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APRS Wingtip solution

Kahuna

Kahuna

Moderatoring
Ive been working on the wingtip mounted solution. Trying to make a single small simple package out of the tracker and GPS. I am also gonna try and mount a simple 1/8" jack in the aft wingtip support rib to allow for quick programming of the tracker. Ill update my progress as time goes. Started studying for my HAM radio test. Geez I feel this nasty urge to run out and buy a ham radio and geek out over the airways.

OK one thig at a time. I went to Rat Shack and believe it or not, right on the shelf they had my panel mount jack I needed to mount. cool.:D
Since the tracker uses the same pin for its gps input and the programming serial input, I needed a way to switch from programming to gps. This will work.
pRS1C-2265991w345.jpg


started a web page to log progress. Thanks goes to Sam and Pete and crew for getting me all spun up on this. This is really neat stuff. more to come.
 
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Ham Cram for Technical License

Mike,

I am a member of the North Fulton Amateur Radio Leage (NFARL) They are having a cram session on October 4th in Alpharetta for locals who would like to get their technical license (all that is required for APRS). You are in class for the day and at the end they administer the exam so you can do a brain dump and put all your new found knowledge to use. Here is the body of the notification e-mail
----------------------------------------------------------------

Back by popular demand is another Ham Cram on Saturday, October 4th. Details are at: http://nfarl.org/hamCram/hamCram.html . Initially we'd like to restrict registration to folks within about a 45 minute drive of our club location. Please encourage folks to register at our web site.
73,
Mack
WB4MAK
 
Last night I wired everything up and at first I could not talk to the Microtrak. A quick trace of wires and I forgot to connect up the serial signal ground through my switch. :mad:.

After fixing that I clicked on the version number in the program and wallah, it worked!. Program a couple items, upload, save and so forth.

Unplug jack and little leds blink away. Neat.

Ill have wire diagrams up in the next week or so along with a parts list.
IMG00038_small.jpg


Here is the rat shack jack plug diagram.
stereojack.jpg
 
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The little micro trak device came in a plastic storage container with caps on the end. Any reason this could not be used to mount with? I coule drill tiny holes in the top and bottom for air flow. I cant imagine this thing generates too much heat.
tracker-1[1].jpg
 
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Should be no problem ...

Kahuna said:
The little micro trak device came in a plastic storage container with caps on the end. Any reason this could not be used to mount with. I coule drill tiny holes in the top and bottom for air flow. I cant imagine this thing generates too much heat.
tracker-1[1].jpg
Click to expand...

Since several people seemed to have taken this approach, I would guess there is no problem. Not too much heat as the unit is on for about 300msecs and then off for 30,000 - 60,000 ... plenty of time to dissipate the heat with such a duty cycle.

If you choose to not go that route, there is a plastic "project box" from Radio Shack that is just the right size for the unit + the AA batteries one would need for a portable version. That is what I did at first (cut a hole for the DB9 and a slot for the SMA connectors. When installed in the wingtip, I just used the box minus the batteries + the 5 volt regulator.

Photos taken but not handy.

Good luck!

James
 
Tube Should be Fine

Hi Mike,

I have a 100 hours on mine operating in the sleeve with no issues, this includes a nearly 5 hour XC with the unit on full time.

Although in the Super8 that would have been a 3 hr XC:D
 
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While reading my ham manual, it mentions NOT running the elements of an antennae near any metal. This is in contradiction to the way I have installed mine right under my wingtip VOR antennae. Is this a violation?
IMG_0003_small.JPG

High res pic here

Updated with a few more install pictures. SHe is ready for flight. Just need to get my HAM license so I can power her up.
 
Kahuna said:
While reading my ham manual, it mentions NOT running the elements of an antennae near any metal. This is in contradiction to the way I have installed mine right under my wingtip VOR antennae. Is this a violation?
IMG_0003_small.JPG

High res pic here

Updated with a few more install pictures. SHe is ready for flight. Just need to get my HAM license so I can power her up.
Click to expand...

Mike, I would move the Ry-pole to the bottom surface of the wingtip. I suspect you have detuned the Archer antenna (and possible the Ry-pole as well) since the directions for it are pretty emphatic about not routing wiring near the elements.

No need to ventilate the tracker case--the plastic sleeve works fine as is.
 
Sam Buchanan said:
Mike, I would move the Ry-pole to the bottom surface of the wingtip. I suspect you have detuned the Archer antenna (and possible the Ry-pole as well) since the directions for it are pretty emphatic about not routing wiring near the elements.
Click to expand...

Is the archer on the top or bottom of the wingtip? Either way, put the J-pole on the opposite surface as far away from the wing skin as possible(maybe glass in some fiberglass clips) There will probably still be some de-tuning, but the only way to tell would be to connect up a SWR meter. As far as how the radiation pattern is distorted, the only way to tell is flight testing. Most of your power should be off the end of the wing tip, and the polarization will be predominately horizontal.

The other thing to consider is coupling from the APRS antenna into your VOR antenna. I'm not sure how much you'll get with the antennas separated, but with the way they are now, it will probably be more than you want. The chances of interference or damage to the VOR equipment go up with proximity and power. My gut feel is with a foot of separation and 300mW you shouldn't need to worry about damage.

Paige
 
The archer is on the bottom.
Todays test flight was a success. I definately dont understand the how the smart beaconing works yet. I had points that were 10 minutes apart. Gonna have to read more. I used the wide2-1 setting today. Gonna park it now till I get this exam completed and Im legal. For now I have satisfactory evidence of it functioning and will not be able to toy with settings until I can run under the rules.


staticmap[2].gif
 
Kahuna said:
The archer is on the bottom.
Todays test flight was a success. I definately dont understand the how the smart beaconing works yet. I had points that were 10 minutes apart. Gonna have to read more. I used the wide2-1 setting today. Gonna park it now till I get this exam completed and Im legal. For now I have satisfactory evidence of it functioning and will not be able to toy with settings until I can run under the rules.
Click to expand...

When I suggested moving the APRS antenna to the bottom of the wingtip I just assumed (and thought I could tell from the photo) that your VOR antenna was on the top surface.

Anyway, I would have the two antennae on opposite surfaces of the wingtip.

Mike, set your config per the settings detailed in the sticky "How to Configure Your Tracker" and Smartbeaconing will work very nicely. You'll get everything running properly once you can fly the tracker with the FCC's blessing. ;)
 
Long trip today at 10k' and the wingtip wide 2 has big gaps.
Ill try wide 1 on my return Monday.
The raw packets have a lot of red in em. Why?
 
What power are you running?

Mike,

Any idea how many watts the 8000 is putting out? I was running 1.5 watts and got much better coverage when I went to about 3.5 watts.

The pot has a Very small adjustment range.
 
Kahuna said:
Long trip today at 10k' and the wingtip wide 2 has big gaps.
Ill try wide 1 on my return Monday.
The raw packets have a lot of red in em. Why?
Click to expand...

Mike, the "red data" has been discussed at length but here is a link authored by the owner of aprs.fi that will help you get up to speed:

http://oh7lzb.blogspot.com/2008/03/on-duplicate-and-delayed-packets.html

If you have gaps in your track it probably isn't due to not using WIDE1-1, espescially if you were at 10K'. Most airborne trackers don't seem to need to tickle the fill-in digis (that is all WIDE1-1 does). I haven't seen your track and don't know where you were flying but I suspect any serious tracking problems were due to either network issues or something that needs to be attended to in your installation.
 
Pete I have the Micro 300, 300mW unit.
Sam thanks for the link and Ill research.
A Sw would not hurt. I have several HAM guy slocally willing to help tune.
Ill report back.
Best,
 
Interesting that in reviewing the raw packet data, all of the receivers were slightly right of course(mile or 2), or left to very left (up to 50 miles). Antennae is mounted in the left wingtip. Will be interesting to see on my flight back if that continues. Wonder how much the plane is blanking out transmissions.
Next flight will tell. Im running direct back over a 2.5 hour flight.
Best
 
Kahuna said:
Interesting that in reviewing the raw packet data, all of the receivers were slightly right of course(mile or 2), or left to very left (up to 50 miles). Antennae is mounted in the left wingtip. Will be interesting to see on my flight back if that continues. Wonder how much the plane is blanking out transmissions.
Next flight will tell. Im running direct back over a 2.5 hour flight.
Best
Click to expand...

Mike, I took a look at your data. Overall the tracker is working fairly well.

It looks like the "red data" is limited primarily to just a handful of digis. At least of couple of them seem to be decompressing the MIC-E data your tracker is sending. This is not good digi practice but some operators haven't yet gotten totally up to speed on this issue. As I understand the situation, this causes a problem since the decompression process will often round off the MIC-E lat-long data which makes the plane appear to have moved faster than it really did. Hence aprs.fi will say you "broke the speed limit". The decompression can also delay transmission of the data to the aprs server which means it arrives so close to a valid beacon the server spits out the [Rate limited (< 5 sec)] flag. You can tell which digis are decompressing by looking for the lat-long data in the beacon instead of the MIC-E characters.

This is a problem with digis/igates not being configured properly, not with your tracker. That is why the red data didn't really kick in until you got close to your destination and you started working the problem digis. Remember...we are dealing with amateur radio. :)

Hope this helps with understanding some of what is going on.

Your concerns about the airframe blanking the antenna don't apply to a 1/4 wave whip hanging on the belly of the plane....... ;)
 
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Return trip update.
Got lots of red below.
Track looks ok, but certainly not getting every 60 seconds a dot on a path.
Some areas gaps are 15 min long, they are in the same places coming and going in South Ga..
I have ruled out the plane blanking out anything being in a wingtip. I have several hits 70 miles away, at 90 degrees, on the side away from the wingtip antennae. SO thats a good sign. While Im sure that a belly is better, wingtip suffices so far.
Now need to spend time on the wide2 paramater and try and determine why all the red packets. Over a 30 minute period, which would be over 100nm, there are a ton. Over other 30 min periods, there are none. hmmm....
aprs090108.jpg
 
Kahuna said:
Return trip update.
Got lots of red below.
Track looks ok, but certainly not getting every 60 seconds a dot on a path.
Some areas gaps are 15 min long, they are in the same places coming and going in South Ga..
I have ruled out the plane blanking out anything being in a wingtip. I have several hits 70 miles away, at 90 degrees, on the side away from the wingtip antennae. SO thats a good sign. While Im sure that a belly is better, wingtip suffices so far.
Now need to spend time on the wide2 paramater and try and determine why all the red packets. Over a 30 minute period, which would be over 100nm, there are a ton. Over other 30 min periods, there are none. hmmm....
Click to expand...

Mike,

'Fraid I have exhausted my list of possible solutions for you. You might be interested in this map of known digis:

digis-GA.jpg


Please note the good population of digis in south Georgia, many more than in SW Alabama. I mention that because a local pilot with a 300mw tracker had great tracking between Muscle Shoals and Mobile at 3500' over the "dead zone" of lower Alabama.

I have had flights where there was a lot of "red data", then a nearly identical flight at a later time would be clean. Same, tracker, same plane, same antenna, same location......very different data. I can only attribute this to digi, network and/or server issues. As long as the tracker is configured properly (and configurations that work are now commonly known) and an acceptable antenna is used, I think we have done all we can do to create a solid APRS rig.

I look forward to seeing any info you uncover; however, your knowledge base will be enhanced as you accumulate more flights. If every flight you make has bad data, then you would be justified in having concerns about your tracker installation. But if the problems are occasional, then it will be more likely you are seeing network glitches.

APRS is not a perfect technology, just a very intriguing application of amateur radio that offers aviation a great addition to the safety tools already available to us...and its fun to mess with. :)
 
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Thanks Sam,
I have more learning and research to do. Theres lots of good stuff off the aprs.fi site that helps alot as you have already mentioned. I want my track to look like this.

Now thats a good track of an airplane!:cool:
 
Kahuna said:
Thanks Sam,
I have more learning and research to do. Theres lots of good stuff off the aprs.fi site that helps alot as you have already mentioned. I want my track to look like this.

Now thats a good track of an airplane!:cool:
Click to expand...

Well, you bring up a good point. The data errors you are seeing are related to the parsing software used on the aprs.fi server. That software has been configured to filter out some of the more common network errors, but it isn't perfect, especially for aviation. You might want to explore using a different APRS mapping provider if you can get better service from them.

I like aprs.fi because the maps and user interface are the best I've seen and overall the reliability is good. More often than not I (and many other pilots) get great tracks through aprs.fi.

But there are other options, and some might work better for you.
 
I thought all the didi peaters sent the data to aprs.fi servers for parsing and saving then others read from their servers.
Looking at findu.com for example, the dots from my last trip are in the exact same place as aprs.fi.

Do these digipeaters send to other locations others than aprs.fi?
What are they?
 
Kahuna said:
I thought all the didi peaters sent the data to aprs.fi servers for parsing and saving then others read from their servers.
Looking at findu.com for example, the dots from my last trip are in the exact same place as aprs.fi.

Do these digipeaters send to other locations others than aprs.fi?
What are they?
Click to expand...

Mike, you are rapidly outrunning my knowledge of the APRS network. :) Hopefully someone with a deeper background than mine will chime in and give you (us) definitive answers.

As I understand it, aprs.is is the clearinghouse of the APRS net:

http://www.aprs-is.net

I think the various APRS mapping sites pull data from aprs.si and then display the info according to their own protocols. It is my understanding that aprs.fi has its own proprietary parsing software and is only one of several different services outputting aprs location info. It is interesting that you see the same track data on findu.com as on aprs.fi....

But....I may be off-base here and certainly don't want to lead you in the wrong direction. More research is needed.... ;)
 
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Upon further research Sam,

Yes Digi's send their data to the APRS-IS network who does some filtering of the data but not much. The standard for the interface is very simple and straight fwd. One data stream contains all the fields necessary. They rely on the TCP network protocol to handle failures in the network transmissions and to handle the confusion a bit.

Then others providers, like findu and aprs.fi access the data from APRS-IS (actually its a feed). Now some sites, like APRS.Fi for example, allow others to acces their site. ANd there you have a cascade effect. but it all originates from one place.

So in a sense, there is one source of the truth so to speak. The way in which the information is presented canges from site to site, but the raw data comes from one place. You should not be able to go to 2 different places and see diferent raw facts, like where the position reports were from. That data comes from one source.
 
Kahuna said:
You should not be able to go to 2 different places and see diferent raw facts, like where the position reports were from. That data comes from one source.
Click to expand...


A friend of mine was getting his tracker up and running and as a test he carried it along on a flight in the Citation he flies. The track on aprs.fi had a huge hole in the enroute portion of the flight as you would expect due to the 500 km/hr speed limit the parsing filters impose at aprs.fi.

However, on findu.com, all the packets were displayed since that site must not have the "speed limit". It was via findu that I was able to determine his tracker was functioning properly.

To make it more interesting, my iGate/digipeater software (UIView) requires me to specify a particular aprs provider. I don't know if it limits outgoing packets to just the provider I specify (aprs.fi) or if that is to indicate which portal it uses to download packets from the APRS net.

The education continues............and we thought the question of whether or not to prime was complicated...... :)
 
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Performance update

I was able to do some formation flying with another ARPS RV. He also had a wingtip install with the j-pole wingtip antennae, only he has the 8w version. Same software configuration. He had 3 times as many hits, and better performance down low. This is expected, but comfirmed through actual airborn tests with high degrees of maneuvering. I think Im going to change out to the new 8000FA. The only thing I really care about with this APRS is someone finding my smoking hole. Low alt performance is key for me. Looks like ill dump another $200 bucks into the thing and try for better performance. Ill report back on the new unit. Ordered it today.
Best
 
Reporting back.
Operator error cused me to cook my gps. Applied 12v to the 5v source on my new FA 8000 and GPS. . ARGH!:mad:

I ordered the micro amp to beef up my micro 300. Turn the 300mw transmitter into an 8w. Hookup was easy and I had instant success. The only issue Im having right now is that Im getting bleed over from the transmitter into frequencies on my com. Im scratching my head as to what Im hearing.
Its 3/4 second bursts of noise, 1/4 sec break, and repeat. Constant. I know Im not transmitting every second cause the raw data would show that. I can not explain why Im getting this on one particular frequency. Of course its the frequency I use all the time.
If I turn the APRS off it goes away.
The APRS is in the wingtip with the vor antenna.
I have not tried disconnecting vor antenna coax at the antenna but thats what I am goin to do next.
Question is, why and I hearing a transmission over com every second when I know Im not transmitting packet data every second?
Oh and I did get this once before, and that was BEFORE I installed the Micro Amp.

Who knows what Im hearing and why?
 
Kahuna said:
Reporting back.
Operator error cused me to cook my gps. Applied 12v to the 5v source on my new FA 8000 and GPS. . ARGH!:mad:

I ordered the micro amp to beef up my micro 300. Turn the 300mw transmitter into an 8w. Hookup was easy and I had instant success. The only issue Im having right now is that Im getting bleed over from the transmitter into frequencies on my com. Im scratching my head as to what Im hearing.
Its 3/4 second bursts of noise, 1/4 sec break, and repeat. Constant. I know Im not transmitting every second cause the raw data would show that. I can not explain why Im getting this on one particular frequency. Of course its the frequency I use all the time.
If I turn the APRS off it goes away.
The APRS is in the wingtip with the vor antenna.
I have not tried disconnecting vor antenna coax at the antenna but thats what I am goin to do next.
Question is, why and I hearing a transmission over com every second when I know Im not transmitting packet data every second?
Oh and I did get this once before, and that was BEFORE I installed the Micro Amp.

Who knows what Im hearing and why?
Click to expand...

Mike, I suspect you are hearing something related to the GPS receiver updating every second.
 
You know I thought of that.
It is right near the VOR antenna. Couple inches maybe.
I can experiment with another location thats further away. Also I did not ground the shielded wire from the gps. I cut the 9pin DB off cause I did not need all that wire. Perhaps a grounding pigtail from the gps wire shield to ships ground would do the trick.::confused:
 
Kahuna said:
You know I thought of that.
It is right near the VOR antenna. Couple inches maybe.
I can experiment with another location thats further away. Also I did not ground the shielded wire from the gps. I cut the 9pin DB off cause I did not need all that wire. Perhaps a grounding pigtail from the gps wire shield to ships ground would do the trick.::confused:
Click to expand...

There ya go. Ground the GPS shield to the tracker ground terminal.
 
GPS Noise

I have seen instances where the GPS clock caused intermodulation noise. The problem was easily resolved by placing a 4700 PF capacitor across the GPS power and ground connection on the Micro-Trak PC board. (where the holes are above the DB9 connector)

Allen
VHS
 
Coupling ...

Kahuna said:
Reporting back.
Operator error cused me to cook my gps. Applied 12v to the 5v source on my new FA 8000 and GPS. . ARGH!:mad:

I ordered the micro amp to beef up my micro 300. Turn the 300mw transmitter into an 8w. Hookup was easy and I had instant success. The only issue Im having right now is that Im getting bleed over from the transmitter into frequencies on my com. Im scratching my head as to what Im hearing.
Its 3/4 second bursts of noise, 1/4 sec break, and repeat. Constant. I know Im not transmitting every second cause the raw data would show that. I can not explain why Im getting this on one particular frequency. Of course its the frequency I use all the time.
If I turn the APRS off it goes away.
The APRS is in the wingtip with the vor antenna.
I have not tried disconnecting vor antenna coax at the antenna but thats what I am goin to do next.
Question is, why and I hearing a transmission over com every second when I know Im not transmitting packet data every second?
Oh and I did get this once before, and that was BEFORE I installed the Micro Amp.

Who knows what Im hearing and why?
Click to expand...

Mike, how close to the antenna or antenna wiring is your APRS?

Is it grounded? Is there good shielding on the antenna? I chose the non-antenna wingtip for my fear of such coupling. Also, you are likely to get a slight buzz when your APRS transmits (about 1/2 sec worth) as even though there are filters, 8 watts that close by, with the antenna (APRS) where it is, is a lot for the radio to ignore.

I am sure you will get there! :)

James
 
No noise during transmission.
j-pole antennae inches from vor antennae and other lighting circuits
 
VHS said:
I have seen instances where the GPS clock caused intermodulation noise. The problem was easily resolved by placing a 4700 PF capacitor across the GPS power and ground connection on the Micro-Trak PC board. (where the holes are above the DB9 connector)

Allen
VHS
Click to expand...

Allen this solved the problem. Grounding the shield from the GPS did nothing. The cap took care of it. unsquelching the com on my offending frequency I could just barely hear the noise with the volume turned up.
Thanks
 
GPS Noise

I am glad it was a .05 cent solution! Would you mind telling we what your Comm frequency is?

Allen
VHS
 
VHF

Mike,

I wanted to know the specific frequency so I can test for noise coming from the GPS. I received the info off list.

Allen
VHS
 
There aint "one"

Allen, we can use most, if not all the frequencies on the list.

The airport where I live is on 123.05, and the next airport east is 122.80. Both non tower airports. A major airport may have six or more active frequencies going-----left/right runways, ground, ATIS, etc.

When we fly around, many of us will use flight following from the ATC system, and they might give us a freq of 124.xx or whatever. A lot of folks just out flying for pleasure use 123.45 to jabber on, because it is easy to remember----not an approved use of the freq IIRC, but very common.

The VOR system is a receive only function in our planes, but there is a constant signal from the ground based transmitters, 112.000 through 117.950.

There is no single answer to your question, two major variables involved here, location, and activity.

That is why I posted the chart with the available freqs-----

And, there is the transponder:confused:

Hope this helps the understanding a bit.

Thanks for your participation here.
 
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Mike S said:
Allen, we can use most, if not all the frequencies on the list.
Click to expand...

Mike,

Kahuna was getting interference from the GPS clock on one particular com frequency.

The cap took care of it. unsquelching the com on my offending frequency I could just barely hear the noise with the volume turned up.
Click to expand...

Allen was just asking which frequency was affected so he could run some tests on his bench by setting up a similar scenario. Glad this was resolved, this is another excellent data point.
 
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Sam is correct. Its was LOUD on one frequency. May have been others but Ive only had my aprs running for a few weeks and have not been on too many freq's.

The cap instantly cured the problem on that freq.
So I believe Im now squawk free running the Micro 300 w/ the micro amp and the J-pole in the wingtip. A wonderful package. Simple, effective. Fire and forget tracking all the time. I love it. Time will tell how durable the system is. I have ~10 hours now.

Later on this month I have several x-country trips back and forth to NM, Vegas, Wisconsin, and a few other places. Im excited to see how she does outside the heavily i-gated Atlanta region.

Best,
 
Kahuna said:
Later on this month I have several x-country trips back and forth to NM, Vegas, Wisconsin, and a few other places. Im excited to see how she does outside the heavily i-gated Atlanta region.
Click to expand...

Be sure and let us know when you launch on the trips so we can fly along with you. :) I think you can expect excellent coverage for those routes.
 
Had some issues with my GPS power from the board on the first couple of legs. Some looser really made a bad solder joint(me). Got it back going around San Antonio. An old mechanic friend, owner of the only flying super 7 im aware of.

Today was a nice flight 1k'agl and less for around 200nm in the desert. Pretty good coverage. Will be bee boping around Texas and NM for a week. Tracks look pretty good. This is the frequency agile 8000 version with the 12v regulator adjusted to a 6w output with the J-pol3 wingtip antenna.
Best.
 
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