2
U
U
S
S
E
E
R
R
M
M
A
A
N
N
U
U
A
A
L
L
1.
Introduction
The ultra-compact non-linear junction detector “LORNET-24” (further NLJD) is used for
search and location of electronic devices both in active and switch-off state.
NLJD operation is based on the property of semiconductor components to generate a
response at the 2
nd
and 3
rd
harmonics when radiated by an UHF probing signal. Semiconductor
components of artificial origin will have a higher level second harmonic while semiconductor
components of natural origin (e.g. oxide films) will have a higher level third harmonic
respectively. NLJD analyzes the 2
nd
and 3
rd
harmonics response of the radiated objects, which
enables a quick and reliable identification of electronic devices and natural oxide
semiconductors.
NLJD automatically finds the best receiving frequency channel free of noise and distortion
providing flawless operation even in the complicated electromagnetic environment. The
frequency tuning algorithm implemented in NLJD automatically selects the probing signal
frequency such that the noise level in the 2
nd
harmonic receiving channel is held minimal, while
digital processing of a demodulated signal gives maximum sensitivity.
There are two types of radiated signals:
-
continuous wave carrier (CW);
-
pulse modulated carrier with a duty cycle 44 (pulse).
This enables to combine wide detection range and reliable identification of the devices
found.
The output power automatic control mode significantly simplifies operator’s work. NLJD
simultaneously displays the 2
nd
and 3
rd
harmonics levels at its LED panel. Besides, the 2
nd
and
3
rd
harmonics levels can be estimated in turn aurally by the click repetition rate reproduced
through a built-in loudspeaker or earphones connected to a pocket-size receiver.
A detector of the returned UHF signal envelope enables at to detect radio devices with
acoustic converter aurally at continuous frequency carrier radiation.
2.
Specifications
2.1.
Radiated signal types:
-
continuous wave carrier;
-
pulse modulated carrier with a duty cycle 44.
2.2.
Carrier frequency step 2 MHz within a tuning range of (2406 … 2414) MHz.
Automatic frequency selection. Possibility of radiation at the carrier frequency with a minimum
noise level in the 2
nd
harmonic receiver path.
2.3.
Maximum radiated power in the CW mode
≥
0.2 W.
2.4.
Peak radiated power in the pulse mode
≥
10 W.
2.5.
Manual or automatic control of the radiated power level.
Dynamic control range of 20 dB down from the maximum output power value with 11 level
gradations.
2.6.
Receivers sensitivity better than –110 dBm (one LED lights up at the indicator scale).
2.7.
Receivers tuning frequencies equal to the transmitter double and triple frequencies.
