VK6MIB

Obtaining a DMR id with the Australian class licence

Sun, 18 Jan 2026 00:00:00 +0000

One of the very first things you need to use DMR (Digital Mobile Radio) is your DMR id. These are provided by RadioID. Naturally, they require a copy of your licence to prove you hold your call sign, and show a stern warning along with a mock up of an Australian licence saying if it doesn’t look like this, you can’t proceed.

Unfortunately, since Australia moved to a class licence system in 2024, I no longer hold a licence with an expiry date etc. I googled around for what to do with no luck, but in the process discovered there was an Australian DMR group on Facebook - “VK DMR Network [OFFICIAL]” It’s a request-to-join type thing, but my application was approved, and about five posts down was someone asking that exact question I had.

Back to APRS

Wed, 07 Jan 2026 00:00:00 +0000

I once owned an expensive Kenwood handheld - perhaps a TH-D74 - that I had been excited about because I wanted to try APRS. To get on APRS at the time the option was to buy an expensive radio or to piece together (or home-brew) the audio interface, a GPS and the board to pull that all together.

Recently, Chinese radios have started to integrate these in reasonably priced handhelds so the last couple of weeks I’ve been trying the Vero VR-N76.

Follow up

Mon, 30 May 2016 00:00:00 +0000

So… this arrived in my email this morning

What a nice surprise, well done to the organisers. If their plan was to get people thinking about the next contest in July, it’s working. I’m not a dedicated contester by any means, but the Trans-Tasman was relaxed fun last time, so I’m keen to sort out the problems with my dipole and have another shot. I’m pretty much a 40m only operator for this due to the difficulty of squeezing in enough wire on the block. I have looked at plans for some loading coils but I’m finding it difficult to find the time to get to that and a number of other projects.

More Space APRS

Sun, 20 Mar 2016 00:00:00 +0000

NO84

Using space based digipeaters this weekend I had a couple of firsts. One was successfully having a packet digipeated by PSAT (Parkinson Sat - NO84). This is a 1.5U CubeSat launched in 2015 carrying a APRS transponder and a PS31 experiment.

I’ve heard this satellite before, but yesterday I had a shot at sending it a packet, I heard it digipeated, but didn’t receive it back well enough to decode it. I waited 30 seconds or so and had another shot with the same result.

Terrestrial APRS

Thu, 10 Mar 2016 00:00:00 +0000

I took my first road trip within range of some earthbound digipeaters and iGates tonight. The D72 was secured on the dash of the ute, but using the dual band whip on the roof. I decoded one packet just out of Narrogin, I assume via VK6-RAW (I haven’t read enough of the manual to work out how to sort the list by time yet) but didn’t get any of my own packets digipeated back to me until I got much closer to Perth.

Accessing the ISS Digipeater

Mon, 07 Mar 2016 00:00:00 +0000

With a long weekend, and a major project at work behind me, I had a tiny bit of breathing space to play radio this weekend. What I should have been doing is putting in a couple of hours on the AllStarLink for my club (currently at about 30% finished). What prevented this was a new toy scored second-hand from eBay that arrived this week – a Kenwood TH-D72A handheld.

I grabbed this off eBay, the main attraction being it’s APRS capability, including: built in GPS, stand alone digipeating, and the ability to plug it into a PC and use it as a TNC. My first big plan for this, since I’m miles from anywhere, was to use it to get my staion on the ARISS map by having it digipeated by the International Space Station

FM320 Nominated Channel Modification

Tue, 26 Jan 2016 00:00:00 +0000

The Phillips FM320 UHF CB has the facility to be locked to a particular channel. This is controlled by the existence or absence of a number of diodes on the circuit board. I’ve been looking into this for a telecommand project I’m working on. I wasn’t able to find the information of how to do this anywhere else, but it was pretty straight forward to figure out.

This post describes how modify the FM320 radio to set the nominated “NOM” channel.

Phillips FM320

Tue, 26 Jan 2016 00:00:00 +0000

Here’s a blast from my radio past, the Phillips FM320 UHF CB radio. I’ve dusted one off from the slowly collapsing box of radios left over from my farming days. My plan is to use one as the receiver for my DTMF pump switch.

As a kid I had always been encouraging Dad to consider radios for the farm. I was a regular reader of CB Action and it seemed like the perfect excuse. He never succumbed to this until the advent of UHF CB. We had seen them at one of the field days, and organised for a Phillips representative (a German guy called Hans) to come out to the farm and do a demonstration. Hans arrived with a wind up mast that he set up at the house and wound up to the same height as our TV antenna. Then we drove around the farm to see what the coverage was.

DTMF Tone Control

Wed, 20 Jan 2016 00:00:00 +0000

I’m in the process of replacing a windmill on the farm with a solar pump. The windmill, carefully adjusted, can keep up with the water consumption at the house and troughs a couple of kilometers away. It isn’t perfect; sometimes the house tank overflows and we either water the garden or go down and turn the windmill off for a few days. Sometimes the tank sounds a bit empty and I drive down to the windmill and adjust it for a bit more flow.

The solar pump is not so analogue. In order to lift the water the height needed, the centrifugal pump is oversized in relation to the actual flow required. The pump controller can be turned down to some extent, not not enough to avoid overflowing the tank and wasting water. Some system is needed to turn it off an on remotely. My current plan for this is to use DTMF tones over UHF CB radio.

Dual-tone multi-frequency signalling (DTMF) tones are used widely in telephone systems. The frequencies are chosen to be easily transmitted in the narrow voice bandwidths and using two tones for each key allows for a small amount of frequency drift as well as good rejection of noise.

The frequencies were originally chosen far enough apart to use analogue bandpass filters for detection, so it’s possible that someone smarter than me could implement a simplified Fourier transform that would run on the Arduino. As I need this to be robust, I rejected that idea and decided to use an MT8870 Integrated DTMF Receiver.

Portable Kit

Sun, 06 Dec 2015 00:00:00 +0000

I’m always fascinated with the operating kits people take portable. There are a heap of interesting trade-offs to make. Here’s my usual HF kit:

Getting it up

Sun, 15 Nov 2015 00:00:00 +0000

Common advice to new Amateur radio operators asking questions about antennas is that “anything is better than nothing”. The idea being that you can always improve things later, but for now do something to get on the air.

I live in a small rental unit in a rural town, with overhead power lines across the front of my block. As far as antenna’s go, the only thing in my favour is that many houses nearby have UHF CB colinears mounted on roofs or free standing at around 6-7m. This proliferation of CB antennas is not a symptom of a thriving CB culture – more that mum and dad usually retire into town when sons take over the day to day operation of farms, and that before the widespread use of phones UHF CB was a staple of farm communications.

Inkscapades

Wed, 23 Sep 2015 00:00:00 +0000

I’m a member of a fairly active group – the Bunbury Radio Club. The club’s history stretches back to the 1970’s boom in CB radio and we are open to all radio enthusiasts, not just amateur radio operators - although almost all current members are licensed. As the club has experienced some growth in the last couple of years, we are increasingly conscious of the need to project a positive image for the club and amateur radio in general.

Diamond in the Sky

Sat, 19 Sep 2015 00:00:00 +0000

I’ve been meaning to write a follow up to my earlier post about the Feature Tech antenna analyser. The short summary of that post was that when I hooked up the antenna analyser to a mobile whip on a magnetic base, I saw all sorts of SWR values which were often not repeatable and changed even as I was taking my hand away from the meter. I was disappointed with the device.

Fast forward a few weeks, in a QSO with Martin VK6ZMS and he was strongly of the opinion that I was doing myself a disservice by running a mag mount without grounding the antenna to my vehicle close to the base of the antenna. Another clue was one idle afternoon at home, I threw the analyser on my WARG Pogo Stick 2m antenna and it had none of the problems I had seen. The SWR readings were reliable (you could read of a value for a frequency, change the frequency then change it back and get the same SWR value) and did not alter as I handled the coax or moved away from the meter. One of the features of this antenna is that it has an coax choke at the base.

RTS-SDR Sleuthing

Sun, 13 Sep 2015 00:00:00 +0000

Yesterday on the way back from a BRC meeting, I stopped in at Harvey to try and track down some interference we are getting on the 70cm repeater VK6RBY that is located on the scarp just east of the town. Listening on the input frequency 433.650 MHz the squelch was breaking as I entered the town limits. Within a few minutes of driving I’d tracked it down to a particular town block.

I hopped out of my ute and tried to use the scanner to try and narrow it down further – without much luck. I’ll have to come back with a yagi to do any better. Since there seems to be a constant carrier with the occasional burst of pulsing, it’s probably a telemetry device of some sort.

The Download

Sat, 05 Sep 2015 00:00:00 +0000

I’ve been drawn away from time playing with radio for a couple of months, working away in another town to backfill someone else’s (harder) job. In addition to the time involved in getting my head around the new job, it means starting from scratch again with antennas etc, and I haven’t brought all my gear so whenever I do have an hour to play, I’ve often not got the tools or equipment I’d like. As a result I’ve been keeping in touch by catching up on a number of podcasts and I thought it might be interesting to talk about a couple of them plus some other ham news sources.

SSTV

Sun, 26 Jul 2015 00:00:00 +0000

The enterprising ex-secretary of my club, Brian VK6TGQ coordinates an “experimenters net” most Sunday mornings in Bunbury wherein different aspects of Amateur radio are played with. Over the last month or so they have been experimenting with sending Slow Scan TV over 2m simplex. From this distance I have not been involved in this apart from occasionally joining them on the IRC channel to see what they are up to.

The equipment to do this can be pretty basic. They started out just with an app on their phones, to transmit, the app loads the image and plays a series of tones (FSK) as each line of the image is transmitted. If you don’t have a cable into your transmitter, you key the transmitter and hold the phone speaker up to the mic. A similar arrangement is possible for receive – the phone is left near the transceiver speaker and converts the tones (and any nearby noises) back into an image. Crude, but results are possible. A much improved result can be obtained by connecting the transceiver to the decoding device (usually a computer tablet or smartphone).

Trans-Tasman Contest

Sun, 26 Jul 2015 00:00:00 +0000

Now my dipole is up semi-permanently, I can sort of operate every weekend I’m home. I say ‘sort of’ as it’s much noisier here in town than at the lookout where I made my first contacts, and I suspect I don’t get out as well with this little half size G5RV at only 6m high.

I turned the radio on last Saturday afternoon to have a tune around and heard VK6QM calling CQ contest. I wasn’t aware there was a contest on, but when no one else was answering I called back and got a quick lesson in what the exchange was (signal report and contact serial number) and scrawled that and my times on a piece of paper.

Contact!

Tue, 14 Jul 2015 00:00:00 +0000

I went out for my first shot of HF operating today had had some success as well as learning a couple of lessons.

The set up was at a local lookout - it has a slight elevation compared to town, it’s out of the noise (nearest power-line is about 400m away) and partially surrounded by the salt lake that the town is named for. The lookout has an iron railing that is perfect for strapping my 7m squid pole to. The plan was to hook 20m of wire from that down to the back of the ute and run it as an end-fed.

Lesson 1 - there is only so much tension that can be placed on a squid pole before it snaps.

Rike RK-560 Frequency Counter

Sat, 27 Jun 2015 00:00:00 +0000

I got another BF-888S in the post today. This one was $18.03 from ebay seller jeenygq. It continues to amaze me that I can buy a frequency agile 70cm transceiver for less than a packet of cigarettes. My ‘reason’ for needing another one is that in addition to my uncompleted 70cm foxhunt project, I’m starting an AllStar Link Node project. I’m always keen to test eBay purchases straight away while they are inside the 45 day PayPal refund timeline, and this seemed to call for one of my other recent purchases – a Rike RK-560 frequency counter.

Sky Talker

Sat, 06 Jun 2015 00:00:00 +0000

On the F-Troop net this morning, VK6AS mentioned there was another good pass of SO-50 today. With last weekend’s mistakes learned from, I had another shot at it. I thought I could hear snippets of voice modulation down in the static when the satellite was still at -5º elevation which seemed odd. It wasn’t until about 40º that I got anything readable, and even then it was only for half a second at a time.

The pass was almost directly overhead for me, so at the apex I was able to just point the Arrow straight up, and copied VK6AS’s call. I put out a call to him and was thrilled to hear his reply of congratulations. So thrilled in fact that I wobbled the antenna and lost him. I was so frantic from then on trying to find the satellite again that I completely forgot to keep adjusting my downlink and didn’t copy anything for the rest of the pass.

Space Adventures

Mon, 01 Jun 2015 00:00:00 +0000

In February, I attended a meeting at HARG that included a talk and demo by Chris VK6FCGB on using the FM repeater payload on SAUDISAT 1C (SO-50). Satellite work is definitely in my ham radio hobby plan, both because of the technical challenges and my remoteness from other hams here.

AW07A Antenna Analyser

Sun, 24 May 2015 00:00:00 +0000

I like measuring things, this is perhaps best illustrated with this photo of the current contents of the second drawer in my kitchen. Apart from the usual cooking implements, it contains an infra-red thermometer, a compass, luggage scales, gas bottle scales, 10.5 GHz dopper speed gun and a Geiger counter. I also own numerous electronic meters of various kinds. My most esoteric measuring device is probably a Brix sugar refractometer (uses the bending of light to measure the concentration of sugar in a liquid).

So it caused great excitement here when my antenna analyser arrived this week. At over $300 it’s my most expensive piece of equipment in the hobby. I purchased it on ebay, from a seller I’ve dealt with before and it took about exactly a month to get here due to some story about the stock they had being damaged. To their credit, they air freighted it when they finally had stock.

Baby fox

Sun, 10 May 2015 00:00:00 +0000

One of the exciting things in amateur radio at the moment is the unbelievably low price of the Chinese handheld radios. One of the very cheapest is the BF-888S. It’s a 16 channel 70cm unit putting out about 2.5W. I got a pair for $42 from a Chinese ebay seller.

These radios are so cheap, they make you want to invent projects to use them. One project I’ve had in mind for a while is to use them for ARDF/fox hunting (you hide a transmitter, and people drive/wander around with receivers trying to find it) with kids armed with little Yagis.

About

Tue, 14 Apr 2015 00:00:00 +0000

I am Ian, VK6MIB. This blog documents some of my adventures fiddling around with radio. My interest in the magic of radio electronics goes back a long way - I built crystal radios with Dad as a kid - but I’ve only been a licensed amateur radio operator for a few months.

I live and work in rural Western Australia as a teacher.

2m Tape Measure Yagi

Mon, 06 Apr 2015 00:00:00 +0000

My club (BRC) is looking at getting in to some fox hunting as a way of creating some shared activities, so I’m going to need a simple, portable beam with a good front to back ratio in order to play.

I had a look around and vk3hra’s blog had a nice step-by-step so I decided to copy his. It’s based on the fairly common PCV pipe & tape measure approach. The idea with steel tape measure is that it bounces back from being folded, so it’s easy to fold the elements for transport etc. Here’s his design:

Baofeng UV-B5

Tue, 31 Mar 2015 00:00:00 +0000

I purchased a UV-B5 for my first radio. In general the cheap Chinese hand held radios are incredible value for money. I assume they are selling thousands into the business market in Asia and that’s what’s allowing these prices.

Similar to the best selling UV-5R, the UV-B5 can transmit anywhere in 136 - 174 MHz and 400 - 480 MHz including being field programmable. A result of this, and their lack of certification, they are only legally able to be owned by licensed ham radio operators in most developed countries.

The reason for choosing this model over the ubiquitous UV-5R is a couple of things. One of the common faults of these wide band radios is that the front ends can be easily overloaded. According to Brick O’Lore the UV-B5 handles this better than the other radios in this price range.

QSL Cards

Sun, 08 Mar 2015 00:00:00 +0000

I was looking on ebay for radios and saw some old QSL cards being sold. This inspired me to design my own while I wait for my licence to come through. I really love the look of these old cards, the typefaces and cardboard remind me of the wool consignment books in which we used to record details of each bale of wool during the early nineteen seventies.