Ground station for APRS tracking

Hi,

I'm very interrested into APRS tracking to use with my plane. But, as I live in France (near Paris), I've not found any information about the location of repeaters. So I'm considering of setting up my own reciever.

I've read here and there that I'd need a 2 meter reciever, a sound card and a computer connected to internet. That sounds fine. But which reciever should I get (sorry for my stupid questions, but i'm a totally newbie in amateur radio).

I also hope after some testing, to use numerous of these Microtrak in planes during a competition to allow people on ground to see the positions of the planes simultaneously in Google Earth (and not in Google Maps). What kind of antenna will I need to display the position of planes at a distance of about 100 km around the antenna at heights variing between 500 and 1500 ft ? (flat country)

I'm collecting as much information as possible, as the RECIEVER side of this problem is never dealt with on the websites I found.

Thanks for all your information, and first of all, thanks to Pete Howell for his post !
Michel

flyjodel said:

Hi,

I'm very interrested into APRS tracking to use with my plane. But, as I live in France (near Paris), I've not found any information about the location of repeaters. So I'm considering of setting up my own reciever.

I've read here and there that I'd need a 2 meter reciever, a sound card and a computer connected to internet. That sounds fine. But which reciever should I get (sorry for my stupid questions, but i'm a totally newbie in amateur radio).

I also hope after some testing, to use numerous of these Microtrak in planes during a competition to allow people on ground to see the positions of the planes simultaneously in Google Earth (and not in Google Maps). What kind of antenna will I need to display the position of planes at a distance of about 100 km around the antenna at heights variing between 500 and 1500 ft ? (flat country)

I'm collecting as much information as possible, as the RECIEVER side of this problem is never dealt with on the websites I found.

Thanks for all your information, and first of all, thanks to Pete Howell for his post !
Michel

Click to expand...

Michel, try this link to see digipeaters in the Paris area:

http://wa8lmf.net/APRSmaps/EuropeLarge.htm

No doubt there are many additional home stations that act as repeaters that aren't listed on this map.

Good luck with your project! Hopefully some readers with good background with various receivers will reply.

you are a great help for me as the french forums seem to quite inactive about APRS. I found in your post the information I need to have a direct contact with people dealing with APRS in this region. Thanks a lot ! I will keep advised here of my tests...

APRS for Paris

Michel,

I have been told that there is an extensive netowork of functioning digipeaters in, and surrounding Paris. Our Micro-Trak 300 is popular there, leading me to believe that even our lowest power transmitter is offering good performance. For general use, I monitor APRS on the internet, but for portable use, I use a Kenwood TH-D7 and an Avmap GPS display receiver. It beats carrying a laptop and there is virtually no boot-time.

Allen
VHS

You are welcome Michel!

Just doing my little part to better Franco-American relations......

I will look in this direction. Inbetween I found a map showing some digipeaters around Paris, it sounds good to me.

2 question to VHS :
- when you use the TH-D7, do you just use the standard antenna and is it sufficient for a good reception ? What is the farthest signal (in the air) you ever recieved with the TH-D7 ?
- I read somewhere that it is necessary to get a TH-D7(G). Is that true ? (seems to be a second generation)

thanks for your help,
Michel

flyjodel said:

I will look in this direction. Inbetween I found a map showing some digipeaters around Paris, it sounds good to me.

2 question to VHS :
- when you use the TH-D7, do you just use the standard antenna and is it sufficient for a good reception ? What is the farthest signal (in the air) you ever recieved with the TH-D7 ?
- I read somewhere that it is necessary to get a TH-D7(G). Is that true ? (seems to be a second generation)

thanks for your help,
Michel

Click to expand...

Michel,

My understanding is that the TH-7a (G) has the latest software, with significantly better features and benefits. I can't see any value to an older gen unit.

Where I live in Northern Calfornia, there is virtually nowhere that is not within the range of a digipeater, so antenna performance has not been an issue for me with my Kenwood. I have been able to directly monitor the 300 mW signals from my smallest Micro-Trak ( the 300 milliwatt version) from about 7 miles, ground-to-ground, which is pretty good. That being said, I always recommend going with the best antenna you can on your receiver.

I use my Kenwood to test transmitters to make sure I am sending good packets, and as a ground station. In truth have never used it while airborne.

Allen
VHS

ok,i see. my first intention is not to use the th-d7 in the air, as there is the microtrak for this purpose. I'm looking for info about a (cheap ?) ground reciever capable of recieving the APRS packets of the microtrack , to connect to a computer in order to display the plane's position,locally, or send it tru the web.

I 'm also looking about the disadvantages of using the high power version (microtrak8000) against the microtrack 300. i understand the 8000 has a much bigger output power. this is positive to me, as I think I will use it far from any digipeater in some cases. But is there any issue with MT8000 that would lead me to prefer the MT300 instead ? ( i read something about the admitted supply power ...)

thanks, michel

Low cost APRS receiver

There are lower costs solutions to ground monitoring, the lowest of course being just a straight internet connection. To do a budget system requires a bit more technical and computer knowledge, but its not impossible. I suggest buying a cheap VHF receiver ( Scanner, ham radio, etc. ) that can tune 144.800 MHZ ( the European APRS frequency), and connecting it to your lap top computer throiugh its sound card. You need an easily made or purchased audio cable, and some software that you can download from the web for free, or nearly so. AGWPE (google it) is a software that will take packets received through your computers sound card, and decode them. All this will give you is "plain language" text, so you need to add mapping software on top of that. WinAPRS, (which you can find a link for on the AGWPE page) is supported as are many others. These vary in capabilities, and kinds and types of maps used, and range from no cost to high cost.

If you have a GPS rdisplay receiver that can accept GPS waypoint uploads ( and I don't really know which ones do, but Byon of Byonics can probabaly help you) You can buy and assemble a TinyTrack 4. Among other things, when conne ted to your transceiver or receiver, the TT4 can upload waypoints of APRS positions to your GPS display receiver. You need to be able to assemble the PC board, and load it with software, so its not for the complete techical virgin....

A good friend of mine once told me that :"There is no human problem that cannot be solved with brute force and ignorance" (it would probably sound better in Latin....) I think that the Micro-Trak 8000 is a better choice than the Micro-Trak 300 in all respects, save price. Would you want to limit the power of your VHF Comms radio?

Power in a tracking transmitter is like power in a pistol: You don't need it until you need it badly! You can turn the power of a Micro-Trak 8000 down to almost nothing, but you can't increase the power of a Micro-Trak 300 without adding an amplifier, cable, wires, bypass capacitors, etc. The 8000 is a more elegant solution.

We produced an inexpensive litlle power regulator called the Micro-Volt. Its one inch square, and provieds a regulated 12 volt supply for the Micro-Trak with no bells and whistles.

Bon chance,

Allen

Micro Volt

I have been running the Micro Volt for 2+ weeks now and several flights. It is rock solid, small and easily mounted to the tube of the MT8000.

The MT8000, even with the internal wingtip J-pole antenna, works great. I get repeater hits on the ground even with the the RF amp set for 3-4 watts.

all that sounds great. Thanks Allen for all that very precise information. I first thought it was not possible to change the output power of the MT8000 so I considered the MT300 because I thought the powerfull one would disturb the other people on the same frequency...

I am trying to get some contacts with the local amateur radio fans to get some info on the "cheap VHF reciever". If I don't find it, I will do some work on the little scanner I have to convert the aviation band to get 144.800 MHz.

As soon as I have solved the technical aspect of a reciever (mine or the availability of some digipeaters around here), and the official aspect of getting a ham license, I will then order the MT8000 + Microvolt
Merci pour tout, Michel

APRS ground station

Michel,

You will not be able to convert an AM aircraft receiver to FM, or if you can, it would not be worth the time and effort. With luck, we may have our TT4/Micro-Trak reday for you by the time you get your license and have a turn-key receiver for you, ready to plug into your PC or GPS display receiver.

Avec plaisir,

Allen