Do FCC regulations affect depth?

[Anonymous]

Are detectors sold in Britain or Australia getting more depth than those sold here in the US? Keep hearing of huge gold nuggets being found in Aussyland.Talked with my local store guy and he said they have more power because of no fcc regs.
Thought one (or a bunch...hey hey)of you guys would know the truth.Give me the low down.What do the fcc regulations hear in the US of A regulate?
how does it affect us detectors (if any)Thanks
Glacial Hills

 

[Anonymous]

That's just a story because he didn't have a sensible answer. Were not dealing with CB radios. They are no such FCC regs. The Eric Foster PI detectors, and the "SD" series detector

 

[Anonymous]

[No message]

 

[Anonymous]

Are you sure about that? I remember reading somewhere that there are regs that limit the max output.

 

[Anonymous]

The FCC only cares if the device in question interferes with other devices in a frequency allocation band that they regulate. Most metal detectors that I've studied, and there probably are some exceptions, use operating frequencies that fall outside or below the bands the FCC cares about. Normally, the operating frequencies are so low that even the harmonics of the operating frequency will not cause any problems in this regard.
Theoretically, PI detectors could possibly be a strong source of interference due to switching noise generated when the coil is turned on and off. However, I have not noticed any interference problems with my TV or Radio during experimentation with PI circuits.

 

[Anonymous]

I posted this a while back on another forum:
>FCC Title 47, Part 15 is what you want to read.
>It's on their web site. Below 9kHz there are no
>restrictions whatsoever. Above 9kHz, the limit
>is stated as a field strength of 2400 microvolts
>per meter divided by the frequency in kHz,
>measured at a distance of 300 meters from the
>antenna. So for a 10kHz Tesoro, that's
>240uV/meter at 300m.
>There is no "100 milliwatt" power limit (or
>whatever the number batted around) as many
>people believe. Keep it below 9kHz and you can
>legally melt snow with your detector.
>There is, however, a 10 watt power limit
>on "cable locators".
- Carl

 

[Anonymous]

The problem the FCC and the agencies for other countries have is that a PI switches a high current in a super fast time. This generates harmonics which go up well into the high MegaHertz range.
I asked John Reed who is head of rulemaking at the FCC about PI's etc some time ago. John basicaly admitted that most (if not all) Pi's are in violation of the FCC rules. He went further and stated that ALL GPR (Ground Penetrating Radar) units being sold violatate FCC regulations.
John told me that the FCC simply do not have the staff or other resources to enforce the regulations. He also said that there were few if any complaints about such equipment so there is no urgency for the FCC to act. For those who have one available, take a look at the output of a PI with a spectrum analyzer. You will be surpised by the number and strength of the harmonics.

 

[Anonymous]

Hi Carl and all,
I have submitted several PI detectors, both hobby and industrial for EU emissions tests over the past few years. Radiated emissions are measured from 30MHz to 1GHz and all passed by a substantial margin. Below 30Mhz, they test for conducted emissions, which only really relates to mains (line) powered equipment. Again there was no problem. With a properly shielded coil, grounded metal case, as in the Deepstar, and low speed logic, there is little risk of interfering with any other electronic equipment. The main difficulty with wide band detectors is not emissions, but immunity from radiation from other rf sources, particularly those that are amplitude modulated.
Eric.

 

[Anonymous]

I read in some metal magazine (can't remember which) that as unlicensed transmitters, the FCC limits metal detectors to 100 mW TX power. Maybe there is some government website (or fcc.org?) to look it up.