Hearing more DMR on 446.
Posted: Thu Nov 11, 2021 8:57 pm
Recently I have been hearing a lot more DMR activity from businesses and schools on 446.
Now I want to make a distinction as there is confusion over digital modes on 446, DMR is DIFFERENT to dPMR.
DMR is a digital protocol that relies on TDMA (Time divison multiple access) which allows two groups to communicate simutaniously on the same frequency (The frequency is split by time, one timeslot after another).
dPMR is also a digital protocol but relies on FDMA, frequency division multiple access, the channel is split into two smaller channels allowing two groups to communicate.
Now when I mention DMR on 446 , I am in fact talking about the first type, not the second dPMR.
The DMR channels are the same as the 16 analog channels in frequency, whilst dPMR has 32 channels (Because each channel is split by frequency into two channels side by side).
License-free DMR sounds like a machine gun or helicopter sound in an analog radio, in order to receive if you must use an SDR running DSD+ (Digital speech decoder) or own a scanner/radio capable of decoding DMR.
An example of a license-free PMR446 DMR radio would be the Retevis RT40 or Hytera PD365LF.
Prices have gone down signifcantlly on these types of radios, so we may see an increase in traffic as a result.
Have you heard any DMR traffic on 446 in your area? If so post about it.
Now I want to make a distinction as there is confusion over digital modes on 446, DMR is DIFFERENT to dPMR.
DMR is a digital protocol that relies on TDMA (Time divison multiple access) which allows two groups to communicate simutaniously on the same frequency (The frequency is split by time, one timeslot after another).
dPMR is also a digital protocol but relies on FDMA, frequency division multiple access, the channel is split into two smaller channels allowing two groups to communicate.
Now when I mention DMR on 446 , I am in fact talking about the first type, not the second dPMR.
The DMR channels are the same as the 16 analog channels in frequency, whilst dPMR has 32 channels (Because each channel is split by frequency into two channels side by side).
License-free DMR sounds like a machine gun or helicopter sound in an analog radio, in order to receive if you must use an SDR running DSD+ (Digital speech decoder) or own a scanner/radio capable of decoding DMR.
An example of a license-free PMR446 DMR radio would be the Retevis RT40 or Hytera PD365LF.
Prices have gone down signifcantlly on these types of radios, so we may see an increase in traffic as a result.
Have you heard any DMR traffic on 446 in your area? If so post about it.
