Knotmeters

[Steve S.]

Anyone have advice on getting the knotmeter to work?  I clean it, and it seems to spin freely, but then when I put the sender unit back, it rarely works.  Has anybody found where you can get a new sender unit?  I'd rather not have to replace the instument panel.

[rirvine]

Steve:

If it is Raymarine, I suggest that you go to their web site and search through their FAQ’s using various searches.  You can buy replacement transducer and replacement wheels for Raymarine instruments.  If the knot meter reads when you spin the wheel with your finger, it would indicate that when it is mounted in the through hull, the either wheel does not spin with the water flow or there is something wrong with the cable.  I have found that the wheel can jam if the transducer is not correctly aligned (they only work wheel the wheel spins in one direction) with the flow, or the wheel is worn on the shaft and jams.

Good luck

Ray

[HydroTherapy]

Hi Steve,

I had trouble with some of my instruments on my C34 hull # 363.  I have the original instruments and I had to reconnect the coax on the inside box by the nav station to get everything to work.  Give it a try.

David

[Tweetybd]

The ST50 knotmeter transducer has been replaced by the ST60, which also requires a junction box (which is, of course, an extra-cost item).

However, Gem Electronics in South Carolina has the ST50s (they buy discontinued parts from Raymarine, and I just bought one last week).  They can be reached at 843-394-3565, and new ST50 transducer, with all wire and connector, costs $97.90 (89.95 + 7.95 S&H).

[Mike Lofstrom]

Steve:  You didn't say what kind of instrument you have.  I was having problems with my ST50 knot meter recently, and sent the display back to Raymarine for testing.  They diagnosed an intermittent signal problem on the board which was causing the speed readout to fluctuate.  (at one point,  I was hitting 24 knots in 20 knots of wind!!)  They repaired the unit by putting a new board in.  It was about $150 for the repair. If you have a raymarine unit and the temp sensor is not reading correctly, this can also indicate a problem with the display unit.  Mine was also way off prior to the repair.  Hope this helps.