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[aprssig] aprs & balloon experiment

Jim Lux jimlux at earthlink.net
Mon May 14 13:48:53 UTC 2012

On 5/14/12 5:00 AM, aprssig-request at tapr.org wrote:
> Content-Type: text/plain; charset=us-ascii
> Hi all,
> A friend of mine is a science teacher of high school students.  He
> wanted to launch a balloon with a scientific payload, having seen
> the ARRL promote student balloon launches that use APRS to transmit
> telemetry and balloon position at http://www.arrl.org/news .  So I
> contacted my local ARRL rep, Dick Norton N6AA, Director ARRL
> Southwestern Division, to find a local speaker on balloons and APRS.  Dick
> replied, CC'ing Din Henderson N1ND, the regulatory guy at ARRL
> http://www.arrl.org/regulatory-advocacy with
> "As Dan Henderson said, simply installing an APRS unit in a balloon as you
> suggested and turning it on would be considered broadcasting, which is
> not legal in Amateur Radio."

Obviously, since lots of hams run APRS on balloons, and transmit only 
APRS trackers, the FCC would have said if there was a problem by now. 
Bear in mind that the FCC usually only gets involved if someone 
complains. Hams are a pretty tolerant bunch when it comes to dumb 
mistakes, preferring education to retribution.

But, maybe the question/answer to ARRL was misunderstood.

There are *significant* problems cropping up with the use of amateur 
radio frequencies by educational and research activities, particularly 
with respect to things like CubeSats.

Here's the issues:

1) just because it's an educational or research activity doesn't make it 
ok for ham-radio.  There's a line somewhere between "building and 
testing a radio" and "using ham radio for the campus security HTs".  The 
question one would ask is "is someone being paid to do radio".  In high 
school this is less of an issue, but in college, one asks, "is that paid 
grad student operating the radio as part of their job"?  Another similar 
situation would be the faculty advisor of a radio club, if they are 
being paid to be that advisor.  It might be that the kids in the club 
are fine to operate, but the advisor can't.

2) the "broadcast" thing doesn't necessarily come into it.  The payload 
is presumably transmitting back to the balloon operator.  The fact that 
others can hear it is incidental.  If you were to attach the 
transmitter, and then cast it to the winds, without a ground receiving 
capability, that might be an issue.

3) remote control of the payload is something you need to look at.  I 
haven't looked at this in 10 years or so, but I think there are bands 
where this is legal and bands where it is not (e.g. UHF is almost 
certainly ok, HF is a bit dicey)

4) The whole "if another radio service should be used" rule is kind of a 
tricky area. the intent is that nobody use ham radio as a substitute for 
something like an Experimental (Part 5) license or for commercial 
services.  Some of the links cited by previous posters skate pretty 
close to the line on that one (e.g. using ham frequencies to develop a 
product, then changing to non-ham frequencies when they "go into 
business" selling the product.. that's really something that should have 
been done with a Part 5 license)

5) It goes without saying that there is a "control operator" with the 
appropriate licenses who is responsible for the transmitter on the 
balloon, and they need the ability to turn it off (or to make sure that 
it can't fail "stuck on" for a long time).  I don't know if there's any 
license class restrictions on this.

6) You need to coordinate your frequency.  There was a case last year 
with a kid (with a license) doing a balloon for a science project in 
Southern California who didn't bother to check with anyone and picked a 
frequency that happened to be on top of several fairly busy repeaters, 
completely screwing things up for a day, 'til the balloon came down. 
There's been more than one cube sat launch that almost didn't go off 
because they didn't get regulatory approval for their frequency until a 
few days before.

In any case, none of this is complex. It's more a matter of checking off 
the boxes and making sure you follow the rules.

Go have fun with the balloon!

Jim, W6RMK

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