To Eric, On the Goldscan5receiver sensitivity

[Wirechief]

Hello again Eric and gang, I am wondering what measurement is used to show the sensitivity of the receiver in your Goldscan detector and what would the spec be? Also does the atmosphere around the search coil, in other words the air we breathe, have an effect on the field generated at the coil or is it too small to worry about? Thanks and God Bless Eric. I almost forgot where do you live Eric?

 

[Eric Foster]

Hi Wirechief,

Working back from the output of the final dc amplifier and taking all the circuit gains into account, a just detectable signal on a good PI is equivalent to just a few microvolts at the first amplifier input. Because there is an integrator/averager stage, the wanted signal is lifted out of the pickup noise, which is usually several orders of magnitude greater than the signal. Longer integration times can resolve smaller signals, but at the expense of response speed. Everything in a metal detector is a compromise. If you are ground balancing, then that affects the result, but as yet, I have not done any calculations or measurements to this end on the Goldscan 5.

Eric.

 

[Wirechief]

Thank you very much Eric for the response and that is what I was thinking the measurement would be in microvolts. Yes it appears if you change one spec another can suffer somewhat for that change. I gotta tell ya this is truly fascinating stuff Eric and be warned I will ask more questions! Thanks again and God Bless ya Eric. Wirechief, John's Detectors.