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Sonic Speed Replacement
greatketch@...
I installed an Airmar CS4500 in the hole where the old B&G depth transducer was, and for depth readings, used an Airmar P79 in-hull transducer. So we kept full functionality--and put no new holes in the hull.
---In amelyachtowners@..., <divanz620@...> wrote :
The CS4500 is an ultrasonic speed device that operates on a different principle than the sonic speed unit. I decided to try it because it is less susceptible to biofouling than the standard paddle wheel, and, at least in specification, gives the superior low speed (< 1kt) performance that the sonic unit was so good at.
So far, I am moderately happy. At normal sailing speeds it is not more accurate than a clean well maintained paddlewheel, but it is not claimed to be. Low speed performance is good, measuring down to 0.1 knots to help with sail trim and distance logging on those SLOW days, a situation where most paddlewheels struggle.
I no longer have to fret that my distance log will have a brain freeze every time I turn the inverter on (like the sonic speed) It does not need to be cleaned on a frequent basis like a paddle wheel. I don't have to worry about a little piece of flotsam interrupting my distance log. Since the reason for replacement of the sonic speed was to improve reliability from that side of things it's all a win.
The raw data of speed measurement does tend to bounce around a bit, requiring a higher damping factor on display than I would prefer, but the data output give good results from my chartplotter's calculation of true wind, and current set and drift. To be fair, I have no idea what internal damping B&G has on the sonic speed data. Certainly the damped response of the CS4500 does not look dramatically slower than the B&G.
If I was a buoy racer looking for fast and stable instantaneous readouts to help me make minor sail trim adjustments, I'd might be unhappy, but that's not me. A reliable distance log for navigation is my priority and this setup seems to be doing the job.
Bill Kinney
SM#160 Harmonie
Providenciales, Turks and Caicos Islands
Under way today (we hope!) for Mayaguez, PR
---In amelyachtowners@..., <divanz620@...> wrote :
Hi Bill,
We get the travel lift slings placed in line with the masts.
re the sonic speed....mine is totally unreliable also...I was thinking of putting in an Airmar thru hull sonic sensor....I believe B&G once offered this device in their options for Hydra / Hercules.
What did you replace the B&G sonic system with ?
Cheers
Alan
Elyse SM437
greatketch@...
I put my P79 about 75 cm to starboard of the port for the orignal Amel installed sounder. The Amel hull does not give the level of performance for me that I know the P79 is capable of from previous installations on other boats. My Amel install is than adequate for navigation, but limiting in fishfinding ability.
---In amelyachtowners@..., <divanz620@...> wrote :
Bill Kinney
SM#160 Harmonie
Mayagues, Puerto Rico
---In amelyachtowners@..., <divanz620@...> wrote :
Thanks Bill,
That sounds like a good solution.
Where on the hull did you install the P79 ?
Cheers
Alan
Elyse SM437
greatketch@...
No, not connected to the Hydra system. Ours is connected to a Navico (B&G) sounder module, which interfaces via ethernet directly to our chart plotter.
Right now our hydra system is being used really only for transmitting the wind data to the chartplotter via NEMA1083 so it can be distributed to other instruments via NMEA2K. Once that wind instrument dies, the hydra will likely be history.
Bill Kinney
SM#160 Harmonie
Mayaguez, Puerto Rico