GPS

Yes

... or are there any small, not fabulously expensive units

I wouldn't say they're inexpensive though.

There is also the new ARTS GPS system at

However, I don't think these are what he's asking about as neither will do the 10-20Hz sample rate. I have seen a unit that will do 10Hz, but I can't find the data sheet right now. I'll keep looking. It wasn't insanely expensive, IIRC, but was certainly more than the 1Hz units.

-Jeff Taylor

Why do you want a 10-20Hz sampling rate? If you're wanting to log vertical velocity type information (either from a vertical velocity output or a delta-z determination), I don't think any comsumer GPS systems have algorithms that can reliably determine vertical velocity AND rapidly changing altitude at even 1Hz. Now, once a rocket is slowing and coasting up to apogee, the GPS can probably determine altitude more reliably. Anything during the thrusting period is probably not reliable with consumer units.

Secondly, all the consumer GPS units I've seen specs for use 1Hz. If you wanted a 10Hz sample rate, you'd need to either increase your baud rate and/or limit the number of NEMA sentences you're sending. And there's really not a big consumer market for GPS units that need location/altitude data at a rapidly changing rate.

Dave

You could always modify these for the job.

There's also the GPS system sold by ATHA Aerospace.

GPSFlight units do 10hz, but the GPS data is only 1hz or 4hz, depending on the engine you use. The Baro data is 10hz.

And let's not forget this one for all you ham radio enthusiasts out there:

-- Greg, K7RKT

Oh, to have money right now...

We used a BeeLine transmitter to track one of the wayward Delta pieces and it worked like a charm!

-Kevin

But the GPSFlight and ATHA transmitters are unrestricted - you don't need a license to use one.

yes, but compare the prices.

a ham license only costs $12 or so, and you'll save $100's with a BeeLine vs. the others.

-- Greg

True, but the cost of entry on a HAM license is dirt cheap -- $25 for the study guide (although you can do it online if you want) and $14 for the test.

That's $39 more; I'm still way ahead cost-wise against anything else on the market.

-Kevin

Is that a actual ham license or radio tech license? Reason I ask is that I'm toying with the radio tech class license myself, eventually.

Ted Novak TRA#5512 IEAS#75

After careful thought and consideration, I invested in BRB transmitters and a Ham (Technician) license. It took a few hours to study for the exam,. However the exam itself was quite easy and inexpensive> I had already ordered an inexpensive single band Transceiver prior to taking the test. Once I began studying, I realized I wanted the ability to do more with my handheld and immediately ordered something better.

Furthermore, the BRB system is much more flexible (programmable) and cost effective than the competitors.

Mark A Palmer

There are three levels of ham license -- Technician, General and Extra (if I remember the current names correctly).

It costs $14 for a testing session; you can take one or more exams at a session. Technician is the "lowest level" and requires part 2 (no CW).

General and Extra both require part 1, which is CW.

For the BeeLine stuff, you just need a Technician license. The hardest part of it is staying awake through the book.

-Kevin

What is the BRB system?

And unfortunately careful reading of the FCC rulebook gives no indication that rocket use is ok in many of these bands that are reserved for animal tracking and the like, they are quite specific and to possible uses, and hence I believe popular products like rockethunter etc are in fact not legal.

Really? OK, here's a scenario:

I plan to track an animal. I want to photograph its habitat from the air. I'm going to use a rocket to do this. I need to make sure I don't lose my rocket. In order to make sure that I don't lose it in the field, I have to 'practice' with it in other areas.

Or same as above, but I'm planning on selling my rocket to animal trackers...

David Erbas-White

Read the FCC rules. This is not a valid scenario. Why PO the FCC when we're already fighting the ATF? Let's (as a hobby) next allow breaking DOT rules. I'm sure that will back the case that the hobby is regulating!

Sorry...BRB= Big Red Bee- from Beeline....great product!

Mark Palmer