The subject of Sensitivity in metal detectors has been on my mind lately. Detector electronics is very interesting to me although I know little about them. I tend to try to compare them to radio electronics. But to get the ball rolling one must have a way to intercept the desired signal and get it amped to a usable level. But there is something that stands in the way of obtaining a great signal and that is noise. And some of this noise comes from inside the very instrument you are using and it is called thermal noise created by electron activity inside the components, namely resistors. This noise can be lowered by a cooling process that is expensive and impractical. So I suppose we have to live with it. So we have a signal/noise ratio to work with.
So in the first amp of a metal detector receiver it is best to find a device with the lowest noise figure and highest gain to help mask the high noise figure, am I on the right track? An EE may want to step in here to correct me. But if you try to amp it up too much you might have spurious noise also. but overall it is not good to use excessive gain and cause more problems.
I am hoping someone will step in here to tell me that my thought process is way off on Mars! I am always willing to learn and I suppose I just wanted to ramble a bit. Ok evryone is welcome to come by John's Detectors to get help for your needs and if I don't have it, most likely I can get it. Good hunting and be safe everyone!
John Tomlinson,CET
John's Detectors
Blackwell,Tx.
No comments:
Post a Comment