[GPS Tracking] Garmin Astro DC30 (Dog Tracking System)

Greetings TRF,
I would like to show how I modified the DC30 dog collar for rocket tracking. Now a lot of rocketeers have done this but not many of them take it completely apart so it will be a rocket dedicated system. I modified this GPS system to fit inside any 54mm airframe. It just took a little bit of thinking and viola! The problem is that the DC30's GPS unit is separate from the rest of the board so that presents a slight challenge when trying to put it inside a minimum diameter rocket since there are multiple parts to account for.

Anyways I will be posting pictures soon of how I did it and the work in progress. It is almost done.

Tools/Etc I Used:
- Dremel
- Dry Erase Marker
- Pencil Tip Soldering Iron
- Solder
- Clear Acrylic Sheet (for sled)
- Drill
- Various screws, nuts, & nylon spacers (most where 2-56)
- Small Phillips & Flat Heads Screw Drivers

STEP 1:
Now to initially take apart the tracking system from the dog collar you can watch this simple How-to video. (I did not make this video)
[video=youtube;5lqWtmLvYWE]https://www.youtube.com/watch?v=5lqWtmLvYWE[/video]

STEP2:
You will then need to remove the cover and then separate the circuit board from the plastic housing case. You will need to use the "Pencil Tip Soldering Iron" for this. You must heat up the solder connecting the board to where the antenna screws in. The result of this will allow you to pull the board out and away from the housing unit. YOU MUST BE VERY CAREFUL NOT TO DAMAGE THE BOARD WITH THE SOLDER GUN AND EVEN FROM THE HEAT!

STEP 3:
Next I then removed the antenna screw that is in the black plastic housing unit. I used the Dremel to cut it out and sand it down. This will be used to later reconnect and mount the antenna to the board.

STEP 4:
Go ahead and grab your pencil tip soldering iron and your solder and you will need to re solder where your antenna screws into back onto the board. Be very careful also in this step!

STEP 5:
Next I wanted to make a sled that would replace the destroyed black plastic housing and act as a new permanent home for the Astro DC30. I chose to go with clear plastic acrylic sheet from Home Depot. Its about $5 for a decent sized sheet. I chose clear because I wanted to see all the electronic boards and components.
I used the Dremel and the cut wheel, to cut it to spec. Take the dry erase marker and draw lines with a ruler to get nice straight measures. Next take tape and roll it into a circle so you have double sided tape and stick it to the ruler and put this along the drawn line to act as a guide for cutting. Then just go ahead and cut to spec.

STEP 6:
I used 2-56 (I think by 3/8ths) to mount the board to the sled. It will have to be a little higher than normal due to the antenna mount underneath the board. I also used nylon rubber type washer to cushion the board from the screws. So you will need to go to your local electronics store and grab all your necessary equipment. If you are in Houston, Texas I recommend going to Ace Electronics! I got all above mentioned stuff for $1.75.

STEP 7:
Now all you have to do is mount up everything to your liking and secure it into place. To make the holes on this clear plastic i decided to use the pencil tip soldering iron to first make a small melted hole and then drill it bigger to size. I did it this way because otherwise it is hard to drill it and will end up scratching the sheet.
I am still in this phase and will UPDATE it with my chosen method later(antenna mounting). I can tell you for the GPS wire I decided to just tape it into place, as seen in photos.

Also I chose to just put a layer of mattress foam in the nose cone to cushion the sled carrying the dog tracker.
Now this sled is designed to be the permanent mount for the system and can then in turn be bolted onto your normal sled for a bigger diameter rocket to go onto the all threads.


20121226_201759 by AstroAnon, on Flickr


20121226_201819 by AstroAnon, on Flickr


20121227_183959 by AstroAnon, on Flickr


20121227_184032 by AstroAnon, on Flickr


20121227_211726 by AstroAnon, on Flickr


20121228_150403 by AstroAnon, on Flickr

Please feel free to comment and ask any questions you may have!
Cheers.

TO BE FINISHED.................

Nice find. I have hear that someone got it in a 38, but I have never seen a build thread.

How do you get around the MURS restriction? Did you change to a different transmitter?

What is the MURS restriction? People have been using these for years. First time I have heard of a regulatory problem.

Garmin's Astro series uses MURS (Multi-Use Radio Service) for telemetry between the GPS and the receiver. In 47 C.F.R part 95.1303(b) Authorized locations: MURS operation is not authorized aboard aircraft in flight, and 47 C.F.R part 95.1315 Antenna height restriction: The highest point of any MURS antenna must no be more than 18.3 meters (60 feet) above the ground or 6.10 meters (20 feet) above the highest point of the structure on which it is mounted. So MURS cannot be used aboard aircraft in flight (and our club has received clarification that model rockets are considered aircraft) and the antenna cannot be more the 60' above the ground.

https://en.wikipedia.org/wiki/Multi-Use_Radio_Service

I have the DC30 and Astro 220
It WILL lose lock when it hits a certain speed.
Mine blinks blue not Red.

He modded his for better signal strength.
He mods them as a part of his business.


JD

cwbullet said:

What is the MURS restriction? People have been using these for years. First time I have heard of a regulatory problem.

Click to expand...

The antenna height restriction refers to the fixed side of the system, not the dog collar itself. It means that a tower receiver cannot be more than 60' above the top of the building it's mounted on; typically, the network providers try to get the tallest structure they can find and sign a lease with the owners.

The "aircraft" restriction is a bit more troublesome, however if you can get your altimeter to power it on after landing or very close to the ground then you'd be OK. From what I've heard, these things lose their signal in-flight so they're only useful for finding you rocket on the ground anyway.

tonka said:

Garmin's Astro series uses MURS (Multi-Use Radio Service) for telemetry between the GPS and the receiver. In 47 C.F.R part 95.1303(b) Authorized locations: MURS operation is not authorized aboard aircraft in flight, and 47 C.F.R part 95.1315 Antenna height restriction: The highest point of any MURS antenna must no be more than 18.3 meters (60 feet) above the ground or 6.10 meters (20 feet) above the highest point of the structure on which it is mounted. So MURS cannot be used aboard aircraft in flight (and our club has received clarification that model rockets are considered aircraft) and the antenna cannot be more the 60' above the ground.

Click to expand...

cerving said:

The antenna height restriction refers to the fixed side of the system, not the dog collar itself. It means that a tower receiver cannot be more than 60' above the top of the building it's mounted on; typically, the network providers try to get the tallest structure they can find and sign a lease with the owners.

The "aircraft" restriction is a bit more troublesome, however if you can get your altimeter to power it on after landing or very close to the ground then you'd be OK. From what I've heard, these things lose their signal in-flight so they're only useful for finding you rocket on the ground anyway.

Click to expand...

From what we have been told the 60 foot height restriction does apply to the dog collar antenna, notice the "any MURS antenna" portion of the CFR.

Yes they do loose signal a lot but once they are on the ground it will navigate you right to the rocket.

cwbullet said:

Nice find. I have hear that someone got it in a 38, but I have never seen a build thread.

Click to expand...

Yes I know the guy who put it in a 38mm. But I believe he is using the DC40 which is an all in one chip set. So it is a little easier to get it into a 38 with the DC40 He did do a beautiful job however.

You guys had me worried. I love my Garmin.

It's actually only 20' above the building, if you look at other Part 95 sections you'll see identical wording but with a little more explanation. It's basically FCC boilerplate text, for fixed antennas. Regardless, since it's not gonna work anyway unless it's close to the ground some kind of power switch that's activated on landing would satisfy everybody. This may also apply to the GPS/cellular dog collars too, but that one's apparently a little bit more of a gray area.

tonka said:

From what we have been told the 60 foot height restriction does apply to the dog collar antenna, notice the "any MURS antenna" portion of the CFR.

Click to expand...

cwbullet said:

You guys had me worried. I love my Garmin.

Click to expand...

Same here.

My only complaint is its strength. It has fried altimeters and blown charges (almost became permanently blind) because I had them in the same av bay. It send 5W of signal I am no expert but I think that is 50x more powerful than the 100mW High Power Beeline.

It stayed on lock the entire 32,000ft flight in April this year with my schools 75mm Minimum Diameter rocket.

Watching this thread.

cwbullet said:

You guys had me worried. I love my Garmin.

Click to expand...

Same here.

My only complaint is its strength. It has fried altimeters and blown charges (almost became permanently blind) because I had them in the same av bay. It send 5W of signal I am no expert but I think that is 50x more powerful than the 100mW High Power Beeline.

It stayed on lock the entire 32,000ft flight in April this year with my schools 75mm Minimum Diameter rocket.

Watching this thread.

bandman444 said:

Same here.

My only complaint is its strength. It has fried altimeters and blown charges (almost became permanently blind) because I had them in the same av bay. It send 5W of signal I am no expert but I think that is 50x more powerful than the 100mW High Power Beeline.

It stayed on lock the entire 32,000ft flight in April this year with my schools 75mm Minimum Diameter rocket.

Watching this thread.

Click to expand...

Yes they sometimes keep lock the entire flight and sometimes only up until a certain point but normally once you go to the last locked spot you get signal right back. I have been made aware about the problems with the dog tracker and altimeters but I have never had that experience. But again I have never put them together. I am resizing all the photos now to upload. Thanks for watching.

Put it in the NC and no more problems.


JD

bandman444 said:

Same here.

My only complaint is its strength. It has fried altimeters and blown charges (almost became permanently blind) because I had them in the same av bay. It send 5W of signal I am no expert but I think that is 50x more powerful than the 100mW High Power Beeline.

It stayed on lock the entire 32,000ft flight in April this year with my schools 75mm Minimum Diameter rocket.

Watching this thread.

Click to expand...

JDcluster said:

Put it in the NC and no more problems.

JD

Click to expand...

Don't you wish it were that simple...

My rudimentary testing is that within 10ft it will cause mayhem with altimeters. My MAWD AND RRC2.

bandman444 said:

Don't you wish it were that simple...

My rudimentary testing is that within 10ft it will cause mayhem with altimeters. My MAWD AND RRC2.

Click to expand...

10ft wow.... I used the tracker less than one foot away (separated by a bulkhead) with the Perfectflite Stratologger (the new MAWD) and no problems at all. Nonetheless if you did extensive experimentation please post your findings mate!

bandman444 said:

Don't you wish it were that simple...

My rudimentary testing is that within 10ft it will cause mayhem with altimeters. My MAWD AND RRC2.

Click to expand...

i have had not issues wit either altimeter. I have 10-20 flights with my 4 tranmitters.

I've had no problems using the DC40 with 2 RRC2 minis, it's usually in the nosecone or just below the nosecone bulkpalate with the antenna going into the nosecone.

i did not state this: I own 2 DC30s and 2 DC20s. I put them in the nose cones or mount them to the shock cords. No problem.

Hi my button on my Astro DC30 came off and it took the pads under the button with it.

Is there a way to solder pads back on the board so that I can solder the button back on to the pads?

Please help, this is actually for my dear dog.


Cheers.
Will.

Garmin Astro DC40 dog collar transmitter.

Are you still getting good use of the DC collar transmitters?
I am hesitant to use them based on what I have heard about their interference with altimeters.

Is there any way to have the DC40 connected to an altimeter so that the power to the DC40 is turned on only after the final deployment event...This would prevent the DC40-altimeter spoofing problems.

Other suggestions for use of the DC40 safely with no collar-altimeter interference would be appreciated.
I would like to make use of the 2 collars own but I am afraid to use them.

Thank you
Tom C.
MARS Geneseo N.Y.

Just like all other GPS units;
You need lock and communication with your hand held in order for it to work.
If you plan on using it; Ground test you planned setup....
Altimeters and all.


JD

TOM C said:

Garmin Astro DC40 dog collar transmitter.

Are you still getting good use of the DC collar transmitters?
I am hesitant to use them based on what I have heard about their interference with altimeters.

Is there any way to have the DC40 connected to an altimeter so that the power to the DC40 is turned on only after the final deployment event...This would prevent the DC40-altimeter spoofing problems.

Other suggestions for use of the DC40 safely with no collar-altimeter interference would be appreciated.
I would like to make use of the 2 collars own but I am afraid to use them.

Thank you
Tom C.
MARS Geneseo N.Y.

Click to expand...

I have used dc20-40. If you put the tracker in the nose, there is no problem with interference. I would agree with a ground test.

I have used the DC40 mounted in the nose and taped to the recovery harness with zero issues. Altimeters used are Raven II, PF SL100, and Marsa 54. YMMV......

Just a friendly reminder to ground test with bare ematches to make sure the dog tracker doesn't dork the altimeter(s). More details here on page 15: https://www.apogeerockets.com/downloads/PDFs/GPS_Recovery.pdf
the Adept 22 and P6K are two off hand that don't like high RF fields. I saw a 12 inch diameter 16 foot tall project go in ballistic when both adept 22's failed in the Rf field of a Garmin Dog tracker. Kurt

Kurt...

Thank you for the Apogee Rockets article..it is very helpful as is yours and all that posted suggestions to ground test the DC40 with the altimeters.

I use RRC3 from Missle Works if there are specifics re this altimeter and the Garmin dog collar I would appreciate more input.

Thank you
Tom C.

I would not put them in av bay with a garmin. I have used and adept 22 separated by 3 feet from a garmin.