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An Introduction to Network Radios with the Inrico T-320 and the Inrico TM-7


Tim Kirby G4VXE has been trying out Network Radio and getting to grips with a couple of transceivers in the process.



Tim Kirby G4VXE has been trying out Network Radio and getting to grips with a couple of transceivers in the process.



Over the last couple of months, like you, perhaps, I have read plenty about Network Radios. Like you too, I suspect, I have wondered where they fit into the hobby and what they are like to use. Courtesy of Chris Taylor G0WTZ of Moonraker, I had the chance to find out when he asked Don if PW would like to review them. Although I had some reservations about the idea of ‘not using amateur bands RF’, I looked forward to the arrival of the package and to see what could be done.

What follows is a record of my experiences with the two radios – partly the radios themselves and partly the Network Radios experience. I hope you will find it as interesting as I did.


What is a Network Radio?

You might be wondering, what exactly is a network radio? Simply, it is a smartphone that operates on the 3G/4G phone networks, usually with WiFi capabilities as well. The differentiating point between a ‘regular’ smartphone and a network radio is the form factor. In the case of the Inrico T320, it has the look and feel of a handheld radio, with a PTT button on the side. In the case of the Inrico TM-7 it has the look of a mobile radio attached to a microphone by the standard curly cable.

It’s easy to underestimate the difference that this form factor makes. Because the units look and feel like the radios we are used to, you treat them in the same way. It is easy to forget that you are essentially using a phone, rather than an amateur bands transceiver.

Bear in mind that every use that I describe for both the T320 and the TM-7 can be carried out on a ‘normal’ smartphone, either Android or iOS. Indeed, you might want to try out some of the applications on your regular phone to see how you like them, before deciding to use a network radio. My experience is this. If you enjoy using the applications on your phone, curiously – you will find the Network Radio experience even more compulsive! I should also add that one key difference between the operation of a Network Radio and a Smartphone is when an app is running and a phone call comes in, a smartphone will default to the phone call whereas the Network Radio is configured such that the app takes precedence. If you don’t use a SIM card, though, or use a data-only SIM, this is of no consequence.

And, of course, because these units do not use amateur bands RF, you do not need to have an amateur radio licence to use one. Many of the applications I will describe can be used by both licensed and unlicensed users. It is only when an application has a link to an amateur radio RF channel that you will need to prove you have an amateur radio licence. Perhaps the fact that the sets can be used by both licensed and unlicensed people makes you feel concerned? Don’t be and I will explain why in due course [and see also Chris Rolinson’s article in this issue – ed.]


The Inrico T320 4G/WiFi Network Handheld Radio

The T320 handheld was the radio that I unboxed first because I thought I would get it going in the house on WiFi and see what I could do. The first thing was to fit the battery and the small stubby antenna, which gives the rig an ‘authentic handheld’ look. It feels a good solid unit and fits nicely in the hand. The screen is a reasonable size and fairly bright although I had some problems seeing it in strong sunlight.

Powering on the unit displayed a welcome screen for 30 seconds or so as Android starts up. Once started, I swiped the screen to take me to where you can navigate between applications, settings and so on. The first thing was to go into settings and connect the unit to the house WiFi. I was pleased to find that it saw both 2.4GHz and 5GHz WiFi networks.

Entering the password on the small on-screen keyboard was slightly tricky but manageable. Now the unit was connected to the internet. When the rig arrives, there are no applications installed, other than the default Android ones. So, you will need to choose which applications you want to install. Applications are installed from the ‘Play Store’ icon. You will need to log in using your Google account, assuming you have one. Within the Play Store you nominate how you will pay for any ‘paid for’ applications.

The first I installed was Zello. This is a Voice over IP (VoIP) conferencing system. The application is free to install and to use. There are many thousands of channels but I was particularly interested to try out the ‘Network Radios’ channel, which several readers, including Ian Abel G3ZHI and Karl Hobson G1YPQ had kindly told me about. There are no direct connections to the amateur radio bands from Zello – it is wholly standalone – so both licensed and unlicensed operators can enjoy the features. I had already created a Zello account (using my callsign as a username, though you don’t have to, of course) so I logged into Zello and connected to ‘Network Radios’. When you first connect, only moderators can hear you. They have to establish you as a ‘trusted user’ so they will have a quick conversation with you and confirm your interest in communication matters (in the widest sense). This ‘light touch’ moderation seems to work very well and is nicely done. If, and I have not heard it happen, someone was disruptive, then the moderators can simply block that user from the channel. I suspect some repeater keepers would love to be able to do that on FM! Once I had been ‘trusted’ I was able to join in with some very enjoyable conversations with people; mostly although not exclusively, amateur operators from all over the globe.

At first, I was very conscious that these were ‘non-amateur-RF’ contacts. But in answer to the question to my conscience, “what does this have to do with amateur radio?”, I concluded it had a great deal to do with it! Perhaps, like face-to-face conversations at the radio club, we talk about radio, exchange ideas and quite often enthuse each other to try out new things on the radio. It was interesting to hear that a number of users were saying that they had been more active on the amateur bands as a result of using their network radios. It was also really nice to hear that some of the non-licensed people were thinking about getting their licence.

The audio quality from Zello was amazing. Despite having a small loudspeaker, the T320 has plenty of volume and the frequency response is much wider than we are used to as radio amateurs. There are also some nice features that you allow you send pictures or location details to other stations using the camera/GPS on the T320.

There were a few settings within Zello Options that I customised over time – for example, not to start Zello when the phone starts (more on that later) and not to keep history. Otherwise, Zello will record the various ‘overs’ that it hears, which can fill up storage on your phone. You can also adjust microphone volume and several other parameters.

The next application that I installed was Teamspeak 3. This allowed me to connect to the International Radio Network (IRN). You must set up a connection to the server for which you can find instructions at:

Because I had already set up Teamspeak 3 on my iPhone to try it out and had created a Teamspeak account, I could sign in using that. This connected me to the IRN server and I was then free to move to the different talkgroups. When I had first connected to the IRN, there was a very simple validation process to prove that I was licensed. This is because some of the talkgroups are linked through to amateur RF so you can come out on analogue or digital repeaters. Other parts of the IRN such as the ‘DigiComm Café’ are open to both licensed and unlicensed users and, again, appear to be well moderated.

Another free application I wanted to install was Echolink. Many of you will be familiar with Echolink. This is only available to licensed radio amateurs because, other than point-to-point connections, users generally connect to a repeater or a conference. The Echolink application was free to install. This worked very well indeed and I enjoyed connecting to several Echolink-enabled repeaters around the UK and making some nice contacts. I have used Echolink occasionally on my iPhone for years, but it was nice to have the T320’s PTT button rather than having to tap and hold the screen to transmit.

I installed HamGPS, which uses the GPS included in the T320 to work out the locator square where you are, a nice touch if you are out portable.

Chris Rolinson G7DDN suggested I try using the T320 to connect to some of the WebSDR receivers that are available through the internet. Good idea! I used the Chrome browser, which is already installed on the T320, to connect to the Hack Green SDR:

This enabled me to listen on various HF bands, including Topband (160m). I first tried it one evening and was pleased to hear good friend of PW, Mike G3SED coming through very nicely. For VHF, I used the Southampton University WS SDR (link below), which allowed me to listen on 6m, 2m, 70cm and even 10GHz. This worked very well. You may prefer to install the Firefox browser because that seems to be what the WebSDR asks for but, in practice, I found that Chrome worked without any problems.

I also installed the APRSdroid application which connects to the APRS network through the internet. The application is paid for, although I did find a more basic free APRS application that allows you to send your location into the network such that it can then be seen on the website. Using APRSdroid I was able to send APRS messages and see stations plotted on the map as well as use it to send my position as I walked or drove around.


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Network Connectivity

The T320 can take a SIM card so you can use it on the 3G/4G networks, for connectivity but rather than do this, I used my smartphone as a hotspot and connected the T320 to that by WiFi. This worked very well in both portable and mobile situations. Despite patchy network coverage around where I live, I found that my mobile on the front seat of the car, tethered to the T320 by WiFi, was fine for listening to Zello, Echolink or Teamspeak. If you want to use the T320 just for data, rather than as a phone as well, there are some prepaid SIM deals that allow you to buy gigabytes of data for a fixed sum. I found that using Zello, Teamspeak and Echolink was not bandwidth heavy, so it’s very likely that 12Gb or so would last you a long time. Although I did not do so, there are some Bluetooth earpieces and microphones that would allow you to use the T320 in a mobile situation.


The T320 Overall

I enjoyed the T320. It was easy to use and ran all the Android based applications I wanted to, with one exception, AMSATDroid, which said it wouldn’t run with my configuration. The familiar ‘handheld’ form factor was a real plus for operating with the VoIP applications and it was odd how I enjoyed using the unit more than using the same applications on my smartphone. Battery life was excellent and the unit did not need to be charged more than once a week or so (in moderate usage).

Some of the applications conflicted with use of the PTT so I found that I only used one of Zello, Teamspeak or Echolink at a time and when I had finished using a particular application, I would go into the Android applications menu and Force Close that application before using another.

A few users have reported WiFi dropouts and the T320 ‘buzzing’. This appears to happen as a result of some network traffic being received. A reset seems to clear this – other people have used NetGuard, an application firewall, which runs on the unit, to restrict traffic to known sources, and that seems to have eliminated these problems.

The T320 fitted nicely in my rucksack and I enjoyed using it and having the ability to make contacts all round the world from most locations.


The Inrico TM-7 Mobile Network Radio

The TM-7 is a network radio that looks much more like a mobile or a base station radio. Like its cousin the T320, it’s an Android smartphone that has no amateur RF capability. It operates on the 3G network (no 4G) or WiFi. You can also use it as a WiFi hotspot. There are two antenna sockets on the rear, one for the GPS antenna, which is supplied, and one for an external 3G antenna, which is not, should you need to use something better than the supplied internal antenna.

Setup of the TM-7 was very similar indeed to the T320. When I powered it up, the first thing I had to do was to connect it to the WiFi. I noticed that the TM-7 only works with 2.4GHz WiFi rather than 5GHz networks. Not a huge issue, but one to be aware of.

Like the T320, you will need to go into the Play Store and download the applications you want to use − Zello, Teamspeak, Echolink and anything else that takes your fancy. One of the challenges I found with the TM-7 when setting up applications, entering passwords and so on, was the on-screen keyboard. This was quite hard to use, even if you are being careful! Some people I spoke to mentioned that they’d used a Bluetooth keyboard, which sounds like a very good idea. I did find that the on-screen keyboard was very frustrating, particularly if you have lengthy passwords with special characters.

The first application I installed on the TM-7 was Echolink. I connected to GB3IW on the Isle of Wight and had a couple of very pleasant contacts. I did struggle to adjust the volume – I was trying to use what I subsequently discovered was the rotary encoder. If you use the + and − keys to adjust the volume, you will be a lot more successful! It’s worth saying that you can use the Button Mapper application (you may want to go for the paid version) to remap keys on either the TM-7 and T320 as you wish. While you are configuring things, you may want to go into the Display settings and set the display to stay on as long as possible – 30 minutes is the maximum value. If you require a longer time, there are various applications available in the Play Store that will keep the display Always On.

It’s worth mentioning that if you have downloaded any paid for applications on another Android device, you don’t need to pay for it when you download it on a second device. Good news for Teamspeak3 and APRSdroid users!

Zello is free, though, and I installed it on the TM-7 and immediately connected it up to the Network Radios channel where I had a good chat with Steve Smith G0TDJ, Neil Morris G0TVJ and others. The audio quality on the TM-7 was even better than on the T320 because, presumably, the loudspeaker is a little larger.

Next was to install the TM-7 in the car and try it out. It was a little too large, despite its modest size, to fit in the centre console of my car. However, I found a secure place for it and connected the power cable to the cigar lighter socket via an adapter cable I had.

I found the time taken to ‘boot up’ the phone was a bit of a limiting factor because, of course, each time I turned the ignition on, the TM-7 had to boot up again. I did find that one of the Zello settings to start the application automatically was quite useful, so I could just switch on the TM-7, drive off and it would connect to my phone’s WiFi and then into Zello without having to do anything else. I’m not sure whether this is possible with Teamspeak3, if you want to use IRN as your default, but certainly it doesn’t seem to be with Echolink.

The TM-7 and Zello experience was excellent when using them mobile and the audio quality was particularly impressive. I had some great conversations, particularly on the Network Radios channel, at all sorts of times of day. You can also connect with individual users rather than a particular channel and, notably, I had a very enjoyable chat with Simon Parker who writes the always interesting Comms from Europe column in our sister magazine, RadioUser.

A couple of mornings I used the Echolink client and connected to GB3IW to listen to the Breakfast Club net and hear how the morning was going on the south coast.

I did not test each and every application that I had tried on the T320 on the TM-7 but everything I did try worked in the same way.


The TM-7 Overall

The TM-7 was great fun in the car. Audio quality was very good. The screen is too small to read when you are mobile, so you will essentially have to set it up before you leave and forget it – Zello’s autorun feature was very useful here. The fist microphone works well at home, but you can look at a Bluetooth microphone/earpiece to ensure safety when you are mobile. The TM-7 would also be a nice radio to have in the shack where the screen will be much more useful. I have heard of some users running BBC iPlayer on it!

I found the start-up time of the TM-7 a bit annoying while connected to the cigar lighter. If you can get a direct connection to your battery, even better.



I tried to approach the whole Network Radio concept with an open mind. I confess that I started off feeling that I preferred those applications that allowed me to connect onto amateur RF, such as Echolink and parts of the International Radio Network. As time went on, though, my favourite part of the network proved to be Zello, where on the Network Radios channels (there’s now more than one) I encountered nothing but positive experiences and interesting people to speak with.

Rather than replacing ‘real radio’ I found it was a new facet to the hobby. I liked the fact that I could speak to both licensed and non-licensed operators. The conversations I found on Network Radio seemed to draw people into amateur radio in its wider sense rather than take them away from it.

My thanks to Chris Taylor G0WTZ of Moonraker UK Ltd for his loan of the equipment and to the many people that I’ve spoken to during the review period for the interesting conversations and much advice! The Inrico T320 costs £199.99 and the Inrico TM-7 costs £159.95.


This article was featured in the July 2018 issue of Practical Wireless

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