Setting Audio Levels in your DMR Radio
The DMR standard was first introduced to the world in 2005. The principal idea was to introduce an affordable product that was interoperable across manufactures. The end result was the creation of the DMR Association, a consortium of manufacturers who meet and agree on modification and amendments to the DMR standard.
Presently we have Tier II conventional and Tier III trunking standards in place. Both standards utilize two time slot TDMA, which has been the primary nuance that DMR brings to the table one repeater effectively serving as two repeaters. Efficiency and efficient spectrum utilization have been the two main benefits of this mode which continues to grow with more and more manufacturers entering the market place.
Due to the fact that there are many manufacturers in play, we see issues as it pertains to audio in terms of one person sounds soft another sounds extremely hot; while others sound just fine.
Two things come out of this statement that are important to note. The operator does not need to close talk or speak in a strong voice into their microphone. The radio knows how to process the human voice and makes the necessary adjustments internally. For example: the stronger a person speaks into their microphone the worse they sound to the other party they are speaking causing them to constantly adjust their microphone volume which is entirely not needed.
In each radio, there is a setting for microphone gain in both digital and analog. A good place to start is -2 in the digital side in the analog side 0. Northern California DMR has created a tool to set one’s microphone gain in the digital realm. This is referred to as the NorCal audio meter. The first thing a person needs to do is download the latest version of google chrome web browser as this meter only works with chrome. The next thing needed is to put your radio on TG 31068 or NorCal. The last thing needed is to go to the website to view you audio level on the meter at the following website: http://norcal-brandmeister.org/listen-now/. It is important to note that there is a delay of approximately 30 seconds before your audio will be hear and see the result shown on the meter.
The target reading you are going for on the meter is the very high end of green which is a reading on the digital RMS meter of -10 dB. Anything stronger then -10, is considered strong while anything less then -10 is considered weak. Continue to adjust your microphone gain in your radio until you can achieve a -10 in your normal operating position and tone of voice.
It is important to note that radios do not come out of the box set up it is up to the system administrator and operators ensuring their radio is set to the appropriate level to ensure quality is within the specification of the system.
I hope you found this article helpful in helping you get your audio levels set.