The Bench

We all want to be green. It doesn’t make much sense to throw toxic trash all around your house, so why would it make sense to do it out in the open? Lately, there have been more and more laws to help enforce this idea. I would have to say many are a good idea. However, there are also many effects these laws have on our society that could not have been easily foreseen.

Take for instance, the EU legislation called the "Reduction of Hazardous Substances Directive", or "RoHS" for short. The Wikipedia page has some pretty comprehensive information on this. RoHS is intended to reduce the exposure of industry workers, consumers, and the environment to six hazardous substances used in electronics manufacturing. Remember the big flap-doodle about not being able to smoke in European bars and pubs because of the hazard it presented to the staff? RoHS was part of that suite of legislation to improve the environment and the workplace.

In the USA, we are obviously not beholden to the laws of the EU (except in matters where we’ve signed and ratified a treaty, thus superseding the Constitution). So how can this possible affect us? It turns out all the electronics suppliers that sell in the US also sell in Europe, so they must follow these rules. And to add to the pressure and confusion, Japan and China have decided to enact their own versions of RoHS.

This caused the electronics parts manufacturers to re-tool their processes to eliminate the use of the six hazardous substances: lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ether. This would seem simple, except that electronics manufacturing is a very mature industry, with many well-established techniques and processes. Some items have been manufactured using the same materials and methods for nearly 100 years. Much of that prior technique is now void, as many of the replacement materials behave very differently. New solders, fluxes, printing inks, and fireproofing materials had to be developed, along with the techniques to use them in a production environment.

Most parts manufacturers are also completely converting their production to RoHS compliant methods. This makes sense when you think about it. If a separate line was created to do the RoHS compliant parts, then two production lines would have to be maintained, increasing production cost. It could be pretty difficult to determine if a new product were to be produced on only the leaded line, the RoHS line, or both. Also, the issue of cross-contamination comes up when running two lines, since it is pretty difficult to tell if something has one of the banned substances just by looking at it - it usually requires chemical testing or X-ray fluorescence. The possibility of a production problem increases greatly with two lines, so most parts manufacturers are simply stopping their leaded lines.

What does this mean for us and the consumer? Many parts that we have used for many years are no longer available, and those that are still available have some significant changes. In the best cases, the leaded part number is simply discontinued, with a RoHS compliant part number created in its place; all else about the part is identical. In some cases, there are replacement parts that are RoHS compliant in different packaging. The different packaging requires a little "magic" to get the part to fit on the circuit board, if it can fit at all. In other cases, the parts manufacturer has stopped making the part entirely due to low demand or high production costs.

For many discontinued items, we have a supply on hand that should last for a few years at current levels of demand. For a few parts, we can get them, but at greatly increased cost (+500% is not uncommon), and greatly reduced quantities. So far, there have been only one or two parts that we cannot get anymore, but this will become a more common problem as time goes on.

Ultimately, this will mean that it will become economically unfeasible for us to support repairs on some older products. The good news is that we have successors to these products, and a stock of refurbished items to replace failures without too much financial stress.

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On most mechanical systems, you can tell when something absolutely needs more grease. It starts to squeak and things don’t work as well. You add grease, and everything gets better (most of the time).

Do you need grease on electronics? You bet, especially on marine electronics! Now why would you use grease on electronics?

The major reason to use grease on marine electronics is to protect the connections. Connections are the weakest point of any electronic system. You might have the most robust, bulletproof displays and interfaces, but if the connections are weak, then nothing will ever work for any amount of time. You can usually tell when the connections in a system are weak when nothing seems to work consistently anymore. Since connectors must use metal to conduct electricity, they are susceptible to corrosion - at least until someone invents a practical room-temperature ceramic superconductor!

Another thing to note is that you must use the correct grease. Some grease for mechanical systems has detergent as an additive. This type of grease can cause electrical problems because of the slightly ionic (and thus conductive) nature of detergents, so it is best to use a grease specifically formulated for protective use on electronics; this is called dielectric grease. This type of grease is usually labelled as silicone or Teflon type grease, although is can also be labelled specifically as dielectric grease.

There are three or four places on an Ockam system that could use a dab of grease, depending on the system vintage.

The first place that can use protective grease is at every BNC junction, especially on mast displays and any other displays where the back connector is exposed to salt water. BNC connectors can actually freeze together through corrosion if left alone for years. Usually, I just smear some grease around the female BNC connector first, then connect the male BNC on to it, and then smear some more grease around the whole thing. It usually pays off to make sure that everything is clean and dry before you do this, because whatever is on there tends to stay there once the grease is applied. I prefer using grease rather than self-vulcanizing tape since it’s easier to see what’s under the grease. Tape tends to trap water and salt inside.

Another place to use protective grease is on the external switch contacts on the rear of the Matryx and Magnum displays. These displays have the screw terminals to attach N/O momentary switches to change the displayed data. On mast displays in particular, salt water can wash over the terminals and short them, causing the display to flip through data pages. Lightly coating these terminals with grease helps prevent accidental page switching. I’ve also seen a few displays where spray-on or brush-on waterproofing varnish has been applied. This will work to protect these terminals, but it can be very difficult to remove the varnish later. Grease just wipes off when you need to remove it.

The mast cable for the wind sensor can also use a bit of grease. I usually goop some inside the connector with the pins, and then just squish the two together and wipe off the excess. This is especially helpful at the top of the mast. Realistically, you don’t go up there and clean off the connector after every race, so salt does accumulate up there and cause corrosion if you’re not careful. It’s a pretty nice feeling knowing that the connector is fairly safe up there and that you aren’t going to be sending someone aloft to fiddle with the wind sensor.

The last place that typically can use some protective grease is only found on older Ockam systems. The 015 Boatspeed interface uses a TNC screw-on connector to attach the boatspeed transducer to the interface. Applying a bit of grease here helps prevent the connectors from corroding together, and helps keep any salt water out. Just a little salt water inside this connection can cause the boatspeed reading to be quite far off, as salt water is conductive and will prevent the correct propagation of the boatspeed signal.

Dielectric grease can be obtain through a variety of sources. It can be purchased directly from Ockam, from a marine supply store, or through many industrial supply stores. Just remember when purchasing, that dielectric grease must be used, not just any grease!

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Did you ever notice how some boats seem to have strange instrument readings only in certain conditions? Like having boatspeed be off by a half knot only when going between 4 and 6 knots, or the wind readings being off only at certain apparent wind angles? A lot of times, the instruments are actually working correctly, but the peculiarities of the boat’s shape moving through a fluid (either water or air) affect the motion of that fluid, and produce unavoidable local transitory effects on the sensors. These local effects then give rise to the anomalous instrument readings.

So how do you compensate for these local transitory effects? Short of redesigning the boat or moving the sensors, you can use AutoCal tables. AutoCal tables produce correction factors for an instrument reading in certain ranges. For instance, the 0.5 knot error between 4 and 6 knots could be removed by using an AutoCal table.

An important thing to note is that AutoCals should be used as an adjunct to good calibration, not a replacement! The base calibrations should be refined to the point where it is nearly impossible to remove additional errors before resorting to AutoCal tables. AutoCals were developed in response to the need by high-end racing yachts to remove that last bit of error from the calibrations to produce the best instrument readings possible. Keep in mind that many of these programs have one or more people devoted entirely to keeping the electronics in superb operating conditions, so they often reach the limits of the base calibrations.

In days of yore, the AutoCals were done externally to the system processor by an attached PC. The PC would run a piece of software (like OckamSoft) that looked at the instrument readings, and then send a correction factor when warranted. This of course introduces another potential point of failure in the instrument system, which tends to make it a bit more delicate - not something that’s particularly desirable on a boat. With the introduction of the T1 Tryad processor, it became possible to run AutoCal tables internal to the processor and eliminate the need for the external PC sending correction factors. The AutoCal tables are stored on the internal CompactFlash memory card, along with other system information. The only problem with this is that it is difficult to change AutoCals on the fly, as the system needs to be shut off to remove the CompactFlash for file transfer. Another thing to note is that the external PC is still required. It’s best to test and qualify the AutoCal tables using the external PC before moving the AutoCal tables to the T1’s internal CompactFlash memory card.

However, many of the high-end programs demand quicker and easier changes to the AutoCal tables, so we’ve developed a quicker method. This new method allows you to create an AutoCal table and download it directly to the internal memory on the T1, without the need to turn off the system and remove the ComapctFlash! For the end user, this new "live edit" method uses an Excel spreadsheet with a line graph to visually build an AutoCal table. There’s also an API for use by other navigational programs to incorporate this flexibility into their own structure - there will probably be at least one program incorporating this feature in the near future. You can download the end user utility here. Note that this live edit capability requires an update to the T1 firmware to operate correctly.

We also have a "Robocal" program that’s been sitting quietly waiting for a nibble. It helps you determine the correct base calibration for your instrument system using a PC connected to the Ockam data stream. If anyone is interested, write me at dan@ockam.com and I’ll send you a copy to try.

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