Radiometrix Ltd

LMT1/LMR1 Data Sheet

page 9

The antenna choice and position directly controls the system range. Keep it clear of other metal in the

system, particularly the 'hot' end. The best position by far, is sticking out the top of the product. This is

often not desirable for practical/ergonomic reasons thus a compromise may need to be reached. If an

internal antenna must be used, try to keep it away from other metal components, particularly large

ones like transformers, batteries and PCB tracks/earth plane. The space around the antenna is as

important as the antenna itself.

Helical antenna

R

F

Loop antenna

RF GND

RF

C

tune

C

match

capacitors may be variable or fixed

(values depend on loop dimensions)

track width = 1mm

min. area 500mm

2

Whip antenna

410mm @ 173MHz

R

F

wire, rod, PCB track

or a combination of these

length(mm) = 71250 / freq(MHz)

trim wire length or expand coil for

best results

35-40 turns wire spring

length 120mm, dia 10mm

Ordering Information:

Ordering Information:

Ordering Information:

Ordering Information:

Part No.

Part No.

Part No.

Part No.

Description

Description

Description

Description

Frequency band

Frequency band

Frequency band

Frequency band

(MHz)

(MHz)

(MHz)

(MHz)

RF power

RF power

RF power

RF power

(mW)

(mW)

(mW)

(mW)

Channel spacing

Channel spacing

Channel spacing

Channel spacing

(kHz)

(kHz)

(kHz)

(kHz)

Data rate

Data rate

Data rate

Data rate

kbps

kbps

kbps

kbps

LMT1-173-5

Transmitter

173.225 - 173.325 10

25

5

LMR1-173-5

Receiver

173.225 - 173.325

25

5

LMT1-151-5

Transmitter

150.825 - 152.450 100

25

5

LMR1-151-5

Receiver

150.825 - 152.450

25

5

LMT1-173-5-12k5

Transmitter

173.225 - 173.325 10

12.5

5

LMR1-173-5-12k5

Receiver

173.225 - 173.325

12.5

5

LMT1-151-5-12k5

Transmitter

150.825 - 152.450 100

12.5

5

LMR1-151-5-12k5

Receiver

150.825 - 152.450

12.5

5

LMT1-173-10

Transmitter

173.225 - 173.325 10

25

10

LMR1-173-10

Receiver

173.225 - 173.325

25

10

LMT1-xxx-5

10/100

25

5

LMR1-xxx-5

Where xxx is any 2MHz band

from 130MHz to-180MHz

25

5

Figure 7: Antenna types