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#31
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#32
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Buck wrote:
Today I see a lot of antennas preferring above ground radials. Maybe decoupling the radials from ground lowers ground losses? :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#33
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On Mon, 07 Feb 2005 08:40:51 -0600, Cecil Moore
wrote: Buck wrote: Today I see a lot of antennas preferring above ground radials. Maybe decoupling the radials from ground lowers ground losses? :-) There have been a number of changes in technology theory in the last 30 or so years. When I was a Novice, the vertical antenna manufacturers provided information about how to use above-ground radials, but that was typically for a raised antenna such as roof mounting it. IIRC, the above ground Hustler 4BTV and the Taylor antennas both had to be lengthened a little to be resonant in the same place as the ground mount and radials had to be tuned. Reports at that time were that antenna efficiency was best when the antenna was ground mounted and had 8-16 radials buried. However, while not optimum, the minimum ground was to be an 8-foot ground rod at the base of the antenna. Baluns seemed to be a new technology, I don't recall the term "ferrite beads", and RF in the shack wasn't a big issue. One common practice was having a ground rod as close to your rig as possible and making sure the rig, PS, antenna and everything electrical near the rig was grounded to the ground rod. Today the electrical code for homes forbids that due to ground-loops. Some of these changes take some getting used to. It's a strange feeling to realize that what you knew for so long is no longer true. -- 73 for now Buck N4PGW |
#34
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Buck wrote:
Some of these changes take some getting used to. It's a strange feeling to realize that what you knew for so long is no longer true. Think about what will be accepted as being true after someone figures out how to demodulate entangled particle beams. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#35
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I don't know what I was thinking -- I obviously wasn't. Of course you're
right. The loss decreases as the number of radials increases. I apolgize for the mistake. Roy Lewallen, W7EL Buck wrote: On 6 Feb 2005 22:38:33 -0800, wrote: And the loss increases, rather than drops, as the number increases. This has been well known since at least 1937. I didn't catch this either. I misunderstood it to be that the number of radials decrease loss. However, I do well remember that the preferred radial of the day when I was first licensed was below ground radials. Today I see a lot of antennas preferring above ground radials. This has me confused...I must be missing something...I checked the previous posts, but still doesn't make sense to me...Seems the ground losses would decrease as the number of radials increase....Thats what your model showed. |
#36
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On Mon, 07 Feb 2005 13:17:19 -0800, Roy Lewallen
wrote: I don't know what I was thinking -- I obviously wasn't. Of course you're right. The loss decreases as the number of radials increases. I apolgize for the mistake. Roy Lewallen, W7EL I chalk it up to dislexic fingers, just a type of typo! ![]() Strangely enough, I didn't read it that way till someone else reported it. -- 73 for now Buck N4PGW |
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