Tx Power????

[Geo]

Hi.
Does anyone knows who is the allowed transmitted power from the """transmitter""" of an IB-VLF metal detector????

[Qiaozhi]

Hi.
Does anyone knows who is the allowed transmitted power from the """transmitter""" of an IB-VLF metal detector????

I will make a short quote from ITMD (page 246):

"Many people point to FCC regulations (in the US) and claim that detector output power is limited to a certain output level. A number often given is 100mW of power. Exactly where this number comes from is uncertain, but it is erroneous. Yes, there are legal limitations to transmitted field strength in metal detectors, but the reality is that detectorists are not in any danger of exceeding these limitations."

The "Power Output" section then continues with a discussion on the meaning of the term "output power" and its relationship to metal detectors, and concludes with the statement:

"As you can see, the FCC doesn't really need to limit detector "power", physics does it for us!"

[Carl-NC]

The short answer is, "Higher than the melting point of your transistors."

[Silver Dollar]

Hmm I thought Minelab limited their flyback to 200v for some reason. I always assumed it was to
limit radiation to meet government regulations. Maybe it's really a signal to noise thing?

[WM6]

Hmm I thought Minelab limited their flyback to 200v for some reason. I always assumed it was to
limit radiation to meet government regulations. Maybe it's really a signal to noise thing?

Bot probably not famous first series of GPX4500 which was then on ML recall for repairs. Repaired units was then no more comparable in depth with primary devices, but was according government regulations.

[Geo]

Thanks for your answers.
I want to try to modify a TM800 2Box and i wanted to see if the output power" was so small from FCC regulations.
Now i know......

Btw... why TM800 or 808 etc... uses aluminium pipe as wire at loop????? I believe that "phenomenon" Corona is not interesting at so low power and at 12.5 Khz.
Your opinion please!!!!

[Geo]

The short answer is, "Higher than the melting point of your transistors."

Hahaha.....
This time your answer is without any mathematic formula, but it is further understandable than the formulas....

[Carl-NC]

Btw... why TM800 or 808 etc... uses aluminium pipe as wire at loop?????

I suppose it was done that way because it's easy to make an is durable. Jim Karbowski designed this and he's now too dead to ask.

- Carl

[Geo]

Durable.... yes, so justified easily.
Thanks Carl