I have done some work with marine radio installation on fresh-water vessels and also have insights for salt-water. 1. Fresh-water VHF is a snap( I agree ). Simply use a well-waterproofed thick metallic plate of at least 18" by 24" for a ground-plane below a standard NMO heavy-duty constructed antenna. My favorite was a left-over mounting plate for G.E. radios that you might see at hamfests. While this works for 5/8 wave antennas near 2 meter frequencies ( actually, we were a bit higher for public safety & marine ), the quarter-wave antennas with good bandwidth ( eg. Maxrad coil ) seemed to last longer. Use heavy-gauge DC cabling ( think welding cable ) for longer runs and go back to the DC source. This keeps the voltage drop low, so the radio is not 'starved'. 2. HF installations do require some sort of ground plane also. You will always need a 'difference' between elements, yet the 'ground' side does not have to actually contact the water. The problem is that as the hull moves, any 'artificial ground' is moved in relation to that. Do not be fooled by ads for 'artificial ground' products, some do not work with transmit ( yet are fine for receive ). 3. Salt water power sources very often used to involve frequencies other than 60 hz. Do not 'guess' or contract the word assume that if the voltage is correct, you can connect a standard amateur radio. You may be able to charge batteries and then run an inverter, yet the cheaper inverters tend to make noise on the lower frequencies which are best for worldwide communications. 4. New 'Copperweld' wire typically is stronger due to stainless or other than copper core. The stuff you can buy anywhere ( all copper ) has a tendency to droop. Any place where you mate dis-similar ( different ) metals, corrosion is accelerated. It is also accelerated by salt water. Chemicals such as are used to make aluminum to copper hookups for stoves and dryers in households can slow this yet may not tolerate heat and salt for long. Where you actually want to preserve iron, there are alloys used in hot water-heater heaters for the 'sacrificial' anode. I hope that all helps. More experienced amateurs, feel free to 'correct' or improve the above. 73 KB0MNM Tech. for MnDOT assisting DNR, AT2-USN-USS Midway ( CV-41) ret. 1987
----- Original Message ----- From: "Leslie via BVARC" <[email protected]> To: "SETX Telecom" <[email protected]> Cc: [email protected], "BRAZOS VALLEY AMATEUR RADIO CLUB" <[email protected]> Sent: Friday, July 28, 2017 11:33:28 AM Subject: Re: [BVARC] marine radio installation Thank you. I will do so. On Jul 28, 2017, at 11:23 AM, SETX Telecom < [email protected] > wrote: I've done marine radio work in the past...HF is s special art on boats requiring RF ground...VHF and radar are a snap....sometimes a copper plate is used as a protector to the hull and placed where it contacts the water ...providing similar protection like Zinc does on a tower section...it sacrifices itself to protect what's beneath...sometimes there is no ground connection to the hull and the entire radio system floats, so to speak, to prevent galvanic corrosion action. Email directly and we can chat... Chris WB5ITT [email protected] On Jul 28, 2017 11:08 AM, "Leslie Bartosh via BVARC" < [email protected] > wrote: <blockquote> Hello All: My name is Leslie, ad5wb. As some of you know I am involved in activating the 1877 Tall Ship Elissa during Museum Ships Weekend. During this years activation the Bosun asked me if I knew anything about installing radios on ships. I do not know anything about the subject. Does anyone here have any practical experience with installing marine band and hf radios on ships? OR Any suggestions for individuals or companies who can do the job appropriately? They are understandably concerned about the introduction of any form of electrical current to the iron hull of the Elissa. They had to redo the entire hull after hurricane Ike, due to the introduction of electrical current to the hull. Thanks for reading. 73 Leslie, ad5wb _______________________________________________ BVARC mailing list [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org Message delivered to [email protected] </blockquote> _______________________________________________ BVARC mailing list [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org Message delivered to [email protected]
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