Telemetrum vs. AIM XTRA, or others?

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Chris_H

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Trying to select a gps tracking device right now, and am looking at the Telemetrum and the AIM XTRA. The Multitronix unit looks like the dog's dangly bits, but for now, it is out of the question because of the price.

Are the Telemetrum and the AIM XTRA comparable units in real world experience?

For me, ability to run on Mac OS is a slight benefit, as my mobile PC is huge, and drains batteries quickly, but, I do not look forward to protecting my nice Mac from playa dust. If the benefits are there, a dedicated PC for the AIM unit can be located.

The Telemetrum looks like it uses a wire for an antenna, can a more substantial whip be used instead? How do people usually route the wobbly wire of the Telemetrum? Is that just inside the bay?

Am I overlooking some additional, maybe better options? The price is fine with the AIM or Telemetrum. Really the Multitronix too, but not yet.


Are gps trackers run tandem for redundency, or is this an area where interference between multiple units is, or can be an issue?

To me, it looks like the AIM Xtra edges out the Telemetrum, but I have no experience with any of these.

What other units am I overlooking, that are at least at the caliber of these 2?


Thanks to all for the amazing pool of information here.
 
Trying to select a gps tracking device right now, and am looking at the Telemetrum and the AIM XTRA. The Multitronix unit looks like the dog's dangly bits, but for now, it is out of the question because of the price.

Are the Telemetrum and the AIM XTRA comparable units in real world experience?

For me, ability to run on Mac OS is a slight benefit, as my mobile PC is huge, and drains batteries quickly, but, I do not look forward to protecting my nice Mac from playa dust. If the benefits are there, a dedicated PC for the AIM unit can be located.

The Telemetrum looks like it uses a wire for an antenna, can a more substantial whip be used instead? How do people usually route the wobbly wire of the Telemetrum? Is that just inside the bay?

Am I overlooking some additional, maybe better options? The price is fine with the AIM or Telemetrum. Really the Multitronix too, but not yet.


Are gps trackers run tandem for redundency, or is this an area where interference between multiple units is, or can be an issue?

To me, it looks like the AIM Xtra edges out the Telemetrum, but I have no experience with any of these.

What other units am I overlooking, that are at least at the caliber of these 2?


Thanks to all for the amazing pool of information here.

EggFinder or Missileworks
 
The Telemetrum is pretty good. I have had problems getting a GPS lock in a tower though. You can use a cheap Android tablet instead of your Mac or PC. I just bought a Samsung Galaxy Tab A 7" ($120) specifically to use with the Telemetum. It takes some practice to get used to the software, but it isn't difficult.

I just route my antenna through a bulkhead and use a nylon RC car antenna tube to protect it and keep it straight.
 
I use the AIM. I had a Telemetrum but I could never get it to work at my local field. It would bench test fine but would never talk to the base unit at the field. Swapped it for the AIM and never looked back.
 
What do you think it is about the Telemetrum that was causing issues in your specific location?
 
Thank you for that.

More qualitative info...I actually shredded my MAC Villain at Mach 1.4 with the AIM onboard. The unit never lost lock and I knew that it was in good shape because it continued to transmit as it fell in the coupler. I still fly the unit.
 
More qualitative info...I actually shredded my MAC Villain at Mach 1.4 with the AIM onboard. The unit never lost lock and I knew that it was in good shape because it continued to transmit as it fell in the coupler. I still fly the unit.

That is gold...
 
I have a couple of TeleMegas. Love them. Work well. Worth the extra money just for the quality software interface IMHO.

I just use the standard wire antenna on the Tx, sitting inside a 3D printed ABS NC.

Not sure about the AIM. No experience or opinion.
 
Altus Metrum TeleGPS is another one to consider. I can use the TeleGPS or AltosUI software on your Mac. BTW there is no Mac OS X version of software for the AIM, you would have to run either dual boot or virtualize Windows. I had an AIM and sold it for that reason. Great product though and the amount of data it logs is impressive. One thing that I would like to see on this topic is a chart showing the max altitudes that people are realizing. I have only tracked my TeleGPS to just over 22,000AGL, and besides the loss of lock just before and during Mach it picked up lock fast and tracked it right to the top down to landing and recovery.

My take is that these products are good up to "above average" flights but for the more extreme altitude flights Kate is your friend, so how and what you fly should be part of your decision process.
 
I have been leaning toward the AIM, based on what I have found in reading on the net.

Watching some videos of Kate, however, and reading specs, experiences, that is closer to the real deal. Expensive, yes, but so is the time spent in engineering and building these rockets, in addition to the hardware. Seems like money well spent if more involved rockets are being flown to higher altitudes.

I posted this thread to get some other opinions in refining my selection.
 
I got TeleGPS and a TeleBT with arrow antenna, never have had a problem, works everytime, max distance so far 8 miles.
Love my units and now have (2) TeleGPS.
 
Remember that technically one is supposed to have a Ham Tech license for 70cm (433Mhz) stuff.
That said, I don't think the federal cookie cutterz will be gunning for one due to budget cuts.
Me, I got a General ticket so toss out the callsign to stay legal with all my experiment'in. Kurt
 
Oh, absolutely. Already on that one. My Grandfather introduced me to HAM Radio and electronics when I was 11 years old, though I did not go far with the amateur radio at that time. I am working through the hamtestonline now.
 
Wrong. It’s $420.

I was foiled by the comma! I’m going to blame the Germans for this.

Edit: upon further inspection, country code 27 = South Africa. I now blame the Dutch!


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More qualitative info...I actually shredded my MAC Villain at Mach 1.4 with the AIM onboard. The unit never lost lock and I knew that it was in good shape because it continued to transmit as it fell in the coupler. I still fly the unit.

BTW, why did your rocket shred?
 
You have to keep in mind what you have invested in the rocket in the first place. If it is a large rocket that can do a disappearing act, $420 is a small price of insurance to assure it's recovery. Kurt
 
BTW, why did your rocket shred?

Good question. Either the fins liberated or the tube folded. We recovered 3 of the fins, motor case, and altimeter bay relatively intact, the tube was in a million itty bitty red pieces.
 
I have also been looking harder at the AIM XTRA compared to the Telemega. I am looking at these more for their performance and reliability as upper stage avionics so I am wondering how well the accelerometers and tiltometer work for determining safe condition for lighting sustainer motors. I don't know if any of the recent ~100K ft flights used AIM or if it was all Multitronix and Telemega.
 
Trying to select a gps tracking device right now, and am looking at the Telemetrum and the AIM XTRA.

Are you looking for just a GPS tracking device or do you want the flight computer built in?

I haven't used either of those units and have no experience with either. I recently purchased the MissileWorks T3 unit. It is only a GPS transmitter on the 900MHz range and a receiving unit. The receiving unit has a bluetooth chip on it so it links to your cell phone. It says you can use any bluetooth GPS app that accepts several of the GPS formats. I use the Rocket Locator app for android only. It's nice because it shows the phone's location and the rockets. It always keeps the last position it got from the rocket so even if you lose reception or turn off the receiver, it will still guide the phone to the last known rocket location.

I also fly on the east coast so no high altitudes, but it's located my rockets in corn fields and cow pastures.
 
Not so much for the flight computer, though it might get used. This is for tracking. I do not have a deep understanding of the frequencies involved, yet, but I think I understand that the 900hz frequency does not allow configuration for as much range as some of the licensed frequencies offer. Altitude is important, but stll not fully wrapping my head around 30,000+ Maybe later. 20,000 is pretty high.

Cool to hear that the Missleworks unit is working for you.
 
Not so much for the flight computer, though it might get used. This is for tracking. I do not have a deep understanding of the frequencies involved, yet, but I think I understand that the 900hz frequency does not allow configuration for as much range as some of the licensed frequencies offer. Altitude is important, but stll not fully wrapping my head around 30,000+ Maybe later. 20,000 is pretty high.

Cool to hear that the Missleworks unit is working for you.

The Missleworks is definitely working for me. I'm not sure about how frequency affects range. I was always under the impression that power (wattage) was more important for range then frequency. That frequency had more to do with interference and line of sight. Higher frequencies required more direct line of sight then lower. Like the AM vs. FM radio band. Back in the day on a clear night with a good radio you could get the high power Little Rock AR station on AM in Green Bay Wis. but you could never get any FM station from Milwaukee no matter what the power.
 
I am sure you are correct about the differences between frequencies. Maybe the differences are just in transmission power. I understand a little, in different applications, and expect I will be learning more soon.
 
The free space loss of an RF signal is proportional to the square of the frequency of the transmitted signal. All other things being equal, a 900Mhz signal requires 4x the power of a 450mhz for the signal strength at the antenna

Of course not everything is equal and other things come into play. 900Mhz signals are also absorbed by water so clouds would attenuate a 900Mhz signal more than a 450 mHz signal. Generally 900mHz system need more power to achieve parity with 450mHz systems.
 
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