# Rocket Tracker

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#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
Guys and gals,

I am looking for experienced opinions. I am looking for a small rocket tracker that can be used in HPR and MPR. I want to be able to use it for my level 3 and any launches along the way. I would prefer not to get a ham cert, but I have resolved to the fact that it might be required.

I have looked at bigredbee.com, ARTS2, and Rocket Tracker. I have used the Garmin Dog tracker but it is mostly only feasible for a 4 inch diameter rocket.

The telemetry GPS models are nice, but is it better to just use the KISS approach and have a separate tracker?

Chuck

#### n5wd

##### Well-Known Member
... looking for a small rocket tracker that can be used in HPR and MPR. I want to be able to use it for my level 3 and any launches along the way. I would prefer not to get a ham cert, but I have resolved to the fact that it might be required.
Chuck,

You don't have to get a ham license - it just makes it a bit easier and less expensive, not to minimize the legalities either. But, if you've got the extra money....

I have looked at bigredbee.com, ARTS2, and Rocket Tracker. I have used the Garmin Dog tracker but it is mostly only feasible for a 4 inch diameter rocket.
Actually, if you're willing to take the guts out of the plastic package, and re-mount things and add a different antenna, it fits quite nicely into a 3" tube. There was an issue of Extreme Rocketry recently that gave a play-by-play on how to do that, and it was relatively simple to do. I can try and dig it up if you're interested.

The telemetry GPS models are nice, but is it better to just use the KISS approach and have a separate tracker?
A simple tracker only gives you a relative bearing from where you are at the time you receive the signal. A GPS tracker not only tells you where the package has been, but also lets you extrapolate where it will be in the near future, along with bearing, distance, and altitude info relative to where you are. It's not absolutely necessary, in all cases, but having a GPS unit will definitely make things easier - and in some cases I can see it making the difference in finding the package or not.

I still don't understand, though, what you'd have against getting a ham license? It's not like you're giving up any freedoms, civil rights, or having to stretch your mind that much and it definitely makes things easier (legally speaking).

Wayne

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#### rdmmdr

##### Well-Known Member
Chuck there is a search engine on this site. please use it.

that said commercial gps is between 800 and 1400$big red bee gsp is about the same with the ground support equipment. comm spec radio is about 500$ complete.
big red bee trans only is also about 400-500$with ground support, new price. homebuilt gps is about 250$ and is better then the big red bee for tracking, equal to the qzark unit and the gps flight unit for power. longer battery life, easy integration, plus free software.

pm me for more info if you need it

#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
I have first hand experience with about 4-5 flights with mine and I have never came close to loosing a rocket. It adds a little weight to the rocket and can fit in a 3 inch tube if you take it apart or 4 inch native. I took the collar off and cover it with kevlar sock. I then zip tie to the tubular nylon shock cord.

It works awesome. You loose it a little during some flights, but with apogee, you pick it up again.

The issue is, it is not the device for below 3 inch.

Chuck

#### n5wd

##### Well-Known Member
I don't know if the GPS does anything other than track the rocket, but if it doesn't, I'd just get a radio tracker. ... I'm not sure about all the functions of a GPS, but if your main goal is to track the rocket, I'd go with just a radio tracker.
When you point an antenna at a tracker, you get a general idea of the direction the tracker is from you at that point (a bearing). As you get closer to the tracker, you narrow down the direction until you walk up to the transmitter. It's all done manually, and requires the person to interpret the signal strength meter in the receiver to tell where the strongest signal is. This is called "direction finding". If you have only one person receiving the signal, you get a single bearing away from that receiver, but if you have two or three people receiving the same signal at the same time, but at different locations, you get two or three different bearings, and can triangulate where the signal is based upon those different bearings.

With a GPS/tracking unit sending out latitude / longitude and altimeter data, you can take the received data and plot it on a map showing the best way get to where the rocket was last reported, as well as transfer the data into a handheld GPS unit that will give you constant bearing and distance information to the rocket while you're trying to recover it. And since the info has been transmitting all the time the package has been coming down, you can make educated guesses as to where it'll be if it moves behind a hill or something that blocks the transmission - you can see where it's been, and how long it took to drift X yards... etc. You can also do the "direction finding" mentioned in the tracker, above, since the GPS/tracker is still putting out an audible transmission each time it sends the lat / long data.

The GPS/tracker saves time and effort in locating the package (as long as it's still with the rocket). It's not magic - I'm sure there have been GPS/tracker equipped rockets that have been lost. But, when compared to just a beacon giving you a single relative direction from where you are, it's miles more better, IMHO, when you don't visually see where the rocket lands. With a GPS/tracker, you know exactly where to start looking.

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#### timothyterpsalot

##### Well-Known Member
There's something I don't understand... I have read online that the dog collar fits in a 4" airframe but will need to be modified to fit in a 3" airframe. What I am confused about is that the collar dimensions I found online are 1.75 x 3.25 x 1.5 wide. Why would this not fit in a 2" airframe?

#### n5wd

##### Well-Known Member
I have resolved to getting a ham license. It actually is not that hard to get one. Just get the book "Now You're Talking," and they give you every single question that could be on the test. It's only a 35 question test, and you need a C to pass (74%). I thought it is well worth it. I've only been studying for a few days and I already feel I could pass.

As for reccomendations, try this website:
http://www.com-spec.com/rocket/
While "Now You're Talking" is a very good textbook, it's kinda expensive (though, I believe, worth it for the illustrations and explanations it has). There are a couple of free resources I tend to recommend, to be found at www.hamelmer.com . Look for the Technician Study Guide and the K3DIO Question Pool/Correct Answers booklets in the downloads sections - they're the materials I use when I'm teaching a license preparation class, supplemented by powerpoint slides and demonstrations, of course.

#### n5wd

##### Well-Known Member
I have seen many posts on this topic now and I am really torn about whether to buy a the GPS or just a radio tracker. It is more initial investment to buy a GPS tracker, but it seems like you get more function.

The ARTS2 vs combination of the big red bee and parrot are very attractive. I will likely just have to make a decision and live with it.
Chuck,

Yeah, sometimes when life gives us too many choices....

Well, I've hesitated to give you my recommendations, but here goes. It's based upon the idea that you're going to study and take the Technician class license exam, so that you can use the ham radio frequencied transmitters, if you need to.

Once you've got your license, the first tracker should probably be a plain ol' BigRedBee to give you a little bit of experience doing the direction-finding tracking where it all began. The reason being is that even if the GPS/Tracker's GPS part fails and is not giving good data, as long as the transmitter is putting out a signal, you can DF it to find it, just like you would the BigRedBee.

You'll need an HT or scanner that has a signal strength meter, and a yagi. You can build your own ( http://wa5vjb.com/yagi-pdf/cheapyagi.pdf )or purchase an Arrow or similar.

But since you're thinking about your Level 3 flight in the near future, you probably would be well served to also get the Bee/GPS as soon as you can afford it, the decoding method (either a Kenwood or Yaseau HT with the APRS built in, or a accessory APRS decoder with the HT you use with the Bee).

With that, you can also have a laptop running a software APRS decoder at base camp, (you'd need an inexpensive radio to hear the signal and, of course, an antenna - but this can be a little mag mount spike on top of your car) and let your support staff also see where the rocket went, at the same time as you tracking it in the field.

That will get you the best tracking solution the quickest and least expensive. The 900Mhz kluge that rdmmdr is talking about is great if you're into hacking electronics, but I get the idea that you want something off the shelf.

That's basically what I'm going to have our kids do when we do the SLI bird this year - a Bee in the booster, and a Bee/GPS in the payload. It's going to go a mile high, and can drift for quite a bit so having the capability of tracking both parts of the package just makes sense. The kids that are part of my SLI team will be required to get their technician licenses so they can legally operate the club station, and it's the school's club station license we'll use for the tracker and Bee/GPS.

All told, under $1K for dual tracking, including purchasing a new HT. For a rocket that needs to be recovered intact for it to be a successful project (the kids have to do an after-action report and discussion of the data obtained during the flight), dual tracking is not too much to expect and will be just one more line on the budget. By the way - having your ham license (a) doesn't mean that you always have to use a transmitter that's in the ham bands (such as the Astro - personnaly, that's going to be my second purchase, after I get my personal Bee/GPS), but (b) does mean that if it ever comes to the point where some official looking guy wants to know whether you have a license to operate that bird-tracker or Walston or CommSpec transmitter in the 220MHz ham band, you can whip it out and not worry about it like some others. #### rdmmdr ##### Well-Known Member Chuck If you would have used the word tracker/tracking in your search. It would have been a little more productive. yes it was a poke, but a lot of people ask the same question over and over because they are too lazy to do a search. if you searched then i am sorry. The garmin is a nice unit but there have been reports of problems with the altimeters losing baro data. most of them where not designed to work with high powered rf right next to them. it seems that the deployment charge wires are making a good antenna and playing heck with the a/d converters. i know that the parrot has this problem and it has been reported with other units. unless you hack it apart, you are stuck with the basic foot print. if you are not in a hurry give me a couple of more months, i want to do some high g testing on the transmitters. i have a board designed to accept, the xbee pro module, that will interface with either the altimeter or the gps unit. currently testing with the perfect flight altimeters. what you have to understand about commercial gps's is that they shut down due to altitude, speed, and or g restrictions. if you fly high and fast you will lose all gps data for launch, and will not get it back till approaching apogee. without hacking the garmin apart i don't know what they are using, But i do know what everybody else is using. they are using maxstream modules. at 900mhx with a .1 watt output. now for about 150.00$ you can get the 1 watt module for the rocket, for those massive blackrock projects this might be an option but for the rest of us 6/7 mile range is good enough. and the transmitters cost 40$each if you open one of the receivers you will find an antenna, coax, xbee module, and a 3.3volt ttl to usb or rs232 converter.the nice thing about usb it give power/no batteries. all in a pretty box cost is 400.00$

parts
xbee pro xsc no connector 34.00
2x3 inch project box 5.00
rpsma bulkhead whip 8.00

-Kevin

#### n5wd

##### Well-Known Member
Ah, nevermind about the dimensions of the dog collar, I figured it out. Those dimensions are for the DC-20 but the DC-30 wouldn't have the same problem and would fit much nicer into a 2" rocket body.
Plus, I don't think that the listed dimensions account for the antenna, either.

But, as I mentioned before - taking it out of the case and mounting on an ebay sled doesn't look hard.

See Extreme Rocketry issue #70 - March 2008 for the article by Mike Konshak (you can also see some of the pictures of his build of the Slipstick II at http://www.telerover.com/ . It clearly shows how the Astro was mounted in the ebay.

#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
That is the old style transmitter for the garmin. The new one has a longer antenna.

#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
You get a little better range witht he new model, but I have seen the old one mounted to a sled also.

#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
I would prefer not to get a ham cert, but I have resolved to the fact that it might be required.
FWIW, a Ham license is a piece of cake to get -- a little bit of time studying, $14 and an hour or so to take the test, and you're good for 10 years. The telemetry GPS models are nice, but is it better to just use the KISS approach and have a separate tracker? ET Phone Home (GPS) is nice, but it DOES add to the cost, considerably. You can have a standard BigRedBee setup, including yagi, radio, tracker and license, for under$200.

-Kevin

#### sylvie369

##### Well-Known Member
A tracking system is worthless unless it's in the rocket when you fly and you have the ground equipment with you and working. It seems to me that the two systems differ not only in how well they work and how expensive they are, but also in how likely you are to use them in a particular rocket.

A BRB tracker is easy to use, and the part that flies can be replaced for (let's take a quick check here...) $70, if I'm not mistaken (transmitter + battery). You also only need your handheld radio and a Yagi on the ground side - something that you could easily bring to a launch without really thinking about it. It's also small, and can be installed almost anywhere. I'd think you'd be a LOT more likely to fly that than you would a GPS system. On the other hand, on an expensive rocket that you fly once in a while, you might well be willing to put up the extra expense, mounting challenge, and ground support hassle in order to have the clearly better information you get from a working GPS system. I'm hoping to fly a little boosted dart in a couple of weeks. It's 38mm in diameter, which pretty much means no GPS, unless there's something out there I don't know about. But a BRB tracker will go nicely in there. I think there are probably lots of other examples of rockets that you'd put a tracker but not a GPS into. Re. the Ham license, I got mine about two years ago after reading some threads here on tracking. I used "Now You're Talking", and passed easily (and oddly enough, passed the General class test at the same time). If the trackers that require a ham license appeal to you, get the license. If you can read and your brain works well enough to fly rockets safely, you can get the license. #### troj ##### Wielder Of the Skillet Of Harsh Discipline, Potent A tracking system is worthless unless it's in the rocket when you fly and you have the ground equipment with you and working. It seems to me that the two systems differ not only in how well they work and how expensive they are, but also in how likely you are to use them in a particular rocket. You know, it's funny you bring that up -- I was talking with Greg Clark (guy who makes the BeeLines) the other day, and he said pretty much the same thing -- they're only useful if you fly them! A BRB tracker is easy to use, and the part that flies can be replaced for (let's take a quick check here...)$70, if I'm not mistaken (transmitter + battery).
Correct

You also only need your handheld radio and a Yagi on the ground side - something that you could easily bring to a launch without really thinking about it. It's also small, and can be installed almost anywhere.
My radios are now part of my standard rocketry stuff that I bring.

I'm hoping to fly a little boosted dart in a couple of weeks. It's 38mm in diameter, which pretty much means no GPS, unless there's something out there I don't know about. But a BRB tracker will go nicely in there. I think there are probably lots of other examples of rockets that you'd put a tracker but not a GPS into.
The BeeLine GPS will fit in a 38mm motor mount tube, so it would fit in your dart. I build mounts for my GPS using 38mm motor mount.

-Kevin

#### sylvie369

##### Well-Known Member
My radios are now part of my standard rocketry stuff that I bring.
I haven't quite reached that point yet. Close.

The BeeLine GPS will fit in a 38mm motor mount tube, so it would fit in your dart. I build mounts for my GPS using 38mm motor mount.
Okay, so there was something I didn't know about.

#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
I have some questions about the beeline / bigredbee:

Can you post a picture of the avionics bay you use?

How easy is the Beeline to use?

What software do you use with it?

Computer or handheld? I have read about using handhelds.

What receiver do you use? What antenna?

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#### troj

##### Wielder Of the Skillet Of Harsh Discipline, Potent
I have some questions about the beeline / bigredbee:

Can you post a picture of the avionics bay you use?
Go to this thread: http://www.rocketryonline.com/modules.php?name=Forums&file=viewtopic&t=552&start=30

Partway down, you can see the photos and description of the bay that's being built in my wife's Level 2, which will hold a BeeLine GPS.

How easy is the Beeline to use?
Turn it on, turn on radio, done. Any tracker requires practice, though, to learn to track. I would strongly recommend flying the tracker in rockets you can track visually, first, then use the tracker to find them, just to get practice with it.

Or, do what I did, and practice by tracking other people's rockets, where you're out nothing if you don't find it.

What software do you use with it?
There's software that you can download, for configuring them -- call sign, transmit intervals, etc.

For the GPS, you can also use software on a laptop to decode the APRS packets, and display them. It's all free, and it works; takes a bit of fiddling, but it definitely works. The key is to turn the volume on the radio down -- barely audible -- it will easily saturate the input of the sound card.

I use a Byonics PicPac for decoding in the field; easier than mucking with the laptop.

Computer or handheld? I have read about using handhelds.
I use a handheld -- radio wired to input on PicPac, which is about the size of 3 decks of cards stacked together, the PicPac has an LCD and displays the GPS data.

What receiver do you use? What antenna?
Yaesu VX-2r and an Arrow Antenna 7 element yagi. Arrow also makes a 5 element Yagi; it works well, the 7 element just gives a more narrow direction. Do not get (or build) a 3 element -- too wide to work effectively.

I'm going to upgrade to a Yaesu VX-8r someday -- it will display the APRS packets directly on the radio.

I don't currently wire my PicPac into my GPS, although it can be done.

-Kevin

#### hgreenblatt

##### Duvious Dogs
TRF Supporter
I just flew the Garmin DC-30 in an Aerotech HV ARCAS (2.6 " dia) at LDRS. I had the receiver and transmitter mounted on a small sled just below the nose cone and the antenna sticking up into the nose.

I flew it on an H-180 and for some reason the ejection charge never went off. It came in ballistic from about 2500 ft. but never lost the signal, even after crashing. It was still transmitting fine when I dug the nose out of the ground. I can't imagine a dog would be that tough on it In any case, the DC-30 and engine case were the only things that survived.

The funny part was that while I was starting to walk over to where the Arcas crashed, the Astro handheld beeped at me telling me that my dog (code named Rocket) had "treed it's quarry" - (i.e. confined it's movements to a small area for more than 60 seconds...) A new term for a GPS tracked lawn dart?

- Howard

#### hardinlw

##### Well-Known Member
This is what I went with. http://www.com-spec.com/rocket/index.html It does require a ham license which I found was pretty easy to get. Here's a place to take practice tests. http://aa9pw.com/radio/ I used Gordon West's audio CDs for study. There was nobody around me that I knew of using tracking. If you have friends with a particular brand of equipment, I'd go for the same kind but make sure the frequencies were different. It never hurts to have a second receiver available to triangulate.