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  1. #1
    Join Date
    2nd January 2013
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    210

    Just cant get this Eggfinder to work right for me

    Launched my Vulcanite on an I500 today. Eggfinder gave me a position on my Android phone as to where the rocket landed, but the rocket was nowhere to be found. Put in the gps coordinates from the Eggfinder lcd screen on my wifes phone, and it gave us the same location where we were standing. Since I had an idea already where it had landed I continued walking and found the rocket about a quarter mile further. If I hadnt seen the rocket coming down I would have never found it.

    Now the rocket did go on the other side of some HUGE power lines. Could those have interfered with the Eggfinder transmitting the coordinates?


  2. #2
    Join Date
    26th November 2009
    Posts
    4,603
    Question: Did the egg finder LCD continue to beep a signal and display a position while you were at the last known location? Kurt


  3. #3
    Join Date
    2nd January 2013
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    210
    Glad you asked that. No, it didn't. It started beeping again as I was walking towards where I thought it was and got closer. I didn't pay attention to coordinates on the LCD or location on my phone. Figured I was on my own at that point.

  4. #4
    Join Date
    11th April 2017
    Location
    Brisbane Australia
    Posts
    536
    One thing to be aware of, check your GPS map app accuracy of input coordinates - I found one of the map apps I got for the iphone that allows pre-caching of maps tiles only accepted 4 decimals of accuracy, not 5.. If you put 5 decimals in, it ignored the last one..

    I have ended up reverting to google maps so far.. I am also gradually testing apple maps when I am wandering looking for the rocket, as I've found it wears the battery down less..
    Reasonably new to rocketry and hailing from the land down under.. I speak metric... I know not of these feet and inches you speak of...

    QRS: #193
    AMRS: #148

  5. #5
    Join Date
    2nd January 2013
    Posts
    210
    5 decimal points. My wife reminded me right now that while I was watching the rocket, I told her to take a pic of the coordinates. She said the LCD stopped beeping well before the rocket was near the ground. That's when she snapped the pic of the coordinates.

    All the nearby roads show up on the map. Just where the finder said my rocket was it wasn't. I'm suspicious of the powerlines. They were buzzing louder than a swarm of bees.

    Edit: Rocket Locator app for Android.

  6. #6
    Join Date
    30th January 2016
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    US > OK > NE
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    3,227
    Quote Originally Posted by ascastil View Post
    5 decimal points. My wife reminded me right now that while I was watching the rocket, I told her to take a pic of the coordinates. She said the LCD stopped beeping well before the rocket was near the ground. That's when she snapped the pic of the coordinates.

    All the nearby roads show up on the map. Just where the finder said my rocket was it wasn't. I'm suspicious of the powerlines. They were buzzing louder than a swarm of bees.

    Edit: Rocket Locator app for Android.
    Congrats on missing them! And yes, high power lines put out tons of interference.

  7. #7
    Join Date
    3rd February 2012
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    So Cal (ROC, TRASD, SCRA)
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    2,510
    Did you have the coordinate units matched on your phone and your LCD? The LCD defaults to degrees and decimals (5), that gives you the highest resolution. Some apps default to Degrees:Minutes or Degrees:Minutes:Seconds... you can either change your app, or change your LCD receiver's setup to match. The power lines might or might not be an issue... the frequency is so much lower than the 900 MHz band or the sub-carrier that it would be unlikely to mess up the actual data, but it might cause some general RF interference.

    BTW, if you turn on your LCD and press the button when you get to "Waiting for Fix" it will show you the last received coordinates. They're saved every 10 seconds or every 10 unique fixes, whichever comes first. If you find that your units were mismatched, you can go back and adjust the units on your navigation app and go get your rocket.

  8. #8
    Join Date
    2nd January 2013
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    210
    Typed in exactly what was displayed on the LCD onto the phone. Gave us the location we were standing in with no rocket. Even went back just now and looked at the pic taken of last coordinates and the map history on her phone, they were the same.

  9. #9
    Join Date
    2nd January 2013
    Posts
    210
    Also, the coordinates typed into her phone gave us the same location my phone was giving via Bluetooth linked to LCD. All 3 told us this is where the rocket is.......

  10. #10
    Join Date
    27th December 2012
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    292
    If you still have the coords then try plugging them into Google Earth (not maps). Zoom in and see if area looks like where you were standing or closer to where rocket was located.

  11. #11
    Join Date
    26th November 2009
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    4,603
    Quote Originally Posted by ascastil View Post
    Glad you asked that. No, it didn't. It started beeping again as I was walking towards where I thought it was and got closer. I didn't pay attention to coordinates on the LCD or location on my phone. Figured I was on my own at that point.
    I think you should have noted the coordinates as you might have lost the signal while the rocket was getting lower
    and it ended up a distance away from your last known position.

    This is a characteristic of GPS trackers. 900Mhz doesn't have the most optimal propagation and perhaps if like
    you say, there were high tension lines nearby, that might have cut your range.

    The other thing is if geography (ie. depression, hillock, mountains or hills) gets in the way of the Rf signal, your
    last recorded position could be quite a distance away from your rockets resting place.

    A live mapping program can be helpful but I tell you, I'm still trying to find an easy one out there that regular
    folks would be able to easily use. The drift trend down low would be most helpful because you could proceed in
    the direction you map suggests the rocket was drifting down low and then get yourself into the ground footprint of the tracker. If one would lose and then regain the signal, they might reacquire a new fix to take them to the rocket.

    Except, I just saw a post from a fellow who had a signal after landing but couldn't find the rocket. I believe the
    GPS antenna of the Mini was facing down or towards the ground with just a 3 satellite lock. That equals lousy
    accuracy. This is much more important when flying with standing corn or high vegetation and was a lesson learned
    for me at a distance. Only thing I can think of to get around that problem is a loud screamer on the harness to give
    one an aural sound to home in on as "ground" insurance.

    Heck, if flying out in the open 1/4 mile is "good enough" as you'll see the rocket long before you get to it and
    who cares what the lat/long is showing in that case?

    Kurt

  12. #12
    Join Date
    2nd January 2013
    Posts
    210
    I was launching in a flat desert. I'd guess the rocket was 5k feet up and if I hadn't seen it, I would have never found it with the Eggfinder.
    I didn't just have a quarter mile field. I was in miles of Arizona desert and farmland. Id like to put the eggfinder in rockets that will go twice that high and wont be visible at all, and most importantly get them back. I'd like to think from what I've read that the Eggfinder is up to task. I think I'll just keep it in some lower power rockets and see if it's reliable for me.

  13. #13
    Join Date
    3rd February 2012
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    So Cal (ROC, TRASD, SCRA)
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    Quote Originally Posted by ascastil View Post
    Glad you asked that. No, it didn't. It started beeping again as I was walking towards where I thought it was and got closer. I didn't pay attention to coordinates on the LCD or location on my phone. Figured I was on my own at that point.
    Quote Originally Posted by ascastil View Post
    Typed in exactly what was displayed on the LCD onto the phone. Gave us the location we were standing in with no rocket. Even went back just now and looked at the pic taken of last coordinates and the map history on her phone, they were the same.
    It sounds like you lost the signal at launch and didn't get it back... maybe the battery got disconnected or glitched, and the GPS didn't reacquire the fix before it landed. The LCD receiver will give you a two-beep signal every 3 seconds if it gets a radio signal but not a GPS fix, and will go silent if it loses the radio signal. Typically with this type of scenario, it will go silent at launch for a few seconds then you'll get the beep-beep, which tells you that it dropped out and didn't get a fix afterwards. It's not unusual for your signal to drop out at launch, but it normally comes back as you slow down before apogee.

    The best way to prevent this from happening is to make sure that your battery is freshly charged, and that all connectors are taped together and all wires are secured so that they can't move during boost. I've seen the pins on the Chinese JST connector clones slide right out with little force, even though the plastic shells themselves are firmly locked.

  14. #14
    Join Date
    26th November 2009
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    4,603
    Cris, I thought he meant it kept beeping after the rocket was down. Doesn't that mean the EF still had power 1/s or 3/s beep?

    ascastil said this, "Glad you asked that. No, it didn't. It started beeping again as I was walking towards where I thought it was and got closer. I didn't pay attention to coordinates on the LCD or location on my phone. Figured I was on my own at that point."

    In response to my question: Did the egg finder LCD continue to beep a signal and display a position while you were at the last known location? Kurt

  15. #15
    Join Date
    2nd January 2013
    Posts
    210
    I cant remember. It doesnt seem to me like it was beeping while I was walking towards it. I mainly remember walking to the location where my phone said it was. As I continued walking past the location my phone said it was, thats when I noticed it start beeping again, but it may have been beeping the whole time, idk. I was caught up in excitement that the launch was good, I saw the rocket, and had a location on my phone where it landed. Adrenaline and excitement I guess got me sidetracked. It was the biggest motor I had launched with an expensive payload, Eggfinder and chute release.

    If I had lost signal at launch, why would it give me a location to walk to? And why would that be the wrong location?

  16. #16
    Join Date
    13th December 2013
    Posts
    5
    I have recently been playing around with the Eggfinder and have used it to successfully locate my rockets a few times, and I'm wondering if you could have had a similar experience to my last launch?

    To keep it short, I confirmed the Eggfinder had lock, was communicating the coordinates correctly, etc. and then put it in the rocket. The launch occurred without incident, and I don't know if it lost lock during the boost, but I could hear the receiver beeping during the decent. I watched the rocket come down and heard the beeping from the receiver stop as the rocket dropped onto or behind a hill about a half mile away from the launch location. I put the last coordinates into my phone and proceeded to head to where it appeared that the rocket had landed. When I got to the area of the last coordinates, the rocket was not visible and I wasn't getting any updated information from the Eggfinder receiver. I then held the receiver up over my head to see if that would get something, and it started beeping again and displayed new coordinates. I put those into my phone and proceeded to that location where I found the rocket. The distance between the two locations wasn't that much (about 40 yards), but due to the terrain and a depression that wasn't really obvious until you walked up to the edge, I could have been wandering around for a long time before I found the rocket, or I might never have found it?

    Could something similar have happened with your launch?

  17. #17
    Join Date
    22nd August 2015
    Location
    Rhode Island
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    1,066
    Quote Originally Posted by 6.5Grendel View Post
    I have recently been playing around with the Eggfinder and have used it to successfully locate my rockets a few times, and I'm wondering if you could have had a similar experience to my last launch?

    To keep it short, I confirmed the Eggfinder had lock, was communicating the coordinates correctly, etc. and then put it in the rocket. The launch occurred without incident, and I don't know if it lost lock during the boost, but I could hear the receiver beeping during the decent. I watched the rocket come down and heard the beeping from the receiver stop as the rocket dropped onto or behind a hill about a half mile away from the launch location. I put the last coordinates into my phone and proceeded to head to where it appeared that the rocket had landed. When I got to the area of the last coordinates, the rocket was not visible and I wasn't getting any updated information from the Eggfinder receiver. I then held the receiver up over my head to see if that would get something, and it started beeping again and displayed new coordinates. I put those into my phone and proceeded to that location where I found the rocket. The distance between the two locations wasn't that much (about 40 yards), but due to the terrain and a depression that wasn't really obvious until you walked up to the edge, I could have been wandering around for a long time before I found the rocket, or I might never have found it?

    Could something similar have happened with your launch?
    I've had similar results. I've seen the rocket land; plugged the coordinates from the receiver into my phone and noticed that they were a little off. As I walked towards the rocket, the receiver started beeping and updated to the correct coordinates.
    NAR #100940, RIMRA & CMASS
    L1 - 4/17/16, Tyrannosaur (by Binder Design), Loki H144
    L2 - 8/19/17, Terrordactyl (by Binder Design), CTI J250

  18. #18
    Join Date
    6th September 2009
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    1,574
    Quote Originally Posted by 6.5Grendel View Post
    The distance between the two locations wasn't that much (about 40 yards),
    This is typical of any GPS tracking, though my "last" and "actual" landings have been as little as 10 yards.

  19. #19
    Join Date
    3rd February 2012
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    So Cal (ROC, TRASD, SCRA)
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    2,510
    Quote Originally Posted by ascastil View Post
    I cant remember. It doesnt seem to me like it was beeping while I was walking towards it. I mainly remember walking to the location where my phone said it was. As I continued walking past the location my phone said it was, thats when I noticed it start beeping again, but it may have been beeping the whole time, idk. I was caught up in excitement that the launch was good, I saw the rocket, and had a location on my phone where it landed. Adrenaline and excitement I guess got me sidetracked. It was the biggest motor I had launched with an expensive payload, Eggfinder and chute release.

    If I had lost signal at launch, why would it give me a location to walk to? And why would that be the wrong location?
    One other possibility is that somebody else was on your frequency/ID and stomped on your location, which is why it showed the last location as being on the pad. Did you change it from the default?

    The "no signal" beep is significantly different than the "I have a fix" beep... it's two staccato beeps instead of one longer beeps, and it occurs once every 3 seconds instead of about once per second. Realizing that this was the first time that you flew it, did you ground test it to become familiar with the sounds and display?

    If you get an updated fix when you approach the last received packet (longer beeps about once per second) then it's virtually guaranteed to be where your rocket landed. It IS possible to get the "I got data but not a fix" beep-beep instead, if either the GPS antenna is pointing straight down or if you had a very hard landing and it got knocked off. That's why I recommend epoxying the antenna onto the GPS module... I've seen it survive lawn-darts that way.

  20. #20
    Join Date
    13th December 2013
    Posts
    5
    Quote Originally Posted by Buckeye View Post
    This is typical of any GPS tracking, though my "last" and "actual" landings have been as little as 10 yards.
    Not meaning to hijack this thread, just wanted to clarify that the two locations were caused by loosing the connection when the rocket dropped below a hill, not because of the inherent issues with GPS accuracy. The final location, updated when I got close, was within feet of the actual location of the rocket (although it wouldn't have surprised me if it had been a few yards off, GPS isn't pin-point accurate by any stretch).

    To the OP, something else you might want to check. You can check the last coordinates that were saved to the Eggfinder receiver using the following process from the Eggfinder's user manual:
    To recall the last saved coordinate, power-cycle the LCD receiver, and at the “Waiting for Fix” display hold the button down for 3 seconds then release it. The last received coordinates will display, along with the “**” in the time-from-fix field that lets you know that it’s “stale” data.
    With that information, you should be able to see if the final location was close to the location you searched around?

  21. #21
    Join Date
    13th March 2010
    Location
    Bentonville, AR
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    719
    Quote Originally Posted by Buckeye View Post
    This is typical of any GPS tracking, though my "last" and "actual" landings have been as little as 10 yards.
    My Eggfinder TRS' last reported position was within 15 feet or so of the rocket's actual landing spot in Argonia yesterday. It tracked the rocket all the way to 5,106' and back down. I never lost the signal. I am looking forward to the GPS add-on module for the LCD receiver so I don't have to plug the coordinates into my Garmin or launch the Rocket Locator app. I have been happy with the system so far.
    Dwayne Shmel
    TRA 13137 / NAR 88172
    Tulsa Rocketry
    K.L.O.U.D. Busters
    L3

  22. #22
    Join Date
    10th September 2013
    Posts
    42
    This thread has been a real eye opener for me. I built by eggfinder system a year ago but just recently started using it. I just thought I remembered everything in the manual. It's also good to hear about the different possible recovery outcomes that could affect gps results.


    Quote Originally Posted by ascastil View Post
    If I had lost signal at launch, why would it give me a location to walk to? And why would that be the wrong location?
    You may have lost signal at launch, then reacquired it during descent, then lost it before the actual landing because of terrain or the power lines. This last good fix was the one your wife recorded and resulted in a location where your rocket passed over but didn't come to rest.

    It then sounds like you reacquired the signal when you continued walking to the actual landing site, but since you didn't check the coordinates displayed at this point you can not definitively say that you were getting erroneous data from your system. It sounds more like procedural issue.

  23. #23
    Join Date
    2nd January 2013
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    210
    All good info. It's the second time I've used it. The first time it lost Bluetooth connection to my phone. Again, I just walked to where it landed. It's good to know that if within range it'll update coordinates, I should have looked. That is if you even know what direction to start walking. I'll keep at it though. I'm itching for some 10k foot launches now. 5k was exciting.

  24. #24
    Join Date
    12th April 2015
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    Arizona
    Posts
    268
    Really sounds like the location you navigated to was not actually the last location the Eggfinder reported - just the last one you got while it was in the air. I'd wager that if you'd updated your GPS to the location you got from the Eggfinder after reacquiring signal, it would be much closer to the actual landing spot. You can recover this position, assuming you've not used the Eggfinder since, by powering up the LCD again. Should report the last location - stick that into your mapper and see if it gives you a more accurate result (then again, if you didn't turn off the Eggfinder right at the landing site, it would have continued updating on the walk back).

    Barring weird government interference, I've never had a GPS actually be 1/4 mile off - it will usually stop reporting a valid fix at all well before it got that bad.

    Just in general, I'd be hesitant to blame the Eggfinder in particular - all the 900 MHz trackers use basically the same tech. I don't think anyone has a "secret sauce" that would significantly impact accuracy (after all, they all use off-the-shelf GPS and radio chipsets). So any problems you have with an Eggfinder, you'll probably have with the other system.
    I aim at the stars. But sometimes I hit London.

    NAR #99868
    L1: MDRM on CTI H175, 7/26/2015 @ NARAM 57
    L2: "Flugel der Freiheit", AT J420R, 11/4/2017 @ GHS Memorial

  25. #25
    Join Date
    3rd February 2012
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    So Cal (ROC, TRASD, SCRA)
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    Quote Originally Posted by ascastil View Post
    All good info. It's the second time I've used it. The first time it lost Bluetooth connection to my phone. Again, I just walked to where it landed. It's good to know that if within range it'll update coordinates, I should have looked. That is if you even know what direction to start walking. I'll keep at it though. I'm itching for some 10k foot launches now. 5k was exciting.
    That's the advantage of the new LCD-GPS Module that goes in the receiver... everything gets updated automatically so you don't have to look to see if the coordinates need to be re-entered into your phone. It just points you in the direction of your rocket and tells you how far to go. If you're using Bluetooth with Rocket Locator it's automatic too, as long as you don't lose your Bluetooth link... they're a little flaky sometimes so it's nice to have a backup.

  26. #26
    Join Date
    2nd January 2013
    Posts
    210
    I'm not blaming the Eggfinder. I want to know what I did or what happened. I'm only guessing it regained a signal as I was walking towards it. BUT, what if I didn't know where it landed?

    Another thing, I had coordinates on the pad. My wife could see the dot moving on my phone as I walked the rocket out to the pad. I remember her telling me the coordinates were changing and so was the location on my phone as I walked to the pad. The battery was tested before flight, connections were taped, then the battery and Eggfinder wires were taped to the sled so they would not move. Plastic nose cone, no all thread used, just tiny bolts to fasten sled inside bay.

  27. #27
    Join Date
    13th March 2010
    Location
    Bentonville, AR
    Posts
    719
    As more and more Eggtimer products show up in the field and are flown, we will see many folks sharing "best practices." My experience is limited to (only) two TRS flights, but the commonalities include:

    I use the manufacturer recommended quarter wave whip antenna ANT-916-CW-QW-ND located on bulkhead plate (outside of the e-bay and away from all threads).

    I use a high capacity 3s LiPo for power. Yes, I use one battery for both power the deployment.

    I use a half wave whip antenna on the LCD receiver via the external RP-SMA connector.
    Dwayne Shmel
    TRA 13137 / NAR 88172
    Tulsa Rocketry
    K.L.O.U.D. Busters
    L3

  28. #28
    Join Date
    13th December 2013
    Posts
    5
    Quote Originally Posted by ascastil View Post
    I'm not blaming the Eggfinder. I want to know what I did or what happened. I'm only guessing it regained a signal as I was walking towards it. BUT, what if I didn't know where it landed?
    Did you check to see what the last coordinates were on the receiver? Just wondering if they were the same as the ones you entered into your phone, or if they had updated, and if they had, if it was still in the area you searched?

    As for what to do if you didn't know where it landed, in the flights I've had, it always was sending data during the decent, and the last position before it loses signal has always been close enough that I was able to reacquire the signal and get the final location.

    And I'm really looking forward to the new LCD-GPS module, it should make the whole process easier.

  29. #29
    Join Date
    12th April 2015
    Location
    Arizona
    Posts
    268
    Best practices I've used:

    1) Before setting off on your search, take a compass bearing from the launch site to wherever you last saw the rocket (or your last GPS point received). The new Eggfinder GPS chip should help with this, but most GPS software should have this ability (bearing from current location to target).
    2) Keep track of when you lose lock on the Eggfinder (the beeping will change/stop) and, if you can see the rocket, estimate how high in the air your rocket is at the time.
    3) Navigate to your last GPS reported location. If you've had lock the whole time, great! Your rocket is probably within 100 ft of this spot (probably less).
    4) If you did lose lock during the flight, there's a very good chance you reacquired it at some point during 3) (LCD will beep). If so, update your GPS map - the new location is more likely to be accurate to the rocket's resting place.
    5) If you're at the spot, don't see your rocket, and haven't reacquired a lock, take note of the bearing from 1) as well as the wind direction at your current location. Those two directions should give you a good idea of a direction to head off in an attempt to reacquire lock.
    I aim at the stars. But sometimes I hit London.

    NAR #99868
    L1: MDRM on CTI H175, 7/26/2015 @ NARAM 57
    L2: "Flugel der Freiheit", AT J420R, 11/4/2017 @ GHS Memorial

  30. #30
    Join Date
    19th August 2011
    Location
    Gilbert, Arizona
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    1,356
    I may have missed it, but what type of antenna were you using on the Rocket and the LCD?

    Kyle G.
    TRA #13906
    Full Time Student, Part Time Rocket Scientist
    www.BlackAero.com

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