Signal Guide

Service Description Selection PMR

Here you will find information about the selected service, along with measurement examples.

PMR Theory & Details
Communication
Typical Frequency Range:

PMR 446: 446.0 – 446.1 MHz (DMR 446: 446.1 – 446.2 MHz)

General:

PMR (private mobile radio), also called PMR 446 because of its frequency range, is an analog voice radio service in the UHF range open to anyone. A digital version is known as DMR (digital mobile radio).

Modulation: FM

PMR 446: 8 FM channels starting from 446.0625 MHz spaced at 12.5-kHz-Raster (DMR 446: 8 or 16 4FSK/FDMA modulated channels spaced at 12.5 or 6.25 kHz)

PMR Measurement Examples
Spectrum
Overview measurement of the PMR band 446.0 – 446.1 MHz. Captured with a single FFT, so no time gaps within a sweep. The device delivers a “snapshot” every 83 ms. The station on the left is transmitting a calling signal. The station in the center is only slightly modulated.
Spectrogram
The same situation as shown in Spectrum. The device delivers a “snapshot” every 82 ms. More than 20 s is displayed. All values within a spectrum are captured simultaneously because the device captures the frequency range with a single FFT. The station in center of the frequency range displays on / off pulses.
HiRes Spectrogram Full
The display shows a period of 1 s without gaps. The width of the frequency range shown is 200 kHz (differs from Spectrogram). The wideband transmission for switch on is clearly seen (trigger point T).
HiRes Spectrogram Zoom
Section from HiRes Spectrogram Full. The width of the freqiuency range shown is still 200 kHz. The time axis can, however be shifted as with a magnifier. This makes it possible to clearly see the transient signal from the transmitter.
Persistence Spectrum
Calculated from the same data as HiRes Spectrogram Full. Shows the frequency of occurrence over 1 s.
Magnitude
Time domain display based on the same data as HiRes Spectrogram Full. The FM signal from -0.5 s onwards shows as a continuous line. The display over a time span of 1 s is without time gaps. Longer recording times of up to 24 h are possible in Long-Time Scope mode.
Scope