I have tried getting a signal at 36K and I didn't receive one.
Where? I am happy to believe:
- there was no tower (coverage is patchy),
- the network provider has improved the algorithms so that towers won't connect when multiple towers get a clear signal. I was told (10+ years ago, when it worked) this was a problem for networks because part of the algorithms assumed signal strength was enough to choose base-station, and cell hand-off was designed for 100 mph, not 500mph.
If it is the network improvements, then I think it has happened within the last 5 years.
- the plane had 'MCA'
http://europa.eu/rapid/pressReleasesAction.do?reference=MEMO/08/220&format=HTML&aged=1&language=EN&guiLanguage=en
"The Network Control Unit stops onboard phones trying to connect directly with land-based cellular networks, which are not designed to deal with high-speed movement. Until now, the potential disturbance to land-based mobile networks was one reason for prohibiting mobile phone use in planes."
I think the phone *might* initially show signals until it gets 'the cold shoulder'.
but I think that a lot of cell towers might use over-the-horizon signals to extend their range.
I think so too. I was told by a contractor (who worked for me) and who was working at the time for a research group within a UK network provider that the industry uses quite sophisticated models of ground terrain to choose sites and improve coverage.
... That would also mean that the signal is reflected off the ionosphere and wouldn't work in space
Not necessarily. The ionosphere isn't the only mechanism for getting over horizon signals.
Also GPS uses 1.57542Ghz and 1.2276 GHz for transmission.
Cell phone use 900MHz and 1800MHz
IMHO it would be an odd choice of frequency for GPS, a system designed for military levels of reliability, to use frequencies which are reflected off the ionosphere.
I actually have a friend who is getting his pilots license.
Ask your friend to talk to the instuctor. If the instructor has been flying more than 10 years, they should remember.
Lastly, my budget is about $100.
I think your weight limit may be too small for a low-cost, off-the-shelf solution.
Can you build and test your own radio?
If not, explain to http://www.radiometrix.com/ what you want, and ask the weight of the lightest transmitter (in a legal waveband). The metal shielding could be removed to reduce weight. CU Spaceflight used radiometrix radio's but CU Spaceflight give themselves a bigger weight budget. I was aiming for sub 50gms, and I am pretty sure radiometrix were feasible, as was CU Spaceflight's own radio design. IMHO 20gms is hard.
Otherwise experiment with 413MHz (I think that is legal in most countries).
You might find the radio transmitter from a car remote control door lock or garage door remote works. They are light weight and small radio transmitters.
I plan to use a really large Gauss cannon primary stage, SRB second stage, and ethanol tertiary stage.
That isn't going to orbit, is it?
Unless flight time is quite big, i.e. it orbits, I don't think there is much value, purely from a power generation perspective, in using a solar cell.
IMHO, though I haven't done the calculations, I would be impressed if the power generated from a solar cell in a 'ballistic' flight exceeded a battery of similar weight, and the battery won't have the problems of orientating towards the sun.
