Eartag VHF Transmitting Subsystems (ET)

ET Models
Three configurations designed for ear tag applications

Eartag units have been used as an attachment method on animals with changing neck girth (i.e. juveniles, buck deer, and some bears) where a collar may not be suitable. These eartag units are constructed using a high impact plastic housing that supersedes the water resistance of older designs using epoxy and acrylic resins as a moisture barrier.

Two basic designs, employing two different form factors, are available.

The ET-5 and ET-6 are designed as a "button" and the antenna penetrates the ear pinnae and exists ut the back of the ear. This design approach uses an electrically foreshortened antenna that avoids the longer "droopy" antenna used in some other designs. The button design allows the transmitter to rotate freely, again minimizing irritation and infection at the attachment site. These eartags were originally designed for use on polar bears, but the design is suitable for use on other species of bear, and on ungulates.

A more classical approach in the design is used in the ET-7 configuration. In this design approach the electronics unit is attached to a standard eartag used extensively throughout the livestock industry. This approach allows for rotation of the eartag about a single attachment point, but in general the weight of the electronics package keeps that part of the configuration near the base of the ear and the antenna up and away from the animal's eye. This design approach is often favored for attachment to ungulate species. A classical whip antenna design is employed and attachment is accomplished quickly in the field.

Eartag configurations that have exposed antennas may have the damaged due to by other animals or mechanically damaged when the animal lives is in thick cover. Antenna breakage can occur and result in reduced range performance over time.

As a note both designs require special attachment tools which can be purchased separately.

Key Features

  • Offers an alternative to other attachments such as collars.
  • Used on juvenile animals during periods of rapid growth.
  • Programmable duty cycling can extend the operational life of the unit.
  • Specialized attachment tools are available for applying the tag.
  • Numerous sensor options i.e. mortality sensing are available.
  • Excellent range performance with the selection of various power level options.

Models

Configuration Dimensions L x Dia (in, cm) Unit Weight (g) Operational Life @ 60 BPM (months) Operational Life @ 35 BPM (months) Transmitter Electronics Microprocessor Control Options
ET-5 0.83 x 1.38
2.1 x 3.5 dia
40 4.1 6.6 MK8 MS6, MA, MS9, MDC, MS4, MS5
ET-6 1.06 x 1.38
2.6 x 3.5 dia
50 8.2 13.3 MK8 MS6, MA, MS9, MDC, MS4, MS5
ET-7-2 1.55 x 0.95 x 0.70
3.94 x 2.41 x 1.78
~40 9.7 14 MK12 MS6, MA, MS9, MDC, MS4, MS5

Specifications for Transmitter Electronics

MK8 Transmitter General Specifications

The MK8 Transmitter is a single frequency, microprocessor controlled pulsed-CW transmitter, designed for operation in the 140 - 220 MHz frequency range.

Frequency Range 140 - 220 MHz
Frequency Tolerance ±17 ppm max @ 25°C
±25 ppm max -40°lC < Temp < +60°C
(<7ppm typical w/ variation in load impedance - 6:1VSWR)
(<3ppm typical over supply voltage range at room temperature)
Temperature Range -40°C to +60 °C (Note: Temperature range is for the transmitter only. The power supply must provide the required peak current and voltage requirements for the transmitter over the expected temperature range.)
Shutdown Component Externally shutdown by presence of a small magnet
Output Power
Output Power Option Peak Power Output Levels
Relative to Standard Power
Low 0.5 x
Standard 1 x
High 2 x
Extra high 5 x
RF Pulse Width 15 msec standard
Can optionally be configured from 12 - 255 msec
Pulse Period Configurable from 200 - 10000 msec (6-300 Bpm)
Spurious Emissions Non-coherent Spurs <-50 dBc
Harmonic Suppression Coherent Spurs <-10 dBc
Available Sensors Motion (Hg switch - activity/mortality) - options MS6, MA
Position (Hg switch - head up/head down) - option MS9
Temperature Triggered Mortality Sensor - option MS5
Temperature Measurement Sensor - MS4
Option Resolution at standard center temperature of 37°C Calibrated Accuracy
MS4-400 0.4 deg ±(0.6°C + cal. uncertainty*)
±20°C from center temperature
MS4-400 0.4 deg ±(0.9°C + cal. uncertainty*)
±40°C from center temperature
MS4-410 0.1 deg ±(0.15°C + cal. uncertainty*)
±10°C from center temperature
*(Note: "Cal. uncertainty" is the error inherent in the calibration procedure. This value is dependant on the end users calibration procedure and equipment accuracy.

For example, if the calibration process measures temperature to within ±0.1°C, then the MK8 calibrated accuracy would be:
- For 0.4 deg resolution option
±(0.6deg + 0.1deg) = ±0.7degC (±20°C)
±(0.9deg + 0.1deg) = ±1.0degC (±40°C)

- For 0.1 deg resolution option
±(0.15deg + 0.1deg) = ±0.25degC (±10°C)
Seasonal Timing 8 factory programmable on-off duty cycles - option MDC
Typical timing accuracy of < ± 30 min/yr is reasonable for most applications
Chart reflects known error limits
Temperature (°C) Error Limits (min/yr)
-40°C ~ -73 to -105 (extrapolated)
-20°C -25 to -58
0°C 2.6 to -29
25°C ±16
50°C 2.6 to -29
70°C -25 to -58
FCC Emission Designator 1k00P0N * California Users - The MK8 transmitter exceeds the emission designator requirement of 2k00P0N for operation in California. The MK8's 1k00P0N emission designator is identical to 2k00P0N except that it occupies only half of the 2 kHz bandwidth allowed by the State of California for wildlife tracking.

MK11/12 Transmitter General Specifications

MK-11 and MK-12 beacons are microprocessor controlled pulsed-CW transmitters, designed for operation within the 137 - 225 MHz frequency range. Each MK-11 beacon transmits on a single, field-programmable frequency (within the frequency range that is ordered). MK-11 beacons also support 3 field-programmable power levels. The MK-12 beacon is crystal based, and therefore each beacon is built to operate on a specific frequency and with a specific power output (four power levels to choose from when ordering).

Frequency Range MK11:
137 - 143 MHz (option 700),
143 - 156 MHz (option 710),
154 - 164 MHz (option 720),
162 - 174 MHz (option 730),
164 - 182 MHz (option 740),
182 - 201 MHz (option 750),
201 - 222 MHz (option 760)

MK12:
140 - 225 MHz
Frequency Tolerance MK11:
Calibration: ±3 ppm max at room temperature / ±5 ppm from -40° to +70°C
Aging: <1ppm/yr
Shock: <1ppm 3000g x 0.2ms x ½ sine x 3 directions

MK12:
Calibration: ±17 ppm at room temperature / ±25 ppm from -40° to +70°C
Load: <7ppm typical for VSWR < 6:1
Supply Voltage: <3ppm typical over supply voltage range at 25°C
Aging: <1ppm/yr
Shock: <1ppm 3000g x 0.2ms x ½ sine x 3 directions
VSWR Stability MK11: RF output stable to 10:1 VSWR, all phases.
Radiated harmonic levels are degraded with poor load VSWR.
Spurious emission specification maintained for > 10:1 VSWR.

MK12: RF output stable to 5:1 VSWR, all phases.
Radiated harmonic levels are degraded with poor load VSWR.
Spurious emission specification maintained for > 5:1 VSWR.
Output Power
MK11: Field Programmable using TPP
Transmit Power Peak Power Output
Relative to Medium Power
Low 0.5 * Medium Power
Med  
High 2.0 * Medium Power

MK12: Ordering Options for Power Level
Option Transmit Power Peak Power Output Levels
Relative to Standard Power
200 Low (Temperature > -20°C) 0.5 * Medium Power (Higher efficiency)
202 Low 0.5 * Medium Power
204 Medium  
206 High 2.0 * Medium Power

Output power is measured into 50 Ω load. Effective Isotropic Radiated Power (EIRP) varies, depending on packaging, antenna configuration, and immediate environmental conditions.
Emission Designator MK11: 2k00P0N -
California users: These transmitters meet the California requirement of EIRP < 0.009 W for all conditions.
MK12: 1k00P0N -
California users: These transmitters exceed the emission designator requirement of 2k00P0N for operation in California. The 1k00P0N emission designator is identical to the 2k00P0N except that it occupies only half of the 2 kHz bandwidth allowed by the State of California for wildlife tracking.
Harmonic and Coherent Spurious Suppression MK11: <-30 dBc into 50Ω load
MK12: Coherent Spurious <-10 dBc
Spurious Suppression MK11: <-35dBc typical at > 10kHz offset from carrier
MK12: Non-Coherent Spurious <-50 dBc
RF Pulse Width 15 msec standard
Can optionally be configured from 10 - 250 msec
Pulse Period Configurable from 250 - 5000 msec (12-240 Bpm)
RTC Accuracy / Seasonal Timing Temperature Compensated:
± 12min/yr max
Temperature Range -40°C to +70°C (Note: Temperature range is for the transmitter only. The power supply must provide the required peak current and voltage requirements for the transmitter over the expected temperature range.)
Shutdown Component Externally shutdown by presence of a small magnet
Available Sensors
MS6 Mortality - Motion Sensor
MA Activity Sensor
MS4 Temperature Sensor
MS5 Temperature-triggered Mortality Sensor
Sensor descriptions available separately

Conventional Control Options

Mortality (S6A, S6B) and activity (S9) sensors are available with all eartag configurations.

VHF Transmitter Sensor Option Descriptions

An increased operational life may be achieved with the use of a microprocessor to establish a transmitting duty cycle. Microprocessor controlled transmitters provide capabilities beyond those offered by any other conventional VHF transmitter designed for tracking and/or wildlife monitoring. These new capabilities include MDC duty cycling (turning transmitters on and off at predetermined intervals), and MA transmission of activity indices. More traditional options such as MS6 mortality sensing and MS9 activity sensing remain available, but with increased flexibility.

MK8 Microprocessor Control Sensor Options

MK-11 or MK-12 Sensor Options

Eartag Attachment Tools