SCX20 vs HS60 vs S33 Sat Compass

[Dockhead]

I am in the States for another week or so and had intended to some electronics including a DX900+ speed log and a Furuno SCX20 satellite compass.


Both are unobtainium, on indefinite backorder, so have to make some compromises.


For the speed log, I've ordered a UDT850 which is more or less the same as the DX900+ except without leeway. This should do for a while.


The compass is more perplexing. Should I stump up for the SC33, which is much more accurate (0.4 degrees vs 1 degree RMS accuracy on heading, heave, pitch, yaw), but is twice as expensive (about $2000) and much bulkier? The bulk might be the fatal flaw because I need to fit this in a certain instrument nacelle over my scuttle, which the SCX20 will but the SC33 if 650mm long.


So that would leave the HS60, but this is a much worse spec with 2 degrees accuracy RMS, and is similar in cost to the unobtainable SCX20 (about a grand).


Anyone have experience with any of the above?

[Matt Johnson]

Have you talked to Hemisphere about who has what available in stock? They are the producer of almost all prosumer level sat compasses in the marine market.

You could go with their Vector V200 - It's .75 degree accuracy and dimensions of 348mm x 158mm. Hodges Marine shows two of the Si-tex rebranded versions in stock for $1168.

https://www.hodgesmarine.com/sitvect...e-mount-n.html

The HS60 is Navico's rebranding of the Vector Compact. We had the Vector unit and loved it.

Matt

[Dockhead]

Originally Posted by Matt Johnson

Have you talked to Hemisphere about who has what available in stock? They are the producer of almost all prosumer level sat compasses in the marine market.

You could go with their Vector V200 - It's .75 degree accuracy and dimensions of 348mm x 158mm. Hodges Marine shows two of the Si-tex rebranded versions in stock for $1168.

https://www.hodgesmarine.com/sitvect...e-mount-n.html

The HS60 is Navico's rebranding of the Vector Compact. We had the Vector unit and loved it.

Matt

Thanks; hot tip. Which Vector did you have?

[Matt Johnson]

We had the Vector Compact. It was perfectly adequate for our needs, but I understand you'd like more accurate MARPA and would need better accuracy.

Matt

[Statistical]

Originally Posted by Matt Johnson

Have you talked to Hemisphere about who has what available in stock? They are the producer of almost all prosumer level sat compasses in the marine market.

You could go with their Vector V200 - It's .75 degree accuracy and dimensions of 348mm x 158mm. Hodges Marine shows two of the Si-tex rebranded versions in stock for $1168.

https://www.hodgesmarine.com/sitvect...e-mount-n.html

The HS60 is Navico's rebranding of the Vector Compact. We had the Vector unit and loved it.

Matt

SitTek's website shows the V200 only having 2 degree heading accuracy (heisphere shows 0.75 deg). Is that just them being caution or has it been downgraded.

Same thing with the $1500 Stitek V500 clone (0.67 degree heading accuracy in the SiTek docs and 0.27 deg in the Hemisphere docs).

[Dockhead]

In the event, the Furuno SCX20 started shipping a few days before I left the U.S., and I managed to snag one.

Delighted to see that according to the manual, the accuracy in dynamic conditions is 0.5 degrees RMS! As opposed to the advertised 1.0 degree.

Pitch and roll accuracy is also 0.5 degrees -- wow.


Heave accuracy is 5cm (!)

Attitude update is 50hz (!); position 10hz. I hope the 50hz updated attitude data doesn't overwhelm my network.

SOG is accurate to 0.02 knots.

I can't wait to get to the boat to get this installed. The very high quality and very fast updated attitude data should have a dramatic effect on autopilot performance and radar stabilization (and target trails). I can't wait to see this.

If I can ever figure out (see separate thread) how to get corrected wind data into my network, this very high quality data should greatly improve the quality of that.

Total thread drift, but I accidentally watched a YouTube video on basic GNSS theory and was amazed to learn that problems of general relativity -- specifically, the differential curvature of space-time due to difference in proximity to the earth's mass between satellite and receiver -- would produce kilometers of position error if we did not understand, and had not been able to correct for that. Wow! Einstein actually touching our lives. Makes my hair stand up. GPS and Relativity


The technology is altogether beyond amazing. That we can measure time so finely that the difference in timing at the speed of slight between four antennae a few cm apart is simply mind-boggling.