Any tips for finding rocket in cornfield?

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rklapp said:
So which Mavic is good enough for finding rockets in a cornfield, the $400, $800, or the $1600 one?

https://store.dji.com/shop/mavic-series
At least you don't have to fire your rockets between the ocean and a sewage treatment plant.
Click to expand...
I bought a DJI Phantom 3 Standard that was refurbished. It shoot 2.7K video. I paid $300 for it a few years ago. And it is old tech comparatively speaking but it more than suffices. Any DJI that has a camera will work.
 
For some competition models like egglofters, Matt Steele would put a long, thin mylar streamer in the model that would aid in finding the model in corn or soybeans or weeds or... The silver streamer would often lay on top of the crop.

Chas
 
Chalk it up to experience and learn to fly the field. Do you really want to buy a drone and start a new hobby just to find a $25 Estes rocket that is probably mushy cardboard by now?
 
Charles_McG said:
I've used one of these in over-my-head cat-tail reeds. Egginder got me within 30', but ground was too soft to just wander/crash through reeds. The directional mic could hear the altimeter beeping out and gave me a good idea of direction.

https://www.amazon.com/dp/B00EEZQPHO/ref=cm_sw_em_r_mt_dp_cRMtFbC9WGXJB
Click to expand...
Does that device work pretty well? I'd like something like that to find birds in trees around my farm. I've been try to identify birds by their calls.
 
Charles_McG said:
I've used one of these in over-my-head cat-tail reeds. Egginder got me within 30', but ground was too soft to just wander/crash through reeds. The directional mic could hear the altimeter beeping out and gave me a good idea of direction.

https://www.amazon.com/dp/B00EEZQPHO/ref=cm_sw_em_r_mt_dp_cRMtFbC9WGXJB
Click to expand...
I liked this in the Amazon product description

“Recommend to children 6 year old and older.”

That’s what I want my 6 year old to play with, a spy microphone!
 
I had a minnie magg beeping out in the field and the area was off limits due to the farmer's decree
I got back the casing after the field had been harvested, it was the only part to survive
 
I have an idea. Dont fly a rocket into a corn field. If you point a rocket towards a corn field then you have wasted a perfectly good rocket.

Now if during recovery it floats into a corn field then just wait until the combine goes over the field. You will find rocket but it will be in pieces.

Just having a laugh. I have landed in a corn field before but it came in ballistic. I found it in pieces.
 
Buzzard said:
For some competition models like egglofters, Matt Steele would put a long, thin mylar streamer in the model that would aid in finding the model in corn or soybeans or weeds or... The silver streamer would often lay on top of the crop.

Chas
Click to expand...
not a chance. even with a large chute and or steamer dumb luck is it will sag into corn field and still be unseeable.
 
The other surefire way to help with recovery in a cornfield is a GPS tracker and a loud screamer on the harness.
Of course, successful deployment of the recovery system is helpful here too. That is about the best one can do to minimize loss. Kurt
 
ksaves2 said:
The other surefire way to help with recovery in a cornfield is a GPS tracker and a loud screamer on the harness.
Of course, successful deployment of the recovery system is helpful here too. That is about the best one can do to minimize loss. Kurt
Click to expand...
you are always the voice of reason on this forum kurt.
 
Tim Crabtree said:
You could put a Marco Polo tracking tag on your rocket and if it goes into the cornfield you can walk right to it (assuming the farmer doesn't mind). If you look at the 3rd slide on this page you will see a picture of your nightmare cornfield... https://eurekaproducts.com/rc-model-tracking-and-recovery/
Click to expand...
Their web page says "no GPS, cellular or internet required." So how does this system work? Is it similar to a 900mhz Eggfinder?
 
billdz said:
Their web page says "no GPS, cellular or internet required." So how does this system work? Is it similar to a 900mhz Eggfinder?
Click to expand...
stay away from egg finder. go for a rf tracker from comspec or missileworks or altus metrum.
i dont like egg finder they seem cheap. there is alot of stuff to back up altus metrum, missile works, and comspec. fantastic hardware and reputation.
 
Rocketcamper123 said:
stay away from egg finder. go for a rf tracker from comspec or missileworks or altus metrum.
i dont like egg finder they seem cheap. there is alot of stuff to back up altus metrum, missile works, and comspec. fantastic hardware and reputation.
Click to expand...

Baloney. I don't use Eggfinder, but many people do. They work great.

Comspec, Missileworks, and Altus Metrum are nothing alike. Compsec is RDF only, MW is GPS only, and AM may be both, not sure.
 
Buckeye said:
Baloney. I don't use Eggfinder, but many people do. They work great.

Comspec, Missileworks, and Altus Metrum are nothing alike. Compsec is RDF only, MW is GPS only, and AM may be both, not sure.
Click to expand...
sure people can buy anything. i wont nor trust egg finder.

duh!!! comspec is rf, always a good idea to fly redundant. i fly gps and rf in same flight. altus metrum is gps
 
Rocketcamper123 said:
sure people can buy anything. i wont nor trust egg finder.

duh!!! comspec is rf, always a good idea to fly redundant. i fly gps and rf in same flight. altus metrum is gps
Click to expand...

Ummm, I and others have had flights “way up there” who successfully recovered their projects no problem on the 900 Mhz band. I’m a Ham too and can track on the 400Mhz (70cm) band that the Beelines are on. I have 3 of Greg’s GPS trackers and 3 of his RDF ones. Can also GPS track on the 2 meter (144Mhz) with some trackers that would fit in a long Von Karmann 4 inch nosecone. The propagation on that frequency would be awesome at the 500Mw to 1 watt level. Ahhh I agree, redundancy is good if one has the room on the rocket to do it. If not, make derned sure the primary tracking system is mounted in a “bullet proof” fashion.

If one doesn’t trust an EggFinder, they probably don’t trust their electronic building skills quite frankly. Since I built a “Foxmitter” in the late 60’s and a “Minimitter” too, I don’t have an issue with soldering/building electronic stuff. In fact I “broke the FCC law and substituted a final Rf transistor so the Foxmitter put out 300Mw instead of the allowable 100Mw. Me bad, bad, bad!!! That was in a letter to the editor in Model Rocketry magazine so I did it..... I lost my early rocketry stuff in a box in the late 80’s but remember when I last plugged in my Foxmitter to a 22.5V Burgess battery, it still transmitted on channel 14 on the Citizen’s band albeit ”illegally”. I wished I hadn’t lost it. My Minimitter worked too. With the Eggfinders, one can solder a socket on the board and screw in an aftermarket 900 Mhz antenna with higher gain. (ie. receiving sensitivity and transmitting power)

The 900Mhz trackers, whatever manufacturer flavor one uses, work fine as long as one practices with the system “BEFORE THEY GO OUT AND FLY WITH IT!” Practice, practice, practice and if something “weird” happens, you’ll figure it out and get your rocket back anyways. Even if it’s a lawn dart. I had that happen and only received one position from the tracker. No chute as I under charged the ejection. Yeah, I ran it through a simulator but still managed to “undercharge”. I belatedly walked out to the position plotted on the map and lo’ and beholden, there is the fincan sticking out of the ground. It was a small fiberglass apogee only rocket 54mm in diameter with a 38mm motor hole. I busted the NC getting the rocket out of the ground but with a new NC and electronics it still flys.

If one flies high and far with a 900Mhz tracking system, get a good omni directional antenna for in-flight monitoring then invest in a 900Mhz Yagi antenna for ground recovery. There are mag mount antennas one can put on the roof of their vehicle. Gives a good “ground plane”. Yeah antennaspeak but trust me here. Use the omni directional antenna for inflight monitoring and when one has that “last known fix“ they’ll be navigating to, plug in the Yagi and point it in the direction of the last known fix. Believe me, the ground footprint is improved quite a bit with a 900Mhz Yagi. I‘ve done a few recoveries with the Yagi on 900Mhz and when I first started receiving positions with the Yagi on the receiver, I unscrewed it and put a standard omni directional antenna on.
The signal disappeared. Screwed the Yagi back in, pointed it in the direction where I knew the rocket lay and the signal came back. Bottom line is the Yagi for a difficult ground recovery is better that using an omni directional antenna. Admittedly most sport fliers probably won’t notice a difference out to 3 miles maybe more.

Why not use the Yagi for in-flight tracking? Well one might get away with it but the beamwidth of a Yagi antenna on 900Mhz is quite narrow which means it is likely harder to be able to point the antenna at an in flight rocket and pick up the NMEA position packets reliably. That’s a physics issue and is unmuteable. On the 70cm Ham band, a 5 element Yagi works nice for in flight tracking and on the 2 meter Ham band, a 3 element Yagi works but the antenna elements are getting pretty long on 2 meters and one has to be careful they don’t, “Poke yer’ eye out!”

I’ve tracked on all three bands with GPS and some RDF stuff on 70cm and 2 meters. RDF one needs to have an attenuator plugged in to attenuate the incoming Rf signal otherwise the directionality will be lost as they get closer to the tracked rocket. A good RDF system with a decent attenuator can work great but one has to, and I mean HAS TO get a good final fix to the rocket as it’s coming in. Even if they can’t see the rocket. They have to peak the incoming signal and hold the bearing on the antenna in order to follow it out to the rocket. Here’s where a hand held GPS with a with a “Sight n’ Go” feature is helpful. Sight n’ Go is a feature on some Garmin handheld GPS’s (and maybe others) where one sights along two arrows on the screen of the GPS to a place in line (in our case a descending rocket) and pushes a button that “locks” the bearing to the chosen target. I’ve found a pile of modrocs using this feature. As long as one can sight the descending rocket and lock a fix, walk the “line” as plotted on the GPS until you come upon the rocket. Of course the farther away the rocket is, the greater the chance for error but I haven’t lost a modroc using this method as long as I was able to get a fix just before it touched down.

Yeah, one has to be able to see the rocket coming in to use the Sight n’ Go feature and it won’t help for totally sight unseen flights. For that one needs to use RDF or GPS tracking.
All the best,
Kurt Savegnago
 
Last edited:
ksaves2 said:
Ummm, I and others have had flights “way up there” who successfully recovered their projects no problem on the 900 Mhz band. I’m a Ham too and can track on the 400Mhz (70cm) band that the Beelines are on. I have 3 of Greg’s GPS trackers and 3 of his RDF ones. Can also GPS track on the 2 meter (144Mhz) with some trackers that would fit in a long Von Karmann 4 inch nosecone. The propagation on that frequency would be awesome at the 500Mw to 1 watt level. Ahhh I agree, redundancy is good if one has the room on the rocket to do it. If not, make derned sure the primary tracking system is mounted in a “bullet proof” fashion.

If one doesn’t trust an EggFinder, they probably don’t trust their electronic building skills quite frankly. Since I built a “Foxmitter” in the late 60’s and a “Minimitter” too, I don’t have an issue with soldering/building electronic stuff. In fact I “broke the FCC law and substituted a final Rf transistor so the Foxmitter put out 300Mw instead of the allowable 100Mw. Me bad, bad, bad!!! That was in a letter to the editor in Model Rocketry magazine so I did it..... I lost my early rocketry stuff in a box in the late 80’s but remember when I last plugged in my Foxmitter to a 22.5V Burgess battery, it still transmitted on channel 14 on the Citizen’s band albeit ”illegally”. I wished I hadn’t lost it. My Minimitter worked too. With the Eggfinders, one can solder a socket on the board and screw in an aftermarket 900 Mhz antenna with higher gain. (ie. receiving sensitivity and transmitting power)

The 900Mhz trackers, whatever manufacturer flavor one uses, work fine as long as one practices with the system “BEFORE THEY GO OUT AND FLY WITH IT!” Practice, practice, practice and if something “weird” happens, you’ll figure it out and get your rocket back anyways. Even if it’s a lawn dart. I had that happen and only received one position from the tracker. No chute as I under charged the ejection. Yeah, I ran it through a simulator but still managed to “undercharge”. I belatedly walked out to the position plotted on the map and lo’ and beholden, there is the fincan sticking out of the ground. It was a small fiberglass apogee only rocket 54mm in diameter with a 38mm motor hole. I busted the NC getting the rocket out of the ground but with a new NC and electronics it still flys.

If one flies high and far with a 900Mhz tracking system, get a good omni directional antenna for in-flight monitoring then invest in a 900Mhz Yagi antenna for ground recovery. There are mag mount antennas one can put on the roof of their vehicle. Gives a good “ground plane”. Yeah antennaspeak but trust me here. Use the omni directional antenna for inflight monitoring and when one has that “last known fix“ they’ll be navigating to, plug in the Yagi and point it in the direction of the last known fix. Believe me, the ground footprint is improved quite a bit with a 900Mhz Yagi. I‘ve done a few recoveries with the Yagi on 900Mhz and when I first started receiving positions with the Yagi on the receiver, I unscrewed it and put a standard omni directional antenna on.
The signal disappeared. Screwed the Yagi back in, pointed it in the direction where I knew the rocket lay and the signal came back. Bottom line is the Yagi for a difficult ground recovery is better that using an omni directional antenna. Admittedly most sport fliers probably won’t notice a difference out to 3 miles maybe more.

Why not use the Yagi for in-flight tracking? Well one might get away with it but the beamwidth of a Yagi antenna on 900Mhz is quite narrow which means it is likely harder to be able to point the antenna at an in flight rocket and pick up the NMEA position packets reliably. That’s a physics issue and is unmuteable. On the 70cm Ham band, a 5 element Yagi works nice for in flight tracking and on the 2 meter Ham band, a 3 element Yagi works but the antenna elements are getting pretty long on 2 meters and one has to be careful they don’t, “Poke yer’ eye out!”

I’ve tracked on all three bands with GPS and some RDF stuff on 70cm and 2 meters. RDF one needs to have an attenuator plugged in to attenuate the incoming Rf signal otherwise the directionality will be lost as they get closer to the tracked rocket. A good RDF system with a decent attenuator can work great but one has to, and I mean HAS TO get a good final fix to the rocket as it’s coming in. Even if they can’t see the rocket. They have to peak the incoming signal and hold the bearing on the antenna in order to follow it out to the rocket. Here’s where a hand held GPS with a with a “Sight n’ Go” feature is helpful. Sight n’ Go is a feature on some Garmin handheld GPS’s (and maybe others) where one sights along two arrows on the screen of the GPS to a place in line (in our case a descending rocket) and pushes a button that “locks” the bearing to the chosen target. I’ve found a pile of modrocs using this feature. As long as one can sight the descending rocket and lock a fix, walk the “line” as plotted on the GPS until you come upon the rocket. Of course the farther away the rocket is, the greater the chance for error but I haven’t lost a modroc using this method as long as I was able to get a fix just before it touched down.

Yeah, one has to be able to see the rocket coming in to use the Sight n’ Go feature and it won’t help for totally sight unseen flights. For that one needs to use RDF or GPS tracking.
All the best,
Kurt Savegnago
Click to expand...
ok...
 
ksaves2 said:
Ummm, I and others have had flights “way up there” who successfully recovered their projects no problem on the 900 Mhz band. I’m a Ham too and can track on the 400Mhz (70cm) band that the Beelines are on. I have 3 of Greg’s GPS trackers and 3 of his RDF ones. Can also GPS track on the 2 meter (144Mhz) with some trackers that would fit in a long Von Karmann 4 inch nosecone. The propagation on that frequency would be awesome at the 500Mw to 1 watt level. Ahhh I agree, redundancy is good if one has the room on the rocket to do it. If not, make derned sure the primary tracking system is mounted in a “bullet proof” fashion.

If one doesn’t trust an EggFinder, they probably don’t trust their electronic building skills quite frankly. Since I built a “Foxmitter” in the late 60’s and a “Minimitter” too, I don’t have an issue with soldering/building electronic stuff. In fact I “broke the FCC law and substituted a final Rf transistor so the Foxmitter put out 300Mw instead of the allowable 100Mw. Me bad, bad, bad!!! That was in a letter to the editor in Model Rocketry magazine so I did it..... I lost my early rocketry stuff in a box in the late 80’s but remember when I last plugged in my Foxmitter to a 22.5V Burgess battery, it still transmitted on channel 14 on the Citizen’s band albeit ”illegally”. I wished I hadn’t lost it. My Minimitter worked too. With the Eggfinders, one can solder a socket on the board and screw in an aftermarket 900 Mhz antenna with higher gain. (ie. receiving sensitivity and transmitting power)

The 900Mhz trackers, whatever manufacturer flavor one uses, work fine as long as one practices with the system “BEFORE THEY GO OUT AND FLY WITH IT!” Practice, practice, practice and if something “weird” happens, you’ll figure it out and get your rocket back anyways. Even if it’s a lawn dart. I had that happen and only received one position from the tracker. No chute as I under charged the ejection. Yeah, I ran it through a simulator but still managed to “undercharge”. I belatedly walked out to the position plotted on the map and lo’ and beholden, there is the fincan sticking out of the ground. It was a small fiberglass apogee only rocket 54mm in diameter with a 38mm motor hole. I busted the NC getting the rocket out of the ground but with a new NC and electronics it still flys.

If one flies high and far with a 900Mhz tracking system, get a good omni directional antenna for in-flight monitoring then invest in a 900Mhz Yagi antenna for ground recovery. There are mag mount antennas one can put on the roof of their vehicle. Gives a good “ground plane”. Yeah antennaspeak but trust me here. Use the omni directional antenna for inflight monitoring and when one has that “last known fix“ they’ll be navigating to, plug in the Yagi and point it in the direction of the last known fix. Believe me, the ground footprint is improved quite a bit with a 900Mhz Yagi. I‘ve done a few recoveries with the Yagi on 900Mhz and when I first started receiving positions with the Yagi on the receiver, I unscrewed it and put a standard omni directional antenna on.
The signal disappeared. Screwed the Yagi back in, pointed it in the direction where I knew the rocket lay and the signal came back. Bottom line is the Yagi for a difficult ground recovery is better that using an omni directional antenna. Admittedly most sport fliers probably won’t notice a difference out to 3 miles maybe more.

Why not use the Yagi for in-flight tracking? Well one might get away with it but the beamwidth of a Yagi antenna on 900Mhz is quite narrow which means it is likely harder to be able to point the antenna at an in flight rocket and pick up the NMEA position packets reliably. That’s a physics issue and is unmuteable. On the 70cm Ham band, a 5 element Yagi works nice for in flight tracking and on the 2 meter Ham band, a 3 element Yagi works but the antenna elements are getting pretty long on 2 meters and one has to be careful they don’t, “Poke yer’ eye out!”

I’ve tracked on all three bands with GPS and some RDF stuff on 70cm and 2 meters. RDF one needs to have an attenuator plugged in to attenuate the incoming Rf signal otherwise the directionality will be lost as they get closer to the tracked rocket. A good RDF system with a decent attenuator can work great but one has to, and I mean HAS TO get a good final fix to the rocket as it’s coming in. Even if they can’t see the rocket. They have to peak the incoming signal and hold the bearing on the antenna in order to follow it out to the rocket. Here’s where a hand held GPS with a with a “Sight n’ Go” feature is helpful. Sight n’ Go is a feature on some Garmin handheld GPS’s (and maybe others) where one sights along two arrows on the screen of the GPS to a place in line (in our case a descending rocket) and pushes a button that “locks” the bearing to the chosen target. I’ve found a pile of modrocs using this feature. As long as one can sight the descending rocket and lock a fix, walk the “line” as plotted on the GPS until you come upon the rocket. Of course the farther away the rocket is, the greater the chance for error but I haven’t lost a modroc using this method as long as I was able to get a fix just before it touched down.

Yeah, one has to be able to see the rocket coming in to use the Sight n’ Go feature and it won’t help for totally sight unseen flights. For that one needs to use RDF or GPS tracking.
All the best,
Kurt Savegnago
Click to expand...
Kurt, you’ve got a lot of experience with different systems, maybe you can answer something that’s piqued my curiosity about RDF rocket tracking.
In the late 80s-early 90s, I played at 2m fox hunting. Everyone was using phased arrays and null seeking, rather than the peak seeking I see rocket RDFers doing. Do you know why?
 
Rocketcamper123 said:
stay away from egg finder. go for a rf tracker from comspec or missileworks or altus metrum.
i dont like egg finder they seem cheap.
Click to expand...

That's a cheap shot, and one that is not backed up by any data.
I fly Eggfinder GPS and Misseleworks T3 GPS. Both are 900 Mhz band GPS trackers, both work reliably. The two are virtually interchangeable (you get to solder the first, you buy the other pre-soldered).

You can buy Eggfinders GPS in either 900 Mhz or 70cm / 400Mhz Ham Version.

"seem cheap" is the definition of trash talking.
TRF has a policy of not bashing or denigrating the few vendors we have in the hobby.
Please respect it.
 
Charles_McG said:
Everyone was using phased arrays and null seeking, rather than the peak seeking I see rocket RDFers doing. Do you know why?
Click to expand...

In short, it is easier to get a much deeper null then a pointy peak. A cardoid antenna could have a null of many 10s of dBs, but the peak of a directional antenna may only be a few dB better than various side lobes (and rear lobe). The forward lobe will be somewhat broader, so it is less directionally sensitive than the null. (think "blob" vs "V shape") Plus, usually there is an excess of signal, so you need attenuators anyway.

Oh, and practically speaking, usually antennas designed for a deep null are much more smaller, portable, and lighter than an antenna designed for maximum gain.
 
mbeels said:
In short, it is easier to get a much deeper null then a pointy peak. A cardoid antenna could have a null of many 10s of dBs, but the peak of a directional antenna may only be a few dB better than various side lobes (and rear lobe). The forward lobe will be somewhat broader, so it is less directionally sensitive than the null. (think "blob" vs "V shape") Plus, usually there is an excess of signal, so you need attenuators anyway.

Oh, and practically speaking, usually antennas designed for a deep null are much more smaller, portable, and lighter than an antenna designed for maximum gain.
Click to expand...
I know all that. I might be a biologist by education, but I hung out with e-mag majors in college. My roommate would test my home brewed antennas (I had a thing for quagis at the time) in the RF lab’s anechoic chamber.
So knowing all that - why do rocketeers do RDF by peak seeking? Is it easier? Did nulling fall out of fashion?
 

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