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I don't want to spoil the Elecraft Mojo theory, but does anyone have any details, other thqan what is on the VP6DX web site, on what antennas they are using with the k3's? Do the vertical dipoles have parasitic elements? Are they using low-loss coax? Etc. Inquiring minds would like to know. 73, Henry - K4TMC K3 #98 ************** Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy /2050827?NCID=aolcmp00300000002598) _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by k4tmc
and/or maybe the operators in conjunction with the hardware... If they work down the pileups, they can hear the weaker ones..
Here is some speculation: They talk about vertical dipole arrays. 20m Vertical Dipol Array 17m Vertical Dipol Array 15m Vertical Dipol Array 12m Vertical Dipol Array 10m Vertical Dipol Array I'm guessing they are like phased verticals but don't depend on ground radials and hence are ground independent. Whether or not all elements are driven wasn't stated. It would be nice to know if they had some kind of "x-square" phasing or parasitic elements. It would seem since they could certainly be no more than vertical yagi's. Given the picture on their website, rotating a vertical yagi on guyed poles would be impossible. Thus maybe they are phased with coax lines. I thought I read that the salt water "perfect ground" effect only extends so far inland. Something less than a couple wavelengths. Anyhow, one can't dispute the fact that they have super signals. Given reciprocity, they are also probably hearing well because of the strength of received signals.
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In reply to this post by AC7AC
I agree! Although the K3 is a great radio, 90% of the mojo is antennas and
location. If you are really interested in the secret of vertical antennas near salt water check out this site; http://k2kw.com/k5k/dxcomp.htm 73 de Björn /SM0MDG On 080222 5:41 , "Ron D'Eau Claire" <[hidden email]> wrote: > Being on the edge of a huge salt-water pond gives VP6DX's verticals an > advantage no "land lubber" can hope for. There's a lot of interaction > between the electromagnetic wave and the earth from a vertical antenna for > many wavelengths from the antennas. Real "earth" - dirt - is a terrible > medium. It's sort of the world's worst dielectric, even when soaking wet. > But salt water is a different story. It's a very efficient medium for the RF > to interact with. > > There's a reason why so many DX-peditions like to find themselves on a small > rock in the middle of the ocean, and it isn't just for the view. > > Ron AC7AC > > > -----Original Message----- > I don't want to spoil the Elecraft Mojo theory, but does anyone have any > details, other thqan what is on the VP6DX web site, on what antennas they > are > using with the k3's? > > Do the vertical dipoles have parasitic elements? Are they using low-loss > coax? Etc. Inquiring minds would like to know. > > 73, > Henry - K4TMC > K3 #98 > ************** > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by AC7AC
Ron D'Eau Claire wrote:
> Being on the edge of a huge salt-water pond gives VP6DX's verticals an > advantage no "land lubber" can hope for. There's a lot of interaction > between the electromagnetic wave and the earth from a vertical antenna for > many wavelengths from the antennas. Real "earth" - dirt - is a terrible > medium. It's sort of the world's worst dielectric, even when soaking wet. > But salt water is a different story. It's a very efficient medium for the RF > to interact with. > > There's a reason why so many DX-peditions like to find themselves on a small > rock in the middle of the ocean, and it isn't just for the view. > I'd bet VP6DX success is a combination of factors, salt water and outstanding radios being two of them. That they are operating multiple radios on the small island attests to the value of the K3. I also know several of the ops [one has my last name :-) ] and they're all about as good as you can get. That's another major factor. They sure are loud here in N. Cal. VP6DI was too. 73, Fred K6DGW - Northern California Contest Club - CU in the 2008 Cal QSO Party 4-5 Oct 08 - www.cqp.org _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Bjorn
The Mojo is in the sea water which has a conductivity
of about 500 millimhos/per meter. The best of soils are about 30 millimhos/meter and average soil about 5 mmhos/meter. A small island is as near to a perfect ground plane as you will find. --- Björn Mohr <[hidden email]> wrote: > I agree! Although the K3 is a great radio, 90% of > the mojo is antennas and > location. If you are really interested in the secret > of vertical antennas > near salt water check out this site; > > http://k2kw.com/k5k/dxcomp.htm > > 73 de Björn /SM0MDG > > > On 080222 5:41 , "Ron D'Eau Claire" <[hidden email]> > wrote: > > > Being on the edge of a huge salt-water pond gives > VP6DX's verticals an > > advantage no "land lubber" can hope for. There's a > lot of interaction > > between the electromagnetic wave and the earth > from a vertical antenna for > > many wavelengths from the antennas. Real "earth" - > dirt - is a terrible > > medium. It's sort of the world's worst dielectric, > even when soaking wet. > > But salt water is a different story. It's a very > efficient medium for the RF > > to interact with. > > > > There's a reason why so many DX-peditions like to > find themselves on a small > > rock in the middle of the ocean, and it isn't just > for the view. > > > > Ron AC7AC > > > > > > -----Original Message----- > > I don't want to spoil the Elecraft Mojo theory, > but does anyone have any > > details, other thqan what is on the VP6DX web > site, on what antennas they > > are > > using with the k3's? > > > > Do the vertical dipoles have parasitic elements? > Are they using low-loss > > coax? Etc. Inquiring minds would like to know. > > > > 73, > > Henry - K4TMC > > K3 #98 > > ************** > > > > _______________________________________________ > > Elecraft mailing list > > Post to: [hidden email] > > You must be a subscriber to post to the list. > > Subscriber Info (Addr. Change, sub, unsub etc.): > > http://mailman.qth.net/mailman/listinfo/elecraft > > > > Help: http://mailman.qth.net/subscribers.htm > > Elecraft web page: http://www.elecraft.com > > > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Willis 'Cookie' Cooke K5EWJ _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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For verticals there's a 2 or 3-fold effect:
1 a vertical over sea water will have very much reduced losses in the near field, ie close to the antenna so increasing its efficiency, ie raising the 'power output' compared to a land situation 2 the increased conductivity in the far field reduces losses to the wave travelling across the surface before it launches into space 3 the long travel over the sea water means a lower angle than across land and therefore less bounces to get to you on the other side of the world, so less losses on the way So, the signal is much bigger at your end and your signal has less losses getting to them. David G3UNA > The Mojo is in the sea water which has a conductivity > of about 500 millimhos/per meter. The best of soils > are about 30 millimhos/meter and average soil about 5 > mmhos/meter. A small island is as near to a perfect > ground plane as you will find. > > --- Björn Mohr <[hidden email]> wrote: > >> I agree! Although the K3 is a great radio, 90% of >> the mojo is antennas and >> location. If you are really interested in the secret >> of vertical antennas >> near salt water check out this site; >> >> http://k2kw.com/k5k/dxcomp.htm >> >> 73 de Björn /SM0MDG >> >> >> On 080222 5:41 , "Ron D'Eau Claire" <[hidden email]> >> wrote: >> >> > Being on the edge of a huge salt-water pond gives >> VP6DX's verticals an >> > advantage no "land lubber" can hope for. There's a >> lot of interaction >> > between the electromagnetic wave and the earth >> from a vertical antenna for >> > many wavelengths from the antennas. Real "earth" - >> dirt - is a terrible >> > medium. It's sort of the world's worst dielectric, >> even when soaking wet. >> > But salt water is a different story. It's a very >> efficient medium for the RF >> > to interact with. >> > >> > There's a reason why so many DX-peditions like to >> find themselves on a small >> > rock in the middle of the ocean, and it isn't just >> for the view. >> > >> > Ron AC7AC >> > >> > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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