Is there a "GPS Locators: Comparison guide" out here?

Is there a "GPS Locators: Comparison guide" out here? My search didn't turn up much. Noticed the Sticky post there for "Altimeters: Comparison guide"...

Not one of which I'm aware.


Later!

--Coop

There's tons of information on the forum, but since three-letter searches don't work, you won't find it with a search for "GPS".

Try searching for "ublox" for starters. Eggfinder, various products from Big Red Bee (both ham and unlicensed), and Altus Metrum (all ham) are the big ones.

This was posted last year. It does not include Eggfinder.

https://www.jcrocket.com/gps-tracking.shtml

I am no expert, and this should be taken with a grain of salt!

If you are into amateur radio electronics and have or want a ham license, it is cheaper to go with a 440 MHz transmitter and whatever receiver you prefer/know about.

For more money, the 900 MHz sets are about as simple to use as you can imagine. But again, more expensive.

And in the middle is the Eggfinder, which is dirt cheap, but requires you to assemble the circuitry from at the board level. So you save hundreds in labor costs, but with the risk of screwing it up.

I went with the BRB900. It is probably the most expensive unit out there, but all you do is turn on the transmitter, stick it in the rocket, turn on the receiver, and wait till it gives you coordinates. And though expensive, you can move it from rocket to rocket and it should last you a life time if you don't break it or lose it.

Finally, no matter what you use, you need a GPS navigator (Garmin, Tom Tom, etc.) to enter the coordinates into so that it can walk you to your rocket. Pedestrian mode is a must. Older units that will only route you via roads are not very helpful.

Bat-mite said:

Finally, no matter what you use, you need a GPS navigator (Garmin, Tom Tom, etc.) to enter the coordinates into so that it can walk you to your rocket. Pedestrian mode is a must. Older units that will only route you via roads are not very helpful.

Click to expand...

You can attach a bluetooth module to an eggfinder and have it pipe gps coordinates directly to your smartphone, no other gps required

It's another piece of hardware, but if you're out where there's no cell reception, a Magellan GPS 315 will take you right to the coordinates and is about $20 on eBay.

Bat-mite said:

If you are into amateur radio electronics and have or want a ham license, it is cheaper to go with a 440 MHz transmitter and whatever receiver you prefer/know about.

For more money, the 900 MHz sets are about as simple to use as you can imagine. But again, more expensive.

Click to expand...

Another big difference which often gets overlooked, but has turned out to be critical for me is that the amateur units all send audio data along with the telemetry signal. That means you can use old-fashioned RDF techniques to locate your rocket. Because you're only listening for a faint audio tone, the effective range is many times further than that required to receive and decode APRS or other telemetry signals. That's a basic reality of any communication system -- the less data you're transmitting, the less signal you need at the receiver.

When your rocket disappears over a hill and lands miles from the last GPS coordinate you got from the flight line, you'll have a fallback that will let you get close enough to the rocket to decode the GPS position and walk the final mile or two to the airframe.

Tonimus said:

It's another piece of hardware, but if you're out where there's no cell reception, a Magellan GPS 315 will take you right to the coordinates and is about $20 on eBay.

Click to expand...

GPS Essentials app for the cell phone works great. No cell service required. But if you do have cell service, you can put the coordinates in and see where it is on a google satellite map. That worked so well last year we didn't need GPS or RDF with us to find the rocket once we saw where it was on the satellite map.

Not available for iOS...

Bat-mite said:

...

And in the middle is the Eggfinder, which is dirt cheap, but requires you to assemble the circuitry from at the board level. So you save hundreds in labor costs, but with the risk of screwing it up.

...

Click to expand...

I paid $30 and some freight , Connor did an excellent job.

https://eggassembly.webs.com/

Kenny

I was thinking something like this. It is incomplete but I am working on it between assembly steps and work.


Other columns that need to be added? Corrections? I'll do what I can. :grin:

I can think of one more row to add. Here is the info:
Multitronix, TelemetryPro (aka "Kate"), 900MHz, No, $895, $2290, https://www.multitronix.com

The TeleMega is $400, not $300. You should also add the Telemetrum.

I would also add a couple columns for other functions, ie dual deploy altimeter, accelerometer, extra channels, etc.

VernK said:

I can think of one more row to add. Here is the info:
Multitronix, TelemetryPro (aka "Kate"), 900MHz, No, $895, $2290, https://www.multitronix.com

Click to expand...

Done and I corrected the price on the telemega.

If you're going to add the altimeter functions to the chart, please add the Eggtimer TRS as well since it's an integrated GPS/altimeter. It's $90, $140 for the set with the LCD receiver. Also, there are two Eggfinder configurations, one with the LCD receiver ($120, which you have) and one with the USB dongle receiver ($90). Thanks!

cwbullet said:

Done and I corrected the price on the telemega.

Click to expand...

Much thanks! Is there a way we can have one copy of the table out there that can be edited so we don't get a honking-long (highly technical term :neener: ) thread that might lose the table info? I'm open to all suggestions!

Edit your post and we can get it perfect and I can add it to the top of the thread.

There's the AIM XTRA GPS flight computer (very similar to the telemega)

https://entacore.com/electronics/aimxtra

There are some esoteric trackers from Byonics for the Ham Radio high altitude ballooning people but probably not worth converting for rocket use with all the choices available out there now.

https://www.byonics.com/mt-400

https://www.byonics.com/mf

The MT-400 is likely out of production but the MicroFox can be Flashed for APRS tracking. Probably not worth the trouble now in light of other options.

One likely candidate but again only for the Ham Radio "set" is the Sainsonic AP510. https://www.radioddity.com/us/avrt5...th-thermometer-tf-card-support-aprsdroid.html

One fellow posted he likes using it on this board. High power 1 watt on the 2 meter ham band but probably only realistic in a 4" diameter or maybe 3" diameter nosecone mount. One would have to fastidiously test to make sure
the deployment electronics aren't dorked by the Rf output. Would need an APRS rig like a D72A or other. Could get by nicely with a Mobilnkd TNC, any handi-talkie and APRS Droid on any Android device. I've used the former and the latter with success.

Advantages: High Power = more range. If one bought two of them, one could be used as a receiver and then bonded to an Android device and could track with APRSDroid. Has capability to use your micro SD card to record position
and altitude for later download. Can have it record position 1/sec if desired. (Is selectable)
Disadvantages: Size and weight. Bigger than most of the other options out there. Couldn't be used to claim altitude records due to the SirfIV chipset that is optimized for terrestrial use. Does a fine job for tracking and finding the rocket though. Learning curve is high and instructions poor. Online video available for setting up that can be easily found: [video=youtube;qmtVvKav_LU]https://www.youtube.com/watch?v=qmtVvKav_LU[/video]
The newsgroup has many helpful posts so it's worth joining if considering tackling the device.

I've seen high altitude balloon data with the AP510 flying side by side with a Beeline GPS. The altitude plots were pretty darned close but...... that is in a low dynamic environment. Could be a difference with a high dynamic rocket flight.
Bottom line is if one needs a GPS tracker that has the potential of more range on the playa, this would be an economical substitute especially if one already has APRS tracking capability. Again, couldn't be used to claim records.

Oh, I don't want to forget that there is a 5 watt, 2 meter Beeline GPS tracker: https://www.bigredbee.com/zc139/index.php?main_page=product_info&cPath=66&products_id=183
and the 100mW 70cm GPS tracker: https://www.bigredbee.com/zc139/index.php?main_page=product_info&cPath=66&products_id=207

Remember: Higher power = more range requires more battery power. The 70cm 100mW tracker comes with a Li-Po cell that works fine.
Kurt Savegnago

There's a typo in the EggTimer TRS price.

SpaceManMat said:

There's a typo in the EggTimer TRS price.

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Ah yeah someone put in an extra (1) for the system price. Kurt

70cm BRBGPS pricing is wrong: should be $215 for 16mw, $259 for 100mw

Table updated. Thank you for the corrections! Still working on the Byonics.com data.

I would include the Trackimo from Giant Leap Rocketry.

Swissyhawk said:

I would include the Trackimo from Giant Leap Rocketry.

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Trackimo and others like it are a different breed that require a link to a cell phone system and a service contract. The tracking units above are independent systems not requiring a cell phone system link. Something to consider if flying in a sparsely populated area. It would behoove one to test it out on the field of choice before flying. Kurt Savegnago

FWIW, my first trackers were cheap cellular RF-V16 trackers ($29-39 on ebay, plus prepaid sim card) and I consider them a legitimate option for sport/club level performance, and since every cell tower essentially becomes a repeater for you line of sight is a non-issue. I think the Trackimo is just the first time a rocket company has tried to sell one of these.

Whichever prepaid cellular carrier you choose will have a coverage map that should show whether your intended launch area and the area around it is well covered by cell service, but of course you should test it out in person. I think they are more popular with drone guys than rocket guys, but I've used mine at two different fields in two regions with a high success rate. The only outlier was a high-G flight that caused my modified hardware to reset itself, which I kind of expected, but all the other flights were great. Battery life is way longer than conventional tracker systems, and it's fun to call your rocket on the phone and hear it ring.

jrkennnedy2 said:

Table updated. Thank you for the corrections! Still working on the Byonics.com data.

Click to expand...

I'd mention it for completeness but for practicality sake might not be suited as well for the rocket purposed devices. Byonics does have a 1 watt high altitude balloon tracker: https://www.byonics.com/mt-1000 but the size and cost is an issue. Looking at $240.00 for an APRS tracker with a cable that makes it programmable.

A sport flier with a Tech ham license would be better off with a Beeline GPS tracker quite frankly.

Byonics used to have available some 300Mw up to 8 watt single board trackers most of which are now out of production as can be seen on their website. I believe the 2 meter ham band trackers would have more utility for those going to extremes out on the playa. Again, if going with a high powered tracker, battery weight can be substantial and concern of interfering with deployment electronics needs to be contained and entertained. Kurt Savegnago

smapdiage9 said:

FWIW, my first trackers were cheap cellular RF-V16 trackers ($29-39 on ebay, plus prepaid sim card) and I consider them a legitimate option for sport/club level performance, and since every cell tower essentially becomes a repeater for you line of sight is a non-issue. I think the Trackimo is just the first time a rocket company has tried to sell one of these.

Whichever prepaid cellular carrier you choose will have a coverage map that should show whether your intended launch area and the area around it is well covered by cell service, but of course you should test it out in person. I think they are more popular with drone guys than rocket guys, but I've used mine at two different fields in two regions with a high success rate. The only outlier was a high-G flight that caused my modified hardware to reset itself, which I kind of expected, but all the other flights were great. Battery life is way longer than conventional tracker systems, and it's fun to call your rocket on the phone and hear it ring.

Click to expand...

There's several hundred of these cellular based system costing 10's to 100's of dollars. The problem is that they rely on both the cell phone network and gps. The range of a cell phone on the ground is not as good as in your pocket, and if the rocket lands in a bad orientation, the GPS may not work. The RC crowd can fly in a lot more places than rockets can so they are usually in places where the cell coverage is good. Another concern is the turn off date for 2G GSM service is 2016 so these units will not longer work within a year. https://en.wikipedia.org/wiki/2G

Cell based systems are ok for cheap rockets on fields with good cell coverage, but not good for expensive rockets launched from large rural areas with poor cell coverage. And yes there is a large part of rural America where cell coverage is not good. If you have a grand in your rocket, and have more than 1 rocket, you're better off getting a totally independent ham based system that has both GPS and beacon tracking. The transmitters are rather inexpensive and you only need 1 receiver which is the expensive part.

Bob

Bob, I agree with you on this. Cell coverage can make these systems work well, but coverage is not something you can depend on. 5 or 6 years ago we had no cell coverage on our field. They have since put up a tower near the field and after several years all the major carrier have add their systems to the tower. I now get 4 bars of 4G Verizon service on our field. I still don't trust cell phone based recovery systems.