Can eggfinder mini range be improved?

[Zyzzyva1000]

Several questions here, figured I would get opinions before bothering Cris.

1) I know the resolution is supposed to be about 2.5 meters, but it seems to me when I get within about 100 ft, the direction ability from the handheld gets wonky, which normally isn't an issue, but yesterday I landed in some wheat and it was a problem (luckily the wind whipped my chute up for a second and I saw it). There anything that can be done to improve the direction finding?

2) Main question - with a longer antenna on the eggfinder itself, can the range be improved? At our field I seem to always lose it about a half mile out (some small hills, and some high tension lines running through). I have the large external antenna on the handheld portion, and always mount in the nosecone, but in almost all my rockets would have room for a longer antenna. Putting the last coordinates into google maps got me close enough to re-acquire, but just curious.

3) Can I have 2 trackers paired to the same base station? (if I set everything to the same channel - not to use at the same time, but to decrease the number of times I have to move the tracker between rockets)

 

[StreuB1]

1) Cris has gone into this actually in another thread I believe 1yr+ ago. Give it a search and I think you'll likely come across it. He gives reasoning for what you have experienced and suggestions on a better search process using his units.

2) Your Rx antenna is actually more important than your Tx antenna. Spend time on your Rx antenna and you will see additional range gains. Depending on your FQ Band, there are some out there that are quite good. I am putting Cris' Quasar and TRS to the test at Balls this year more than likely and I hope to see what we can get out of them in their stock configurations, focusing only on increasing Rx sensitivity through good antennas.

3) Cris has also answered this a number of times (no worries! ) Yes you can, absolutely. As you stated though, correctly, you cannot Rx off both trackers at the same time since there is no means of multiplexing the incoming data. Since the Rx stations are very affordable, I have several and plan to fly multiple trackers at the same time at Balls, but with different Rx stations.

 

[Worsaer]

3) Cris has also answered this a number of times (no worries! ) Yes you can, absolutely.

But be careful. Understand this also means you may receive *anyone’s* transmitter on the same frequency. Get them synched up and ready welol before you launch to be sure you are looking at your rocket’s data.

 

[Zyzzyva1000]

But be careful. Understand this also means you may receive *anyone’s* transmitter on the same frequency. Get them synched up and ready welol before you launch to be sure you are looking at your rocket’s data.

Yea I have never had to worry about that, as nobody else at my local club uses eggfinder (several have feather weight), but I am going to LDRS next month and have already been thinking about this.

 

[cerving]

For the direction to work properly on the LCD receiver you have to be moving. If you stand in one place, it can't resolve the vector. We HAVE seen a few cases in which the direction vector seems to change inexplicably... we're looking at that.

 

[Zyzzyva1000]

For the direction to work properly on the LCD receiver you have to be moving. If you stand in one place, it can't resolve the vector. We HAVE seen a few cases in which the direction vector seems to change inexplicably... we're looking at that.

Yes this is what seems to have happened. I would be walking along, and all of a sudden the direction vector would change, like 180 degrees (this is what happened to me yesterday). Seemed fine until I got close, but then it couldn't resolve once I was within about 100 ft. I have noticed this times when I was just walking out to a rocket I could see in plain site. Was good until I got closer, then distance and direction seemed to go a bit haywire.

I guess maybe just attaching a buzzer and using GPS to get close enough is my best option. I am just trying to plan for finding stuff in all the scrub brush at Bong next month.

 

[StreuB1]

Yes this is what seems to have happened. I would be walking along, and all of a sudden the direction vector would change, like 180 degrees (this is what happened to me yesterday). Seemed fine until I got close, but then it couldn't resolve once I was within about 100 ft. I have noticed this times when I was just walking out to a rocket I could see in plain site. Was good until I got closer, then distance and direction seemed to go a bit haywire.

I guess maybe just attaching a buzzer and using GPS to get close enough is my best option. I am just trying to plan for finding stuff in all the scrub brush at Bong next month.

BTW, I have also seen this happen if you aren't stopped, but are walking VERY slowly and or intermittently (because you are staring at the screen and walking in ground cover). As Cris said, it needs a change in position over time in order to resolve a direction vector. I have found that just randomly walking in a brisk direction for a short period of time will give it what it needs to again resolve the direction.

 

[Zyzzyva1000]

BTW, I have also seen this happen if you aren't stopped, but are walking VERY slowly and or intermittently (because you are staring at the screen and walking in ground cover). As Cris said, it needs a change in position over time in order to resolve a direction vector. I have found that just randomly walking in a brisk direction for a short period of time will give it what it needs to again resolve the direction.

This is helpful, I kinda figured this out yesterday. Drove around to the backside of the wheat field that is on the property, and when I parked and got out, it gave me a weird direction (like 180 degrees from where I knew it had to be). I walked in the right direction and after a few seconds it resolved back to the correct direction. Maybe I am just asking more out of the system than is possible (it still got me 2 rockets back that everyone watching lost sight of yesterday, so I am not complaining, just making sure I am using the system to its fullest.

 

[SolarYellow]

Yea I have never had to worry about that, as nobody else at my local club uses eggfinder (several have feather weight), but I am going to LDRS next month and have already been thinking about this.

Would it make sense to set up an "Eggfinder frequency board" like the old school frequency boards at R/C flying fields? (I might be dating myself here since "everyone" has probably been using frequency shifting equipment for a couple decades now.)

 

[Charles_McG]

I’ve successfully done the ‘last 50 feet’ tracking in high cattails (at Bong) with a directional mic listening to the Proton beeps. The reeds limited movement, so the LCD receiver couldn’t get me further.

I flew a two stage with an Eggfinder mini in each stage this weekend. The log file from my ‘eggStation’ ground station software shows a pool of points around the setup area, the pad, and landing spots. If you get within the error of both Rx and Tx GPS units, the vector between them is going to jump around.

 

[schworer]

My 4" diameter eggStation test rocket flown to about 5300 feet on Saturday at URRF/Potter NY went into a very dense strand of trees due to high winds aloft. The way I located it with the GPS receiver when I got reasonably close to the point plotted on Google Maps in my iPhone was I walked in the direction of the arrows maybe 25 feet, then walked perpendicular to that direction until the arrows shifted direction. I then walked in the direction of the arrows perhaps another 25 feet and then shifted to another perpendicular path. I iterated this several more times and then looked up.....there it was hanging about 15 feet away from me. No way would I probably have found this without GPS tracking or a RF beacon. Thankfully it was low enough that I was able to get it down with he assistance of a dead branch leveraging the bottom section to a level where I could grab a fin.

 

[Handeman]

Most rockets that land in woods get draped across the tops of a tree or two. Having it hanging down like that is very lucky!

Hope you bought a lottery ticket!

 

[John Kemker]

2) Your Rx antenna is actually more important than your Tx antenna. Spend time on your Rx antenna and you will see additional range gains. Depending on your FQ Band, there are some out there that are quite good. I am putting Cris' Quasar and TRS to the test at Balls this year more than likely and I hope to see what we can get out of them in their stock configurations, focusing only on increasing Rx sensitivity through good antennas.

Absolutely agree. If you try to lengthen the TX antenna without making sure it's resonant at the TX frequency, you could make it worse. Also, TX antennae usually increase gain by concentrating the signal more towards the area you want them to go, not actually increasing the power of the signal altogether. That means, if the direction you've concentrated the power isn't the direction you're trying to find it from, you may not get the boost you're looking for. RX antennae, on the other hand, can be "aimed" because you hold it in your hand. That way, you can move it until you get a stronger signal. RX antennae also don't have to be as resonant as Tx antennae.

 

[Zyzzyva1000]

Ok, so I have gotten this pretty well worked out then. I guess the final question, is it worth getting a yagi or higher gain antenna for the receiver? I guess since just inputting the last received GPS coordinates into google maps got me to where I picked it up again I am doing ok, I was just trying to see if It was possible to get more than 1/2 mile of range out of this (could just be because I am not in the desert that this simply isn't going to happen)

 

[Charles_McG]

Ok, so I have gotten this pretty well worked out then. I guess the final question, is it worth getting a yagi or higher gain antenna for the receiver? I guess since just inputting the last received GPS coordinates into google maps got me to where I picked it up again I am doing ok, I was just trying to see if It was possible to get more than 1/2 mile of range out of this (could just be because I am not in the desert that this simply isn't going to happen)

If you could arrange for your avbay to always get caught on a bush or branch, so that it's ~5' off the ground, I bet you'd get much better landed range than if it is lying on the ground.

 

[Zyzzyva1000]

If you could arrange for your avbay to always get caught on a bush or branch, so that it's ~5' off the ground, I bet you'd get much better landed range than if it is lying on the ground.

Maybe I should bring some stilts for recovery in the future. All kidding aside, I guess I have all my answers, help has been much appreciated

 

[mtnmanak]

Another thing you could consider - get the transmitter out of the rocket.

I found that the mini + Ovonic 850mAh 2S LiPo wrapped in some anti-static bubble wrap fits perfectly in a 5 in length of LOC 38mm coupler tubing (conveniently, LOC sells them in 5" lengths). Take a corresponding length 38mm airframe tubing and plug both ends (I cut out some 3/4" plywood plugs), make a couple holes in one of the plugs and tie a loop of kevlar through it. Epoxy the plugs in. I hold the sections together with a couple plastic rivets. I attach the tube to the drogue shock cord so it comes out at apogee and gives me an unblocked signal all the way down. The 850mAh 2S last all day at the field and switching it to another rocket is as easy as unclipping the quick link and reattaching it. This will work in any rocket you can get to carrier into.