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SSB Antenna Installation
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bradleyj wrote: Thanks agaifor everyone's input. To clarifwhy I am installing a SSB. My boat is a 28' documented vessel with a fisheries endorsement. I fish commercially as much as 100 nm from shore. snipped for brevity....... Noback to the installation. I'm leaning toward a guyed installation on the pilot house roof. This will get the antenna up and away from all metal structures. I drew up a sketch of the concept, but I still can't seem to upload any picture files to this server. I'm planning on going with a Shakespeare 5390 17.5' fiberglass coated whip. I'm thinking of attaching three stainless guy wires about 4' up from the base. The idea I have for attaching anchors for the guy wires is to fabricate three aluminum brackets with holes to clip the guy wires to and installing them 120apart on the antenna whip by wrapping them with fiberglass tape and encapsulating with resin, much the same way that the eyes on fishing rods are attached to the rod blanks. The stainless steel guy wires will attach to three points on the edge of the pilot house roof. My question is will these metal brackets and guy wires cause problems with antenna performance (or roast the occupants of the boat)? The brackets will be electrically isolated from the conductors inside the whip by the fiberglass coating on the whip, but will RF energy still be affected (shunted down through the guy wires to the pilot house)? Does anyone else have any other ideas? Ok, now we have just about enough information to make some relativly speaking, informed observations. 1. A 17.5 Ft unloaded whip isn't going to be much of a radiator in the MF/HF Marine Radio Bands, below 8 Mhz, no matter what autotuner you put under it. 2. Just who are you planning to talk to with this MF/HF Radio? Most of the High Seas Public Corespondence Stations went off the air a decade ago, so that leaves Private Coast Stations, which may or may not want to handle your traffic, unless you actually setup a scheduale with them. 3. You maybe are thinking that the local USCG will actually be listening to the High Seas Calling Frequencies, and they actually, may be, but for your operational area, the MF and low HF Frequencies give the comm's for that area, and your antenna isn't actually going to preform good enough to allow resonable expectation of succesful communications. 4. As Larry states, it is a very good thing that you have a 406 EPIRB aboard for Distress Alerting, because if you are depending on the above MF/HF Radio to save your life, best you get lots of Life Insurance, and buy a Plot before you go out past VHF coverage. 5. I suppose you could have a Wx Ballon and Hydrogen Canister aboard and use that to lift a decent length MF Antenna for Emergency Communications, but just how well are you going to be able to do that while in an Emergency Situation. Yea, Yea I know that the FVSA says you have to fit a MF/HF Radio in order to be out passed VHF Coverage, in Sea Area A2, but in that area it is designated that MF comms should be used, and your Antenna System is going to be more like a Dummy Load, at MF Frequencies than an antenna. Bruce in alaska -- add a 2 before @ |
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