Satellite Compass Questions

[LarryM]

Ok let's try again. Go to the AP20 and find 2 cables going into the back. One leads to the junction box. The other takes a long and winding route to the master stateroom closet. Tucked up in the corner is an RFC35R rate compass.

Ted,

Since you have a RFC35R Rate Compass, I would examine the compass location and search for and move any ferrous material stowed within 3 feet or so of the compass. I would then record your existing settings and perform a factory reset. Then go through the Dockside setup. Finally go through the Sea Trial and be sure to re-calibrate the compass and run Autotune. I would also spend some time fine-tuning the Parameters and I think you might find the AP20 can still do a very acceptable job of steering.

If not, you can be certain that you have optimized your existing system before spending a lot of money on any new equipment. There are still many satisfied users of the Simrad AP20/21/22 series autopilot in both commercial and pleasure service.

Feel free to PM if I can help you in any way. I have lived with two of these systems for quite a while.

Good luck,

Larry
M/V Boomarang

 

[MYTraveler]

Ted,

Since you have a RFC35R Rate Compass, I would examine the compass location

Uhhh, that may be the problem. Sounds like his A/P is not hooked up to anything.

 

[O C Diver]

Uhhh, that may be the problem. Sounds like his A/P is not hooked up to anything.

It's connected to the rate compass and the plotter at another input point. According to my manual, a second heading sensor (such as a satellite compass) can be connected to the junction box through the nmea input.

Ted

 

[Wxx3]

Hi Ted,

The main difference between running my Autopilot on the Fluxgate (FG) versus the Satellite Compass (SC) is how much the boat wanders along the course I have set. It's a much straighter path running the SC (almost straight) and much more like a drunken sailor driving when running off the FG.

Sea Eagle has two Simrad AP-50's with a switch installed that allows switching heading sources between the SC-60 or RFC-15R fluxgate.

Good Luck,

Exactly my experience.

I added the Maretron SSc compass to get away from that terrible fluxgate. now my ComNav Autopilot has a additional nmea 0183 port on the controller and the maretron has both a 2000 and a 0183 output, so I was able to leave the fluxgate connected and connect the maretron.

Now at the time, I thought I would never use the fluxgate again, as the performance is noticeably better, BUT the SSC is also very susceptible to interference from the microwave and rice cooker.

So the few days I make rice, I switch back to the fluxgate, because unlike those manly folk who hand steer, I don't seem to have the attention span required to steer a straight line for more than 5 seconds.

SO in sum, it depends upon your autopilot connections.

 

[r-rossow]

The innards of my Furuno SC60 satellite compass. Battery is the shiny coin shaped unit on top. The battery is fixed in place with melting glue.

To the left of the battery is the fluxgate compass (Backup in case of missing GPS coverage. Some of the fjords over here are lined with steep mountains blocking all GPS coverage. The Satellite Compass will fall back to the fluxgate under such circumstances and keep feeding AP, Plotter(s), AIS, etc with heading data)
I belive the three identical units below the fluxgate are the GPS receivers for the three SC antennas. Power Supply board to the right. Processor board in the middle. Interface board at the bottom.

 

[Donsan]

Looks like the same type of lithium battery that is found in personal computers and some automobile remotes. I know the PC units don't pop out that easily. Not sure why melting glue is needed. Seems like a lot of unused airspace in that box....definitely not designed by Apple.