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#1
posted to rec.boats.electronics
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Larry,
The 23' whip sounds like an elegant solution to my problem. I have a steel 60' sloop that I built myself. On this I have an ICOM 700 with the AT130 and a SEA 330 with the 1630 coupler. What would you recommend for this installation? There are twin 5/8 rod back stays and an 11' wide antenna bridge behind the center cockpit. Lots of room in this area as well as a solid continuous 1 1/4" stainless rail all around the boat at a height of 30" . Perhaps an antenna switch and a common antenna, as I will never use more than one radio at a time. Thanks in advance, Steve "Larry" wrote in message ... "Steve Lusardi" wrote in : Larry, Your email server is complaining that it cannot deliver email to you. Am I using your correct address? Steve You must be kidding. Never post email addy on usenet. Larry -- QUOTE OF THE MONTH: "I have been to several major Chinese cities and have seen first hand shops crammed with obviously fake American products." - Jon Dudas, Undersecretary of Commerce for Intellectual Property Rights. How can they be fake? The Chinese make all "American Products" I use! |
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#2
posted to rec.boats.electronics
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"Steve Lusardi" wrote in news:fk6u0f$31h$01
: Perhaps an antenna switch and a common antenna, as I will never use more than one radio at a time. The only reason for two radios would be redundancy. If this is what you are looking for, forget antenna switching as you are more likely to lose the antenna than the radio. I'm for dumping one radio, probably the Sea, but your choice as I don't know what their individual conditions are. Backstays are better antennas than whips because of their length. Boaters on HF use the lower, shorter ranged frequencies, like 4, 6 and 8 Mhz. So, the longer the antenna, the better the radiation. On the steel boat, I'm sure your backstay is grounded, unlike the plastic boats, so we're going to need insulators top and bottom wherever the backstay (or its jacks) meets the boat. Congratulations on your most enviable ground, that steel hull. Plastic boaters will all have lots less signal strength than you. Simply ground the tuner's ground screw to the hull with a very short, straight heavy wire. We have an HF ham station, WA4USN, aboard the WW2 aircraft carrier, Yorktown (CV-10), a museum here. "World's Largest Ground Plane" hooked to the Atlantic Ocean. Amazing signals worldwide. If you decide to go with the whip, put the tuner as close to the base of it as you can get. Make sure the whip ISN'T NEAR ANY METAL like boom lifts, as much as practical. Any parallel rigging near it just sucks the signal right off to ground, which does you no good. Larry -- QUOTE OF THE MONTH: "I have been to several major Chinese cities and have seen first hand shops crammed with obviously fake American products." - Jon Dudas, Undersecretary of Commerce for Intellectual Property Rights. How can they be fake? The Chinese make all "American Products" I use! |
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#3
posted to rec.boats.electronics
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In article ,
"Steve Lusardi" wrote: Larry, The 23' whip sounds like an elegant solution to my problem. I have a steel 60' sloop that I built myself. On this I have an ICOM 700 with the AT130 and a SEA 330 with the 1630 coupler. What would you recommend for this installation? There are twin 5/8 rod back stays and an 11' wide antenna bridge behind the center cockpit. Lots of room in this area as well as a solid continuous 1 1/4" stainless rail all around the boat at a height of 30" . Perhaps an antenna switch and a common antenna, as I will never use more than one radio at a time. Thanks in advance, Steve Steve, if you try and use the SEA330/SEA1630 with just 23 Ft of Antenna you will be dissapointed with the result on any Frequency below 6 Mhz. Look around your vessel for ANY way to put 35 Ft of wire under that 23' Whip, and your experience will be considerable better. Sea330's are a bit of a Power Hawg when operating at 300 Watts PEP Output, but they sure to "Talk" well, when the bands are marginal, if the antenna is reasonable. Bruce in alaska who installed a bunch of SEA330's all over alaska... -- add path before @ |
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#4
posted to rec.boats.electronics
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Bruce & Larry,
Ok the whip won't cut it. The back stays are 90'+ each. Do I use 1 inverted V or do I use each back stay as antennae? Steve "Bruce in Alaska" wrote in message ... In article , "Steve Lusardi" wrote: Larry, The 23' whip sounds like an elegant solution to my problem. I have a steel 60' sloop that I built myself. On this I have an ICOM 700 with the AT130 and a SEA 330 with the 1630 coupler. What would you recommend for this installation? There are twin 5/8 rod back stays and an 11' wide antenna bridge behind the center cockpit. Lots of room in this area as well as a solid continuous 1 1/4" stainless rail all around the boat at a height of 30" . Perhaps an antenna switch and a common antenna, as I will never use more than one radio at a time. Thanks in advance, Steve Steve, if you try and use the SEA330/SEA1630 with just 23 Ft of Antenna you will be dissapointed with the result on any Frequency below 6 Mhz. Look around your vessel for ANY way to put 35 Ft of wire under that 23' Whip, and your experience will be considerable better. Sea330's are a bit of a Power Hawg when operating at 300 Watts PEP Output, but they sure to "Talk" well, when the bands are marginal, if the antenna is reasonable. Bruce in alaska who installed a bunch of SEA330's all over alaska... -- add path before @ |
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#5
posted to rec.boats.electronics
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"Steve Lusardi" wrote in
: Bruce & Larry, Ok the whip won't cut it. The back stays are 90'+ each. Do I use 1 inverted V or do I use each back stay as antennae? Steve Parallel them. Put an insulator about 3' from the upper end, not too close to the metal up there, then an insulator on each of the bottom ends right above the deck but not so the backstay touches bimini tops, etc. That wonderful steel hull is the finest ground plane on the planet hooked to that ocean like it is. No grounding blocks or other nonsense is necessary. RF goes right through bottom paint on steel hulls. Put the tuner in the middle of them at the bottom and be SURE to use EQUAL LENGTH FEED WIRES to the base insulators of each so they are fed in phase. This creates an effective radiating conductor diameter as wide as these are far apart....making it broadbanded as hell, a really good thing. "Feed Wires" ARE part of the ANTENNA and are NOT a transmission line. Do not try to use coax cable all neatly tywrapped to the grounded rigging between the tuner antenna insulator and the backstays. This is CRAZY! Use #10 or larger insulated conductors, NOT SHIELDED, as short as you can get them and as far away from anything metal as you can get it. If you come through the steel hull with these antenna wires, we need a fairly large hole with a feed-thru insulator to guide the RF away from the grounded hull. http://www.surplussales.com/Antennas/Antennas-6.html Look at ICR 9548 near the top of this insulator page. The 4" "beehive" goes on the outside of the boat. This makes a very long leakage path in the wet outside environment and the smaller inside-the-hull side keeps the hot RF wires away from the hull. Try NOT to come off these at 90 degree angles on either end. RF doesn't like to turn corners....come off the insulator straight out with a bent lug then make a smooth curve where you have to go, as much as practical. The hole in the hull is large to reduce the capacitance between the high impedance RF high voltage and the grounded hull sucking off your signal. NO - sticking a piece of the center conductor covered with its poly core in a hole in the hull is NOT acceptable. The poly won't last a year in the sun, anyways. Notice how important it is to keep the antenna wire between the tuner and backstays away from the metal: http://www.surplussales.com/Antennas/Ceramic_stof.html Ol' Navy sure does a nice job of it....(c; DO NOT TYWRAP THE ANTENNA WIRE TO ANYTHING METAL! Standoff insulators can be nicely made of common white PVC water pipe and fittings. 3-4" stood off is great but only for SHORT distances. Your insulated backstay antenna is like most AM broadcast stations, except AM stations use a resonant tower. Your 90' long backstay will be self resonant on 234/90 = 2.6 Mhz and will radiate like mad around that frequency in the old 2 Mhz marine band.... If we move the insulators down from the top so there is great radiation in the 4.1 Mhz marine band, the insulators should be 234/4.1 = 57' of backstay between them. The tuner will make it tune the other bands by adding inductance and capacitance in series and parallel. But, nothing radiates as good as a resonant antenna. At 57' 1" long, that top insulator will also be far away from the RF-draining mast. Go for it!..(c; I like the 4 Mhz tuning because most all Caribbean yachties talk on that band. It's useless in the daytime but at night you get solid coverage from where you are straight out 500 miles in all directions. 4 Mhz tuning also resonates the antenna at 3/4 wavelength on 12.3 Mhz, the best DAYTIME marine band, too. You get two great resonant points at 57' 1". Larry -- QUOTE OF THE MONTH: "I have been to several major Chinese cities and have seen first hand shops crammed with obviously fake American products." - Jon Dudas, Undersecretary of Commerce for Intellectual Property Rights. How can they be fake? The Chinese make all "American Products" I use! |
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#6
posted to rec.boats.electronics
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Larry,
Thank you very much. I can do this easily, as the deck is contructed as a steel space frame underneath and the deck is marine ply covered in teak. In the aft cabin, I have 8' of headroom and can fasten the coupler to the deckhead in the center of the span between the chain plates. I can maintain a 6 inch spacing between the antenna feeds and any steel structure. Steve "Larry" wrote in message ... "Steve Lusardi" wrote in : Bruce & Larry, Ok the whip won't cut it. The back stays are 90'+ each. Do I use 1 inverted V or do I use each back stay as antennae? Steve Parallel them. Put an insulator about 3' from the upper end, not too close to the metal up there, then an insulator on each of the bottom ends right above the deck but not so the backstay touches bimini tops, etc. That wonderful steel hull is the finest ground plane on the planet hooked to that ocean like it is. No grounding blocks or other nonsense is necessary. RF goes right through bottom paint on steel hulls. Put the tuner in the middle of them at the bottom and be SURE to use EQUAL LENGTH FEED WIRES to the base insulators of each so they are fed in phase. This creates an effective radiating conductor diameter as wide as these are far apart....making it broadbanded as hell, a really good thing. "Feed Wires" ARE part of the ANTENNA and are NOT a transmission line. Do not try to use coax cable all neatly tywrapped to the grounded rigging between the tuner antenna insulator and the backstays. This is CRAZY! Use #10 or larger insulated conductors, NOT SHIELDED, as short as you can get them and as far away from anything metal as you can get it. If you come through the steel hull with these antenna wires, we need a fairly large hole with a feed-thru insulator to guide the RF away from the grounded hull. http://www.surplussales.com/Antennas/Antennas-6.html Look at ICR 9548 near the top of this insulator page. The 4" "beehive" goes on the outside of the boat. This makes a very long leakage path in the wet outside environment and the smaller inside-the-hull side keeps the hot RF wires away from the hull. Try NOT to come off these at 90 degree angles on either end. RF doesn't like to turn corners....come off the insulator straight out with a bent lug then make a smooth curve where you have to go, as much as practical. The hole in the hull is large to reduce the capacitance between the high impedance RF high voltage and the grounded hull sucking off your signal. NO - sticking a piece of the center conductor covered with its poly core in a hole in the hull is NOT acceptable. The poly won't last a year in the sun, anyways. Notice how important it is to keep the antenna wire between the tuner and backstays away from the metal: http://www.surplussales.com/Antennas/Ceramic_stof.html Ol' Navy sure does a nice job of it....(c; DO NOT TYWRAP THE ANTENNA WIRE TO ANYTHING METAL! Standoff insulators can be nicely made of common white PVC water pipe and fittings. 3-4" stood off is great but only for SHORT distances. Your insulated backstay antenna is like most AM broadcast stations, except AM stations use a resonant tower. Your 90' long backstay will be self resonant on 234/90 = 2.6 Mhz and will radiate like mad around that frequency in the old 2 Mhz marine band.... If we move the insulators down from the top so there is great radiation in the 4.1 Mhz marine band, the insulators should be 234/4.1 = 57' of backstay between them. The tuner will make it tune the other bands by adding inductance and capacitance in series and parallel. But, nothing radiates as good as a resonant antenna. At 57' 1" long, that top insulator will also be far away from the RF-draining mast. Go for it!..(c; I like the 4 Mhz tuning because most all Caribbean yachties talk on that band. It's useless in the daytime but at night you get solid coverage from where you are straight out 500 miles in all directions. 4 Mhz tuning also resonates the antenna at 3/4 wavelength on 12.3 Mhz, the best DAYTIME marine band, too. You get two great resonant points at 57' 1". Larry -- QUOTE OF THE MONTH: "I have been to several major Chinese cities and have seen first hand shops crammed with obviously fake American products." - Jon Dudas, Undersecretary of Commerce for Intellectual Property Rights. How can they be fake? The Chinese make all "American Products" I use! |
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#7
posted to rec.boats.electronics
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"Steve Lusardi" wrote in
: Larry, Thank you very much. I can do this easily, as the deck is contructed as a steel space frame underneath and the deck is marine ply covered in teak. In the aft cabin, I have 8' of headroom and can fasten the coupler to the deckhead in the center of the span between the chain plates. I can maintain a 6 inch spacing between the antenna feeds and any steel structure. Steve Man, that's gonna be one LOUD voice in the darkness....(c; Larry -- QUOTE OF THE MONTH: "I have been to several major Chinese cities and have seen first hand shops crammed with obviously fake American products." - Jon Dudas, Undersecretary of Commerce for Intellectual Property Rights. How can they be fake? The Chinese make all "American Products" I use! |
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#8
posted to rec.boats.electronics
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Larry,
I suspect this will be one hell of a radiator, but the real performance of the set will be in the antenna's ability to listen. Steve "Larry" wrote in message ... "Steve Lusardi" wrote in : Larry, Thank you very much. I can do this easily, as the deck is contructed as a steel space frame underneath and the deck is marine ply covered in teak. In the aft cabin, I have 8' of headroom and can fasten the coupler to the deckhead in the center of the span between the chain plates. I can maintain a 6 inch spacing between the antenna feeds and any steel structure. Steve Man, that's gonna be one LOUD voice in the darkness....(c; Larry -- QUOTE OF THE MONTH: "I have been to several major Chinese cities and have seen first hand shops crammed with obviously fake American products." - Jon Dudas, Undersecretary of Commerce for Intellectual Property Rights. How can they be fake? The Chinese make all "American Products" I use! |
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#9
posted to rec.boats.electronics
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Bruce in Alaska wrote in news:fast-F610FA.11361118122007
@netnews.worldnet.att.net: operating at 300 Watts PEP Output 300 watts?......Oh, wait, I forgot to turn on the linear....(c; Larry -- "Power is our FRIEND!" - Robert Mitchell, owner, paging company. You can tell when your ham station is gittin' out because it dims the lights in your NEIGHBOR's house! |
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#10
posted to rec.boats.electronics
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In article ,
Larry wrote: Bruce in Alaska wrote in news:fast-F610FA.11361118122007 @netnews.worldnet.att.net: operating at 300 Watts PEP Output 300 watts?......Oh, wait, I forgot to turn on the linear....(c; Larry Bzzzt, Wrong conclusion, Larry, would you like to try for what is behind Door #3....... Yes the SEA330 is a 300 Watt PEP Output Transceiver. It was designed for Commercial Vessel and BaseStation Installations. It can be configured for Multiple Full Function Control Heads. (Up to 8, with Special Firmware, and 3000 Wire feet TR Box to Control Head, with #22 4 Pair Wire, with Special Conversions) and is fully GMDSS Certified with the SEA GMDSS Controller. The campanion SEA1630 Autotuner is qualified for 300 Watts, on Steel Hulls, and 35' Antennas, on any Frequency above 3.6Mhz. Oh, how I wish SEA had made a SEA330 version of their SEA325 Tranceiver. Now that would be a Commercial Radio worth owning.... I have installed a Pile of them, as Limited Coast Stations, all over Alaska, and a bunch of them on the bigger Catcher/Processor Vessels that roam the North Pacific and are SOLAS/GMDSS Required. Bruce in alaska -- add path before @ |
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