Alinco DJ-MD5 tx power measurements

Today at the lab, I had the idea of measuring and documenting the transmission power levels of a Alinco DJ-MD5 handheld transceiver.  This transceiver is a DMR capable handheld.  This kind of technology uses TDMA modulation to transmit digital packets down the operating ‘slot’, every ~30mS .  My setup for measuring the peak power produced for every packet was the following:  I connected the transceiver  to a 30dB power attenuator and from there to a power limiter/attenuator and then to the input of my spectrum analyzer.  The trace was set to max hold and a marker was placed on the peak of the signal trace. In Figure.1 you can see my trusty homebred power attenuator connected to the antenna port of the radio.

Fig.1

 

All measurements were carried while keying the unit at a simplex UHF channel (436.175MHz).  The handheld was operated on just its battery. The battery level was indicated as  3/3 bars and the voltage was measured to 8.3V at the beginning of the test.

Results….

 


Power Level Selection 

Tx power (dBm)

 Tx power (Watts)

S (small)   

23.43

0.22

L  (low) 

30.51 

1.12

M (medium)

34.83 

3.04

H (high) 

37.24

 5.29

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