Minelab x-terra 305 Instruction Manual page 6

SECONDARY MICRO
(IN COIL)
SENSING + TRANSMITTING
COIL TYPE, SIZE, FREQUENCY
Analog Signal
Coil
Transmit
Receive
Standard VLF Signal
(Without VFLEX)
For the X‑TERRA user, this precision means
dependable performance and improved immunity
to environmental conditions such as ground
mineralisation, electromagnetic interference and
temperature variations.
VFLEX requires coils that are accurately constructed
and calibrated. Every time the detector starts up,
the micro‑controllers in the control box and the coil
establish communication through a digital data link.
Information about the coil is sent to the control box,
so the detector 'knows' what type of coil is attached
and can set the correct operating parameters.
This optimises the performance, and also makes the
detector 'future proof' , in that it will be capable of
operating at different frequencies depending on the
electronic properties of the coil.
Precision VFLEX Signal