FM radio out of band opperation?

[Guest DeepBlueEditor]

I am an amateur radio operator as well as a kayaker and am wondering if some enterprising hacker type could look at the FM radio app and maybe see if it can be made to operate at frequencies other than just FM radio? Most radios can be forced out of band these days with tweaks in hardware and software.

What I am looking for is an application that would allow operations to at least 148 MHz and maybe as low as 30MHz. Any extra range that is stable is welcome with either hacked software or another app. This would potentially allow some older style scanner listening as well as 2meter Amateur ranges. Just an idea, if someone out there gets bored. Receiving amateur and other freqs is not in violation of any FCC regs as long as the device is clean and doesn't generate any spurious freqs itself so we should be safe to hack the software since it is obviously a type accepted device already.

Hack at will.

S.

[Guest BeamRider]

I am an amateur radio operator ...

Hi, me too

as a kayaker and am wondering if some could look at the FM radio app and maybe see if it can be made to operate at frequencies other than just FM radio? Most radios can be forced out of band these days with tweaks in hardware and software.

Look to FM tuner specs I see that input fre is 76-108 MHz ... but looking at its registers you'll find that the tuner uses a channel selection tuning: each channel is spaced of 50, 100 or 200kHz depending on setup (bottom freq is 87.5 MHz or 76.0 MHz depending on regional setting of the chip). Tuning register uses 10 bits for channel selection (0..1023) so tuning limits are:

76.0 up to 87.5 + (1023 * 0.2) = 76 .. 292.1 MHz

76.0 up to 138.65 MHz in 0.05 MHz steps

up to to 189.8 MHz in 0.1 MHz steps

and up to 292.1 MHz in 0.2 steps

the ony ham band in this range is 2 meters, but only with 100 kHz channel so is practically useless. Air traffic is tunable but I don't know FCC rules about that.

Also please remember that FM broadcast emission has 15kHz up to 60kHz bandwidth .... si4703 filters are wide to be used for ham purposes.

Cheers

Edited March 25, 2009 by BeamRider

[Guest DeepBlueEditor]

Hi, me too

Look to FM tuner specs I see that input fre is 76-108 MHz ... but looking at its registers you'll find that the tuner uses a channel selection tuning: each channel is spaced of 50, 100 or 200kHz depending on setup (bottom freq is 87.5 MHz or 76.0 MHz depending on regional setting of the chip). Tuning register uses 10 bits for channel selection (0..1023) so tuning limits are:

76.0 up to 87.5 + (1023 * 0.2) = 76 .. 292.1 MHz

76.0 up to 138.65 MHz in 0.05 MHz steps

up to to 189.8 MHz in 0.1 MHz steps

and up to 292.1 MHz in 0.2 steps

the ony ham band in this range is 2 meters, but only with 100 kHz channel so is practically useless. Air traffic is tunable but I don't know FCC rules about that.

Also please remember that FM broadcast emission has 15kHz up to 60kHz bandwidth .... si4703 filters are wide to be used for ham purposes.

Cheers

Sadly, air traffic is AM modulated. I don't think this system can handle AM. I'll check into the rest of the specs you mentioned. Have a nasty head cold and not thinking to clearly today. Thanks for the info.

Sean

[Guest BeamRider]

Sadly, air traffic is AM modulated.

Yep I forgot ... and no, 4703 can't demodulate AM.

Cheers

[Guest DeepBlueEditor]

Yep I forgot ... and no, 4703 can't demodulate AM.

Cheers

Got a question... since you seem to be in tune with the hardware, any chance you know what hardware is running the GPS system in the i910? Might help those guys out in that forum if we could find hardware specs. They wouldn't spend time chasing ghosts that way.

S.

[Guest BeamRider]

On my understanding i900 (not sure about i910) uses Qualcomm MSM6281 chipset that integrates gpsONE.

Hope this helps

[Guest DeepBlueEditor]

On my understanding i900 (not sure about i910) uses Qualcomm MSM6281 chipset that integrates gpsONE.

Hope this helps

Turned out to be the MSM6800A chipset. Found another forum where someone opened up their phone and took pics of every chip. We're all working furiously on the GPS thing you know.

Thanks for the info.

S.