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Kevin Reid AG6YO ♦
Kevin Reid AG6YO ♦
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I'm developing a type of ground penetrating radar that does not use pulses. It's extremely narrow bandwidth. As narrow as a good crystal can get it. The frequency I'm shooting for initially is somewhere between 150MHz to 900MHz, but that's not set in stone.

So I'm wondering what the maximum legal power is for such a device in the United States, California. I don't have any HAM license. I've seen GPR units for sale that produce hundreds of watts, but they produce pulses. My device will not produce pulses and will not modulate the frequency. The signal will initially slowly rise to peak, and from there it will maintain a constant power for about 100 seconds at a fixed frequency, followed by a slow decay when it's done.

I've tried googling this. The only thing I find is regarding HAM radios (up to 1500 watt limit). Also there are pulsed GPR units for sale. Perhaps there are less restraints for non-modulating fixed frequency signals. My GPR unit will be slowly rotating. The device will be used far out in rural areas. Perhaps 10 to 200 miles away from any city. I'm guessing that even if the unit exceeds legal power limits there's almost zero chance of being caught since there'll be nobody out there except some hunters and campers and perhaps forest rangers. If caught, then I'm wondering if the authorities will take away my GPR. The GPR unit wouldn't be heard on radios since its at an extremely narrow BW. So the Rangers should be okay. They'll probably be more curious then anything else. At say 300MHz the GPR yagi antenna will be around 7 elements.

Any help is greatly appreciated!

I'm developing a type of ground penetrating radar that does not use pulses. It's extremely narrow bandwidth. As narrow as a good crystal can get it. The frequency I'm shooting for initially is somewhere between 150MHz to 900MHz, but that's not set in stone.

So I'm wondering what the maximum legal power is for such a device in the United States, California. I don't have any HAM license. I've seen GPR units for sale that produce hundreds of watts, but they produce pulses. My device will not produce pulses and will not modulate the frequency. The signal will initially slowly rise to peak, and from there it will maintain a constant power for about 100 seconds at a fixed frequency, followed by a slow decay when it's done.

I've tried googling this. The only thing I find is regarding HAM radios (up to 1500 watt limit). Also there are pulsed GPR units for sale. Perhaps there are less restraints for non-modulating fixed frequency signals. My GPR unit will be slowly rotating. The device will be used far out in rural areas. Perhaps 10 to 200 miles away from any city. I'm guessing that even if the unit exceeds legal power limits there's almost zero chance of being caught since there'll be nobody out there except some hunters and campers and perhaps forest rangers. If caught, then I'm wondering if the authorities will take away my GPR. The GPR unit wouldn't be heard on radios since its at an extremely narrow BW. So the Rangers should be okay. They'll probably be more curious then anything else. At say 300MHz the GPR yagi antenna will be around 7 elements.

Any help is greatly appreciated!

I'm developing a type of ground penetrating radar that does not use pulses. It's extremely narrow bandwidth. As narrow as a good crystal can get it. The frequency I'm shooting for initially is somewhere between 150MHz to 900MHz, but that's not set in stone.

So I'm wondering what the maximum legal power is for such a device in the United States, California. I don't have any HAM license. I've seen GPR units for sale that produce hundreds of watts, but they produce pulses. My device will not produce pulses and will not modulate the frequency. The signal will initially slowly rise to peak, and from there it will maintain a constant power for about 100 seconds at a fixed frequency, followed by a slow decay when it's done.

I've tried googling this. The only thing I find is regarding HAM radios (up to 1500 watt limit). Also there are pulsed GPR units for sale. Perhaps there are less restraints for non-modulating fixed frequency signals. My GPR unit will be slowly rotating. The device will be used far out in rural areas. Perhaps 10 to 200 miles away from any city. I'm guessing that even if the unit exceeds legal power limits there's almost zero chance of being caught since there'll be nobody out there except some hunters and campers and perhaps forest rangers. If caught, then I'm wondering if the authorities will take away my GPR. The GPR unit wouldn't be heard on radios since its at an extremely narrow BW. So the Rangers should be okay. They'll probably be more curious then anything else. At say 300MHz the GPR yagi antenna will be around 7 elements.

Any help is greatly appreciated!

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Max legal power with nearly zero BW

I'm developing a type of ground penetrating radar that does not use pulses. It's extremely narrow bandwidth. As narrow as a good crystal can get it. The frequency I'm shooting for initially is somewhere between 150MHz to 900MHz, but that's not set in stone.

So I'm wondering what the maximum legal power is for such a device in the United States, California. I don't have any HAM license. I've seen GPR units for sale that produce hundreds of watts, but they produce pulses. My device will not produce pulses and will not modulate the frequency. The signal will initially slowly rise to peak, and from there it will maintain a constant power for about 100 seconds at a fixed frequency, followed by a slow decay when it's done.

I've tried googling this. The only thing I find is regarding HAM radios (up to 1500 watt limit). Also there are pulsed GPR units for sale. Perhaps there are less restraints for non-modulating fixed frequency signals. My GPR unit will be slowly rotating. The device will be used far out in rural areas. Perhaps 10 to 200 miles away from any city. I'm guessing that even if the unit exceeds legal power limits there's almost zero chance of being caught since there'll be nobody out there except some hunters and campers and perhaps forest rangers. If caught, then I'm wondering if the authorities will take away my GPR. The GPR unit wouldn't be heard on radios since its at an extremely narrow BW. So the Rangers should be okay. They'll probably be more curious then anything else. At say 300MHz the GPR yagi antenna will be around 7 elements.

Any help is greatly appreciated!