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Radio Verification

PostPosted: Tue Jul 15, 2014 6:09 pm
by Delta_V

I've introduced me and my team (me and myself) elsewhere and briefly stated my intentions. Here I'm just posting in regards to the reception of the radio signal.

As I stated in that post, the transmitter will produce beeps a few seconds apart on a VHF marine frequency. That range was picked because it's high enough to penetrate the ionosphere on a good day, should work with a reasonable free wire antenna length, and yet low enough to not require distributed transmission line elements and the like, all while being reasonably easy to monitor.

So I'm just posting to see what kind of gear the members here have access to that they could use for a potential orbit validation. Besides just marine radios, I imagine a lot (all?) of ham radio enthusiasts would have the equipment necessary.

The satellite will be launched in an elongated polar orbit, so every one at a northern enough latitude should be able to pick up the signal, although in this case the path and hence path loss will be great. For this you'll probably need some sort of reasonably high gain antenna like a Yagi-uda and a quality radio. At any rate, the satellite will of course transverse most parts of the earths surface over its nine (or more!) orbits, so even a low gain antenna should be able to pick up at least something once.


Re: Radio Verification

PostPosted: Fri Jul 18, 2014 5:18 am
by rick m
Hi Chris,

Welcome to the N-Prize Forum.
I've been a ham operator for almost 25 years and have 25-1300 MHz receive capabilities. Our own plan for communicating with our N-Prize sat will be here in California and a host of other amateurs around the world that will be listening. When you get to that point let us know what frequency you will be transmitting on and we will certainly be listening.

Though I got my amateur license for use on the sheriff search and rescue team I was on, I've also used it for other things as a science teacher including a research project for NASA involving students across the country. Currently I mentor several university teams in rocketry and high altitude ballooning that also utilize amateur radio bands.


Re: Radio Verification

PostPosted: Fri Jul 18, 2014 8:15 pm
by Delta_V
I guess if there's any network of technically adept amateurs willing to detect such a feat it's the amateur radio community. After all they played a big part in first detecting sputnik (although sputnik had massive transmitter power by comparison, around a watt).

I was wondering what sort of sensitivity could I guess the average ham radio equipment would have in this frequency range? The transmitter I'll be using will have milliwatts of power, if that, and I would like to check if it's feasible at the levels and distance I was aiming for.

Re: Radio Verification

PostPosted: Mon Jul 28, 2014 7:22 pm
by Delta_V
It looks like I may be going with this for the transmitter:

433 Mhz, 20 dbm/ 100 mW power (intermittent, of course).

It's already used on another tiny (although much larger) satellite:$50sat.htm

Re: Radio Verification

PostPosted: Tue Jul 29, 2014 5:47 am
by Xan
I think the best band is:
435.00-438.00 MHz -- Satellite only (internationally)
( ... dplan.html)

But this band is already quite densely populated: