Baofeng DM-9HX DMR
Notes on the programming and use of a DM-9HX DMR Radio.
I have put these together as a simple reminder to myself on "how I did it" and also as a help to others. The challenge with Digital Radio is that it is binary, it either works or it doesn't, there is no inbetween version of "I can just hear you " or "it nearly works". Playing around with DMR, you will hear a lot of silence!
DMR for Amateurs has evolved from commercial digital systems such as Tetra etc. This means the firmware code in radios tends to be similar to that you would expect to find in a police/security/PMR device, ie. channels are all pre-programmed and the end user has little or no control over channel settings in day to day use. Therefore a lot of the work setting it up is done from the computer and not the radio. Apparently a high end radio such as the Anytone 878 will allow much more Amateur "on the fly" programming, but the Baofeng DM-9HX is only around £65 so the intelligence is in the computer setting up and not the radio.
Contents
Before you can start any DMR operation you need to:
- Get a unique DMR ID. Every radio needs an ID.
- For Europe go to https://register.ham-digital.org/
- For Rest of the World go to https://www.radioid.net/register#!
- Understand the relationship between Contact, RX Group List, Channel and Zone
The DMR ID is your unique identifier, its not a secret as people need to know it to contact you. In DMR you are not a callsign you are a number. The number is used by repeaters and hotspots to look up your callsign and details. The ID is also displayed on most radio screens during a conversation.
The picture on the left shows my ID configured into the radio programming software.
Contacts are your address book. Contacts are of two types, Private Call and Group Call. Within these two types you can record either personal contacts or Talkgroup contacts.
The picture on the left shows a personal entry for a friend. It contains their Call ID. Note that I have also configured a Ring Tone Style (you can choose one of ten styles but on the Baofeng they are hard to tell apart). The "Call Receive Tone" box is checked to play the Ring Tone when a call is received.
The picture on the right shows a talkgroup contact entry. It consists of the group number (note that it does not contain TG or anything similar, it is just the number part). I could also configure a ringtone if I wanted.
Note that the talkgroup is a "Group Call" contact entry, however there are a couple of talkgroups that require a Private Call to access them (but there are, I believe only a couple out of the thousands possible).
Before going any further you need to set up some contacts. If you are going to use a Repeater then take a look at its website, it should list the talkgroups it supports. Configure a few in, particularly TG9 (local chat) and TG9990 (echo or parrot service).
RX Group List is a simple concept but there is an air of mystery about it. When you configure a channel (see later), not only do you have to configure the Transmit Frequency and Receive Frequency but you also have to configure the Transmit Contact/Workgroup and the Receive Contact/Talkgroup. In theory, when you configure a Transmit Contact/Talkgroup the receive side should default to listen on the same Talkgroup. However, this appears to not always be the case and, indeed, there are specific cases when it should not default.
Therefore I always configure an RX Group entry for each Contact/Workgroup so that I can guarantee to listen on the same Talkgroup as I am transmitting on.
In the picture you can see I have a RX Group List for Talkgroup 9 that enables me to listen on Talkgroup 9. Note that you can listen on multiple Contact/Talkgroup within a Group. The only disadvantage to this is that you will hear conversations going on that you cannot transmit to as the transmit side is only set to the single group/contact configured on the channel.
If you have set up Contacts, you should now set up RX Group Lists.
With Contacts and RX Group Lists set up, you can now set up channels.
You will need a channel entry for every Talkgroup contact entry. This is because the Baofeng does not support on the fly Talkgroup operation. So where you want to access both TG2 and TG9 on a repeater or hotspot you will need two channel entries, one with TG2 as the Contact and one with TG9 as the contact. It may seem possible to, in mid call, select another TG Contact from the contacts list and press the PTT to switch to the new TG. It will switch for one over and then will drop back to the original TG. If you have created a channel without a TG Contact then it will default to TG1 and keep dropping back to it.
The significant fields on this page are:
- Mode: DIgital or Analogue (only Digital is considered in this article)
- TX Freq: The transmit frequency of the radio
- RX Freq: The receive frequency of the radio
- Name: Name for the channel
- Squelch: Level 0-5, level 0 is open, level 5 is fully on (Not sure of the effect in Digital terms at present)
- Power: High (5 watts) or Low (1 watt)
- Admit Criteria: What is used to detect the channel is busy/free:
- Always: Aggressively trample over others
- Color Code: The recommended setting, allows access when the specific timeslot/color code is free.
- Channel Free: Effectively squelch based, any activity on frequency causes TX to hold off.
- Scan List: To be investigated
- TOT: Talk timeout, limits talk time
- TOT Rekey: Talk timeout re-key, forces a delay after talk timeout has occurred.
- Privacy: Encodes the conversation to make it private, not recommended in UK and illegal in some countries. This is NOT related to a private call (see below)
- RX Group ID: This sets the contact list that the radio LISTENS to on this channel. The general specification is that the radio should by default (setting = none) listen to the called Contact but I have found this not to be the case all the time, I strongly recommend that the contact you are calling on this channel is set into a list and the list is included here. As it is a list, you can add other contacts to the list so that you are listening to more than one at a time, and example for this would be listening to other talkgroups on a repeater whilst engaged in a contact on a specific talkgoup.
- Color Code: Think ot this like the CTCSS code from the analogue days. Repeaters are allocated a color on a regional basis and you use this color to access the repeater. Equally on a simplex contact you have to set the same color in order to talk, default is 1.
- Emergency System: To be investigated
- Contact: This sets the contact that the radio CALLS on this channel (either a talk group or personal contact). Setting this and setting RX Group ID ensures you are calling and listening to the same contact.
- Repeater Slot: The DMR standard for amateurs has two timeslots, this enables repeaters to have two concurrent channels active. You need to select the correct timeslot for the talkgroup you wish to access. For simplex conversations you need to agree on a timeslot (default = 1).
- Private call confirmed: This permits a private contact to be made over a group call talkgroup, this is not Private as in encrypted or secure. It means you can alert a friend whilst in a public group. eg. connect to TG9 (the local chat group) on a repeater and then send a call alert to a private contact to make his radio ring (see later).
Zones are simply a memory management facility for channels, think of "memory banks" on older radios.
You use it to sort channels into logical groups e.g. per repeater timeslot.
On the radio you then switch between zones to get different groups of channels,
You will need to set up zones of the channels you have previously configured otherwise the channels will not appear to be available on the radio.
This section goes through setting up a repeater and accessing it. My local repeater is GB7BK so the details are based on that. Your details will differ.
Select a repeater from the current UK repeater map.
Make a note of its details, perhaps it has a web page with the full details on. my local is GB7BK and its webpage is here.
On the GB7BK website you can see the frequencies and talkgroups for GB7BK. Listed is TG9990, which is an echo service. It records your voice and plays it back so its good for checking both access and quality, it is used as the sample for this section.
First, using a good old analogue radio tune to the repeater output (439.7375Mhz for BK) and take a listen. If you are within reception range of the repeater you will hear bursts like this (you may have to wait a good few minutes).
Next configure a talkgroup contact for TG9990.
In Contacts, add a new contact as a "Group Call"
Set a name for the contact, note that this contact can be used on any repeater or hotspot system that supports TG9990 so I would avoid a name that was repeater specific. I used "TG990 - Echo".
Finally, the echo service is never going to call you so leave the Ring Style and Call Receive fields alone.
Next configure an RX Group list.
This adds the "Contact" created in step 2 above into the list of contacts you want to receive, select "TG9990 - Echo" into the list and call the list "TG9990 - Echo".
Now configure a channel, this is where the Repeater information and the Contact information comes together. In the diagram you can see
Mode: Digital
RX Freq: 439.7375Mhz
TX Freq: 430.7375Mhz
Power: High
RX Group List: TG9990 - Echo
Color Code: 3
Contact: TG9990 - Echo
Repeater Slot: 2
Hopefully, none of the above entries are a surprise to you. They are from the Repeater page and the local configuration items.
Finally, put the channel that you have created into a Zone so it can be used.
I have created Zones that reflect the grouping into Timeslots on the Repeater, TS1 and TS2. There are a number of channels listed and you can see TG9990 - Echo near the bottom.
In the video below, if you are quick, you will see the TX LED (which is red) come on, go off and come on again. This is as it digitally accesses the Repeater and is granted access. If access had been refused then it would have gone off immediately and a message and deny tone may be shown.
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Recommended settings for Simplex: TG9 , Slot 1 , Colour Code 1
| Band | Frequency | Use |
| 2 Metres | | |
| 144.6125Mhz | Calling Frequency | |
| 70cm | ||
| | 438.6125Mhz | Calling Frequency |
| 23cm | | |
| | 1298.6125Mhz | Calling Frequency |
As the Baofeng DM-9HX is a handheld radio, it is likely that you will either use it through a Repeater or a Hotspot (Hotspots are discussed later). Therefore lets look at Repeater operation first.
