NTR2 RADIOMETRIX [Radiometrix Ltd], NTR2 Datasheet - Page 6

• Manufacturer Part Number: NTR2
• Description: UHF Narrow Band FM Transceiver
• Manufacturer: RADIOMETRIX [Radiometrix Ltd]

Expected range
Predicting the range obtainable in any given situation is notoriously difficult since there are many factors
involved. The main ones to consider are as follows:
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The following are typical examples – but range tests should always be performed before assuming that a
particular range can be achieved in a given situation:
Data formats and range extension
The NTR2’s TXD input is normally driven directly by logic levels but will also accept analogue drive (e.g. 2-
tone signalling). In this case it is recommended that TXD (pin 9) be DC-biased to 1.2V approx. with the
modulation ac-coupled and limited to a maximum of 2V
modulator in the NTR2 introduces some 2
predistortion of the analogue waveform.
Although the modulation bandwidth of the NTR2 extends down to DC it is not advisable to use data
containing a DC component. This is because frequency errors and drifts between the transmitter and
receiver occur in normal operation, resulting in DC offset errors on the NTR2’s audio output.
The NRT2 in standard form incorporates a low pass filter with a 5kHz nominal bandwidth. This is suitable for
transmission of data at raw bit rates up to 10kbps.
Radiometrix Ltd.,
Data rate
Type and location of antennas in use
Type of terrain and degree of obstruction of the link path
Sources of interference affecting the receiver
“Dead” spots caused by signal reflections from nearby conductive objects
Data rate and degree of filtering employed
10kbps
10kbps
10kbps
Tx antenna
¼ wave
¼ wave
helical
Rx antenna
nd
¼ wave
¼ wave
helical
harmonic distortion which may be reduced if necessary by
NTR2 transceiver data sheet
p-p
to minimise distortion over the link. The varactor
urban/obstructed
Environment
Rural/open
in-building
Range
300m
500m
100m
Page 6