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RTx in AV bay question

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Nick@JET

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Have anyone installed an RTX in the AV bay - there wouldn't be an antenna sticking out in the open, have you had any issue with lock?

This is FG
 

mccordmw

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My AV bay has an eggfinder GPS in it, and I've had no problems with lock at 5000' away so far. It has an upgraded RP-SMA antenna. I also have it set up to it's not sitting right between the metal all threads.


Avionics Schematic.jpg
 

timbucktoo

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I have and will be flying it with that setup for the first time next week but I believe when crazy Jim was testing the prototype, he also setup his in the AV bay and said there were no issues. Maybe CJ or Jim Amos will chime in!
 

Nick@JET

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Thx guys that's good enough, I'll try and install today as a backup (main Astro GPS are in NC )

I have this currently setup on a NC bulkhead for only one rocket - that is the issue is I can put it in the AV bay pretty quickly but adapting to NC cone quick changing between rockets is not going to happen before AF and hate to go to AF and not use it lol.
 

djkingsley

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I have the the whip antenna inside my 6" madcow stinger that I used for my L3. I have flown it 4 times in this configuration with no problems to 10K ft.

RRC_RTx_sm.jpg
 

ksaves2

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If you read the information on the EggFinders that Cris has available, the best practice is to avoid paralleling metal with the all-thread if one desires to have
the utmost maximum range. That said, if it works for you then fine. Now you have to remember, the Missileworks product puts out more Rf so it can
potentially overcome a less than ideal setup with more horsepower. (The 900Mhz Beeline GPS too has higher power)

In real time tracking the 100mW Eggfinder will give you enough to find most rockets. On a ground drive around, I get every single 1/sec positions live plotted on
a map with the units in the car. With over a dozen flights, that is not the case. The decoding of positions goes up when the main chute deploys and the descent slows. I have a tendency to blow the main as high as practicable to begin receiving positions so a drift trend can be developed. There are a pile of theories why this behavior is seen in practice but I won't bore you with some of the reasons.

If one wants the best range, use the highest powered unit that won't mess with the deployment electronics, don't do paralleling metal. Optimize the antennas,
ie. Yagi's on the Ham bands for flight tracking and Patch antennas on the 900Mhz units for flight and can use a Yagi to increase the ground radio foot print of the downed rocket. Beamwidth is too narrow to be able to keep a Yagi pointed at a rocket in flight with a 900Mhz tracker. Once down and relatively immobile, one can point the Yagi in the general direction and pick up the signal.

Always, always ground test with contained ematches, and the tracker going full bore. You want to check on your near ground level radio foot print and if something is amiss, fix it before flying. (Sure, if you are certain that the devices in question play well together, just do the range test.)

Kurt
 
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farsidius

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I've flown to 21k ft with the RTx in the AV bay of my Punisher 4. Maintained lock well enough through the whole flight - had occasional (a few seconds here and there) packet loss right after apogee for a couple thousand feet, but nothing unusual for a 900 Mhz system (considering the unit was sitting between two parallel lengths of metal all-thread. I've been really happy with my RTx. This is my second year flying with it. I've flown it in nose cones and AV bays and it's always walked me right to my rockets.

-brant
 

mccordmw

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^^^ What Kurt said.

The sum of my tracking knowledge:
<-->

Compared to the sum of Kurt's knowledge:
<------------------------------------------------------------------------------------------------------------------>
 

Nick@JET

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I hope to one day actually understand what Kurt said&#128077;.
 

ksaves2

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Brant. The Rx/Tx is 250mW so a case of raw Rf overcoming the installation. That's good for folks to know. The 100mW jobs can be a little more finicky.

Nick, 11 years ago there wasn't much out there on GPS tracking and I got a General Ham license to do APRS tracking. There wasn't a lot of information out there and I've made a lot of mistakes along the way. Some concepts are very hard to
explain without being wordy unfortunately and a fair amount of my knowledge was picked up studying for the radio license. That helps immensely as far as tracking is concerned. You don't have to get a Ham License and you can look at a lot of
tracking stuff online. APRS for GPS tracking and radio Fox Hunting for RDF.

I'd like to see an all-in-one live tracking setup on a photomap that anyone could use easily with these NMEA unlicensed trackers. I'm able to do it but it's a real PITA to do and would be too hard for most people to setup. Kurt
 

MWC

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RTx antenna can be internal or external using Xbee module internal wire whip or duck antenna (bulkhead or internal mount). RRC3's and/or RRC2+ altimeters don't care based on all we have tested and learned anecdotally from users. Many fly tethered RTx/RRC3 tandems in the same av-bay (as Dennis has shown).

Best practice for rocket-based transmitters is to avoid metallics as much as humanly possible, including wiring.
Segregation of antennas and metallics is also your friend here.
 

Nick@JET

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Brant. The Rx/Tx is 250mW so a case of raw Rf overcoming the installation. That's good for folks to know. The 100mW jobs can be a little more finicky.

Nick, 11 years ago there wasn't much out there on GPS tracking and I got a General Ham license to do APRS tracking. There wasn't a lot of information out there and I've made a lot of mistakes along the way. Some concepts are very hard to
explain without being wordy unfortunately and a fair amount of my knowledge was picked up studying for the radio license. That helps immensely as far as tracking is concerned. You don't have to get a Ham License and you can look at a lot of
tracking stuff online. APRS for GPS tracking and radio Fox Hunting for RDF.

I'd like to see an all-in-one live tracking setup on a photomap that anyone could use easily with these NMEA unlicensed trackers. I'm able to do it but it's a real PITA to do and would be too hard for most people to setup. Kurt
I meant as a compliment of your HAM knowledge, and I really do want to understand, already started studying for the test. However I really don't want to dive into another hobby as I'm prone to do :).

Always read your posts hoping to learn
 

ksaves2

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I meant as a compliment of your HAM knowledge, and I really do want to understand, already started studying for the test. However I really don't want to dive into another hobby as I'm prone to do :).

Always read your posts hoping to learn
Best way to learn is to go out there and actually track. Ground test and get used to working with the hardware and go fly.
It is prudent to use motors that will give you a flight that will keep the rocket in sight for the first few times.
My first two aprs tracking flights, the one rocket went in ballistic and blasted BeeLine GPS tracker to bits. The second flight (I invested in two of the trackers) went above 10000 ft and I darn near lost it. How was I to know that the metallic paint would absorb the RF energy? Yeah, stupid head here didn't do an adequate range test. One guy caught sight on descent just before touchdown. Otherwise, I'd no idea which way it went. Got one position packet at altitude and that was
it.
I haven't lost an out-of-sight rocket since I've started flying them with GPS trackers. Heck even have a better chance finding the totally ballistic flights. Done that one too. The rocket is likely lying right under the last known position in the ground fincan up or splattered all over the field if it's cardboard/plywood. Kurt
 
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