Friday 10 May 2019

AIS

One of our projects this winter has been attempting to install "active" AIS aboard "Susan J".  The already fitted passive device shows nearby vessels on the aged C120 Raymarine plotter but "Susan J", herself, remained invisible.  After much research on the Internet it appeared that a modern AIS 700 could be wired in the original's place.  So far so good. All the correct status lights, "Susan J" appeared ashore in Penryn but, since launching and sailing to the Helford River, we were still in Penryn!
An inexpensive SWR meter, designed for CB but covering the marine VHF band  (156 to 162 MHz) as well, indicated reflected waves greater than 3.1 to 1. The cables conducted, did not short and the connectors were in good condition. The only thing we couldn't check was the aerial and connector at the top of her mast.
The riggers had been up twice, to check the rig, replace the steaming /deck light and replace the frayed jib halyard. On discussion with them they had observed some slight corrosion, when removing the Windex and fitting a cheek block for a pigstick (and dressing overall!).
This probably explained why, unlike other yachts, increasingly since acquiring her, "Susan J" has needed to be within hailing distance of the Harbour Master, to get any response! We have been reassured that, because we could hear other vessels and the Coastguard, all was well. En route to our mooring we tried our second ever "radio check" with Nare Point NCI, who, after a mobile telephone call, were very helpful and able to confirm a rather weak but readable signal over just one mile in plain sight (but no AIS) on low power.
After the above investigations and further confusing enquiries regarding an aerial suitable for AIS as well as VHF, it appeared that, a modern version at least, of the aerial we had (with wind indicator as Julie already missed the old one!)   should suffice and might be simple to replace.   We also now have a new, relatively inexpensive  VHF/DSC instrument, with all the same features, to replace the aged separate DSC and. VHF boxes, in due course
We have since met David, Ben and Jake of Riggers UK, of Penryn, again at the Falmouth Yacht Haven because the tide was too low at the start of our summer cruise.
We can report the picture shows the new aerial being fitted....


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