[Antennas] Antenna SWR

Wed Mar 2 14:16:28 EST 2011

If the radials are on or very near the ground then the ground detunes them and the length doesn't matter that much.
More wire on the ground for ground mounted increases efficiency. 
But as we're finding from this discussion, better efficiency doesn't necessarily mean better "match".
Jay
--- On Wed, 3/2/11, David C. Hallam <dhallam at knology.net> wrote:
> From: David C. Hallam <dhallam at knology.net>
> Subject: Re: [Antennas] Antenna SWR
> To: "Rick Gouge" <rickgouge at shaw.ca>, "Antennas" <antennas at mailman.qth.net>
> Date: Wednesday, March 2, 2011, 12:53 PM
> Rick,
>> If it really doesn't matter about spacing between radials,
> I will put 
> some more down that are cut to lengths for each band. 
> I've got lots of 
> wire.  I am using a 18ga 2 conductor cable with vinyl
> jacket for 
> radials.  I was given a great big roll of the stuff.
>> Right now I am recovering from a knee replacement
> operation, so it's a 
> little hard to get down on the ground to do work on the
> antenna or radials.
>> On the other hand, maybe I never should have gotten an
> antenna analyzer 
> and remained dumb and happy.  Too much information
> might not be good.
>> David
> KW4DH
>> On 3/1/2011 5:25 PM, Rick Gouge wrote:
> > With that kind of ground i would cut two wires to res
> on each band 
> > where you like to lisen. With that kind of soil i
> think i can see why 
> > your seeing such a big change in your SWR. Rick
> VE7Rik
> >
> >
> > ----- Original Message ----- From: "David C. Hallam" 
> > <dhallam at knology.net>
> > To: "Rick Gouge" <rickgouge at shaw.ca>;
> "Antennas" 
> > <antennas at mailman.qth.net>
> > Sent: Tuesday, March 01, 2011 10:09 AM
> > Subject: Re: [Antennas] Antenna SWR
> >
> >
> >> Rick,
> >>
> >> I live in Clearwater, FL near but not on the
> Gulf.  Our soil is very 
> >> sandy.  There is a very thin layer of top
> soil, then you are into sand.
> >>
> >> David
> >> KW4DH
> >>
> >> On 3/1/2011 1:04 PM, Rick Gouge wrote:
> >>> As long as the radials do not touch. Plus your
> 75 ohm feed line 
> >>> should be below the radials as well. I am
> going to put 35 or 30 foot 
> >>> lenghts fan around the whole antenna. How wet
> does your ground get? 
> >>> My lawn in very wet so lenghts of the radials
> do not matter as long 
> >>> as they are all 30 feet or better. Rick
> VE7RiK
> >>> ----- Original Message ----- From: "David C.
> Hallam" 
> >>> <dhallam at knology.net>
> >>> To: "Rick Gouge" <rickgouge at shaw.ca>;
> "Antennas" 
> >>> <antennas at mailman.qth.net>
> >>> Sent: Tuesday, March 01, 2011 9:47 AM
> >>> Subject: Re: [Antennas] Antenna SWR
> >>>
> >>>
> >>>> Rick,
> >>>>
> >>>> No, I do not have a lot or ground
> radials.  I have 8 - 60ft 
> >>>> radials. Unfortunately, with my 1/4 acre
> lot and trees, I had to 
> >>>> put the antenna along side the
> house.  4 radials fan out slightly 
> >>>> to the east of the antenna and the other 4
> fan out to the west.  
> >>>> the ones to the west fan out more than the
> easterly ones do as they 
> >>>> go out into the back yard.
> >>>>
> >>>> I don't know at what point close spacing
> negates the effectiveness 
> >>>> of radials.
> >>>>
> >>>> David
> >>>> KW4DH
> >>>>
> >>>> On 3/1/2011 12:29 PM, Rick Gouge wrote:
> >>>>> David. Do you have alot of ground
> radials? the one i have does 
> >>>>> change alittle as well. I know i need
> more ground radials Rick VE7RiK
> >>>>> ----- Original Message ----- From:
> "David C. Hallam" 
> >>>>> <dhallam at knology.net>
> >>>>> To: "Antennas" <antennas at mailman.qth.net>
> >>>>> Sent: Tuesday, March 01, 2011 9:22 AM
> >>>>> Subject: [Antennas] Antenna SWR
> >>>>>
> >>>>>
> >>>>> I just got a new play toy, an antenna
> analyzer, and have taken 
> >>>>> some SWR
> >>>>> measurements on my antenna. I have a
> Butternut HF6V. This morning I
> >>>>> measured the SWR. Shortly afterward we
> had a rain storm. Out of
> >>>>> curiosity I measured the SWR again and
> found a significant upward 
> >>>>> change
> >>>>> on all bands. I am confident there is
> no water egress at the 
> >>>>> connection
> >>>>> of the feed line to 20M 1/4 wave
> transformer section. All joints 
> >>>>> on the
> >>>>> antenna were assembled with Noalox.
> Maybe there could have been some
> >>>>> water egress at the connecting lugs of
> the the 1/4 section on the
> >>>>> antenna where they connect to the
> antenna but they appear to be 
> >>>>> sealed.
> >>>>>
> >>>>> Should I expect a SWR change just from
> a wet antenna?
> >>>>>
> >>>>
> >>>> -- 
> >>>> “I bring reason to your ears, and, in
> language as plain as ABC, 
> >>>> hold up truth to your eyes.” Thomas
> Paine, December 23, 1776
> >>>>
> >>>>
> >>>>
> >>>> -----
> >>>> No virus found in this message.
> >>>> Checked by AVG - www.avg.com
> >>>> Version: 10.0.1204 / Virus Database:
> 1435/3475 - Release Date: 
> >>>> 03/01/11
> >>>>
> >>>
> >>>
> >>
> >> -- 
> >> “I bring reason to your ears, and, in language
> as plain as ABC, hold 
> >> up truth to your eyes.” Thomas Paine, December
> 23, 1776
> >>
> >>
> >>
> >> -----
> >> No virus found in this message.
> >> Checked by AVG - www.avg.com
> >> Version: 10.0.1204 / Virus Database: 1435/3475 -
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> >>
> >
> >
>> -- 
> “I bring reason to your ears, and, in language as plain
> as ABC, hold up truth to your eyes.” Thomas Paine,
> December 23, 1776
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