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Well Bruce/Me, I think you need to pull your two "selves" together!
Sifting through the humorous postings, I think your bottom line is that HF/MF vertical antennas will not work well (sometimes I think you mean will not work at all) unless they are (1) over sal****er with a return path capacitively coupled to the sea (at least for nonmetallic vessels); or (2) over land with 100 quarter-wave radials in marshland. You have labored to persuade us that less-than-perfect marine RF ground systems are certain to disappoint. It will surprise you, perhaps, to learn that there are many thousands of vertical HF and MF transmitting antennas in operation in the world today that satisfy none of those conditions, and yet enable effective communications activities. Some on land and some over water. These installations are supported by rigorous theory as well as by on-the-air performance data. If you would like to learn more about how this is being done, often with losses of only a few dB below ideal conditions, drop in at rec.amateur.radio.antenna and "read the mail." You'll find some bombastic assertions and opinions to be sure, but also many reasoned analyses and even quantitative experiments. Hope to see you there, Bruce. Regards, Chuck Bruce in Alaska wrote: In article , Me wrote: In article .com, "Skip Gundlach" wrote: As further background, we have full rails, with the gates combined electrically with brass straps belowdecks, attached to the arch, the pushpit and pulpit. We have about 110 lineal feet of 1" SS tube rail, unless you count the inner rails, plus the arch. In addition we have the standard 4" copper strapping leading to a sintered bronze Guest plane below the boat, and also connected to a 3x5' plate under the workbench top. I think we have a reasonably good ground. You will never know if you have a "reasonably good ground", unless you get yourself an Impedance Bridge, and check it at the frequencies that you commonly work. Anything that is more than 12" away from the water, isn't going to add "diddley-squat" toward building a Low Impedance Wideband RF Ground System, and anyone who tells you otherwise, is just as uneducated about MF/HF Marine Radio Antenna Systems, as you seem to be. I have seen all kinds of Systems that looked very impresive, untill they were evaluated with real insurmentation. 400 Sq Ft of Copper Screen in the Cabin Overhead was proffered, as a really good RF Ground, by a well known Boat Builder, 20 years ago. It didn't work any better than having nothing at all, when tested, in a real radio enviorment. If you got a Plastic Hull, you are NEVER going to get a Real RF Ground, UNLESS the hull builder was smart, (they never are) and put 200+ Sq Ft of screen under the gellcoat down by the keel. Cellulose hulls are just as bad, and harder to retrofit that Plastic ones. Like I said in my first reply, Autotuners were invented to allow any "Dufus" to think he install an MF/HF Marine Radio System, and save himself all that money he would have paid a Compitant Radioman. SGC Autotuners are some of the worst of the lot, even if they did steal the design from the real inventers. SGC couldn't even copy the design correctly, and "Old PeeAir" couldn't design his way out of a "Wet Paper Bag". Me Geeze Louise "Me" give the guy a break...... He was just asking for an opinion.... Bruce in alaska |
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