Big Ree Bee 70cm GPS is here, now how to mount it

[webtech]

Hey guys..

I got my birthday present..now how to mount it on my tracking bay?

and would you add shrinkwrap over the gps chip?
Surprised it wasn't all ready..




I think I got it programmed.. I wasn't sure on the Disable P1.. guessing that removes the path.. which I like having..
I will be using WIDE1-1 in path 1.. this way I don't have to reprogram my kenwoods..

TESTING Coming soon!!!

thanks for your input, your pictures are welcome as well.

 

[ksaves2]

Hey guys..

I got my birthday present..now how to mount it on my tracking bay?

and would you add shrinkwrap over the gps chip?
Surprised it wasn't all ready..

I think I got it programmed.. I wasn't sure on the Disable P1.. guessing that removes the path.. which I like having..
I will be using WIDE1-1 in path 1.. this way I don't have to reprogram my kenwoods..

TESTING Coming soon!!!

thanks for your input, your pictures are welcome as well.

Since there aren't many 70cm digipeaters out there, doesn't matter what path you have set, but if you don't follow the protocol, the device won't save your settings. I'll post some screen saves later that will have the equivalent WIDE1-1, WIDE2-2
for a path but it isn't necessary. So if you get bound up on the path, don't sweat it. Heck you could do a dog and pony trick by setting up a D72A or a laptop/TNC arrangement to digipeat your packets but it wouldn't really serve much purpose on 70cm.
Anyone else with an APRS rig could simply listen in on your frequency like you are when the rocket is in flight. If someone else is there with another D72, one of you could have the '72 set to read out the altitude display and the other could have distance and bearing shown. I highly recommend getting a used Garmin 60Cs or CsX so one can set the '72 for altitude and watch the position on the map. Add your Main deployment altitude to the starting altitude you see with the rocket on the pad and when the rocket is coming in under drogue, you can be looking in the right direction to try to catch a visual of the main deployment. Sometimes you can't see a small rocket on descent and even though you get a good main, if it's really far away, you might not see it at all. But............ You will notice a slower rate of descent and that's reassuring the main is out. Sometimes it's wiser to set a higher main deployment altitude if field size allows it as it takes time at the once every 5 second APRS packet rate to perceive the slowed descent rate on the screen.

Kurt

 

[UhClem]

If you look at the datasheet for the GPS receiver you will find that it exhibits a high level of concern for ESD through the antenna. So you must take precautions.

When I bought mine it came with heat shrink holding the battery in place but that also covered the GPS antenna. Knowing a little something about patch antenna design this concerned me. While it provided some ESD protection it also detuned the antenna and reduced its performance. A quick test showed that without the heat shrink the time to first fix was the expected ~30 seconds while it took more than 45 seconds with it.

That might not seem like a big change but it requires about 30 seconds to download the ephemeris data which means that rather than locking onto the signals almost instantly, it required 15 seconds or more. Which is quite a big deal.

I am working on mounting it inside some 29mm clear plastic tubing. This will be far enough away from the GPS antenna so that it shouldn't alter its performance much and provide some protection from prying fingers with electrostatic charges.

 

[AlnessW]

bubble wrap it and put it in the nosecone.

 

[rms]

bubble wrap it and put it in the nosecone.

+1, all I do

 

[webtech]

This is what I came up with..
I have done this with the tracking beacon in the past without any problems.

 

[webtech]

Here is how I got it programmed,
and I got it to log to my laptop using APRSISCE32

 

[ksaves2]

Here is how I got it programmed,
and I got it to log to my laptop using APRSISCE32

View attachment 284815

That looks perfectly fine Russ. Unless you hit a 70cm digipeater on that frequency the path really doesn't matter. You might want to consider a thrust block aft of the BLGPS depending upon the acceleration you expect with the planned motors.
You wouldn't want it to be thrown free from the tape. Kurt

 

[BrAdam]

Take care to brace the bottom if you're doing high G flights. If you don't the battery or GPS or connection can come loose. Not what you want in flight. I put a dowel through the sled for all to rest on them tape.

I know if you think you tape it tight enough it won't come loose but.....it still can. Trust me. Also on hot days at slow or busy launches that tape can bake and soften quite a bit. Love my transmitter but learned the hard way about mounting. As others have said though, bubble wrap and tuck it in works well too. I do that for my smaller diameter cones.