  We present a purely wave model (based on classical random field) which
reproduces quantum probabilities (given by the fundamental law of quantum
mechanics, Born's rule) including probabilities for joint detection of a pair
of quantum observables (e.g., spin or polarization projections). The crucial
point of our approach is that the presence of detector's threshold and
calibration procedure have to be treated not as simply experimental
technicalities, but as the basic counteparts of the theoretical model. The
presence of the background field (vacuum fluctuations) is also the key-element
of our prequantum model. It is of the classical signal type and the methods of
classical signal theory (including statistical radiophysics) are used for its
development. We stress that our prequantum model is not objective, i.e., the
values of observables (clicks of detectors) cannot be assigned in advance,
i.e., before measurement. Hence, the dilemma, nonobjectivity or nonlocality, is
resolved in favor of nonobjectivity (our model is local of the classical field
type). In particular, we reproduce the probabilities for the EPR-experiment for
photon polarization and, hence, violate CHSH inequality for classical random
signals (measured by the threshold type and properly calibrated detectors
acting in the presence of the background field).
