what I already have for antennas). A lot. I think about it from time to time (this discussion prompted that again). Then realize it is probably not worth the effort.  I remain open to being convinced otherwise, however  ;D
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Offline redhat

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Re: Reception based on East coast/West coast
« Reply #17 on: January 17, 2020, 1520 UTC »
FWIW, wwv is using 5 slanted radials in their systems.

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Offline Pigmeat

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Re: Reception based on East coast/West coast
« Reply #18 on: January 17, 2020, 1649 UTC »
The feedpoint height is critical in the four elevated radiator verticals. Try to get it as close to 8ft. up as possible where it will match up with 50 ohm coax, no tuner needed. All the power goes into the radiator. For a low power SW pirate it's one of the best easy/ easy down antennas with some punch in your arsenal. I used them all the time.

Offline ChrisSmolinski

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Re: Reception based on East coast/West coast
« Reply #19 on: January 17, 2020, 2000 UTC »
I did a quick web search and ran across a few possible articles of interest:

https://rudys.typepad.com/files/elevated-ground-systems-article-final-version.pdf

https://www.qsl.net/kk4obi/Elevated%20Radials.html

https://www.yccc.org/Meetings/presentations/2014/December/40M_V_Vertical_w_Elevated_Radials.pdf

https://www.w8ji.com/counterpoise_systems.htm

My own interest is receiving vs transmitting, losses are still important but perhaps not as critical?  As I am in the middle of the python / KiwiSDR related programming I could only quickly glance at them, but they appear useful. 
Chris Smolinski
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Offline KaySeeks

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Re: Reception based on East coast/West coast
« Reply #20 on: January 17, 2020, 2033 UTC »
Still, you will need a boatload more buried radials for comparable performance to a vertical with elevated radials.

Didn't realize that this was the case. I guess I now have some reading material for the weekend!

Elevated radials might not be practical in all back garden antenna installations.
« Last Edit: January 17, 2020, 2120 UTC by KaySeeks »
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Offline Josh

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Re: Reception based on East coast/West coast
« Reply #21 on: January 18, 2020, 2241 UTC »
For the more permanent verticals, it may pay to drive a ground rod to the water table, if the table is within reach.
Suppose same could be said for any ground rod.
Keep in mind after a few inches below the surface there's no rf due loss, you might get more benefit if you buried the ground rod or wire horizontally and only an inch or two under the surface.
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Offline East Troy Don

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Re: Reception based on East coast/West coast
« Reply #22 on: January 24, 2020, 0234 UTC »
^^^^^ True, the 49 and 41 meter bands are packed with Chinese and other Asian stations in the mornings when conditions aren't dead. I've only heard Europe over the pole or when conditions were better (i.e. 6-7 years ago or more).  Greece sometimes comes in on 9420 khz during the evening, however. How they do it when the rest of Europe is missing (even on the ham bands) is beyond me.

The 170 kw Avlis signal is amazing.   I can pick it up regularly on my 1940 Mantola tuber with an indoor 4 ft speaker wire that came with the radio from EBAY ($67 American......what a deal!!)
Primary: Yaesu FRG-7700  Secondary: ICOM R75 Tertiary: Grundig  750. Tecsun PL-990X, Tecsun PL-880 . Malahit DSP SDR V3,  Alpha Delta  SWL Sloper antenna. : Also, 1940 Mantola am/sw tube. CountyComm GP-5/SSB hand held, Tecsun PL-380 ,et al.  QTH: EAST TROY WI  USA.  Sea Level: + 320 meters .  75 miles (but not far enough) NNW of Chicago