Selling your own designed & built metal detectors

[Prospector Paul]

Hi,

Does anyone know anything about selling metal detectors in the U.S. that's entirely your design and built by you?

Must the detector be FCC certified, and does that only apply to selling the detectors to certain stores? Supposedly big stores won't buy stuff unless it's FCC certified, but that does not mean it's illegal for a store to buy it. Any truth to that?

As for radiated power I've only seen a 5W limit on certain devices. That may be a issue with PI detectors, but it doesn't seem to be an issue for single frequency metal detectors. According to an online antenna loop calculator, the radiation resistance of a 14 inch diameter single loop antenna at 10 KHz is 3.5E-16 ohms-- Multiply that by the square of the turns. IOW, it's nothing!

A few links:
http://www.findmall.com/read.php?34,...816#msg-280816
http://www.findmall.com/read.php?34,...819#msg-278819

Thanks!

[6666]

sell them on ebay

[Carl-NC]

If you sell a complete device then, yes, it has to be FCC-certified. Meaning it has to be tested & approved by a qualified testing lab. It's fairly expensive and getting worse every year; US-only testing is, I recall, north or $5,000. If you want to sell into Europe, triple that. Selling into California requires that you meet (& can prove) compliance to Prop 65, another big obstacle. You can sell as a kit on eBay and probably skirt a lot of this stuff. Caveat Venditor.

[Prospector Paul]

Kit is a good idea. I was thinking about that earlier, but wasn't sure if the buyer must solder everything or if the kit could be easier to build, taking maybe 5 to 15 minutes to build.

So does that mean it's illegal to sell a metal detector without it being FCC-certified, or does that mean stores simply won't buy them?

Thanks again!

[Prospector Paul]

Sorry, I found the answer.

Without FCC certification, it is illegal to import, sell, or lease equipment in the United States.
There are two classes of FCC testing: Class A and Class B. Class A is an easier test to pass, and is intended for products that will be used in industrial applications. Class B is for consumer products and requires stricter testing.
There are also two categories of FCC certifications: intentional radiator and non-intentional radiator, which are determined by whether your product incorporates wireless capabilities. Intentional radiators include cell phones, wireless connections, Bluetooth connections, etc. Unintentional radiators include television sets, digital cameras, microwave, etc.

https://www.acdi.com/certifications-...rdware-obtain/

I'm guessing metal detectors are unintentional radiators.

[6666]

Sell as a kit, but DIL only, or if you insist on SMD, then solder the hard components like micros, but leave the rest as DIL

[Prospector Paul]

Sell as a kit, but DIL only, or if you insist on SMD, then solder the hard components like micros, but leave the rest as DIL

Seems like a good intro approach. Keep the first design as simple as possible, low price, no MCUs.

[Carl-NC]

I'm guessing metal detectors are unintentional radiators.

Under 9kHz is unintentional, above 9kHz is intentional.

[ivconic]

Caveat emptor too, i'd say.
I was about to post this on another topic...
I am still waiting SMD pcb's with mcu and several other components soldered on it, to arrive from China.
3 months delay!!! And still nothing!
Than i saw this:

[ivconic]

So much from my "business"!
And at the end i am a liar, telling people about the kit.
Yoyos from China are not reliable anymore (if ever were).
PCBway, JLPcb ... "next time to do not pick China postal as option", their answer!?
Next step is to establish my own personal SMD pcb manufacturing.
Not to be dependable on any sorrow yoyo on this world.
One man band.

[6666]

Seems like a good intro approach. Keep the first design as simple as possible, low price, no MCUs.

Are you talking vlf or Pi, land or sea, GEB or not, what brings all these things un done is the coil, nobody supplies a coil ready made or parts to make it.

[Prospector Paul]

Are you talking vlf or Pi, land or sea, GEB or not,

For kits it would be VLF, land, with auto GEB. For a FCC-certified version, maybe sea as well.

what brings all these things un done is the coil, nobody supplies a coil ready made or parts to make it.

You're only referring to garage shop type operations who sell on places like ebay, right? Are there legal issues with selling it with a custom ready-made coil?

[kt315]

3 months delay!!! And still nothing!
---
i bought CD4538 micros. and that is i received! a piece of rag for dog -!!!
https://www.aliexpress.com/item/3282...6ee84c4dj5scNz

[Carl-NC]

You're only referring to garage shop type operations who sell on places like ebay, right? Are there legal issues with selling it with a custom ready-made coil?

As long as what you sell is completely non-functional then you are probably OK. But one of the most painful things you can do is build coils, especially for VLF. Instead, consider a design that uses an existing coil, preferably one that is plentiful & cheap.

[ivconic]

3 months delay!!! And still nothing!
---
i bought CD4538 micros. and that is i received! a piece of rag for dog -!!!
https://www.aliexpress.com/item/3282...6ee84c4dj5scNz

Sure... that makes me happier now!
You have luck and i don't.
God only knows what will be the content of parcel when i receive it!!?!?