World's smallest rocket GPS tracker - Silicdyne Reperix

[Ulyu]

That is surprisingly good performance for that size of antenna and ground plane. Good job! If you want to benchmark against the Featherweight GPS performance, this is from the ground station log of a test I did on my deck just now:


I turned on the tracker at and got the first packet at 11:00:14 AM. The first lock was 21 seconds later, and 12 satellites was 37 seconds after the cold start. It was locked on 20 satellites 1:25 after power on. The numbers >40, >32, etc. are the reported signal strength in dB. I have read once (not sure if it's still true for this generation of receivers) that a signal strength >=32 is needed to download the ephermeris data (orbital elements) from the satellites initially, but once the receiver has the data it can continue to track at lower signal strength. If there is a rocket installation that blocks most of the GPS signal, then it can help to get a lock with the av-bay out in the open where the receiver can download the data, and then install the av-bay inside the rocket. I took advantage of that with my carbon fiber booster, where I cut the CF and made a small FG-covered window next to the tracker. This was needed when I was flying a uBlox 8. Later with the uBlox 10, the window was enough to get a lock when the av-bay was in place inside the booster.

Amazing ! Thanks for that, I will run the same benchmark soon and post the results here.

 

[Titan II]

2m band requires entirely different radio modulation....

For some reason you have my name associated with another persons post. I just do not want to be associated with those trying to get you to make significant changes.

 

[Ulyu]

For some reason you have my name associated with another persons post. I just do not want to be associated with those trying to get you to make significant changes.

Sorry that was a weird bug, I edited the post.

 

[FMarvinS]

I am curious what rocketry/balloon type application you have that needs 1+ watt? Going to the edge of space is going to require special programming in the GPS RX unit to make sure it works for the Speed/Altitude limit imposed on them. But I suspect you know that.

FYI the Byonics units are mostly for Ham tracking use in 2D, not for Balloons or rocketry. Their small 2 watt unit needs a separate GPS receiver. They have been out of stock on that and some of that stuff for awhile. I don't think there is that much market for it.

These are used on PICO balloons: https://www.wimo.com/en/picoaprslite
US seller: https://www.dxengineering.com/parts/wmo-picoaprslite
I have one in my electronics bin, was waiting on making a balloon that never happened, at least I got it years ago for less.

The high power really drains a battery faster on the 2 I have , compared to the same brand unit in lower power amplifier. I have a BigRedBee 2 meter high power and an AVRT5 China unit. The China unit is too heavy and not really good for rocketry.

I have also used Big Red Bee GPS 440 standard power units since about when they came out*, on most all my high L2 and 3 flights and they worked well. I used BigBee RDF 440 trackers and still do.

I've lost two of the BeeGPS, one to a supersonic Shred that separated the nose cone from it's shoulder and the Green Bee-GPS board was never seen again in the grass, even after seeing it float to the ground. [They come in Red now it seems, my last two were] The other one was reporting right were it was, in a tree in the Middle of a Bog next to Manchester TN Sod farm. I still have one left.

*PS, I have a video where the M1400 rocket in my avatar has one in the nose, and Greg from Big Red Bee who's camp was next to our club's trailer camp, is calling out the Altitude up and down on my fight to the LCO.

** I've also flown the old OOP OZARK/Loki GPS/900mhz telemetry add-on for the ARTS flight computer on an M1400 as well. I have a video of that kicking around some place on the web. After it went OPP, I sold it here to someone who wanted it for their ARTS boards on a project they were doing. It worked well, but cost seems to have limited the market for it.

Art- Both Byonics (several microtrack units and Big Red Bee produce and promulgate units for high altitude balloons that transmit at 1 watt and 5 watts as exemplified in: https://www.byonics.com/downloads/MicroTrak-1000_Manual_v0.9.pdf
https://shop.bigredbee.com/products/2-meter-5-watt-aprs-transmitter
Also, amateur rocketry websites such as [email protected] document flights to approximately 90,000 feet utilizing Byonics GPS units. Thus the use of higher power transmitters are evidentally in use. Whether one chooses Pico set ups or higher power ones, they are both effective under the right conditions. Again, my purpose was to potentially expand the choices of Ulyu's products. If you'd like to further discuss, please send me a PM.

[email protected]

 

[cerving]

Ulya, I've been through this process... make what you think will fulfill the biggest need (and don't forget that you should be making some money off this, too.) We sell 70cm Ham stuff because there is some demand for it, and because the products that support it did not require a lot of modification to make it work. If you're talking complete redesign for 70cm... probably not worth your effort. Also, set a price point, and make the nicest product you can that hits it... there will always be those that want "more" that will jack up the price beyond what most people will pay.

 

[Simon Auty]

Be aware that different markets have different frequency requirements.
In Australia and New Zealand (although small markets) you will need to have the unit broadcast on the 921mHz channel rather than 915mHz, so an ability to program that would be useful and increase potential sales and increases flexibility rather than having fixed frequency units

 

[cls]

Both Byonics (several microtrack units and Big Red Bee produce and promulgate units for high altitude balloons that transmit at 1 watt and 5 watts

APRS is perhaps the worst possible encoding: (no FEC no coding) AX.25 over (intended for BER -8 phone lines) Bell 202 tones over (-20dB vs QAM etc) FM over noisy (BER -5) 2m band. Gah! It needs that power for the link budget because the encoding is so poor. And 2m APRS doesn't decode most of the time, around 1 out of 3 or 4 packets, under most conditions.


It's easy with modern understanding to make an encoding that is noise resistant and has much better link budget numbers. That means much less power required and smaller batteries and longer xmit life.

2m antennas are too big for rockets, too.

 

[ksaves2]

Back 10 to 15 years ago the smaller the APRS/GPS receive antenna the lower the receive gain. Am sure the technology has improved a lot since then though I haven't flown for awhile due to being widowed and have to take care of a mentally handicapped son. He's in decent enough shape but I just have to get fired up to fly again. I can take him along and he does fine at launches and won't wonder to the flight line except with me to prep for launch. I give him a walkie-talkie and can keep tabs on him.
He will generally go way down wind and watch rockets fly and point them out to me and other fliers out for recovery of their projects when their rockets are down. He stays away from them coming and or when they're down unless I catch up with him or other fliers take him out to the recovery site. Fliers who don't know him recognize quickly he's mentally handicapped, cooperative and are so kind to him. Sometimes they direct him to recover their rockets and he's careful with someone else's project. Kurt

 

[Adrian A]

Back 10 to 15 years ago the smaller the APRS/GPS receive antenna the lower the receive gain. Am sure the technology has improved a lot since then though I haven't flown for awhile due to being widowed and have to take care of a mentally handicapped son. He's in decent enough shape but I just have to get fired up to fly again. I can take him along and he does fine at launches and won't wonder to the flight line except with me to prep for launch. I give him a walkie-talkie and can keep tabs on him.
He will generally go way down wind and watch rockets fly and point them out to me and other fliers out for recovery of their projects when their rockets are down. He stays away from them coming and or when they're down unless I catch up with him or other fliers take him out to the recovery site. Fliers who don't know him recognize quickly he's mentally handicapped, cooperative and are so kind to him. Sometimes they direct him to recover their rockets and he's careful with someone else's project. Kurt

I’m glad to hear that you and your son can enjoy rocketry events together. Thank you for sharing this; it helps us get to know you.

 

[ksaves2]

Hi Ulyu-many flyers are ham radio operators, how about a 2 meter or second choice a 70 cm band frequency? If possible-APRS based would complement those with APRS capable hand transceivers. One advantage is that the transmision range on 2 meters is significantly better than the 900 MHz band. I'd also like to see 2 meter or 70 cm transmission on the Fluctus. In the USA 1 watt plus transmissions are legal on the above bands-so how about a 500 mw or 1 watt transmitter?

1 watt is not necessary for sport rockets and can prove incompatible with deployment electronics. What I mean by that is the deployment electronics either deploy charges on ascent or don't deploy at all. Garmin dog trackers are high powered and one should be careful with those. Saw one dork three altimeters in a large project that made for one big lawn dart. Always ground test the tracker with a dissimilar deployment device(s) with live contain ematches. If the matches don't pop right away or the altimeter constantly resets or simply locks up one is good to go if they stay in the "ready" mode. I learned the hard way a couple of times many years ago. Of course the combo tracker/deployment devices on the same board, the maker has already tested so one is good to go. Also some purveyors of rocket electronics have a list of what plays well with what.

 

[ksaves2]

APRS is perhaps the worst possible encoding: (no FEC no coding) AX.25 over (intended for BER -8 phone lines) Bell 202 tones over (-20dB vs QAM etc) FM over noisy (BER -5) 2m band. Gah! It needs that power for the link budget because the encoding is so poor. And 2m APRS doesn't decode most of the time, around 1 out of 3 or 4 packets, under most conditions.


It's easy with modern understanding to make an encoding that is noise resistant and has much better link budget numbers. That means much less power required and smaller batteries and longer xmit life.

2m antennas are too big for rockets, too.

Agreed, 2m APRS was conceived in the 80's for Ham radio use. Not necessarily rocket tracking and is an old mode. I find I generally start getting positions on descent. The reliability is even better when the main chute blows hence I'll try to blow mine at 800 to 1000 feet if possible.
Yes a good antenna for 2m would be too long for rockets. Usually no positions received even after apogee. Maybe under drogue if lucky but settles down while a slower descent under the main chute.

 

[Steve Shannon]

That is surprisingly good performance for that size of antenna and ground plane. Good job! If you want to benchmark against the Featherweight GPS performance, this is from the ground station log of a test I did on my deck just now:

View attachment 653969

I turned on the tracker at and got the first packet at 11:00:14 AM. The first lock was 21 seconds later, and 12 satellites was 37 seconds after the cold start. It was locked on 20 satellites 1:25 after power on. The numbers >40, >32, etc. are the reported signal strength in dB. I have read once (not sure if it's still true for this generation of receivers) that a signal strength >=32 is needed to download the ephermeris data (orbital elements) from the satellites initially, but once the receiver has the data it can continue to track at lower signal strength. If there is a rocket installation that blocks most of the GPS signal, then it can help to get a lock with the av-bay out in the open where the receiver can download the data, and then install the av-bay inside the rocket. I took advantage of that with my carbon fiber booster, where I cut the CF and made a small FG-covered window next to the tracker. This was needed when I was flying a uBlox 8. Later with the uBlox 10, the window was enough to get a lock when the av-bay was in place inside the booster.

Ulya, I've been through this process... make what you think will fulfill the biggest need (and don't forget that you should be making some money off this, too.) We sell 70cm Ham stuff because there is some demand for it, and because the products that support it did not require a lot of modification to make it work. If you're talking complete redesign for 70cm... probably not worth your effort. Also, set a price point, and make the nicest product you can that hits it... there will always be those that want "more" that will jack up the price beyond what most people will pay.

This is off topic, but I just want to acknowledge how generous Adrian and Cris are to our hobby and what a positive contribution they make by participating like this. We are very fortunate to have such truly talented and sincerely helpful vendors.

 

[ksaves2]

Art- Both Byonics (several microtrack units and Big Red Bee produce and promulgate units for high altitude balloons that transmit at 1 watt and 5 watts as exemplified in: https://www.byonics.com/downloads/MicroTrak-1000_Manual_v0.9.pdf
https://shop.bigredbee.com/products/2-meter-5-watt-aprs-transmitter
Also, amateur rocketry websites such as [email protected] document flights to approximately 90,000 feet utilizing Byonics GPS units. Thus the use of higher power transmitters are evidentally in use. Whether one chooses Pico set ups or higher power ones, they are both effective under the right conditions. Again, my purpose was to potentially expand the choices of Ulyu's products. If you'd like to further discuss, please send me a PM.

[email protected]

Some years ago I picked up a balloon through a one hop digi-peater that was 436 miles away. Routinely heard some directly at > 100 miles away. At those altitudes Rf can really carry. For giggles one can use this calculator to determine radio line of sight: https://www.everythingrf.com/rf-calculators/line-of-sight-calculator.
One balloon group flew the "expensive at the time" Kenwood D7A with a GPS and recovered it. They probably had $600.00 tied up in the radio setup alone.
Too rich for me if it could go down in a body of water or end up in high tension power lines. Not to mention trees which would be easier to get and possibly some "nasty" landowner who won't let anyone "on their property" no matter what. I imagine some rocket fliers had to deal with that last one.
A flier doesn't need that much power. To increase sensitivity on the receiver side, can always use a Yagi antenna on the receive end. Invest or build a receiver attenuator and can do directional tracking of "beep-beep" Rf trackers.

 

[AlexBruccoleri]

This is off topic, but I just want to acknowledge how generous Adrian and Cris are to our hobby and what a positive contribution they make by participating like this. We are very fortunate to have such truly talented and sincerely helpful vendors.

I had the exact same thought. Thank you @Adrian A and @cerving

 

[Rocket Prophet]

Hey,

I'm the guy behind Silicdyne, a company dedicated to providing the best in advanced rocketry electronics at low cost.

You may have heard of my first product, the Fluctus flight computer. It's a project that's still ongoing development and on the market, but in parallel I'm also developing my next product.

This thread will be dedicated to that new project, called Reperix.

Reperix is a GPS tracker for rocketry.
Its principle is fairly standard: a module, which knows its position via GPS satellites, is placed in the rocket and transmits its coordinates by radio wave to a ground station. The ground station then retransmits the information to a software application (in this case a mobile app) so that you can monitor your flight and be guided back to your rocket on recovery.

In terms of performance, Reperix is up there with the best with its 140mW long-range radio, and latest-generation GPS chipset (ublox M10) for excellent dynamic tracking up to 80km altitude and 500m/s.

One of Reperix's greatest strengths is its size:
the module itself measures down to just 12 by 30mm, making it the world's smallest rocketry GPS tracker. Perfect for your wildest projects!
*For reference, that's more than 2 times smaller than the Featherweight.



And the best part is... I've already got a fully functioning prototype of that thing!

Quick hardware notes:
The battery is intended to be plugged through the bottom USB C connector (capable of voltages from 3.5 to 16 volts), but this might change in next versions.
The actual 915mhz antenna is connected through a robust IPEX radio connector, and there is exposed pad for soldering a thin ~8cm copper wire instead.
All in all you should be able to make a super lightweight and compact tracking setup (reperix+antenna+battery) within 9 grams.

View attachment 653824


2 euros coin for size reference:

View attachment 653832


The ground station used - SteadyBluetooth:

View attachment 653833


I'm planning to do plenty of ground and flight tests soon to properly validate the specs.

On the software side, I'm also making good progress and already have functional firmware/application foundations.
Here's a list of the features that are being / will be implemented:


On the Reperix tracker:

• Configurable radio channel selection with automatic switch on frequency occupancy
• Launch/Apogee/Touchdown detection algorithms
• Flight trajectory recording in internal memory
• Possibility of sending location packets automatically over TheThingsNetwork to track Reperix almost anywhere in the world (useful for potential high altitude balloon usage)
• Battery voltage monitoring, LED status indication...

On the mobile app (Android/iOS), connected to SteadyBluetooth ground station:

• Flight data display / GPS details
• In-app distance/bearing and live tracking on a map
• Voice telemetry during flight
• Settings config
• Convenient and plug and play user experience

For trajectory data download/view, and firmware updates, I'm planning to build a web tool (thus usable anywhere on any PC, without installing anything).


The aim is to have a first user-ready version in about 2 months, in order to launch a small betatest campaign.
I don't have a proper pricing estimate to share yet but it should be quite attractive.
More is coming soon.

If you have any suggestions or questions, feel free to react to this post!

I am very interested in being a part of the Beta test campaign. I have a Wildman Punisher 3" build that I have just started. I think this Reperix tracker system would be perfect for Punisher 3"! If, it is not too late to be a part of the Beta Test Campaign, please let me know what I need to do?

 

[Ulyu]

That is surprisingly good performance for that size of antenna and ground plane. Good job! If you want to benchmark against the Featherweight GPS performance, this is from the ground station log of a test I did on my deck just now:

I've discovered that the downlink radio transmission interferes a little with the GPS receiver. It's really not a big deal, but it "rises" the noise floor enough to make the satellite locking a bit longer.
The solution to that was quite simple: when the tracker is powered up and the GPS chipset is trying to lock the first satellites, I made the radio transmit power to automatically reduce down to 25mW. Which is more than enough when a rocket is on the pad.
Once it has downloaded the ephemeris data (which as you said, requires a good signal to noise ratio), the radio transmission switches back to nominal power (up to 160mW) while keeping track of the locked satellites.

Now I'm able to get even better performance without it making any functional difference to the end user:
the first position fix is 35 seconds after power-up !



I'll be doing further benchmarks with different configurations and taking DoPs (dilutions of precision) into account.

Speaking of benchmarks, I'm planning to test it in flight tomorrow in a tiny 26mm rocket to about 2kft and collect the data:



I'll post the results here.

This is off topic, but I just want to acknowledge how generous Adrian and Cris are to our hobby and what a positive contribution they make by participating like this. We are very fortunate to have such truly talented and sincerely helpful vendors.

I agree too, thanks again Adrian for sharing these details !

 

[Tractionengines]

The solution to that was quite simple: when the tracker is powered up and the GPS chipset is trying to lock the first satellites, I made the radio transmit power to automatically reduce down to 25mW. Which is more than enough when a rocket is on the pad.
Once it has downloaded the ephemeris data (which as you said, requires a good signal to noise ratio), the radio transmission switches back to nominal power (up to 160mW) while keeping track of the locked satellites.

Now I'm able to get even better performance without it making any functional difference to the end user:
the first position fix is 35 seconds after power-up !

Good testing and diagnosis. GREAT Solution to the issue. Good luck with the rest of the testing.

If you need another engineer as Bata tester let me know. I DON'T have access to a high waiver, (4500ft) but we gave LOTS of corn and soybean fields. Trackers working in them with all the interference is important too. How close until it locks, and how well does it work with both rocket and receiver, in 10ft tall corn?

 

[OzHybrid]

Thank you !!



It was quite a pain to get the circuit board design RF-efficient, but surprisingly it's pretty good!
With sort of optimal conditions (no antenna obstructions and clear sky), it managed to fix 12 satellites in about 3 or 4 minutes, and it provides me position with a fairly small uncertainty radius (about 2m). I'll be doing more tests soon to see how dynamic tracking performs during a flight.



From tip to tip, the board with the mounting tabs is 19mm wide.
I'll have to see if I change them or rotate them to get the true 12mm width without having to break them.
To respond to @Titan II , the idea of placing them like that is to make it easier to install the tracker in a bay, and that the few people who want to go below 19mm won't be bothered to break the tabs and use another mounting method. I've made that choice for this first version because it seemed the most convinient for me. I like them too.



It's intended to be mounted using M1 screws.

Supply some M1 screws and nuts with the board. That's not a common size and you'll make everyones life easier.

 

[Ulyu]

Supply some M1 screws and nuts with the board. That's not a common size and you'll make everyones life easier.

New design went to M2 mounting, and yes, I'll supply screws in the box.

 

[Ulyu]

Update on what's been happening over the past 2 weeks:

I received the version 0.2 of Reperix and the few modifications are quite perfect. Basically, this revision has more convenient mounting tabs, and a smaller/lighter USB connector which has reduced the tracker by a further 2mm.
There are 10 units that will be distributed to betatesters (who haven't yet been selected... that's coming soon).




This photo also shows the final and working version of the new Bluetooth ground station. I've got nearly a hundred of them built and ready to go !

I haven't had the occasion to test the tracker in a real rocket flight yet, because I preferred to have solid software and simulating it a bunch of times before going any further with benchmarks.
BUT for other testing purposes, I have indeed tested it many times in flight on a racing drone. And the high-dynamic tracking performance is... just INSANE. To spoil a bit, it's actually even better than what I had originally set out in the specifications.
Here's the raw trajectory recorded by the tracker on one of these tests:



(You can't really see here, but the thing really kept a 3D accuracy close to a meter and didn't lose track of any satellites, while I was doing literal loops in the air at 100km/h... If you want more details on the tests I have already made, let me know, but I'll skip because this thing is going to be put in a rocket in no time anyway.)

Apart from that, the mobile application has also made good progress;




It's robust and functional and I'm starting to add some pretty cool features. For example, I'm working on a frequency scanner to check every channel and see if there's already any device (likely to cause interference) or Silicdyne product powered up.


Also a small preview of the webapp I mentioned last time, used for updates, trajectory download, and probably more :




Finally, to reply to questions I had no answers yet:

• In terms of downlink range, with base antennas:
  • On the ground, line of sight: at least 2 or 3 km
  • Just before the rocket hits the ground (~100m altitude): more than 10km
  • In flight: over 40km
• In terms of power consumption, the maximum continuous average is 180mW. A low-consumption cyclic standby mode is planned.
• For trajectory recording, as for now it's done on the tracker itself, with 4 points per second for 20 minutes. Local recording on the application is planned.

Stay tuned !

 

[xSwaggyMcjaggyx]

These are sick! Are these FCC or CE certified in the United States or Europe? I wouldn’t want to get into any legal trouble while using this product, but I’m not too familiar with the laws here.

 

[Ulyu]

These are sick! Are these FCC or CE certified in the United States or Europe? I wouldn’t want to get into any legal trouble while using this product, but I’m not too familiar with the laws here.

Thanks !
Yes you can use it without licence in the USA on 915Mhz, FCC ID: VPYLBAA0QB1SJ
For Europe I'll add an option to switch to 868Mhz, but it also already have a CE certificate.

 

[ksaves2]

One should be aware if using a separate tracker and altimeter, they should ground test with bare ematches. I had 100mW trackers dork deployment devices and it took me two flights to realize Rf can whack deployment devices. Of course if one is using an all-in-one tracker/deployment device, the maker has already done the testing to make sure everything plays well before release. When I used to track balloons, the local digipeater was on a 100 foot tower. It digipeated positions from over 400+ miles away directly on 144.390mhz.
Oh I saw a Garmin 2 watt dog tracker dork three deployment altimeters in a large project leading to a lawn dart. Flier didn't ground test. Kurt

 

[xSwaggyMcjaggyx]

Thank you !

You can use it without licence in the USA on 915Mhz, FCC ID: VPYLBAA0QB1SJ
For Europe I'll add an option to switch to 868Mhz, but it also already have a CE certificate.

I did some research today and found some great information that might help you out with your future endeavors.

I'd recommend checking out an article that was published by SparkFun for more information about the FCC and how they're able to operate under these Rules and Regulations:
https://www.sparkfun.com/tutorials/398

And of course, check with the Federal Communications Commission (FCC) Rules and Regulations for Title 47 Part 15 for more accurate information regarding the legality of operations within the United States.
https://www.ecfr.gov/current/title-47

The general construct I've found when reading online articles/blogs is that even if you do construct your product from FCC Certified components, it's more than likely that you'll need to do testing to prove compliance with the FCC with all components working together in harmony. I'm not saying that you're product does or will not work (it obviously works), but the FCC is established so that there is no interference within the public spectrum. Items such as ham radios, cellphones, radios, satellites, etc. are technically "at risk" from jamming whether its intentional or not. Therefore, it is up to the manufacturer/company to do their due diligence in ensuring that these products are and have been FCC certified to be allowed to operate within the United States legally. The FCC has two ways to find out how your product operates: 1. By coming into a test lab, getting a compliance test, then achieving certification and getting it filed or by 2. Getting caught by the FCC and receiving a hefty fine from them.

I guess the first question is do you have a FCC certificate for any of your products? and if not... Does Wildman Rocketry know that? As a vendor they could be liable as well since they're selling them directly from their website. I'm no lawyer, but I'm sure you can see how this could be bad not only for the parties involved, but for the rocketry community as a whole.

Before I end up buying a Fluctus device, I want to ensure that this product is safe to use within the United States. If I ended up flying this device at the next launch, I want to make sure I'm not putting anyone in harms way at the launch field especially dealing with pyrotechnic capabilities. Food for thought. I hope this helps and I hope I'm not stirring things up, I just want people to be aware of the FCC and the serious nature of it within the US. You could possibly contact the folks over at Eggtimer Rocketry or Featherweight Altimeters and they might be able to further assist you on how to proceed.

 

[Ulyu]

I did some research today and found some great information that might help you out with your future endeavors.

Thank you for your research.

Concerning this new tracker product, the OEM radio transmitter is already certified to be compatible with FCC title 47 part 15, as well with CE, IC, MIC, KC, NCC, and ANATEL. I'm pretty sure that the assembled product itself doesn't need to be re-certified, since there are no intermediate components between this single radio emitter and the antenna that radiates. I'll contact Murata Manufacturing (the company that makes the OEM module, as well as its internal radio front-end) to get more information from themselves, but note that this pre-certifications are precisely something they offer to ease implementation.

For my part, I tested my system as with the few analyzers I have available to make sure the transmitters were working properly. My tests are rudimentary and have no legal value, but I'm willing to share more if you wish. I am acting in good faith.

As far as Fluctus is concerned, it has no certification (neither the product itself, nor even the OEM transmitter, although the manufacturer, Vollgo, assures me that it is compliant-ready).
Also, as explained in the documentation:

Although not certified under FCC Title 47 Part 15, Fluctus, used for educational and experimental purposes in remote locations, is considered by the Federal Communications Commission to be "generally exempt" from authorization requirements.

*But I don't live in the USA and have had no contact with the FCC authorities on this subject. The only thing I did is following and trusting the guidlines of other small manufacturers in the USA who seem to know what they're doing. If you have any additional information about this grey area, I would love to hear from you !

Concerning Featherweight, it seems like its complete tracker has passed FCC certification.

Regarding Eggtimer, their products are not certified, and it seems that some of the OEM transmitters they use aren't either. I learned about this "tolerance zone" in FCC regulations from them.

As for Wildman and the other resellers I deal with, they've supposedly all read the documentation.

 

[Rocket86]

Watching with interest!

 

[cerving]

This comes up from time to time... as we state in our legalese at the beginning of the manuals, the FCC's Chief of Enforcement ruled quite awhile ago that kits are "generally exempt" from certification.

We actually caution the people that are assembling Eggtimer kits for a fee that they cannot sell assembled products unless THEY go to the considerable expense to certify them; selling an assembled product makes you a "manufacturer" in the FCC's eyes. Assembling a kit that somebody else purchased is allowable.

 

[Frozen]

Out of curiosity, what's the approximate cost for the unit and a combo with the ground station looking like right now? This looks like a very nice product.

 

[FredA]

the FCC's Chief of Enforcement ruled quite awhile ago that kits are "generally exempt" from certification

Exempt is OK as long as it's actually legal too.
Claiming an exemption due to a "loop hole" while trouncing all over some frequency is beyond poor form.
Not saying that's what you're doing - but your statement sounds very evasive.

Legal but uncertified as a hobby device is OK.
Illegal regardless of origin is not.
Please make sure your device is the former.

 

[FredA]

I'm pretty sure that the assembled product itself doesn't need to be re-certified, since there are no intermediate components between this single radio emitter and the antenna that radiates.

If you can change the antenna, you'll need a "light weight" cert to confirm you're not radiating too much power with a high-gain antenna. That's what "compliant-ready" means.

No free lunch.