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GPS Tracker for less than $150

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mattvd

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Has anyone tried the "PupPod" GPS tracker? I have read many posts/articles about the Garmin dog tracking system -- but, nothing on this system.

The PupPod is less sophisticated, but really all you would need to find a rocket -- which direction, and how far to walk. And, it is substantially cheaper -- about $125 on eBay for the receiver and collar.
 

jderimig

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I am thinking of trying that one.

The biggest problem will be getting my dog to get into the rocket...

Thank you very much, I'll be here all week, try the veal.....
 

Pem Tech

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I am thinking of trying that one.

The biggest problem will be getting my dog to get into the rocket...

Thank you very much, I'll be here all week, try the veal.....
ba dum dom
*rim shot*
 

bobkrech

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http://www.roameoforpets.com/index.php

It probably does not have the range or the update rate of the Garmin, but as a lost rocket locator it might be a lighter and cheaper solution than the Garmin.

e-bay has some (questionably) prices as low as $50.

Bob
 

Uncrichie

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I believe that the lower priced ones on E-Bay are the receiver only? I also see that there is a 2 watt transmitter in the collar on 154.6 mhz. The battery is a 800 mah capacity. Not sure how long that is going to power the transmitter at 2 watts unless its very intermittant. From the little info that is available I think you get an initial reading from the GPS and then use the transmitter from the collar to locate through the handheld receiver as you get closer? Does that make sense? If not what purpose is it to have the 154.6 transmitter and a GPS unit. Maybe someone else can explain that has more electronics experience. If this unit works its definitely affordable! Uncrichie.
 

Uncrichie

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I went to the video downloads section of the manufacurers site. The advertised range is 1-3 miles yet they say it tracks from 50-7250 feet, not sure what that is all about. Unless once you enter within that radius you get an additional 7250 feet, etc. etc.? I wonder whose going to take the plunge and try it? Uncrichie.
 

jderimig

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The range should be approximately 'forever' in the air. If you use signal the last good range and bearing should be able to get you well close enough to re-acquire the signal. If the transmitter bursts out data every second or show the battery should be able to last a reasonable length of time even at 2W.
 

mattvd

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Well . . . since I posed the question, maybe I will give it a try. I think the range should not be a big deal for most launches where you can see the general area where a rocket comes down . . . it's just the last half mile or so to find the right tree!
 

Uncrichie

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Hi Matt. I placed a bid on one this past weekend but wasn't high enough. Another ones coming up in a few days, I might try again. My only concern is no external antenna on the transmitter (collar). Most other brands units have an antenna. Possibly this could be added to permit more range by opening up and skeletonizing the collar transmitter unit to a board? In any event should you try one please let us know your results. Thanks. Uncrichie.
 

mattvd

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I bought one on eBay for about $85.00 for the collar and tracker. I hope to try it out this weekend. Results to follow . . . .
 

Uncrichie

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Thats great Matt. I'm looking forward to your evaluation. Uncrichie.
 

Diosces

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I bought one on eBay for about $85.00 for the collar and tracker. I hope to try it out this weekend. Results to follow . . . .
Great! Matt please keep us posted. I'm looking at this versus the 380+ for a refurbed garmin astro 220/dc20 combo.
What's your projected altitude, etc?
 

mattvd

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My plan is for a very simple attachment to the shock cord with some heat shielding. (Basically a simple Nomex or Kevlar pouch with some Kevlar loops. I want it to be very quick/simple to move from rocket to rocket.) The collar GPS module seems to be pretty sturdy. Altitude will probably be under 3,000 feet, and the field is pretty flat, so the testing should not overly stress the system. But, I will also do some "manual" testing. For example:
1. Can it track the collar while still inside a fiberglass airframe (in the event it does not fully deploy the chute.)
2. Collar behind the house, tracker in front.
3. Collar behind a lot of trees (sorry, I hope I don't have to actually test it in the trees!)
4. Collar in a low spot below visual line of sight.
5. And finally, just straight distance with reasonable obstructions (high grass, bushes, a few trees.)
 

lmt56

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Here is the results of a very simple ground test I did last weekend with one of these units.
I placed the collar at one end of a mile long farm road. After walking to the other end of the road I was still receiving distance and heading.
At this point I turned the receiver off and was not able to reaquire the signal until I was within 1/2 mile of the collar.
After recovering the collar I turned it off and started walking back to my car.
I noticed as I walked away the receiver was giving me a distance and heading back to where the collar had been located.
 

Diosces

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LMT Thanks plenty for the info , my main concern is re-acquiring a lost signal which your test showed needed aprrox 1/2 mile
Hopefully Matt will give us his results soon.
 

lmt56

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LMT Thanks plenty for the info , my main concern is re-acquiring a lost signal which your test showed needed aprrox 1/2 mile
Hopefully Matt will give us his results soon.
Hello John
Re-acquiring a lost signal was main concern also.
One reason I did one of the test. Turning the receiver off one mile away.
The last test I did which was by accident tells me if the receiver looses the signal it will remember the last known position and will guide you to that position.
So I am thinking if the rocket lands within 1/2 mile of that location you should be able to go to that location and re-acquire the signal.
To me the unit shows some promice.
 

jderimig

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So I am thinking if the rocket lands within 1/2 mile of that location you should be able to go to that location and re-acquire the signal.
To me the unit shows some promice.
The range in the air will be MUCH longer than on the ground. If the unit remembers the last good signal then that fix will probably we well within 1/2 mile when then the signal can be reacquired.

--jd
 

Uncrichie

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The range in the air will be MUCH longer than on the ground. If the unit remembers the last good signal then that fix will probably we well within 1/2 mile when then the signal can be reacquired.

--jd
All depends on how often it updates and if it doesn't get confused by altitude. I'm sure looking forward to some real flight information.

LMT, when you did the test was the collar on the ground or elevated, like on a post or something? Thanks. Uncrichie.
 
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lmt56

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All depends on how often it updates and if it doesn't get confused by altitude. I'm sure looking forward to some real flight information.

LMT, when you did the test was the collar on the ground or elevated, like on a post or something? Thanks. Uncrichie.
Collar was on the ground in some tall grass.
Ground level was flat.
 

mattvd

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Some preliminary results -- unfortunately my wife had the flu the weekend I was planning actual launch tests. So, I have some ground test results, but it will be a while before I get the chance to launch again.

GENERAL- Seems pretty solid. Heavy rubber collar and a reasonable seal around the GPS unit and battery compartment.
- It does not require any modifications for my application. (For example, the Garmin unit cannot be easily mounted in a 3" airframe without moving the antenna.)
- It does have an external antenna. The antenna is built into the collar.
- It is about 12 inches long. You might be able to shorten it a bit, but I did not want to start cutting wires (at least not yet.)
- About 2 inches wide. Fits easily in a 3" airframe.
- Battery duration was pretty good. Both the collar and the reciever were left on overnight. The receiver ran out of juice at about 18 hours and the collar was showing just a little life left at that time.

RECEPTION/TRACKING
- All tests conducted with the collar double-wrapped in a Nomex chute protector as that is how I intend to use the unit. (Nomex "pocket" attached to the shock cord.)
- To test the ability to track the unit with a lot of obstruction, the collar was left behind my house. In addtion to the house, several trees, bushes, and a six foot brick wall between the collar and receiver.
- YES, the key to successful use is the ability of the receiver to regain the signal from the collar. If you get a lock while the unit is sitting in your rocket on the launch pad, and the receiver losses the lock immediately after lift-off, the receiver will think the rocket is still on the pad.
- SO, how close do you need to be to regain a lost signal? With the obstructions noted above (Nomex, house, trees, brick wall, etc.):
-- ~1300 feet with the collar just in the Nomex laying in some grass
-- ~700 feet with the collar in the Nomex, INSIDE a 3" Blue Tube airframe
-- ~400 feet with the collar in the Nomex, INSIDE a 3" fiberglass airframe

OVERALL
- More testing is needed.
-- Can the unit stand up to the stresses of HPR launches?
-- Will my Nomex "pocket" work? (I, for one, don't want a complex mounting system that makes it difficult to move from rocket to rocket.)
- I think that if you completely lose sight of your rocket and don't have at least a reasonable vector to start walking a search line, this might not work for you.
- But, if you have a reasonable lauch site where you can see your expected landing zone, this has good possibilities.
- As some others have posted, with a less obstructed area the range to re-acquire the signal is about half a mile. Except for the really high-flying stuff, that drifts miles away, getting to within a half mile should be reasonable.

Once I get to actually launch this thing I will post an update.
 
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Diosces

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Matt thanks for sharing that info!

Please keep us updated as you get into actual launch tests.
 

Uncrichie

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Sailorbill, I have one that I'm going to test at the MDRA Redglare event next weekend. If I can find the room to stuff it in a stretched out 4" EZI-65. Hoping for 3000'. If all goes well it will come out at appogee for a free fall til main event at about 400 feet. I'm hoping it will still be gps linked during the boost, if not it should reaquire the link during the free fall. By the way you know how these things work? It'll land 100 feet from the pad! Uncrichie.
 

Sailorbill

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Sailorbill, I have one that I'm going to test at the MDRA Redglare event next weekend. If I can find the room to stuff it in a stretched out 4" EZI-65. Hoping for 3000'. If all goes well it will come out at appogee for a free fall til main event at about 400 feet. I'm hoping it will still be gps linked during the boost, if not it should reaquire the link during the free fall. By the way you know how these things work? It'll land 100 feet from the pad! Uncrichie.
Where I launch if you put a tracker in the rocket it will land on the pad if you don't install a tracker you may never find it. :D
 

PemTech's Squeeze

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I too lreally look forward to hearing how it turns out! :pop: And I like your scientific thinking in testing it out.

Thanks!!
 

Uncrichie

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I knew it was going to happen. I flew my stretch EZI-65 to 2340' with an I-450 sugar load. Landed 108' from the launch console. So yes the Pup-pod works but will have to wait til I pop a chute at appogee to get more distance. One thing to add: After loading the rocket on the pad I went back to my truck to get the handheld unit. Signals were strong enough that the unit on board stayed linked through the rocket and I could see the readings change on the handheld unit as I moved around. Stay tuned for more reports. Uncrichie.
 

AndyC

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I tested one of these Puppod trackers at Red Glare as well. I put the the collar above a bulkhead in my 7.5" V2 fiberglass nose cone. For the entire exercise it stayed there. I did not do any special mounting or padding, it was clipped around a shock cord in the cone, but free to bounce around otherwise. This compartment is separated from the main bay, but has a 1" hole for the shockcord, so does see the ejection pressure to some extent. As far as I know the tracker never lost signal, and the collar is fine. The flight was to ~2000' where the main deployed, and the rocket landed about 800' away. I actually thought it landed in a ditch, but after I started walking the signal direction was a bit different than I thought, but the tracker took me straight to it, down a dip in the field (out of direct sight from the pads). Very cool. Not a very extreme flight, but increases my confidence in the system. It was nice to see that I did not need to dangle the collar out with the laundry, but tracked fine from within the nosecone.
 

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