Cheap Capable GPS Tracker

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BEC

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From which cellular carrier do you get your SIM card to put in this thing? Apparently they have coverage where you fly in order for this to be useful. They claim position accuracy to "about 10m". I can think of recovery scenarios where that's not close enough even if there is service from the right cellular provider at the flying site.
 

rharshberger

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From which cellular carrier do you get your SIM card to put in this thing? Apparently they have coverage where you fly in order for this to be useful. They claim position accuracy to "about 10m". I can think of recovery scenarios where that's not close enough even if there is service from the right cellular provider at the flying site.
You mean like a certain corn field...or BMRs alfalfa..
 

heada

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Nearly all 2G services are shut down and most 3G services will be shut down by end of 2021 so more than likely it has a limited lifespan.
 

BEC

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You mean like a certain corn field...or BMRs alfalfa..
Yeah....that's what I was thinking of. And at least for me, BMR's alfalfa is a place where I don't have a cell signal (which is why the new logbook feature of the next major update of FlightSketch's app—I have a beta version— is useful as it allows data to be stored locally and uploaded later. But that, of course, is for another thread, not this one....
 

billdz

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From which cellular carrier do you get your SIM card to put in this thing? Apparently they have coverage where you fly in order for this to be useful. They claim position accuracy to "about 10m". I can think of recovery scenarios where that's not close enough even if there is service from the right cellular provider at the flying site.
I have been using cellular trackers for 3 years and am very satisfied, I've posted about them several times, e.g.
You do have to have T-Mobile cellular coverage at your launch site for these to be useful. I use the $5 a month SIM card from SpeedTalk, see https://www.amazon.com/SpeedTalk-Mobile-Tracking-Locators-Wireless/dp/B01HE3V7UW.

Position accuracy is much more accurate than 10m, I'd say closer to 1m.
 

billdz

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Nearly all 2G services are shut down and most 3G services will be shut down by end of 2021 so more than likely it has a limited lifespan.
I've been hearing that for 3 years, yet my SpeedTalk 2G SIM (on the T-Mobile network) just keeps on going (knock on wood). It won't last forever, that's for sure.

What seems odd to me is that, although there are still dozens of cheap 2G trackers available, 4G and even 3G trackers are very hard to find, no one has ever explained why. These trackers are very useful for pets, cars, seniors, etc., one would think that by now there would be plenty of 4G trackers available. Note that some of the "4G trackers" sold on eBay are not really 4G (e.g., this one: https://www.ebay.com/itm/GPS-Tracke...Device-Drone-GSM-Child-Motorbike/274104624012) and/or require a substantial monthly fee (e.g., this one: https://www.ebay.com/itm/LandAirSea...-4G-LTE-GPS-Tracker-for-Vehicles/112353029563).
 

ksaves2

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Spend the money for a dedicated, made for rocketry GPS tracker. They’re no longer $1000.00 and in price ranges for most pocketbooks. If one invests in a Ham Radio license and a Kenwood D72a, this tracker:
https://www.ebay.com/itm/New-AVRT5-...854588?hash=item56cf86063c:g:0AwAAOSwXk1d1dYD
would more than likely cover anyones needs into the high 5 figure and maybe 6 figures of altitude. Would require a 4 inch diameter though. 1 watt output on 2 meter band and the range will be excellent.
Beeline GPS is still great, I have 3 of them and the AIM tracker/device is good. I believe the Ham band trackers have better range and propagation than the 900Mhz stuff but for most sport fliers the difference shouldn’t be noticeable at all. I’ve used both. Kurt Savegnago
 

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All I know - and my reason for the original post - is the tracker is $20, the sim card is $5 per month (no contract) and I don't lose my rockets anymore. When the flight is over, I send a text to the gps unit, and it texts me back coordinates on Google Map on my iPhone where I can walk right up to where it landed. That is all I wanted it for, and it does the job.
 

ksaves2

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Sure it does until you proceed to have prolonged out of sight flights in a venue that has spotty cell phone coverage then don’t expect it to work all that good. If it works where you are, continue with it because if you have a core sample it’s a lot easier to swallow the loss of a $20 tracker than a $70 or $260.00 one.
It is not a one size fits all tracking needs though.
 

billdz

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All I know - and my reason for the original post - is the tracker is $20, the sim card is $5 per month (no contract) and I don't lose my rockets anymore. When the flight is over, I send a text to the gps unit, and it texts me back coordinates on Google Map on my iPhone where I can walk right up to where it landed. That is all I wanted it for, and it does the job.
Yes, if you have decent T-Mobile cellular coverage at your launch site, a cheap tracker is all you need (at least until T-Mo turns off its 2G network).
 

billdz

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Sure it does until you proceed to have prolonged out of sight flights in a venue that has spotty cell phone coverage then don’t expect it to work all that good. If it works where you are, continue with it because if you have a core sample it’s a lot easier to swallow the loss of a $20 tracker than a $70 or $260.00 one.
It is not a one size fits all tracking needs though.
Yes, if your launch site has spotty cell coverage, don't bother with a cellular tracker. Before buying, check the T-Mo coverage map at https://maps.t-mobile.com/. I've been to every launch site in Florida and there's good service at each one.

What kind of self-contained tracker can be purchased for $70? The cheapest I'm aware of is the Missileworks T3 for $150, or an Eggfinder in kit form for $125.
 

afadeev

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I've been hearing that for 3 years, yet my SpeedTalk 2G SIM (on the T-Mobile network) just keeps on going (knock on wood). It won't last forever, that's for sure.
T-Mo is officially shutting down 2G by Dec'20.
Verizon and AT&T have already shut down theirs (2G and CDMA 1X, respectively).
Until then, T-Mo is aggressively re-farming 2G spectrum, so 2G reception may disappear in your area long before the shut down date.

What seems odd to me is that, although there are still dozens of cheap 2G trackers available, 4G and even 3G trackers are very hard to find, no one has ever explained why.
That has everything to do with the module cost.
2G chip-sets have been around since mid-90s, and have been cloned endlessly. Their cost is down to $4-5/per, in quantity of 10+K.
Cat-6 LTE chipsets are still in the mid-/high-teens, Cat-1's are in low teens.
Now that Cat-M's are become popular and are available in mid-single digits, I expect a lot more LTE cat-M trackers to come out at price points similar to those of the 2G units. Being lower-power and easy on the batteries, Cat-M's will be a good fit for the job.

a
 

SecondRow

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What kind of self-contained tracker can be purchased for $70? The cheapest I'm aware of is the Missileworks T3 for $150, or an Eggfinder in kit form for $125
You’d have to replace only the transmitter if the rocket comes in ballistic. You wouldn’t need a new receiver. The EggFinder Tx is $70.

FYI, you could the get the EggFinder Tx and Rx for as little as $95 $90 if you forego the LCD option.

EDIT: Had the price of the EggFinder wrong, as pointed out by Cris down below.
 
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cerving

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You’d have to replace only the transmitter if the rocket comes in ballistic. You wouldn’t need a new receiver. The EggFinder Tx is $70.

FYI, you could the get the EggFinder Tx and Rx for as little as $95 if you forego the LCD option.
Actually, the TX/RX (which is equivalent to the "other guys" Bluetooth setup) is $90. If you want the Mini transmiter, that adds $5 (and it's a bit more difficult to build), but you can wrap it up in a nomex burrito with the battery and fly it that way, without having to build a special nose cone bay for it.
 

billdz

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You’d have to replace only the transmitter if the rocket comes in ballistic. You wouldn’t need a new receiver. The EggFinder Tx is $70.

FYI, you could the get the EggFinder Tx and Rx for as little as $95 $90 if you forego the LCD option.

EDIT: Had the price of the EggFinder wrong, as pointed out by Cris down below.
Good point, I was thinking $125 for the Eggfinder tx ($70) plus the LCD rx ($55), but you are right, you would not need a new receiver in the event of a crash landing.
 

ksaves2

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Good point, I was thinking $125 for the Eggfinder tx ($70) plus the LCD rx ($55), but you are right, you would not need a new receiver in the event of a crash landing.
I crashed in EF in a fiberglass rocket. The one position I received was just above the fincan sticking out of the ground. I think I got a replacement during a black friday special. I’ll tell you, a lot easier to swallow than losing a Beeline GPS. I lost one of those too in ‘07. More like $256.00. Interestingly the BL was forward and the Raven 1 deployment altimeter was behind it with a thick plywood bulkhead. Replaced the onboard mini lipo on the Parrot altimeter and I downloaded a perfectly parabolic ballistic flight. G forces on impact were crazy high and probably inaccurate as they exceeded the G limit. Been meaning to put it in a beater rocket and see if it still would perform. The diagnostics say it’s ok.

I’d expect like anything else 4G and probably down the road 5G trackers will become available. The 2G units are likely so freaking cheap because there is such a large ready stock of them on hand and the sellers know 2G is going away. Hence, they’re unloading them. 4 and 5G (yeah science fiction for now) are probably going to cost moolah when they first come out and it will take time for the initial cost to come down. That is what will make a dedicated rocket tracker more enticing. There is a live mapping option for some of the units too. GPS Rocket Tracker is quirky but workable. Hacked Ham Radio software is doable and I’ve used it on a half a dozen recoveries successfully. I’m still learning.

Some folks just want to find a rocket, period. Nothing else. If that’s all that’s all fine and good. Push launch button, rocket disappears, try to scan around with the eyes to see the main event but if it’s not seen due to being too far away, ok just have the rocket phone home. That is if one doesn’t care what’s happening in between launch and recovery. In the case of a core sample, rocket is not likely going to be able to phone home due to the destroyed tracker so that could be a problem with a totally sight unseen flight.

With live streaming, live mapping one can see on a map where the rocket is in flight and with various map presentations, see the GPS mean sea level altitude too. Once a rocket disappears from sight it’s a waste of time to be staring at altitude because winds aloft can make rockets go in screwy directions. It’s not going to end up where you expect based on the ground windspeed direction. I know that from several Ham APRS tracker flights and NMEA 900Mhz tracker flights. What happens with a live tracked flight is as long as one has a “navigator’s brain” they can transpose on the map a bearing to where the rocket is supposed to be in realtime. In otherwords, one knows where to look to have the prospect of “seeing“ the actual main chute event. I’ve tracked rockets (using mainly Ham radio APRS) and the crowd is staring 180 degrees from where I know where the main event is to occur. Of course I call out loudly where to look and sometimes we see it and sometimes we don’t. When we don’t see it it’s because the rocket is too far away to be seen even under parachute. In that regard, the altitude read out gives the good or bad news. If it’s coming in hot one will know it from the readout. If the main deploys, the descent rate slows strikingly, is easily seen on the readout and a sigh of relief can be had as one knows the rocket is in a safe terminal descent. Even if it cannot be seen!
Also if the rocket is seen on descent, if there is concern it will land on a road or say a lake (heaven forbid!) that is easily discernable on the live map. I’ve called out several times that a fliers rocket landed on the launchsite and not a road. There are advantages to live tracking over 2G trackers.

When I got lazy and didn’t want to set up a tablet computer, I’d break out my trusty Garmin 60CsX and run an interconnect cable to a Kenwood D72A to run with a Beeline GPS tracker. Yeah, I know, takes a Ham Radio license but is not that hard. The Garmin will keep track on a map though it’s not a breadcrumb track like can be had on a tablet app. The D72A can have the screen switched to show the GPS mean see level altitude live.

In this case, I didn’t care in realtime where the rocket was because the Garmin would capture the last known position. What I was interested was whether or not the events occurred as planned. The altitude readout gives that information readily. If I looked at the Garmin screen while the rocket was in flight, I’d sometimes see the rocket moving but there is no bread crumbing so the only thing seen is the last known position. That paradigm as everyone knows works very well for recovery. The APRS system is great for being able to concentrate on the altitude and hence whether or not the apogee and main events occurred nominally. Yes it keeps tabs on the position too so one can make the recovery. I’ve been to launches in the past where there was another flier flying a Beeline GPS/Garmin combo. In that case the flier was more interested in watching the Garmin screen and I’d volunteer to tune to his Beeline GPS frequency and set my D72A to call out the altitude while he concentrated on the rocket track. The teamwork approach actually worked very well. I can go solo and steal glances on the Garmin to get the direction and still monitor the altitude readout satisfactorily.

The EggFinder LCD and others I believe can do the same thing as long as positions are received. There are quirks with 900Mhz but enough positions are received to make it a very viable system. The Ham stuff was the only game in town when I started out.

Now with these very small windows tablets it makes it easier to run full featured Ham Radio APRS software with really cool displays such as bread crumbing tracks and live altitude readouts. Some of this stuff can be hacked for the NMEA trackers too. Hence if one gets a Ham Tech license it will give them more choices though for sport fliers, it’s my opinion that 900Mhz is more than adequate.

Kurt Savegnago
 
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HHaase

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I find I prefer the standard eggfinder TX over the mini, if you have the room. The mini may be smaller, but the standard has a few more features that make life easier. Particularly when it comes to reprogramming, or knowing the GPS status of the transmitter.

I think I'm probably going to re-build my LCD though at some point. The more I use it the more I want to change some things in the layout of the system. The features set is definitely outgrowing the original PCB layout.

-Hans
 

ksaves2

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With the Eggfinder, I was able to hack APRSIS-32 to run two instances of the software. One to monitor the local position and one to monitor the rocket and paint both positions on one photomap. Really nice except I was losing a lot of the rocket positions and I suspect running two instances at once was the problem. Driving the system around for testing in a car was no problem but with the dynamics of rocket flight, there was an issue in that I wasn’t painting all the positions I believe I was receiving from the rocket due to packet collisions of running two instances of the software. I had a “Eureka” moment where I thought to just shutdown the instance of APRSIS-32 that was monitoring my local position. Heck, I didn’t need local positioning until I had to walk out to the recovery site. Shutting it down during the flight would only free up processing time for rocket tracking. Alas, life got in the way. Got prostate cancer that required surgery, radiation and chemo in the form of Lupron that effectively chemically castrates one. (Yes there are a lot of Eunuchs amongst us! Believe it or not.). My dad died then my lovely spouse died of radon induced lung cancer which was a bit#* as she never smoked a cigarette in her life (in the avatar) so life has been hectic the last 4 years. Once I get the house uncluttered, I hope to go out to one of the QCRS sites and fly a tracker in a photomap mode with the software dedicated to tracking the rocket in flight. Once down, fire up an instance to give local position so I can effect recovery. The goal is to paint as many positions of the rocket in flight, in real time as much as possible.
Some trackers such as the Beeline GPS can record a flight for later download and my 10,000 foot flight with a Wildman rocket that I “stretched” into a long neck ship, I belatedly attempted a download of data and had a very nice presentation of the position and altitude information. I didn’t have realtime information as the metallic paint I used on the rocket shielded the Rf emanations and I totally lost position and altitude information while the rocket was in flight. Nothing came in over Rf. Fortunately the rocket came down from 10,000 feet within sight and was able to be recovered. The download from the Beeline GPS showed it was able to receive the GPS positions but the metallic painted airframe shielded the Rf output. Hard way to learn but I knew not to repeat that mistake again. Put the tracker in a nosecone or rocket body without METALLIC paint. Incidentally, I used Rustoleum metallic paint. Don’t do that unless one places their tracker in a non-metallic painted nosecone. Rf shielding is frequency dependent. The 400 Mhz band was shielded by the metallic paint but perhaps 900Mhz wouldn’t be. I’m not about to try to experiment and will install my trackers in non metallic painted rockets or nosecones. One could put a GPS tracker on an apogee harness and that should work as long as one allows the GPS to get an initial lock while on the ground. Kurt Savegnago
 

cerving

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...The features set is definitely outgrowing the original PCB layout.
-Hans
Agreed. The LCD receiver layout is from 2014, with the 3-pin connector added on for the GPS module a couple of years ago. It will get a refresh "soon"... when I get a chance to do it.
 

HHaase

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If there's anything we can do to help, I'm sure there's a few of us out here both willing and capable.

-Hans
 
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