There used to be a product available called CARD. I believe it was short for Collision Avoidance Radar Detector. As I understand it, it picked up the signal of a ship using its radar and had a nifty little display in the shape of a ship to show you what sector the ship was in, relative to you, and a means to interpret its distance away.
I cannot find info on the unit anywhere, and since I do not have radar on our boat, I thought it would be a good addition. Do you have any knowledge of it? Have you reviewed it?
Windswept II, 1982 CT 47
St. Mark’s River, Fla.
Practical Sailorreviewed Survival Safety’s CARD 050 system in the Nov. 1, 1994 issue. The company has since released the CARD 060. We’ve gotten mixed reviews of this product. Some singlehanders credit it with saving their lives, others complain about its reliability. Contributing PS writer Scott Rosenthal, who reviewed the Nasa AIS (Automatic Identification System) for the March 2007 issue, also had a CARD device installed on his boat. He reports that the alarm has very limited range, and of course, doesn’t detect the many ships that seem to be underway without their radar operating. He added that the alarm would go off when any pump on the boat (including the galley faucet pump) turned on, and that it was impossible to run the CARD system and radar at the same time because the CARD was easily overwhelmed by the local radar. Corrosion was also a problem. Rosenthal cautioned against placing the CARD antenna near an SSB antenna (as he did), because it can fry the receiving diodes in the CARD antenna.
He eventually replaced the CARD system with the AIS Radar. To find out more about Survival Safety’s CARD, visitwww.survivalsafety.com online or call 888/475-5364.
Homeland Security & AIS
Thanks for the informative report on the low-cost Nasa AIS (Automatic Identification System) receiver (March 2007). The larger issue, of course, is the prospect for not just AIS receivers, but transmitters. These could logically be required on all craft large enough to carry a nuclear weapon, a dirty bomb, a land attack missile, or small, unmanned aircraft. If the nation is to get serious about defending itself from potential seagoing threats, as it does from aircraft, such an identification system will be essential to permit the authorities to concentrate on boarding and inspecting only non-compliant craft. It will be interesting to see how the traditionally independent, but always patriotic, recreational boating and commercial fishing communities respond to this emerging need
According to U.S. Coast Guard Rear Admiral Joseph Nimmich, the U.S. Coast Guard is initiating a dialogue with recreational boating groups regarding the "small boat threat" to national security. In our interpretation of Rear Admiral Nimmich’s well-honed bureaucratese at a recent press conference, a law requiring AIS transmitters on recreational boats (as is required on large commercial vessels) seems much less likely than a standardized national licensing and boat registration program. Nevertheless, we would not be surprised if the manufacturers of these devices were already lobbying hard in Washington to require AIS transmitters on your Walker Bay.
Why did you report on this obviously low-tech and hardly usable AIS system when there are excellent AIS receivers on the market that interface with long lists of chartplotters and PC nav software to give users useful, readable, and important collision avoidance information?
We will soon be testing the devices you describe. Our tester of the Nasa AIS Radar (March 2007), Scott Rosenthal, is a software engineer who knows well the pitfalls of networking. He prefers to keep all of his instruments independent so that a single failure doesn’t bring down the whole boat.
The Nasa AIS Radar allows excellent redundancy and—just as important—it consumes far less power than some chartplotter- or laptop computer-dependent AIS systems. This is an important point for the long-distance voyager who doesn’t want to waste fuel to replenish wasted amps. The Nasa AIS Radar, at least from Rosenthal’s 2,500 miles of experience with it, is extremely useful, readable, and supplies invaluable collision information. Could it be better? Absolutely. But for his needs and budget, it works well.
I enjoyed your article on corrosion blockers ("Crusade Against Corrosion," April 2007). It fueled some electrical connection questions that I have been needing to ask.
When crimping wires and fastening electrical connectors, I have always tried to ensure clean areas of contact by spraying with WD-40 or the like. Sometimes, I even take a toothbrush to the area to get it clean. When done, I spray on some more, like an artist.
If WD-40 or CRC sprays act like blockers, then has my work been counterproductive. Do these and other products act as a dielectric and increase resistance at the connection? This even brings up questions about grease under battery clamps and connections. Is there a preferred crimp, fasten, seal procedure out there? From your test, and other product experiences, is there a single cleaner-corrosion blocker for the saltwater environment that you could recommend or lean toward on electrical connections?
Capt. Ralph Crapps
Stand by, Ralph. Our current project is to test the same products (and perhaps a few others) from our corrosion test for their dielectric properties. Ultimately, we’re looking for the best product to protect exposed terminal connections (running lights, circuit panels) without damaging terminal sleeves or insulation.
Most of the products in our test were billed as dielectrics. What they do (or what their manufacturers claim they do) is prevent electrical short circuits via an electrolyte—in our case seawater or salt-laced condensation. However, the film created, in most cases, is sufficiently thin so that when you exert pressure, such as is created when operating a switch or, very likely, when you crimp a connection, the product displaces and allows metal-to-metal connection. The manufacturers warn against using these products around membrane switches, which don’t have enough internal pressure to displace the coating. Also, you should avoid spraying near LCD displays, which are essentially made up of multiple switches whose functioning the coating will impair. Greasing crimp terminals and the wire that will be inserted may help minimize corrosion, but it also makes slippage of an under-crimped terminal more likely.
A much better corrosion abatement approach is to use an appropriately sized tinned copper terminal with a built-in heat-shrink tube over the terminal. The best tubing is made from polyolefin plastic; it’s tough and shrinks to one-third of its original size at about 250 degrees F. Such terminals are manufactured by Ancor (www.ancor.com). These also have a built-in adhesive that helps to keep out moisture. Naturally, it’s best if the crimping is done with a tool specifically designed for the terminal used.
The use of white lithium grease on battery terminals is an old standby that continues to work well in a marine environment, and there are also non-greasy, dry coatings designed specifically for such protection.
Four years ago, we purchased a sailboat with a Magellan Map 410 GPS. The unit works well and serves my needs on the Great Lakes. It has a mounting bracket at the helm that has been bumped a few times. I suspect the UV has made the plastic brittle. I have epoxied it back together before, but now it has to be replaced. Magellan no longer sells replacement mounting brackets. Is there a company that sells after-market universal holders that would work?
I tried to purchase a data cable a couple of years ago, and Magellan no longer stocked them. I also have a Garmin GPS at the nav station that is older than the Magellan. Garmin has a full selection of accessories for the older Garmin unit.
Lake Huron, Ontario
RAM Mounts(www.rammounts.com) manufactures a variety of mounts for these kinds of devices. They were our top pick in our last handheld holders test (April 1, 2003). We suspect you should be able to find something useful on the website for about $30 or less. You also may want to read about one reader’s
project using RAM mounts, see "Readers’ Workbench," above.
I have 14 years experience with Morad Electronics, a manufacturer of high-performance, high-durability antennas used by the Alaskan commercial fishing and commercial tugboat industries, military, government, as well as pleasure yachts in the Northwest and Alaska. I have had extensive experience in marine antenna design, testing, and manufacturing.
I wholeheartedly agree with the manufacturers that your test method was misleading. The proper mounting, use/type of coaxial cable, and environmental conditions can have a greater affect on antenna performance than the antenna itself.
Antenna testing is best done on land in a large field free of powerlines. The antenna is tested horizontal to the ground on a turntable at a specific wavelength above the ground to nullify reflected energy. The antenna is fed with a signal generator and monitored from a distance with a spectrum analyzer. While being monitored, the antenna is rotated 360 degrees. By doing this, the field strength can be measured at all angles to the antenna.
Signal strength and radiation pattern can then be plotted and compared to other antennas with the same test.
Quality of materials, physical size of the radiation element, proper impedance matching, dielectric properties, etc., can have a much greater influence on performance than the length of the antenna. While it is true that for every 3db gain you double the radiation power, doubling the radiation power only increases range minimally.
Another interesting test is of the coaxial cable. Your picture shows the Bird wattmeter connected at the radio output. Measure the output and then move the wattmeter to the antenna end of the coax and measure again. Coax losses are huge. This will convince you of the need to eliminate excess cable. When I was involved in this type of test, RG213 excelled over any of the RG58 classes. Only use the smaller diameter RG58 types when installation requires it.
David L. Blaine
Thanks, David. We wanted to do a real-world test that mimicked the challenging conditions for radio communication at sea. As we pointed out in the article, environmental variables were unavoidable, but we believe that the methodology ruled out the chance of bad data drastically upsetting the final conclusions. Interestingly, the last time we performed a land test, similar to the one you described, readers and manufacturers criticized the report for not conducting the test at sea. We feel our testers properly balanced the weight of construction details and field performance in making their final determinations.
masking Tape mystery
In the past, I have used 3M’s Scotch No. 2090 blue tape on my boat with success. However, the last time I used it, I found that a lot of residue (and some blue paper) would not come off the gelcoat when I removed it (less than 24 hours after application).
When I contacted tape manufacturer 3M, a representative told me that No. 2090 should not be used on gelcoat and that No. 2080 is the tape to use. This is not clear on the 2090’s packaging. The label actually reads: "UV and Sunlight Resistant" and "Adhesive does not like raw gelcoat."
The 3M rep attributed the residue to the warm temperature and sunlight affecting the bond. However, I used the tape on both the sunny and the shady sides of the boat, and the temperature was in the 70s.
Please consider reviewing different tapes soPS readers will have accurate information about the different tapes available.
Island Packet 350
Mr. Thurn’s story is very reminiscent of problems several readers reported in 2004. They too had "gooey, adhesive residue" after removing 3M’s 2090. Those reports led editors to investigate and launch their own masking tape test, which was published in the December 2004 issue. The 3M 2090 left some residue after six and 10 days, but it was easily cleaned off. While we did not experience the severe problems our readers had, the 2090 was not the top performer in the test. Intertape’s ProMask Blue outperformed 3M’s tapes and is less costly (about $2/roll cheaper according to a general web search). Interestingly, testers—on the advice of several varnish experts—found that black electrical tape works just as well and is the cheapest to boot.