The appearance and specifications can be changed without ant notification for the purpose of upgrade product.
Global TSCM Group, Inc.
12 W 32
nd
St, Suite 604, New York, NY 10001, USA
Tel.: +1 212 967 4030 +1 646 233 0383 Fax: +1 212 967 7560
THE STEALTH
The Confidential Catch
a)
T
he antenna unit consists of 5 horizontal metal bases ( = antenna boards ) and 4 vertical antenna
elements. The each DF antenna module is connected to the main antenna module with 40cm (15.7
inches) cable. It can be secured to a vehicle roof with strong magnetic on the bottom of each module,
and the sponge pad can serve as cushions to prevent paint damage to the vehicle roof. ( right photo)
b) The antenna is 12 to 18 inches long each, but never greater than 1/4 wavelength. They are connected
into each module with BNC
c) The four DF antenna modules must be arranged into a square, with all sides of the square being of
equal length, within 1 inch. The main antenna module should correspond to the center of four DF
modules to ensure uniform RF sensitivity in all directions for the finished antennas. The size of the
square should never exceed 1/4 wavelength on any side.
d) The RF output of the ANTENNA module is provide with a SMA connector, which must be connected to
the antenna input of the FM receiver with a coaxial cable (RG-174 cable provided) with BNC connector
e) The antenna control signal from the main antenna module must be connected to the main unit with the
antenna control cable provided.
The FM Receiver (NB FM Receiver)
1) When installed, the antenna input of the FM receiver is connected via a coaxial cable to the BNC connector
located on the main antenna module of
KN2C-2020T
. The FM receiver speaker output is connected to the
KN2C-2020T
audio input.
2) The
KN2C-2020T
DF requires a NB FM receiver, which the user must provide. This receiver determines the
operating frequency for the DF (DF radio channel). The receiver must be a FM receiver, because Doppler
shift is a form of frequency shift, so the receiver’s detector must be a "frequency shift detector" (FM detector)
to recover the Doppler signal.
3) The intended operating range of the KN2C-2020T DF is 100 to 1000 MHz, but reasonable operation beyond
these limits can be expected, with a suitable antenna unit.
4) No internal modifications to the FM receiver are required. The Doppler modulation (caused by the antenna
switching) results in an audio "tone" or "whine" that is detected along with any "voice" audio in the received
signal. The frequency of the Doppler tone is about 430 Hz, and it passes easily through the audio circuits of
the FM receiver, just like any other audio tone.
The GPS RS232 Input Port
The GPS RS232 input accepts 4800 baud NMEA data, scans the data for the $GPRMC, $GPGGA and
$GPVTG sentences, ( very common ) and relays these sentences ( if found ) through the
KN2C-2020T
RS232
output port, to the display computer. GPS Data is NOT fed to the IR port. To increase the amount of DF data
provided, every 3rd GPS message is relayed, instead of each message. Furthermore, only the $GPRMC
message is relayed, if found. Otherwise, the $GPGGA and $GPVTG messages are relayed, if found.
The GPS itself must generally be configured to transmit NMEA data, because a variety of data formats are
available. ( NMEA is the most common format ) In some cases, it will be necessary to buy a special cable from
the manufacturer, to get the data. The $GPRMC, $GPGGA and $GPVTG sentences are the most common
NMEA sentences provided, but if you wish to confirm their presence in your GPS output, you can examine the
data stream with HyperTerminal, which is provided ( free ) with every Windows operating system, in the
PROGRAMS / ACCESSORIES menu.
If you do not wish to employ the GPS input, simply leave it disconnected
