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GPS telemetry using APRS

I put together a telemetry package so I can know where my rocket lands. The link is:

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I assembled this to go in a minimum dia rocket I will be flying later in the year. I am looking at close to 30,000' so I figured I needed something to help find it. Here is a link to the rocket:
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Robert DeHate

Reply to
Robert DeHate
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Reply to
Will Marchant

Did you consider the Pocket Tracker from Byonics? That is the system I am going with.

Perhaps you will need the rf power output of the Alinco...

John N2AFU

Reply to
jderimig

I have my own tracking transmitter that outputs 50mW. I have used it for telemetry. No need for APRS there since I just stream the data from the GPS, or any serial source like my altimeter. Then to stay legal it spits out my call sign in morse code every 10mins.

But the Alinco puts out 300mW so I get increased range.

What output power does the BeeLine have? I looked at the parts he used, very interesting chips. I have debated using them or the PIC based RF designes.

Robert

Reply to
Robert DeHate

Reply to
Will Marchant

I looked at it. It is too big to fit in the 4in NC.

Reply to
Robert DeHate

I can never remember the conversion. Whats that in watts??

Reply to
Robert DeHate

Reply to
Will Marchant

I need a good 6 to 7 miles of data. He is getting data TX from 5 miles?? Or just picking up a signal??

Thats 70cm right?

5 miles at 16mW. That almost seems unbeliveable. 300mW is only good for maybe a couple miles on the ground at 70cm. But thats with 1/4whips looking for inteligible voice.

I have a 5mW TX on 70cm I hardly get a 1/2mile out of it on the ground. Hmm

RDH8

mass/volume.

Reply to
Robert DeHate

-20 dBm = 10 uW

+12 dBm = 15.85 mW
Reply to
DaveL

An initial APRS range testing comment is: "decoded it 3 miles away (line of site)." He includes a topo map and it looks like he drove as far up two facing ridges as he could get. So, my guess, is that that was not an attempt to go until the packets didn't make it through.

He has online forums at

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where you can see this info first hand. You should probably get into a chat with him directly: I'm worried about passing along incorrect information.

I bought a BeeL> I need a good 6 to 7 miles of data.

Reply to
Will Marchant

I think just picking up signal

from what I saw it was

ground to ground is different than air to ground. ISS only uses a 35w tx with (i think) a real short yagi (or maybe just dipole)

fly it from a kite and see what you get. I think the rule of thumb was for every 6 feet add 3db gain to your estimated output

Reply to
tater schuld

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