Sorry if this flags as a redundant thread (no pun intended), but the only other thread I found on this didn't answer my questions, so I decided to start my own. Anyway...
For my L3 project, I'm planning to build a 75 mm MD and stick an M2245 in it, which by all accounts and sims looks like I'll easily be over 40k ft, so obviously some tracking is required. I've already got a Telemetrum V2.0 that's worked well for me in the past and will serve as my primary ejection altimeter and tracker, but I was worried about signal strength and wanted to add some redundancy to my tracking, so I was thinking of putting a BRB or other brand of higher-powered RDF Beacon in there....both units would be mounted in a nosecone avbay, about 2 inches apart, with the antennas parallel, but slightly staggered -- the base of one is a couple inches above the base of the other, and correspondingly sticks up a little higher, too. Neither can be moved for better spacing, bc that's the only radio-transparent part of the rocket. For receiving, currently I'm using a 3-element Arrow yagi with the TeleBT, and if I added a 70 cm RDF I'd likely buy a 5-element and hook it up to my HT, then build a boom to keep the two antennae well-separated but still able to be held and monitored by one person. All that said, my questions are:
- First off, is this even worth it? Has anybody taken a Telemetrum V2.0 to 40-50k and has some feedback to offer on their signal transmission reliability at those altitudes? Also a bit worried about line-of-sight distance after it's on the ground...Every time I've used the TM2.0 for tracking it's only been able to give me a "last GPS fix" rather than live tracking all the way to recovery, and a windy playa might take it and run.
- If I'm running them both at 70 cm, I assume that even on different frequencies I'll get at least some level of interference, but how much? Too much to make the redundancy worth it?
- Would it help to run one of them in 915 MHz (BRB is also available in this band)? If so, can someone recommend a good handheld antenna for that band? Maybe Arrow's Fox Hunt Loop, then I'll just null-line it?
Thanks for your help.
For my L3 project, I'm planning to build a 75 mm MD and stick an M2245 in it, which by all accounts and sims looks like I'll easily be over 40k ft, so obviously some tracking is required. I've already got a Telemetrum V2.0 that's worked well for me in the past and will serve as my primary ejection altimeter and tracker, but I was worried about signal strength and wanted to add some redundancy to my tracking, so I was thinking of putting a BRB or other brand of higher-powered RDF Beacon in there....both units would be mounted in a nosecone avbay, about 2 inches apart, with the antennas parallel, but slightly staggered -- the base of one is a couple inches above the base of the other, and correspondingly sticks up a little higher, too. Neither can be moved for better spacing, bc that's the only radio-transparent part of the rocket. For receiving, currently I'm using a 3-element Arrow yagi with the TeleBT, and if I added a 70 cm RDF I'd likely buy a 5-element and hook it up to my HT, then build a boom to keep the two antennae well-separated but still able to be held and monitored by one person. All that said, my questions are:
- First off, is this even worth it? Has anybody taken a Telemetrum V2.0 to 40-50k and has some feedback to offer on their signal transmission reliability at those altitudes? Also a bit worried about line-of-sight distance after it's on the ground...Every time I've used the TM2.0 for tracking it's only been able to give me a "last GPS fix" rather than live tracking all the way to recovery, and a windy playa might take it and run.
- If I'm running them both at 70 cm, I assume that even on different frequencies I'll get at least some level of interference, but how much? Too much to make the redundancy worth it?
- Would it help to run one of them in 915 MHz (BRB is also available in this band)? If so, can someone recommend a good handheld antenna for that band? Maybe Arrow's Fox Hunt Loop, then I'll just null-line it?
Thanks for your help.