Every user on the DMR network has a 7 digit ID number. This ID number is sent with every transmission.
Numbers are internationally coordinated, with the first three digits representing the user’s country. VK uses 505, the UK uses 234, etc.
The complete DMR number database is available for download at the radioid.net web site.
If you download all or part of the database into your DMR radio, it will do an automatic lookup on the ID in every received call and, if it finds a match, show the user’s name and callsign on your radio’s display screen:
The shortcoming of this arrangement is that it requires a user to download (or type…) the contact list into their radio. The list changes quite often, so a new list must be downloaded every few weeks or so.
The international DMR standard has a feature called inband caller alias. This allows all radios to transmit a user-defined text string of up to 31 characters with every call – for amateur use, this would obviously be callsign and name.
When I first got into DMR some 6-odd years ago, my first radio was a Tait TP9300 portable. The ergonomics were the best I have ever used – it fitted your hand beautifully.
There was one problem, however – it didn’t play well with our
network of Motorola repeaters. There was
a software incompatibility that meant the radio dropped receive audio after about
20-30 seconds. The problem was eventually
fixed with a firmware update, but it was very annoying at the time….
So, I migrated to the big M.
Of course, their portables and mobiles work perfectly with their
repeaters, as you would expect.
I’ve also dabbled with some of the Chinese portables and
mobiles from TYT and Anytone, as a club project and for my own research.
So, I’ve used DMR radios at both ends of the scale –
expensive high end commercial units, and economical Chinese models.
The Motorola radios are commercial land mobile products
designed for a non-technical user. From
an amateur perspective, they are expensive, you must load contacts manually
(i.e. type them into the programming software one by one…), the number of
contacts is limited to 1000 and the radios can’t be programmed directly from
You grit your teeth and put up with the inconvenience, because
the RF performance, the build quality and the reliability are first rate.
The Chinese radios are a lot more flexible for amateur DMR –
you can load 15000 contacts directly into some radios via an excel spreadsheet,
and many offer keypad programming.
However, the build quality is very variable, and the programming
software is often buggy and finnicky (drivers can be a nightmare and anti-virus
programs often block the programming software).
The Chinese radios will also sometimes crash and lock up. Some radio displays are small and difficult
to read, the operating routines can be illogical, and the operating manual is
often not written by a native English speaker.
So, I was very interested to see that Tait had released a
new DMR portable recently, the TP3. I
got chatting to Tim, VK3TIM (great callsign…) who was using the TP3 on DMR. After some discussion, I purchased one.
Tim was right – it is a great little radio. It bridges the gap between the high and low end radios, by offering the best of both.
The TP3 is a commercial quality, type approved land mobile
radio. It offers IP67 water integrity
and MIL STD environmental compliance (temp, rain, vibration, shock).
It comes with integrated GPS, Bluetooth and man down
functionality (the latter is not used in amateur DMR).
The radio can be programmed from the front panel – all channel
parameters can be altered: frequency, slot, TG, colour code. This function can be locked out with the
software – which you would normally do if the radio was being used
The programming software works faultlessly – there are no
hassles with drivers, just load it and away it goes. It runs very smoothly on any Windows
machine. Similarly, the programming
interface/cable to the radio just….works, as you would expect.
The radio can be loaded with 2000 contacts via an excel
spreadsheet…OK, it would be nice to have about 5000 contact capability…but
loading 2000 via a spreadsheet is better than typing 1000 by hand, believe me….
The channel table can be exported as an excel spreadsheet,
edited in excel, and loaded back in – this simplifies programming considerably.
I always check DMR radios I have programmed by watching the IPSC server while keying up on each channel. As we all know, there are so many variables in DMR programming software that if you get one check box wrong you end up on the wrong slot or TG for a channel. With the TP3, you can just edit the incorrectly programmed channel directly via the keyboard, and the problem is solved…
Transmit and receive audio is typical Tait – very good. The radio is obviously designed for noisy
environments – it has plenty of audio gain on receive and a nice big speaker.
RF performance is fine – I haven’t put it on a service
monitor yet, but it is as sensitive as my Motorola portable with a simple side
by side test of a weak signal. Tait claim
a receive sensitivity of -119dBm for 5% BER, which is comparable with Motorola.
It provides 4W or 1W of RF out and does analogue as well as
It is relatively small and light (327g) and the PTT is easy
One feature I have always liked about Tait is that they offer their radios in a variety of colours – not just boring black. This is very useful if you are using the radios in a big network with different work groups – each group of radios could be a separate colour.
The front panel can even be changed to a different colour if
you get bored….
The radio is offered in VHF and the usual UHF 1 (400-480 MHz)
and 2 (450-520 MHz) bands.
Price is around $650 (including GST), which is very
competitive for a commercial type approved DMR portable with as many features
as the TP3.
I’m very impressed with the TP3…so much so, I’ve just
ordered the matching VHF version.
More detailed information is available on the Tait website, or use Mr. Google.
There are a few new users that have some TG (Talk Groups) set wrong.
If you have a simplex hotspot, you can still use both TS 1 & TS 2, but only use (RX) 1 time slot (TS) at a time until that TS passes the setting you have for hold of the TS.
Go to the IPSC2 Hotspot Server, and click on the Service button on the Left hand side of your screen, and scroll down to your callsign. If you see a brown (Tan) colour in your line you have an error in your Hotspot configuration for connection to the VK-DMR IPSC2 Server.
If you look at the Dashboard Web page on the left side of the screen you will see tabs, click on the Matrix Tab.
The page will show the TGs configured for the VK-DMR Network, it will have Repeaters listed if you are on the Repeater IPSC2 Web Page and you will see Hotspots if you are on the Hotspot IPSC2 Web page.
At the top of the page you will see a group with 8/1 to 8/9 listed, these are the TG8s for Hotspots that are connected to the VK-DMR IPSC2 Network
The table below shows the TG to be programmed for each region.