Saturday, February 2, 2019

AIS getting overloaded!

Automatic Identification Systems (AIS) are causing problems for mariners transiting waters where there are high concentrations of fishing vessels, particularly in the East China Sea. It seems the real problem is fishing nets where AIS has been installed to fool ships into steering clear of them (hundreds and hundreds of them).  Just be aware if you are a sailboat as it sounds like a place to avoid when possible.
Anyone who googles AIS Security will find out a lot about other spoofs/fake/distress fake broadcasts; re,

Inexpensive AIS Receiver

Large ships and passenger boats are required to broadcast an identification signal containing position, course, speed, destination, and vessel dimension information to help prevent sea collisions. This system is known as the “Automatic Identification System” or AIS for short. There are dedicated AIS receivers intended to be used on boats, or by hobbyists, but they can be expensive. A radio scanner, or the cheap RTL-SDR software defined radio (or a more advanced SDR such an Airspy) can be used to receive these signals, and with the help of decoding software, ship positions can be plotted on a map

Watermaker 100 lph block diagram

The credits are on the picture so I do not need to do many disclaimers; however, I did pick this up from somewhere in my sojourn as a sailor. I do know Cruiser Forum had a recent watermaker article on the subject so I will put that link here too (I do not know if you need a subscription to see it though).

Also, here is another way, Salt Water Pro , to go with so many ways to configure.  I think individual components is a good way to construct yours since you can put the bits and pieces anywhere.  The quiet motor option sounds good (pardon the pun) but I have never heard one running so I do not really know.

I am a patreon of Emerald Steel watermaker and they maid their own watermaker.  It is presented on Youtube and has names, places and how-to's for building watermakers.  Well worth the listen but it has the usuak Youtube commercials at the front.

Marine & Other Solder Joints


Almost everyone using leaded solder on a boat or shop bench will be using the much cheaper, older style, 60/40 solder with an unknown flux. The solder can be oxidized or corroded on the outside of the reel as well.  I know this has happened to me and continues to happen as I do not really solder a lot any more.  So only buy a limited quantity from Digi-Key, Mouser or other reliable supplier.  Quite often I use Amazon but lately Digi-Key is getting most of my business.  There is no minimum order with then anymore.

63/37 solder is better. It has a higher tin content. The main advantage is this is a eutectic solder. Basically this means the solder only has one melting temperature. 60/40 solder has a temperature range. Once it is hot enough to melt, it has to cool down to a lower temperature before it solidifies. An joint movement during this solidification process will result in a poor joint. Joint movement is a joint killer and this happens even with professional had solderers. You can imagine what some of mine look like.  A cold solder joint will be dull colored, whereas, a good joint will be shiny.

Image of Kester's 285 Flux-Cored Wire
Here is an example of  what you should look for:

Kester 24-6337-0027 Solder Roll, Core Size 66, 63/37 Alloy, 0.031" Diameter

This is only an example so be aware that many different lengths and diameters are available.  I tend to use the smaller diameter solder and if it has to be thicker for major joints I double or triple, etc. the solder and twist it to make a bigger diameter. Since this is not ideal, if you have a lot of bigger joint work to do buy the larger diameter. Kester solder has been around for a long, long time and I used to use it back in my early electronics days.The link above will take you to their site and you can download literature and specs on their products.