vlad
Well-known member
Today detectors are made frequency specific, meaning there is a very low/no tolerance for any variance from that frequency. This is the easiest way to
achieve a perfect null, full resonance-and fill the Q of the loop. Your depth, discrimination, emi resistance and other results are all part of this.
When you get away from the frequency the detector is designed for, things may work-to a point but usually suffer. Off resonance you simply do
not have the TX power to make up for the loss. Induction balance means a target is detected and a frequency shift occurs in the TX winding and
this shift is picked up by the RX winding--the detector alerts you. A frequency mismatch and this is [can be] degraded to the point that performance is lost.
Also something to consider is the ground mineral effect--proper adjustment is a must but not going to be possible with a mismatched loop and this phase
error in mild to moderate ground makes the problem worse. If you are using a preset ground balance machine it is probably not going to be of much use.
It also still holds true that bigger coils see more mineral that drive the circuitry negative while a small good deep target is trying to fight that and drive a signal
positive. If possible before you take someones word and buy-try out combinations-there are impedance differences too.
*The Tek Mk-1 was not designed frequency specific and will work with newer loops of other frequencies {some better than others.}
achieve a perfect null, full resonance-and fill the Q of the loop. Your depth, discrimination, emi resistance and other results are all part of this.
When you get away from the frequency the detector is designed for, things may work-to a point but usually suffer. Off resonance you simply do
not have the TX power to make up for the loss. Induction balance means a target is detected and a frequency shift occurs in the TX winding and
this shift is picked up by the RX winding--the detector alerts you. A frequency mismatch and this is [can be] degraded to the point that performance is lost.
Also something to consider is the ground mineral effect--proper adjustment is a must but not going to be possible with a mismatched loop and this phase
error in mild to moderate ground makes the problem worse. If you are using a preset ground balance machine it is probably not going to be of much use.
It also still holds true that bigger coils see more mineral that drive the circuitry negative while a small good deep target is trying to fight that and drive a signal
positive. If possible before you take someones word and buy-try out combinations-there are impedance differences too.
*The Tek Mk-1 was not designed frequency specific and will work with newer loops of other frequencies {some better than others.}
At least I learned a new word today.."impedance", which may come in handy at my Mensa meeting later this week!...Regarding the Euro fluctuation and the adverse sociological impact the concept of Grexit has on German pensioners planning a trip to Disneyword in October! ...see what I mean? 