Help getting started with MT-AIO

I am just getting started with APRS. Passed the test and purchased the MT-AIO to use in a certified airplane while I build an RV9A.

I have not touched the settings that came from byonics. Flew around for 25 minutes today and only got 9 hits. The track is missing most of the data points that I expected. Where do I go from here?

http://aprs.fi/?call=N847X

The raw packets are:

2008-11-10 20:52:36 UTC: N847X>SYSSTQ,KB7NV*,SLIDE*,WIDE2*,qAR,KG7HH:`.Hvu#@[/"HW}KE7WPB
2008-11-10 20:56:35 UTC: N847X>SYSVTQ,LEWIS,WIDE1,CNABAR,WIDE2*,qAR,W7MJR:`.Ktu-L[/"ND}KE7WPB
2008-11-10 20:58:33 UTC: N847X>SYSYWT,SNOW*,WIDE2-1,qAR,KG7HH:`.K['\5[/"MY}KE7WPB
2008-11-10 21:00:34 UTC: N847X>SYTSTV,KB7NV*,SLIDE*,WIDE2*,qAR,KG7HH:`.J<0x1e>&sE[/"Oa}KE7WPB
2008-11-10 21:01:10 UTC: N847X>SYTSTV,KB7NV,SLIDE,WIDE2*,qAR,KB7PUX:`.J<0x1e>&sE[/"Oa}KE7WPB
2008-11-10 21:06:32 UTC: N847X>SYSWXY,SLIDE,WIDE1,MTOSO,WIDE2*,qAR,K6JMH-1:`.FQ&q_[/"Ng}KE7WPB
2008-11-10 21:07:08 UTC: N847X>SYSWXY,SLIDE,WIDE1*,WIDE2-1,qAR,KB7PUX:`.FQ&q_[/"Ng}KE7WPB
2008-11-10 21:12:32 UTC: N847X>SYSPXR,COREY*,WIDE1*,SLIDE*,WIDE2*,qAR,KG7HH:`.Irt^8[/"DE}KE7WPB
2008-11-10 21:13:07 UTC: N847X>SYSPXR,COREY,WIDE1,SLIDE,WIDE2*,qAR,KB7PUX:`.Irt^8[/"DE}KE7WPB

Hi John,
Welcome to APRS tracking. It looks like the Smart Beaconing is not enabled.
Can you take a look at your configuration and see if it matched the settings here?

In a turn, you should see a track like this one if your in good coverage.
Report back and we will continue to diagnose.

Best,

OK Ill poked around a little more.
I was not familiar with this unit.
You got this pre configured.
Probably means you have not configured a computer or serial cable.

Also since you are running off batteries, you may not want Smart Beaconing turned on. Or maybe other timing settings set different. I can envision increasing the fast rate seconds to the 300 range to save juice, and lowering the turn angle time (would mean a higher number here).

You will have to draw a balance between saving transmition power and getting good corner beacons. It will be a trade off.

If you are not very computer literate and/or dont want to mess with the serial cabling stuff, Im sure a buddy or any one of us users would be glad to configure it for you to the settings you desire.

Hollor if we can help.

Oh and one more thing,
Looking at your area of coverage, the I-Gates in the area are at least 20miles away from your flying position. Given the terrain and distance, you can expect intermittent coverage at lower altitudes.

I on the other hand have the opposite problem. We have lots of i-gates, flat areas, and frequency overloads in Atlanta here. Means lots of transmissions from APRS devices get stepped on and the i-gates cant gate them all.

Best,

Kahuna said:

OK Ill poked around a little more.
I was not familiar with this unit.
You got this pre configured.
Probably means you have not configured a computer or serial cable.

Also since you are running off batteries, you may not want Smart Beaconing turned on. Or maybe other timing settings set different. I can envision increasing the fast rate seconds to the 300 range to save juice, and lowering the turn angle time (would mean a higher number here).

You will have to draw a balance between saving transmition power and getting good corner beacons. It will be a trade off.

If you are not very computer literate and/or dont want to mess with the serial cabling stuff, Im sure a buddy or any one of us users would be glad to configure it for you to the settings you desire.

Hollor if we can help.

Click to expand...

I do have the configuration program and cable and will try smart beaconing (it was off) next time up. At this point, battery usage is secondary to getting a good track. I have read the manuals a couple of times and the MT-AIO unit is set to optimize battery usage and may not be optimal for airplane use. I'll post results when they are available.

Kahuna said:

Oh and one more thing,
Looking at your area of coverage, the I-Gates in the area are at least 20miles away from your flying position. Given the terrain and distance, you can expect intermittent coverage at lower altitudes.

Best,

Click to expand...

New data! I enabled Smart Beaconing and set the parameters per your suggestions. I mounted the MT-AIO on the glare shield so that the GPS chip was horizontal. That means that the antenna was also horizontal.

http://aprs.fi/?call=N847X&dt=1226448000&mt=m&z=11&timerange=3600

Better, but still some issues. Flight was from KFLX to KSPZ, a couple of minutes on the ground, and return with some maneuvering. Field elevation varied from 3960 to 4290 and I got zero hits below 500 agl. I did get some good points during a 360 turn about 10-12 sec apart.

I copied the raw packets and this time there are 49 (some were thrown out). I believe you can look at them from the link, but I will post if necessary.

Suggestions?

Thats looking like a pretty good track to me.
I rarely get beacon drops below 500'.

Is there something that you feel its not doing now?

Parameters

Kahuna said:

Thats looking like a pretty good track to me.
I rarely get beacon drops below 500'.

Is there something that you feel its not doing now?

Click to expand...

I'm confused. I see a lot of tracks for land vehicles that are clearly not 500 agl. Why wouldn't I see taxi points? Is it sparse coverage in my area or antenna orientation? It seems to me that the MT-AIO package forces horizontal orientation (GPS - good, TX - bad) or vertical (GPS - bad, TX - good).

Looking at the raw data, I see 15 error packets out of 49. My goal at this point is to reduce the errors and experiment with parameters to achieve straight line points 3-5 miles apart and turning points 10-20 seconds apart.

This HAM stuff is more fun than I thought.

JohnInReno said:

I'm confused. I see a lot of tracks for land vehicles that are clearly not 500 agl. Why wouldn't I see taxi points? Is it sparse coverage in my area or antenna orientation? It seems to me that the MT-AIO package forces horizontal orientation (GPS - good, TX - bad) or vertical (GPS - bad, TX - good).

Looking at the raw data, I see 15 error packets out of 49. My goal at this point is to reduce the errors and experiment with parameters to achieve straight line points 3-5 miles apart and turning points 10-20 seconds apart.

This HAM stuff is more fun than I thought.

Click to expand...

surface coverage issues is antenna. The only 2 car aprs guys I know have a vert mount magnetic antenna on their cars. Verticle antenna is ideal. We get away with it in the air due to line of sight.

I get packet errors all the time. THats not you.

straight line points, 3-5 miles, is timing and speed. THe configuration is all about timing. If set to 60 seconds, then if every packet was heard and gated (which they arent), then you could expect an RV cruise beacon drop every ~2.5 miles.

If you REALLY wanted the best coverage, then you need a vert belly antenna with your current unit. Since your tossing between horz & vert usage with that all in one box, Id do nothing. Your track is really pretty good.

JohnInReno said:

I'm confused. I see a lot of tracks for land vehicles that are clearly not 500 agl. Why wouldn't I see taxi points? Is it sparse coverage in my area or antenna orientation? It seems to me that the MT-AIO package forces horizontal orientation (GPS - good, TX - bad) or vertical (GPS - bad, TX - good).

Looking at the raw data, I see 15 error packets out of 49. My goal at this point is to reduce the errors and experiment with parameters to achieve straight line points 3-5 miles apart and turning points 10-20 seconds apart.

This HAM stuff is more fun than I thought.

Click to expand...

If you look today, you will see lots of errors in my raw packets, but the track is pretty good. Im now testing cold weather operations with trips to NH and N. Wisconsin this week. Brrrr... was 2deg F flying yesterday with aweful headwinds. off to NH78 this morning.