Missile Works RTx?

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CORZERO said:
I would love to hear their rationale for ground RF absorption being related to RF attenuation to the point of loss of signal. That statement makes so little sense I'm not even sure where to start the argument against it.
Click to expand...

640
 
CORZERO said:
I would love to hear their rationale for ground RF absorption being related to RF attenuation to the point of loss of signal. That statement makes so little sense I'm not even sure where to start the argument against it.
Click to expand...

You can argue until you're blue in the face; the reality of the situation is that Kurt is right. I've been using RF trackers in my rockets for 12 years; I cannot recall ever losing a rocket with a RF (Rockethunter, now Com-Spec) tracker onboard....I fly mostly off of farm field and prairie-like areas in the Midwest. My one single trip to the Black Rock area, I thought I would still rely upon my trusty RF trackers despite warnings about the playa absorbing signals. Long story short: while the RF signal was great when the rocket is airborne, it was completely, 100% GONE as soon as the rocket touched down....FACT! I had a very interesting recovery of my Hamster Dance flight at Smoke Creek, our group lost a rocket due to no signal once down, and were fortunate enough to recover another that only had RF trackers onboards solely because another group located it, entered the GPS coords which allowed us to then drive right to the area. Bottom line: the RF trackers were useless once the rocket was on the ground!

I was warned, I was a skeptic, but I found out first hand that the warnings were valid....GPS is a necessity for out-of-sight flights at Black Rock. The most reasonable theory I've heard is that the water table is so close to the surface of the alkali playa, that the RF signals are simply absorbed into the matrix of the semi-conductive sync...or something like that!:)

Very much looking forward to putting the RTx system to use and testing it out at Black Rock in a few short weeks!!! Thanks Jim for making this possible!

-Eric-
 
ECayemberg said:
You can argue until you're blue in the face; the reality of the situation is that Kurt is right. I've been using RF trackers in my rockets for 12 years; I cannot recall ever losing a rocket with a RF (Rockethunter, now Com-Spec) tracker onboard....I fly mostly off of farm field and prairie-like areas in the Midwest. My one single trip to the Black Rock area, I thought I would still rely upon my trusty RF trackers despite warnings about the playa absorbing signals. Long story short: while the RF signal was great when the rocket is airborne, it was completely, 100% GONE as soon as the rocket touched down....FACT! I had a very interesting recovery of my Hamster Dance flight at Smoke Creek, our group lost a rocket due to no signal once down, and were fortunate enough to recover another that only had RF trackers onboards solely because another group located it, entered the GPS coords which allowed us to then drive right to the area. Bottom line: the RF trackers were useless once the rocket was on the ground!

I was warned, I was a skeptic, but I found out first hand that the warnings were valid....GPS is a necessity for out-of-sight flights at Black Rock. The most reasonable theory I've heard is that the water table is so close to the surface of the alkali playa, that the RF signals are simply absorbed into the matrix of the semi-conductive sync...or something like that!:)

Very much looking forward to putting the RTx system to use and testing it out at Black Rock in a few short weeks!!! Thanks Jim for making this possible!

-Eric-
Click to expand...

Sorry to detail thread, but Black Rock, few weeks?? Man that's big! Hope u post some info

Ohh and can't wait for the RTx
 
CORZERO said:
I would love to hear their rationale for ground RF absorption being related to RF attenuation to the point of loss of signal. That statement makes so little sense I'm not even sure where to start the argument against it.
Click to expand...

Listen. I'm repeating what was said by the bodies that fly there. Conceivably with the rocket lying on the ground, the salts on the surface could have an attenuating effect and cut down on the ground footprint. No, it shouldn't have an effect in the air.
The correspondent said they noted a range decrease on the ground, even with handheld radios as opposed to flying from a Midwest farm field. I had no reason to believe I was being B.S.'ed. The rationale for blowing the main higher would be
to take advantage of better propagation at altitude to have an idea of the drift pattern so one knows where to go. That would hold also if one is doing RDF work. If you can't get a good bearing on the rocket and it goes out of range, one can be S.O.L.
GPS will give you an edge and if you have established a direction of drift, it tells you which way to proceed if you "do not" get a new position packet when you get to the last known position on the ground. It has nothing to do with Aliens.

Now, if you see your rocket on descent, shoot that's half the battle. In that case, one could take a handheld mapping GPS with a "Sight 'n Go" feature and shoot a line to the rocket just before it touches down. Doesn't tell you how far but gives a stable line to walk.

Eric. Thanks for the comments. It supports what I've been told. For folks confined to RDF, using a mapping GPS with a "Sight n' Go" feature might be helpful to "lock in" a bearing to follow. Hold the GPS parallel you your tracking antenna Yagi or otherwise. Lock the bearing when you get the peak signal. This is much more important if you can't see the descending rocket. I've been in that situation more often than not with small projects that go out of sight for a long time. With a GPS
tracker, it's no sweat.

If I'm not mistaken, There is a lot of wide open spaces on the playa and unless the rocket lands in the scrub it seems to me from some of the pictures posted, one can see their downed rocket from quite some distance away if it lands on the flats.
Again anyone who has flown there please comment. Kurt
 
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ksaves2 said:
If I'm not mistaken, There is a lot of wide open spaces on the playa and unless the rocket lands in the scrub it seems to me from some of the pictures posted, one can see their downed rocket from quite some distance away if it lands on the flats.
Again anyone who has flown there please comment. Kurt
Click to expand...

I'm not yet a high-altitude flyer (out of 38 HPR flights my highest flight has been to 8500', my next highest just below a mile), but my first BAR flights were at BRD and it's still my favorite place to fly (and watch others fly). But I can agree with everything you said, there certainly seems to be some sort of RF black-hole once rockets are close enough to the ground. I found this down at ROC's dry lake site at this year's LDRS also (which seemed like a mini-BRD to me). I lost my Eggfinder's signal once the rocket touched-down, and it was much closer to me that I've had it land at either LUNAR's Snow Ranch or TCC's Maddox Dairy field where I was still receiving an uninterrupted signal on both my handheld EF LCD and the EF RX back at camp. I had to get quite close to the rocket before I'd start getting a signal on the LCD again, and my EF RX back at camp picked up the signal again almost immediately once I was holding the rocket to carry it back. And another flyer using a 70cm BRB at BRD seemed to have even worse luck than I was having with 900MHz Eggfinders.

But the visibility at BRD can be pretty amazing also. Things often appear much closer than they really are, you can see your chute/airframe out there and the walk towards it will probably take much longer than you expected, but you'll eventually get there. :) Just have to make sure you brought enough water to make it there and back. :p Or even if you can't see the chute for some reason (bad place to use a yellow or white chute, IMO) provided someone can point you in the right general direction (the hills to every side make for decent landmarks) you can just start heading that way (this was before flying with trackers) and we've always found our rockets without too much searching. I even had one that everybody lost sight of before apogee, turned out it was a failed deployment so it came down ballistic, was still pretty easy to spot a few minutes later as a lawn-dart. :facepalm: But it's significantly easier since I started flying with Eggfinders since they'll at least get you in the ballpark, and generally close enough that you'll pick up the signal again if you can't visually spot it from the last reported coordinates.

More relevant to the thread, I'm definitely interested in giving the RTx a go, though it looks like the overall setup for the rocket is a bit bigger so I need to find something I can fit it in first. I'm happy with my Eggfinders (and Eggtimer TRS's) but I have been thinking about staging where I'd want something for the booster and something for the sustainer, so I'll eventually need a second setup anyway.
 
900 MHz just doesn't propagate well over ground, it's due to the relatively short wavelength. 2.4 GHz is even worse. 70 cm is much better, which is why you don't see 900 MHz being used for RDF... it just doesn't make much sense. The best range is with the 216 MHz Comspec trackers, lower frequency = better ground range for a given amount of power.

Of course, with GPS the ground range is pretty much irrelevant... you only need go get a packet close to the ground, then you're going to pretty much walk up to your rocket. If it drifts a bit or gets blown around, chances are excellent that you'll pick up a ground packet as you get to the original spot.
 
CORZERO said:
I would love to hear their rationale for ground RF absorption being related to RF attenuation to the point of loss of signal. That statement makes so little sense I'm not even sure where to start the argument against it.
Click to expand...

Cant comment on the product, but on rf effects, I recommend some reaearch on the topic, simply googling "rf attenutaion by soil type" should give you plenty of documentation. There are many factors that affect RF propagation close to earth beyond frequency, to include: moisture, soil composition, heights of tx and rx, and fresnel zones.
 
cerving said:
900 MHz just doesn't propagate well over ground, it's due to the relatively short wavelength. 2.4 GHz is even worse. 70 cm is much better, which is why you don't see 900 MHz being used for RDF... it just doesn't make much sense. The best range is with the 216 MHz Comspec trackers, lower frequency = better ground range for a given amount of power.

Of course, with GPS the ground range is pretty much irrelevant... you only need go get a packet close to the ground, then you're going to pretty much walk up to your rocket. If it drifts a bit or gets blown around, chances are excellent that you'll pick up a ground packet as you get to the original spot.
Click to expand...

There is a 1.1 watt $95.00 APRS tracker out there for Ham types on the 2 meter band. In fact there are a few of them but since this is about 900Mhz, I'll leave it at that for respect of the thread. 2 meters is simply not needed for sport fliers
and at the high end with the Multitronix product, 900Mhz has been sufficient for some very extreme altitudes likely due to it's 1 watt 900mhz transmitter. (And premium price) Not going to 100k' routinely? Can look at alternative GPS trackers.

Oh, one other tidbit that might help with recovery. I did testing with an actual launch and tracking situation using a Yagi for the ground recovery. I had a flight that was totally unseen land 1.66 miles away from me. Once the rocket was down, I proceeded towards the last known packet position with the duck antenna replaced with a 900Mhz 13Dbi Yagi. (Probably Chinese units! We all know their specs are shall we say, exaggerated a bit.) I knew where to point the Yagi from the mapping program I was using. The second I started receiving positions again, I removed the Yagi and replaced it with the simple duck antenna. The signal completely disappeared. Put the cable to the Yagi back on and the signal returned. Bottom line is if one needs to increase the ground footprint of a 900Mhz tracker, a Yagi on the receive end can help once the rocket is down. Yagi not good in flight due to the narrow beamwidth and hard to point at a moving, perhaps out of sight rocket. In the case for in-flight monitoring besides the duck antenna a patch antenna
can give a modest 6-8Dbi gain increase with a wider beamwidth.antennastick.jpg That's a patch antenna for 900Mhz mounted on a pole. Haven't had to use it yet. Was an $18.95 special I couldn't pass up

The only other thing I can think of is having a live mapping situation with the rocket being plotted in real time on a map. For close in sport flying not absolutely necessary but for completely out of sight with long distance recovery, can be very helpful if you arrive at the
last known position and no sight of the rocket or signal from the GPS tracker. Now with reception of positions with the rocket coming in at the lower altitudes, the drift line on your map will give you an accurate drift trend and you just have to follow the trend line until you pick up a signal or see the downed rocket. If one just manually inputs the last known position into a handheld mapping GPS, sure once you get to that position you can "assume" the current wind you are experiencing is what the rocket was experiencing before touchdown but if the wind had shifted before you got to that spot, could end up going in the wrong direction. All these little details can provide a insurance you get your project back, some of which aren't that pricey to partake of.
There is nothing worse than losing a pricey rocket. Believe me, I've done it with a Beeline GPS but that was a deployment failure in a metallic painted rocket with ballistic recovery. I got the remains back from the landowner 18 months later. No positions at altitude.
Kurt
 
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blackjack2564 said:
Here is a list of all the things used during testing & final use, everything I ordered came from USA shipping address & was Ok'd by Missileworks.

For battery connectors I got these, 100 or 50 pair sound like a lot, but they were so cheap. If you want less just enter JST connector in search box at top of page to find lesser quantities.

https://www.ebay.com/itm/100PCS-Battery-Plug-JST-RC-Model-Socket-Connector-Cable-Wire-Male-Female-50Pairs-
/111441374190?hash=item19f26c6bee:g:gGwAAOSwPe1T9V6z

10 pair.

https://www.ebay.com/itm/USA-10-pai...872406?hash=item43b34b6856:g:PqkAAOSwa-dWqIoF


These batteries give rocket unit over 10 hrs continuous runtime. about 3.00 3.7 volt

https://www.hobbyking.com/hobbyking...ck_Walkera_V120D02S_QR_Infra_X_QR_W100S_.html

Battery I use on base.7.4 volt No room inside, I just tape to exterior, it very large. The LCD and base use more juice.

https://www.hobbyking.com/hobbyking/store/__26564__Turnigy_1500mAh_2S_25C_Lipoly_Battery.html

Turnigy charger [25.50] I got after recommendation from Jim Amos, AC or DC comes with all connectors for charging recommended batteries & cord for AC & clips for DC to car battery. You can get cigarette type power connector also.[does NOT come with] this unit is small...size of 2 packs of cigarettes.

https://www.hobbyking.com/hobbyking...put_AC_DC_45W_Digital_Balancing_Charger_.html
Click to expand...

Not trying to hijack the thread or anything, but can you tell me what you set your charger to when charging the 1500mAh battery? I have it set to LiPo 1.5A (didn't really see any other options) and I'm getting an ERR2. I've contacted HobbyKing to see if they had any ideas, but I figured I would check with you since you have the same setup. Also, what are you using to charge the 750mAh batteries? That charger doesn't seem to support the tiny connector on those. Thanks!

Mike
 
MikeMann said:
Not trying to hijack the thread or anything, but can you tell me what you set your charger to when charging the 1500mAh battery?
Click to expand...

0.60 setting.... used for charging all sizes of LiPo's I use.

[/QUOTE] Also, what are you using to charge the 750mAh batteries? That charger doesn't seem to support the tiny connector on those. Thanks!

Mike[/QUOTE]

Charger unit comes with cable bundle. use the red JST.....not the tiny white connector on battery.
 
[/QUOTE]Charger unit comes with cable bundle. use the red JST.....not the tiny white connector on battery.[/QUOTE]

I'm an idiot. Completely new to these kind of batteries. That charger didn't come with the charging harness for those batteries. At least mine didn't. It only came with one that looks like two prongs running horizontal and vertical. No wonder I was getting the error battery not connected. I'll have to order the one for the JST, etc connectors but it looks like it's backordered through them. Duh...
 
Charger unit comes with cable bundle. use the red JST.....not the tiny white connector on battery.[/QUOTE]

I'm an idiot. Completely new to these kind of batteries. That charger didn't come with the charging harness for those batteries. At least mine didn't. It only came with one that looks like two prongs running horizontal and vertical. No wonder I was getting the error battery not connected. I'll have to order the one for the JST, etc connectors but it looks like it's backordered through them. Duh...[/QUOTE]

I cut the end off of the one set an soldered a jst connector in its place. Seems to work well.
 
djkingsley said:
Charger unit comes with cable bundle. use the red JST.....not the tiny white connector on battery.
Click to expand...

I'm an idiot. Completely new to these kind of batteries. That charger didn't come with the charging harness for those batteries. At least mine didn't. It only came with one that looks like two prongs running horizontal and vertical. No wonder I was getting the error battery not connected. I'll have to order the one for the JST, etc connectors but it looks like it's backordered through them. Duh...[/QUOTE]

I cut the end off of the one set an soldered a jst connector in its place. Seems to work well.[/QUOTE]

That is what worked for me too. What I wonder about is the single cell LIPOs that have a "Balance connector" attached but there is no 1S point on the board that came with my charger. I have the one that Jim recommended above.
 
Single cells don't need a balance connector. It might be that there's an extra connector so it can be used with other devices. I have some large capacity 2S batteries that have a JST and a Futaba connector along with balance connector. I guess the deal here is when storing one's batteries over the winter, should connect them to the charger and run the "Storage" setting
that brings the cells down to 7.6V. They say the lipos "keep" better that way and last longer. Kurt
 
Extended Beta Test update:

If anyone has attempted to use the RTx System tethered up with an RRC3, you'll likely not have reliable RF packet syncing to your base unit. Ben Russell was first to report this issue last week and I finally replicated and discovered the underlying issue.

A transition was made in the XBee radio configuration, specifically changing up packets from unicast mode into a multicast mode. This was done to provide Rocket/Base unit "interchangability". However, when running in multicast mode the packet timing becomes less determinant.

This skew in packet timing causes the base unit to constantly lose sync as it's running a predetermined multiplexing operation between all the devices it must monitor and stream with... Multicast operation is OK for RTx ONLY operations and only manifests when one tethers up with the RRC3.

If you're an extended beta user, please email me to arrange for radio reconfiguration should you want to utilize this feature.

If you're not daunted by some minor jumper pad desoldering/resoldering and you have a USBIO module (btw, this requires 2mm male pins on the comm cable end) I can instruct you on the steps required to reflash the radio modules.
 
ksaves2 said:
I guess the deal here is when storing one's batteries over the winter, should connect them to the charger and run the "Storage" setting that brings the cells down to 7.6V. They say the lipos "keep" better that way and last longer. Kurt
Click to expand...

I'm able to fly in the winter (wind permitting) but I appreciate the good storage advice.
 
I have the basic system. Tells me how high I went and how far and which way the rocket is. I walk right to my rocket every time.
I'm going to be adding another Tx, and RC3 to my MW collection over the winter. So user friendly and it really is a "buy n fly" system.
 
I suspect Jim is working on some issues that were reported on another thread and perhaps is refining the design before opening it up again for general sale. Perhaps he can comment for himself. If I knew there were many folks with credit card ready for
a service that I do, I wouldn't want to disappoint. Another way to look at it is one would certainly like a robust, carefree, long-lasting system and it's better to wait until the development is complete. Kurt
 
ECayemberg said:
I was warned, I was a skeptic, but I found out first hand that the warnings were valid....GPS is a necessity for out-of-sight flights at Black Rock. The most reasonable theory I've heard is that the water table is so close to the surface of the alkali playa, that the RF signals are simply absorbed into the matrix of the semi-conductive sync
Click to expand...

Heck I fly a fancy expensive GPS transmitter and I still lose signal upon landing out there. Great trick, as you get close to the last known coordinates, open up squelch and you can get a heartbeat even when there is not enough of a signal to decode APRS.

Nick@JET said:
Sorry to detail thread, but Black Rock, few weeks?? Man that's big! Hope u post some info
Click to expand...

He had a great flight! I think it was an N2540 to 45k -
14355101_10154601440604525_348434845847057193_n.jpg
 
ksaves2 said:
I suspect Jim is working on some issues that were reported on another thread and perhaps is refining the design before opening it up again for general sale. Perhaps he can comment for himself. If I knew there were many folks with credit card ready for
a service that I do, I wouldn't want to disappoint. Another way to look at it is one would certainly like a robust, carefree, long-lasting system and it's better to wait until the development is complete. Kurt
Click to expand...

Well, of course. And since it's likely we're now into looking at the 2017 season for flying anything I buy now anyways...not in any super hurry. Just you know... excited and about as patient as a 3 year old who just drank a big gulp and has to pee and you just passed the last rest stop for 180 miles....
 
ksaves2 said:
I suspect Jim is working on some issues that were reported on another thread and perhaps is refining the design before opening it up again for general sale. Perhaps he can comment for himself. If I knew there were many folks with credit card ready for
a service that I do, I wouldn't want to disappoint. Another way to look at it is one would certainly like a robust, carefree, long-lasting system and it's better to wait until the development is complete. Kurt
Click to expand...

Yep, I think I was #2 in line for the 2015 BF pre-pay credit deal. I passed mostly because I was moving into hip replacement surgery and knew I couldn't make use of the system for a good 6 mos, but also because I never buy first articles of anything from new cars to iPhones. I will circle around in the Spring and finally pick one up.
 
watermelonman said:
Heck I fly a fancy expensive GPS transmitter and I still lose signal upon landing out there. Great trick, as you get close to the last known coordinates, open up squelch and you can get a heartbeat even when there is not enough of a signal to decode APRS.



He had a great flight! I think it was an N2540 to 45k -
14355101_10154601440604525_348434845847057193_n.jpg
Click to expand...

That is a #1 excellent strategy that works as reassurance when approaching a 2M or 70cm APRS tracker. Open the squelch while approaching the rocket and it you hear the "brrrrrrrrrrppppp" of a packet, you'll know you
will be able to get a final position packet soon.

This strategy is not valid for 900Mhz trackers but some of them give a beeping indication when a valid position is received. With the open squelch method one can hear through the static long before the electronics can decode the
APRS packet. You know your tracker survived the flight. Technically, if the tracker is sending a signal without a valid packet, could track using a standard RDF method but usually when one gets within range a new position is decoded.
Might happen if the GPS receive antenna is facing "down" towards the ground rather than "up" where it lies. Kurt
 
DavidMcCann said:
Well, of course. And since it's likely we're now into looking at the 2017 season for flying anything I buy now anyways...not in any super hurry. Just you know... excited and about as patient as a 3 year old who just drank a big gulp and has to pee and you just passed the last rest stop for 180 miles....
Click to expand...

I can understand your anticipation David after experiencing the "magic" with APRS trackers. It's a really great way to fly with confidence for the completely out of sight flights. Kurt
 
Thanks to all who have continued to test and provide files, feedback, and user experience in our extended beta test of the RTx/GPS System.

I continue to receive updates from users, and from all indications the system has performed extremely well. This performance extends to all aspects of the system which include GPS data downlinking during flights, persisting GPS data to flash and upload/capture, and the navigational ability to locate and retrieve rockets. The overall user experience feedback has also been very encouraging.

Some of our beta testers have already posted here in this thread, and some we have still yet to hear feedback from. In general I interpret this void of feedback as they are satisfied in general or just have yet to fly with it... I'm hoping that we'll have more usage reports and data posted up here by beta test users for the TRF community to review.

We have made a couple of programming changes as a result of testing, specifically to radio configuration along with a new feature to support an audio "muting" operation (to turn off the sync loss notification). We have also continued to refine the 3D case design with improved fitment and functional changes.

We're going to continue collecting data and feedback, and provided there's no other glaring oversights that are uncovered we're going to make plans for general release in late October or early November as time and situation permits.
 
Jim,
Thanks for the update. I too am excited and anxious to get my hands on the RTx. Appreciate your efforts to make sure it's right (and keeping us informed), and I'll still be here with credit card in hand when you're ready.
 

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