NR-900S Operation Manual
4. FUNCTION
NR-900S represents a portable tool that consists of antenna system,
transmitter and two receivers adjusted for double and triple
frequency of the transmitter’s signal.
Two operational modes are available: SEARCH and LISTEN.
In a SEARCH mode the probing signal is converted into a poly-
harmonic one on the radiated nonlinear elements (semi-conductive
items or corroded metal-oxide-metal junction) and retransmitted,
better say –scattered into ambient space.
Retransmitted 2nd & 3rd harmonics of the probing signal are received
and processed by receivers. Signals strength is indicated by LED
bar-graph display: scales 2and 3accordingly. Moreover, it is
reproduced via headphones in the form of interrupted beep-beep
audio signal. The audio signal volume is proportional to the received
harmonic signal level.
The receiver inputs switching as well as headphones volume control
is available from the device control panel.
NR-900S has three output levels for radiated probing signal with 6
dB step and four levels of the receiver input signal attenuation each
of 10 dB. The probing signal output level and receiver input signals
attenuation can be switched over by Control panel buttons. This info
is confirmed by LED display.
An auxiliary LISTEN mode is intended for the 2nd & 3rd harmonic
signals investigation for possible modulation imposed by internal
processes in some active electronic circuits irradiated by the probing
signal generated by NR-900S transmitter. At that, ‘active’ means the
circuit is in an operational mode carrying out its particular function.
Moreover, this can be done against the existing interference
environment.
