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#1
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![]() "maxlynn" wrote in message news:Ygppb.52870$hp5.43787@fed1read04... Okay, now that you have given your opinion on Kevlar as a backstay, how about addressing the original question - i.e., is there any conceptual problem with wrapping a bare copper wire around it and using it for an antenna? Has anyone done this? The original question (Glenn's), has to do with extending the SSB foil lattice to the fuel tanks. In response to that, the consensus of the sources I've referenced for my SSB ground system is that running the foil to the tops of the tanks is a good thing to do. I've done this on my tanks, and merely laid the foil on top of the tank surface with an adhesive bonding agent (it was probably Sikaflex). I don't believe there's any need for an electrical bond, since induction should do the job nicely. Tom Dacon |
#2
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In article ,
"Tom Dacon" wrote: I don't believe there's any need for an electrical bond, since induction should do the job nicely. The above doesn't take into account that we are dealing with impedance in the frequency domain. By not having an good electrial bond, you induce capacative coupling to additional surface area for your RF Ground, That means that this coupling is frequency sensative, and then the RF Grounding System will react significantly different depending on the frequency being transmitted. Autotune Antenna Couples have very specific tuning firmware, and this code doesn't react very well to a highly variable Rg Ground impedance. They are designed to operate against a FLAT RF Ground Impedance, and the more bumps in the RF Gropund impedance the harder the tuner has to work to tune the antenna, and the more phantom, and quirky Low SWR points that the tuner will find, and lock on to. Bruce in alaska -- add a 2 before @ |
#3
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When I could not tune out the ground impedance bumps, I installed a cheap
manual antenna tuner in the ground circuit leg. Then I got perfect impedance matches at all frequencies into a long ground wire. This was in addition to the normal automatic antenna tuner for the antenna. Tuning was simple. Just adjust the ground tuner until the SWR was down to the lowest you could get. Larry DeMers Bruce in Alaska wrote: In article , "Tom Dacon" wrote: I don't believe there's any need for an electrical bond, since induction should do the job nicely. The above doesn't take into account that we are dealing with impedance in the frequency domain. By not having an good electrial bond, you induce capacative coupling to additional surface area for your RF Ground, That means that this coupling is frequency sensative, and then the RF Grounding System will react significantly different depending on the frequency being transmitted. Autotune Antenna Couples have very specific tuning firmware, and this code doesn't react very well to a highly variable Rg Ground impedance. They are designed to operate against a FLAT RF Ground Impedance, and the more bumps in the RF Gropund impedance the harder the tuner has to work to tune the antenna, and the more phantom, and quirky Low SWR points that the tuner will find, and lock on to. Bruce in alaska -- add a 2 before @ |
#4
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In article , Larry Demers
wrote: When I could not tune out the ground impedance bumps, I installed a cheap manual antenna tuner in the ground circuit leg. Then I got perfect impedance matches at all frequencies into a long ground wire. This was in addition to the normal automatic antenna tuner for the antenna. Tuning was simple. Just adjust the ground tuner until the SWR was down to the lowest you could get. Larry DeMers If your going to use a manual tuner in the ground system, and have to readjust it for every large frequency change, why would you not just put the manual tuner on the antenna and just do manual tuning??? Kind of redudndent isn't it. The whole point of a autotuner is so that the operator doen't have to know or understand what the tuner is doing. That, and so appliance operators could install their own SSB Radio's systems and cut the Marine Electronics Tech's out of their Installation Money. Same thing, as when the FCC changed the rules for Radar Installations, by users, only with many more consequencies. Bruce in alaska -- add a 2 before @ |
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