Tracking Devics

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For sometime I've been looking for a reliable tracker that is not priced higher than my rockets fly. Tried SpyTech and that didn't work; tried Egg Timer and have no idea how to begin with that thing. Thinking now about a BRB900 TX/RX. Appreciate any thoughts and suggestions.

Steve Hunter
 
For sometime I've been looking for a reliable tracker that is not priced higher than my rockets fly. Tried SpyTech and that didn't work; tried Egg Timer and have no idea how to begin with that thing. Thinking now about a BRB900 TX/RX. Appreciate any thoughts and suggestions.

Steve Hunter

The BRB900 costs much more than the others you noted. I have been a fan since the debut in 2010. The TX/LCD combo works right of the box, but you need another device to punch in the lat/lon coordinates for finding the rocket.

Missileworks T3 is also good at a much lower price, but you need to be savvy with phones, apps, Bluetooth, and making connections. Batteries, wiring, switches, case, programming software, mapping software, and Android device not included.
 
I like the eggfinders, but they aren't everyone's cup of tea, so I'm going to offer two out-of-the-ordinary alternatives. If you have cell phone service at your launch area, you may want to look into the insane rocketry app. You just load it onto an android device, and it claims to provide tracking, video, and accelerometer data.

The other alternative could be a Trackimo. It also requires cell service and you would have to purchase a dedicated sim card for it.

The issue with both of these devices that neither are particularly small, but they are probably easier to use than any of the other options out there.

(Take all of this will a grain of salt--I haven't used either of these devices.)
 
Do you want a reliable tracking system? What are you willing to pay? That is usually the question and for the most part, you get what you pay for. No matter what system you pick you have to understand the limitations and failure modes of the systems.

RDF trackers are almost bullet proof but take skill and practice to get good with. It's a simple transmitter outputting a pulse and a directional antenna to receive it. If you don't crash the rocket, the transmitter is almost certain to continue transmitting. You many not receive the pulse when the rocket is on the ground and have to rely on experience and knowledge of the launch site to get within range of a transmitter on the ground, but it will usually still find the rocket for you.

GPS trackers are much more complicated and subject to failures for various reasons but tend to be really easy to use. Unlike the RDF which only needs a pulse of radio energy, the GPS have to be able to receive satellite signals, calculate an accurate position, and transmit data packets. The receiver then needs to get the whole data packet. A single pulse of radio energy just won't do. Even if you are receiving the transmitted signal, if you don't get the whole data packet, you don't get anything. One advantage is the recieve system can save the last good packet and give you a place to start searching. The problem is if you lose communications between the two early in the flight and don't reacquire, you are generally hosed. You are then stuck wondering around with the receiver until you get close enough to the transmitter to start getting data packets again which is generally a much shorter range then what a RDF can pick up a pulse from.

Buzzers, chirpers, dog/wife trackers etc. tend to have many more drawbacks when used in rockets because of their short audio ranges or dependence on cell services. While very good in certain situations, they tend to have limited usefulness overall.

Check with the club you fly with. Many of them have older RDF systems, like a Walston, that may be available for use by club members. We have a Walston system the is seldom used, but it is very reliable and has very few "failure modes". It does take a little practice to get good at RDF, but it's kind of fun and has certainly saved my rockets multiple times.

I also use the Missleworks T3. No cell service required. If you can pair your Android phone to a bluetooth earpiece or your car's system, you can pair it to the T3. I use Rocket Locator and have had very good luck with it. The Play Store makes it a quick download and install. You'll need a couple of S1 LiPo batteries or a 3/4 battery pack of AAA or AA. The LiPos are easier and last longer. You will need a charger for the LiPos and some extra connector leads are also nice. Expect to spend another $50 above the T3 price if you don't have a LiPo charger and S1 batteries already. If you've build av-bay's before, you shouldn't have any problems setting up the transmitter in your rocket. A plastic 1U outlet box can work well for mounting the receiver and antenna.

There are lots of options and we all have opinions on which are best. You will have to decide which is best for you. I would suggest you talk to the folks at your launch site. Geography is a huge consideration. The open spaces and lake beds of the west are very different from the rolling hills, woods, creek bottoms, and crop fields of the east. The local folks should be able to give you some good insight into what works at their launch site.
 
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Counterpoint:

If any system loses power or the radio Rf energy can't get out of the airframe, there's going to be a problem. I remember seeing people free packing a Beeline GPS tracker that's very easy to have the battery power cable loop around behind the pc board.
Push the button, high G flight ensues and board cuts the battery cable. If any system is installed inappropriately there is going to be a problem. Break or distort the antenna in flight and there is going to be a problem. Having a GPS tracker
with an RDF tracker backup is reasonable for projects that have the room.

That said, I've heard of folks with totally sight unseen high powered filghts that couldn't keep an RDF bearing locked and lost the rocket. Try as they may, they couldn't get within the ground footprint of the tracker. Out on the playa, the ground footprint
is very short. I've been told that a reasonably powered GPS tracker is mandatory for completely sight unseen flights there. Listen, if one can get a visual on any rocket in the terminal phases on descent under the main chute, doesn't matter whether
it's a GPS tracker or RDF tracker, as long as they're working you are going to get it back. You can see right off where to proceed.

The edge of GPS is one has the potential of getting a position on a map when the rocket is so many feet in the air. It's likely going to have to be higher up the farther out the rocket is. Nonetheless, a position from 100 feet in the air or lower is likely going to get one within the ground footprint of the tracker for terminal recovery. Especially if it's a totally sight unseen flight. RDF, you got a bearing and no distance. GPS you got a bearing and distance.

One other GPS advantage that is totally lacking with RDF is with an off-nominal or ballistic flight. Experience that and even if the rocket is a few hundred feet in the air when the last position is received, walk to it and there is a good chance you'll find the hole
or the pieces. I'm talking totally sight unseen. One might be able to salvage most of an FG rocket in that case. RDF? Unless one can keep the bearing and keep walking (there is no idea of the range) they are SOL because the tracker (GPS or otherwise) dies on the hit.

A possible mistake with any tracker is using the wrong device with an aggressive flight profile. 900Mhz doesn't have the best propagation period. Someone is going to lose an EggFinder (if it hasn't already happened) or some other 900Mhz GPS tracker because they used it in an extremely high flying rocket that drifted too far. That's the bad news. The good news is for most sport fliers that's not the issue because one is not routinely sending sport rockets up to 20,000' with a 1 mile diameter launchsite radius. Sport fliers have no trouble tracking no matter what is used because their rockets land relatively close. (Multtronix is in a league by itself and uses higher 1 watt power
on 900Mhz.)

Rich is a dedicated RDF guy and I've done some of that but I'm lazy and find if I can go get the rocket without diddling around, I can get back quicker with a properly functioning GPS tracker than with an RDF one. Again, if at any time one sees the rocket on the terminal descent under main, all bets are off. One is going to find it no matter if GPS or an RDF tracker is used. You see an RDF rocket coming in, one can use a handheld GPS with a "Sight 'n Go"
feature to lock in the bearing to proceed. I wear an Etrex Vista HCX around my neck at every launch for that that purpose (good for modrocs too) Take the Yagi antenna, radio and attenuator with you and you'll get it back.
Totally sight unseen flight there is an advantage with a GPS tracker as long as one receives positions on descent. A GPS tracker generally settles down once the main chute has blown and the descent speed has slowed down.
A good strategy here is to blow the main chute up higher rather than down lower so one has the advantage of better propagation and more time to develop a drift pattern before LOS (loss of signal). This might be more important if one
expects the rocket to land a fair distance away.

Another bit of advice is put a screamer on the harness no matter what you use, GPS or RDF. In standing vegetation one's hearing (if intact) beats any GPS or RDF any day!

If one wants the absolute "best range", get a Ham Ticket and use 70cm or if you have the room in the rocket, a 2 meter tracker:

https://www.radioddity.com/sainsonic-ap510-aprs-tracker.html#

https://www.tracksoar.com/
I kinda am leary about the small GPS antenna on the tracksoar as it's meant for a sedate balloon flight

https://www.db1nto.de/index_en.html
https://www.hamradio.com/detail.cfm?pid=H0-015928

All of the above take a Ham ticket and again, if one one is not routinely going above 10k with a lot of vegetation around, or a significant drift distance, the unlicensed trackers should be fine.
The LoRa technology in the upcoming Featherweight offering would be about the "highest" end of the low end trackers. It will probably be one notch below Multitronix and more affordable. Looks like the cost of two (the minimum needed to track) would be about what a Beeline GPS Ham tracker would cost although the price might go up the more time it takes to develop. Stay tuned. There was nothing but APRS in 2005 and it was all Ham and it cost.
(There were I believe a couple of 900Mhz GPS trackers back then but the cost was pretty steep. Much more $$$ than getting a Ham license and getting the Ham equipment.)

One other tidbit. Don't use a 900Mhz Yagi antenna to try to track a rocket in flight. The beamwidth is very narrow as compared to 70cm, 1.25M and 2M hence people flying transmitters on those bands can use
Yagis for in flight monitoring. A cheap 900Mhz Yagi is still a decent tool for ground recovery as the rocket isn't moving so fast and it's easier to aim at a stationary target. Proved it to myself a couple of times.
Used a 900Mhz Yagi to recover a TRS on one flight and an EggFinder on another flight that were completely sight unseen. Screwed on the Yagi cable to the EF LCD and pointed the Yagi horizontally in the direction
of flight after looking on the map. Proceeded to the rocket and once the signal was reacquired (still couldn't see the rockets either) I put the vertical dipole (or duck antenna) on the receiver and the signal
disappeared. Sure, I was going to find the rockets anyways and the Yagi wasn't needed but if the recovery was under more difficult circumstances, ie. rocket drifted farther than expected and one had to resort to
following the drift pattern the larger ground footprint afforded by the Yagi could be a recovery saver. Any "edge" one can acquire with a recovery system is just cheap insurance at getting a rocket back.

Kurt
 
If you have cell phone service at your launch area, you may want to look into the insane rocketry app. You just load it onto an android device, and it claims to provide tracking, video, and accelerometer data.

The other alternative could be a Trackimo. It also requires cell service and you would have to purchase a dedicated sim card for it.

The issue with both of these devices that neither are particularly small, but they are probably easier to use than any of the other options out there.
+1 on Insane Rocketry, it works great, as long as your rocket is big enough to carry an Android phone and your launch area has cell service.

I would not recommend a Trackimo or other device that requires a monthly fee. If your launch area has cell service, a cheap $20 GPS tracker will get the job done, e.g., https://www.ebay.com/itm/K8-Mini-Sm...hash=item36253cd2aa:m:mRY7dmVeS_juMjvxn6acW2g
 
+1 on Insane Rocketry, it works great, as long as your rocket is big enough to carry an Android phone and your launch area has cell service.

I would not recommend a Trackimo or other device that requires a monthly fee. If your launch area has cell service, a cheap $20 GPS tracker will get the job done, e.g., https://www.ebay.com/itm/K8-Mini-Sm...hash=item36253cd2aa:m:mRY7dmVeS_juMjvxn6acW2g

It will get the job done as long as the GPS antenna is not facing the dirt where it lies and it has a lock of some kind. You could try calling it several times on descent to get a
drift pattern but unless it writes to lat/long serially to a table and can send the table of all the positions to you, you could be SOL. If you are depending on it to get you the "final position" lying on the ground well, just hope it has a lock of some kind. Even then the area of resolution could be lousy and you better have a loud screamer on the harness.
Kurt
 
It will get the job done as long as the GPS antenna is not facing the dirt where it lies and it has a lock of some kind. You could try calling it several times on descent to get a
drift pattern but unless it writes to lat/long serially to a table and can send the table of all the positions to you, you could be SOL. If you are depending on it to get you the "final position" lying on the ground well, just hope it has a lock of some kind. Even then the area of resolution could be lousy and you better have a loud screamer on the harness.
Kurt
At least for me, although the GPS tracker may lose lock for a few seconds during rapid ascent, it has always retained lock during descent and on the ground. On one occasion, the rocket had a hard landing and the tracker lost power, but it recorded the location where it was just before impact, so I found the rocket at that point. The $20 tracker is small, about 1.5" x 1.5" x 0.5" and there's no external antenna. The only problem is that it just works on 2G, which means borrow a T-Mobile sim on launch day or buy a SpeedTalk sim and pay $5 per month. I'm still looking for a 3G tracker that could use a free Freedom Pop sim, but so far the cheapest 3G tracker I've seen is around $75 (buyer beware, some trackers on eBay say 3G but actually are not). If the rocket is big enough, you can use a free Freedom Pop sim with the free Insane Rockets app and a cheap, used Android phone (e.g., Nexus 4, about $35 on eBay). Then you have not only a tracker but also an altimeter, flight data recording, Google Earth flight map, even video. I use this setup with my larger rockets and it hasn't failed me yet (knock on wood).

+1 on the screamer, a cheap backup, you can never have too many tracking devices on a high altitude rocket.

@Kurt - "try calling it several times on descent". It seems you are referring to the older SMS trackers where you send a text to the tracker and it replies with a text stating its latitude and longitude. My trackers do not involve texting, they are used with a phone app that shows the rocket's location on a Google map. I use the K8 (link above) and the MD-601. I like the MD-601 better but its price seems to have doubled since I bought mine, see https://www.ebay.com/itm/Mini-Perso...-LBS-Tracking-Free-Web-APP-Track/282621259341
 
Okay I stand corrected a second time today. The insane rocketry app is something one can load into a beater Android with service, that will send tracking data to a server that one can monitor with a second cell phone with data service.. it looks like it's doing live tracking so that would be acceptable to me. Kurt
 
Okay I stand corrected a second time today. The insane rocketry app is something one can load into a beater Android with service, that will send tracking data to a server that one can monitor with a second cell phone with data service.. it looks like it's doing live tracking so that would be acceptable to me. Kurt

Kurt, I tend to agree with this post and your previous posts. Tracking devices can be technology dependant, dependant on conditions, require user knowledge and skill, or just have features that work better in some places or other.

I like DRF because I've used it, have become, (I think) skilled at it, and use it on the east coast where there is no playa to suck up the ground signal. I don't have enough experience with GPS to determine if it's advantages outweigh RDF yet. I've recently started using a GPS tracker that has worked well so far. Again, I haven't had a problem with radio distortion because of ground feature, or technology limitations. The use of cell phones as a tracker seems to be the method most susceptible to issues since it depends on GPS satellite receiving along with having cell service available.

I keep thinking about the KISS principle (Keep It Simple Stupid). RDT is usually the simplest. There are gaps in RDF where GPS has advantages and can fill in. When used together the two systems are pretty reliable. If you go with anything cell service dependant you have gotten a long way from KISS. Not to say it won't work, but what's your risk factors?

When you get right down to it, what type of tracker(s) you use are design decisions that are affected by many variables and how much weight you apply to each of those variables. Typical engineering questions. Don't you just love rocket science!!!!
 
I'm all for Big red bee basic transmitter, not that expensive,small, can take a beating, programmable. Most the cost is in the receiver however, you do have to obtain HAM technicians license to purchase one from the website.
 
All great comments. A lot of the recovery strategy has to do with the nature of the flight. If at any time one gets a visual on descent, doesn't matter what kind of Rf tracker is involved, if on can "lock a bearing" by whatever means, they'll get it back. Rich's KISS philosophy is well taken and RDF is an acquired skill. The key is getting a bearing lock on descent that is the kicker to get one into the ground footprint of the tracker. Me, I'm pushing towards 20 flights with GPS tracked rockets with only one loss due to deployment failure (and the fact that Rf couldn't get out of the rocket) and another "tracker practice" rocket with a ballistic descent to terra firma. Found the fincan sticking up as I went to the last received position (which was one of two positions) and dug the rocket out. Rocket survived, tracker gave it's life.

Now, these weren't M+ power screamers that landed 2 to 5 miles away but smaller rockets only one of which was an L motor. Most flights were from 5 to 8,000 feet (except the 10k on the L) and nothing was seen except a smoke trail. They landed under 2 miles away and several I had no idea where to proceed except from the map position of the last known position. I live track on a map so it's easy. A lot of work to setup but once started rock steady.

Several of the rockets I likely would have been able to wave the Yagi, dinked with the attenuator if needed and locked a likely terminal descent bearing in but some that did some funky gyrations due to winds aloft would have been a difficult RDF recovery for me.

If one has a good hunch as to where the rocket has gone, good chance they'll get within the ground footprint of the tracker. If totally sight unseen, one really has to concentrate on locking in a bearing with RDF before the signal is gone and then get within the ground footprint to home in.

I messed around with a modroc on an E30-7 with an XFM-1: https://www.jbgizmo.com/page30.htm The rocket had the room for a vertical wire dipole and it indeed had a 400 yard range on flat farmland ground. Test flight landed within sight but if it was in grass or corn, the attenuator on my
3 element Yagi would have had to been activated. I did fire up the attenuator and indeed was amazed by the directivity afforded by it as I walked in closer to the "seen on the ground" rocket.

My attenuator of 2m that can work on the 70cm ham band too is this one (For Beeline 70cm RDF trackers in mind) https://www.west.net/~marvin/k0ov.htm.

If one wants a 2 meter band RDF tracker, Marvin's 50mW tracker is a decent choice: https://www.west.net/~marvin/microhnt.htm

He'll customize it with callsign and morse message for one too. If one can fit it in with a 1/4 wave antenna, propagation would be very good
in rockets that have the room to carry it. For any tracker, the better the antenna, the better the range. Kurt KC9LDH

Kurt
 
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