What kind of measurement tool do you have? Since the radio is on for a very short time for each packed, you would need a measurement tool with a high resolution, like an oscilloscope or a power analyzer. Then you can measure the current consumption over a few seconds to get a good average.
Also remember that the current drawn in sleep mode is very small (~4uA), so the sensitivity of the scope/analyzer must be high enough.
You may also try to even out the current flow with an RC filter, if you have a large enough cap you should be able to use an ampere meter to measure the average current. But you should still check the input of the filter with an oscilloscope to check if the ripples are even enough.
Do you have the developer board PCA10028? If you get it ,you can connect an ampere-meter between the pins of connector P22. This will monitor the current directly.
Or if you want to get the detail of the current change,you can mount a resistor on the footprint for R6. The resistor should not be larger than 10 Ω. Connect an oscilloscope in differential mode or similar with two probes on the pins of the P1 connector and measure the voltage drop. The voltage drop will be proportional with the current consumption.For example, if a 10 Ω resistor is chosen, 10 mV equals 1 mA. Hope it works;
