Radio Network

‘Resilience’ has been a catch-cry for many people over the last few years. Rebuild Free Radio Network (RFRN) Radio Area Coordinator for North Waikato, Trish Murray, is part of a scheme to build a national, community-led radio network.

A licensed ham radio operator operator herself, Trish said the network was aware ham wouldn’t work for everyone interested in connecting via radio, so RFRN is utilising a network of PRS handheld radios.

Radio ham licences come at a cost, and with compulsory training and testing, they’re not suitable for many time-poor people.

Trish said she was familiar with the feeling of being ready to ‘get talking’ after completing her ham radio licence.

As a coordinator with the RFRN, she knew there was a mix of people out in the community, at varying stages of their radio journey.

“Many people bought radios, and some had started using them,” said Trish. “Some radios were still in the box. And many hadn’t decided yet if they even want a radio.”

As a result, Trish decided to offer some training in the form of very hands-on, interactive workshops.

“We talked about why the need for a radio, how they work, different types of radio, channels, repeaters, antennas, distances covered, and even what to say. Some of the concerns related to me were that they wouldn’t know what to say, or who would they talk to.”

So Trish used a whiteboard to create a rough diagram of the areas the attendees lived in, and showing local repeaters.

But the goal was to get people talking, so Trish marched the attendees outside.

“We had radio users there, so we went outside, split into groups, and literally got people calling each other. We used repeaters and simplex, doing channel changes, and practising putting calls out.”

Trish said the workshop attendees responded well to this strategy. They left the workshop feeling more confident, and some even decided to buy radios as a result.

The interactive workshop format also meant that Trish could make personalised recommendations to suit each situation.

Some radio users needed to know they could reach their mum in a rest home where no roof antenna was possible, or contact a family member an hour’s distance away.

“This meant travelling with a helper after the workshop to these locations and doing some radio calls for range tests. Additionally we have been doing test nets and seeing who we could reach and on what type of antenna.”

Trish said she found extended range whip antennas to perform very well, although roof antennas are the preferred option for practical reasons.

“But we’re trying out a range of solutions to see what’s best. Magnetic roof mount car antennas are also working really well. We use a repeater as a “gathering point” and then do a ‘by area’ split to go to simplex. The area we are working within is from Papatoetoe to Te Kauwhata, and then coast to coast, so a number of simplex areas.”

Trish said the community network contains people who are mostly new to radio.

“It’s really inspiring seeing their confidence grow, and to hear their first tentative calls.”

RFRN also involves experienced radio users, with others now keen to go on and work towards their ham licences, which Trish is encouraging them to do.

“Personally, I am loving seeing friends and family connecting on radio, and finding it really heartening having others jump in to offer help building the Rebuild Free Radio Network.”

Frequency = The cycles per second of the radio transmission.

Hertz = the unit of measurement for frequency.

Mega = million (1 megahertz is 1 million hertz)

Mhz = Megahertz. This is how many million hertz (MHz should not be confused with mhz (millihertz) which would be millionths of a hertz!)

CB = Citizen’s Band. (about 26/27mhz) This is the frequency of the long range radio.

SSB = Single Side Band. This is a more efficient way to transmit, thus increasing the distance you can communicate over.

PRS = Personal Radio Service. Sometimes incorrectly named as “CB” (This is the new version of public radio which superseded CB radio, but CB is still able to be used.)

HF = High Frequency (the long range CB radios are in the HF band).

VHF = Very High Frequency (marine radios are in the VHF band).

UHF = Ultra High Frequency (PRS radios are in the UHF band).

Band = A range of frequencies labeled as a group to identify what area of the radio frequency spectrum is being used/discussed. This can be used to identify either a wide range of frequencies, such as “The HF band”, or a narrower range of frequencies within a wider band, such as “The CB band” which is within the HF band.

Squelch = the setting of the level at which your radio will allow an incoming signal to “open the channel”. For example, a low squelch setting of 1 will allow distant weak signals to be heard out of the speaker on your radio, whereas a high setting of 9 will only allow nearby strong signals to be heard out of the speaker on your radio.

VOX = Voice operated transmit function. When enabled, your radio will transmit on the selected channel whenever you speak into it.

Channel = the selected frequency your radio is set to, labeled by numbers. (The PRS band has 80 channels)

SWR = An acronym for Standing Wave Ratio. This is a measure of how well the antenna matches the transmission output frequency. A value of “1” means “unity” or in layman’s terms; a perfect fit. A value any higher than “1.5” is not acceptable to transmit.

Following our National Coordinator Linc’s first presentation to keen radio enthusiasts in Hawke’s Bay, a group of ten people made the investment in PRS radios.

Initial reports were good, using whip antennas for short range connection, and the group began to erect their roof antennas.

Linc reported:

“I helped with two roof antennas, and did some testing at both ends. The expectation was that these two parties, about 15kms apart, would be able to talk to each other but we couldn’t establish communications, which was disappointing. We could hear some static on the radio, but it wasn’t performing very well.”

Having had a previous experience in the Marlborough area—where a pocket of interference had been resolved with a Techoman-supplied filter—Linc determined that the Hawke’s Bay issue may also potentially be filtering.

Acquiring a few handsets with improved filtering, Linc arranged for testing in several locations.

Because the use of these handsets resolves interference issues, they consequently provide better range.

Further testing helped the Hawke’s Bay pair that Linc was supporting to communicate across 15kms easily with the improved equipment, and double that distance to another point-of-contact.

As a result, the radio group has been recommended to upgrade their PRS to the handset with improved filtering.

The equipment will help them connect, provide better range, and is slightly more water resistant. However, it is a little more expensive.

Supplier, Techoman, can provide a small trade-in rebate of $30 on a returned radio upgrade, but a better option for the Hawke’s Bay group was to sell their existing PRS radios—secondhand but barely used—to interested people in other regions.

While the cause of the interference issue in Hawke’s Bay remains a mystery, thanks to connection and communication between Linc and the group, a resolution to the problem has at least been found, which may prove useful in other areas facing similar issues as time progresses.

This map shows our Rebuild Free Radio Network locations to date; areas where people are connecting via PRS or longer wave radios.

RFRN Network Map, September 2024

Imagine the unthinkable: There has been a natural disaster, the cellphone system is overloaded with calls, much of the hardware connecting you to the internet is down, and you’re hearing constant pleas to only text people, but text messages are taking hours. How do you connect to your support groups?

Now, stop imagining. This is what happened in Christchurch after the earthquake. Not only was the local cellular system overloaded, but much of the NZ infrastructure suffered serious congestion, Luckily this was only a local event and the rest of the new Zealand system managed to carry the traffic, and supply additional resources, the system did not fail, but it highlighted a problem with our internet-based systems. What happens when they go down.

While many candidates are looking to enter this market as potential solutions, there is an old-school method that may not cost you very much and you won’t need any contracts or monthly fees. Yep, we are talking basic two-way radios.

For most people, this conjures the image of walkie-talkies, and some 70s tv shows with “Breaker 19” being called by truckers, and CB radios are still used today in trucks, but two-way radio has a lot more going for it than just strange lingo and lids walkie talkies.

Modern radio systems are still used by Ambulance and Fire and Emergency as their primary communication, The systems carry both voice and data and can even provide basic internet connectivity. But for our applications, let us just consider voice options.

1. Buy a Commercial License. Commercial licensing is possible and can work, or you can share a frequency with others by leasing space on a system. The lease idea is what you do every month with your cellphone, but with a radio, you might be able to talk direct radio to radio, even if the system goes down. But bit the rentals costs and the equipment cost make this an expensive exercise.
2. Use Unlicensed radio bands. CB Radio (27Mhz) and PRS (477Mhz) frequencies have been allocated for use by private citizens using low-cost, low-power radios. These can be handheld or designed to be installed in a vehicle with an external antenna… Once you own the radio, you can use it with no license required, but you have to share the space with other users, but there are up to 80 channels to use. The low power means low range with handhelds giving about a 1 kilometre range and vehicle-mounted units getting up to 7 kilometres if there is nothing between you.
3. Use the amateur radio bands. Amateur radio operators are given many frequencies, and power limits up to 1,000 watts. This allows communication not only within New Zealand but around the world. In addition “Hams” have also set up repeaters, and even networks of repeaters that allow them very long-range communications, and HF radios can communicate hundreds or even thousands of kilometres.

For easy entry and short-range communications, PRS radio is usually the cheapest and easiest option. You purchase some off-the-shelf, type-approved, radios and you are all good to go, some cities have local repeaters that allow you to get more range, but remember everyone can hear what you say, and may even join in, so many people use a “handle” (nickname) rather than their real names. You no longer need callsigns but some of us use callsigns (letters and numbers) to help us identify as a group. A list of NZ repeaters is kept here: https://blowonthepie.co.nz/prs-uhf-repeaters-nz/

Ham Radio (amateur radio operator) requires that every user sits and passes a competency examination, and gain a General User Radio License (GURL) which can be obtained by any NZ citizen who has passed the exam, and paid the fee to Radio Spectrum Management (RSM), currently 100 dollars for a lifetime license. There is no age limit for anyone who wishes to sit the exam, many clubs arrange local classes, and there are online classes you can use to prepare for the 60-question test.

Amateur radio equipment can be expensive, but there is also a lot of good quality second-hand equipment that can be purchased by anyone holding a GURL that can be used on the amateur radio bands, and many amateurs will be so happy to see new members that they will help. Amateurs use both commercial and also home-built equipment to run their stations, and many hams have gone on into careers in electrical or electronics using the skills they gained as amateurs. In a later article, I will explain how to get your license.

So unlike a cellphone Radios do not need a network to operate. Radios can talk directly and once you know-how, an amateur radio operator can set up a station anywhere. Many use batteries, solar panels, and homebuilt antennas to perform field operations from any place they need to. So it can be both a hobby and also a way to gain technical skills.

So, what’s your backup plan to communicate?