AV 30 E GPS track vs Avmag ?

[Python]

Hi , I have a VFR RV 6 with a AV 30 E & am reasonably happy with the instrument however I was considering either coupling a Garmin 660 or getting an Avmag( external magnometer) to use for DI. I’m aware that the GPS will only give GPS track & that the Avmag will only give heading. Just wanting an opinion on either off someone who has used either system. The Avmag is considerably cheaper but of course the GPS gives me more features. I currently use a device & flight planner for guidance but find that the standard DI on the AV 30 needs regular adjustments to align to the compass. Thamks .

 

[Stevea]

AV-30-E GPS track vs AV-Mag

I have both the AV-Mag external magnetometer and a panel mounted GPS data stream connected to my AV-30-E. For me, the GPS data is useful, but not absolutely necessary since I have the same data (and more) displayed on my panel mounted GPS, and on my iPad (running Foreflight).

My AV-30 is typically set to display magnetic heading. I find this more useful, because the magnetic heading comes up and is accurate as soon as the AV-30 finishes booting up. Makes it very easy to know which way the airplane is pointing (like at an unfamiliar airport), even before starting to taxi. Also, there is no lag to the magnetic heading displayed as the airplane turns.

The GPS track info does not display until the airplane is moving fast enough for the GPS to calculate track information.....seems to be somewhere between 15-20 kts. The GPS track info also has a lag to it as the airplane turns. When taxiing onto the runway and turning to runway heading the GPS data is typically not displayed....kind of makes it tough to verify the runway number matches the GPS track/aircraft heading.

My suggestion is to get the AV-Mag first. If you eventually end up adding a GPS to the panel, you can always wire in the GPS output data stream to the AV-30 GPS input connection, and run with both.

 

[Python]

Thanks for the reply, do you need to reset the heading at all with the Avmag or does it just stay on heading ?

 

[Stevea]

The AV-30/AV-Mag needs to be calibrated after installation, starting at North, and then every 30 degrees around the compass circle. The process is similar to swinging a standard magnetic compass...and actually a bit easier since the AV-30/AV-Mag is doing all the magnetic measurement and storing the result in its memory. Setup should be a one time event.

Since mine was calibrated (about 9 months ago) I have not had to adjust the compass heading at all. The nice thing about a magnetometer driven compass is that it does not precess like a mechanical directional gyro does, so there are no in flight heading adjustments required.

After powering on the AV-30/AV-Mag, wait for the red ALIGN flag to disappear. After the ALIGN flag disappears, the magnetic heading will be set to the direction the airplane is pointed. There should not be any heading adjustment necessary.

 

[blaplante]

Looking at the install manual, it looks like a NMEA GPS source, either 4800 or 9600 speed, RS-232 interface is what the AV-30 is looking for. NMEA is a standard, and if everyone is following the standard, things should link up.

There are a good number of dumb puck receivers that appear to output that protocol. Several normally used for boats. I sure wonder / suspect that one of those might work. The boat ones are under $100 used on eBay. The dumb made in china pucks are less than that.

Oh, and if you ask uAvionix if it'll work you'll get a firm denial. Basically if they haven't tested it they'll say it won't work so you aren't bugging them about your problems. I have a bit of first hand experience with this. As in something that "doesn't work" but when we hooked it up... did.

 

[Python]

The AV-30/AV-Mag needs to be calibrated after installation, starting at North, and then every 30 degrees around the compass circle. The process is similar to swinging a standard magnetic compass...and actually a bit easier since the AV-30/AV-Mag is doing all the magnetic measurement and storing the result in its memory. Setup should be a one time event.

Since mine was calibrated (about 9 months ago) I have not had to adjust the compass heading at all. The nice thing about a magnetometer driven compass is that it does not precess like a mechanical directional gyro does, so there are no in flight heading adjustments required.

After powering on the AV-30/AV-Mag, wait for the red ALIGN flag to disappear. After the ALIGN flag disappears, the magnetic heading will be set to the direction the airplane is pointed. There should not be any heading adjustment necessary.

Hi Steve, Where did you mount yours ? I see it suggests tail or wingtip. My RV 6 has flashervunits in the wingtips so I assume the tail would be better for mine ? Any suggestions ?

 

[jliltd]

I would go for both if able. Or if not just start with the AV-Mag. I have coupled the AV-30 with aera 660s, 796s and 760s. When on a direct to or flight plan the AV-30 will show the way to the desired way point. The HSI has on option to show EFIS arc. I don't know if a dumb puck GPS can provide way point navigation since it only feeds current position to the AV-30. I don't know. But I can only imagine you will have some sort of aircraft GPS onboard anyway. As for the AV-Mag I just got two certified units for a Tri-pacer and a Mooney I prewired for the magnetometer. I am eager to try those out as reports from the field are that they work great.

 

[Cth6]

GPS over AV Mag

I would prioritize the GPS over AVMag. Rarely I fly a magnetic course. Normally flying against a GPS course. My AV-30 is set to show GPS heading not magnetic. The rare times I get an ATC request to fly a magnetic heading, I get close with GPS heading, glance at the compass and adjust. Then bug the GPS heading.

 

[Stevea]

AV-Mag location

Hi Steve, Where did you mount yours ? I see it suggests tail or wingtip. My RV 6 has flashervunits in the wingtips so I assume the tail would be better for mine ? Any suggestions ?

I mounted it one bulkhead aft to the aft baggage wall. Used a 3/4”x3/4”x.062” thk angle. There is a small platform for the magnetometer to mount to.

 

[Doug Eves]

I have to agree with Cth6. Been flying vfr many years now on two AV30’s with the DG reading gps track. Been to both coasts of Canada and Florida serval times and many places in between on flight following most of the time. I was asked by ATC once to turn right to a heading “xxx” for about 10 minutes before they said “resume your own navigation”. I honestly have not looked at my compass for years and manage not to get lost or go where I should not be. IFR different story. I’m not to worried about the AV-mag or setting one up.