User's Manual

Lotek Biotracker Receiver User’s Manual Page 23
Full Specifications Table
Specification Value Explanation
Frequency Bands
4, 8 or 30
MHz bands
between 138-
and 174 MHz.
Most tracking receivers cover a 1-2 MHz band
only. Biotracker can cover up to 30 MHz! If such a
wide band is not required there are versions with 4
or 8 MHz bands (these cost less). Receivers with
narrower bands can be upgraded.
The main benefits of the 30 MHz band version are:
 Biotracker can be used almost anywhere
 Biotracker is ‘future-proof’ against
changes in frequency allocation
Sensitivity
MDS -150 dBm
The more sensitive a receiver, the better the
chances of you hearing very weak signals.
MDS means ‘Minimum Discernible Signal’ and is
the weakest signal that can be heard on the
receiver.
The more negative the MDS, the better the
sensitivity (e.g. –150 is better than –145).
Selectivity
6 dB
60 dB
± 2 kHz
± 4 kHz
The more selective the receiver, the less
chance you will hear ‘interference’ from
adjacent frequencies (including radio tags and
signals from other radio users).
However, beware selectivity that is too narrow
(e.g. < ±1 kHz at 6dB). This will make tuning
more critical and increases the risk of missing a
transmitter that has shifted frequency slightly
(e.g. due to a change in temperature).
Gain Control Range
Receiver gain 90 dB
When tracking powerful tags at close range you
have to be able to reduce the gain to very low
levels, otherwise the signal will no longer appear
to be directional.
The greater the Gain Control Range, the less
likely you are to encounter problems with
close range tracking. Receivers with inadequate
gain control range need attenuator switches.
Channels
Number of channels
(user programmable)
256
Having channels makes the receiver easier to
use in the field and enables memory scanning
for lost animals. Two-digit numbers (up to 99
animals) are easier to remember than 3, 4 or 5
digit frequencies. Also, if you routinely track
animals in a particular sequence, you can arrange
the channel order to match this. One press of the
channel ‘up’ key then selects the frequency of the
next animal.