Intel iMac Late 2014 Ubuntu notes

We had an old but beautiful Intel iMac from 2014. It could not be upgraded beyond macOS Big Sur 11.7.10. I used the OpenCore Legacy Patcher and managed to get macOS Sequoia 15.6 (but not 15.7) going on it quite well. There were a few graphics glitches and it felt fragile.

I normally run Linux for ham radio operation so decided to try the latest Ubuntu 25.10.

The machine is a 4GHz Quad-Core Intel Core i7 24GB RAM, with AMD Radeon R9 M290X 2GB. Wifi did not work from the installer. The machine has a Broadcom Inc. and subsidiaries BCM4360 802.11ac Dual Band Wireless Network Adapter (rev 03).

It turns out that rev 03 is important and means that the normal driver won't work. I did the install by plugging in to ethernet. 

After some messing about, apt installing broadcom-sta-dkms got the built-in wifi to work.

Sound, bluetooth and camera all work. (The camera looks very dark though).

The only major issue is that running the Chromium or Chrome browser would hang the machine hard. Frozen mouse, needs a long press of the power button to re-boot. The workaround is to run the browser with the --disable-gpu command line switch. I've made a .desktop file with this built-in. It still performs quite well.

These old Intel macs are very cheap since the transition to Apple Silicon - which runs astonishingly faster - but they are still useful machines. It seems such a pity to waste a fantastic big screen.

A minor issue is that fldigi doesn't handle the high dpi screen and comes up looking microscopic. If anyone knows a single app fix for this I'd appreciate a comment. 

Kanga pocket transmatch - goes up to 12

To go with my fantastic QMX portable radio (now with SSB) I wanted a compact antenna tuner and so ordered the Kanga pocket transmatch. It's actually a Z-match with a Wheatstone bridge SWR indicator.

Documentation is pretty good although deviates slightly from the supplied board which now has a place for C3. This is a very compact device and the construction has its challenges.

I misunderstood the wiring of the pins from the variable capacitors on the first go but when it didn't tune I went back and read more closely. It wasn't hard to fix. What you get is a very compact tuner that sits nicely beside a QMX.

I'd love to see a single box housing a QMX and a tuner like this. And yes, it goes up to 12!

Z-matches can tune up a wide variety of bits of wire quite nicely and this one is very capable and easy to use with the QMX's tuning setting.

Tech Talk on ABC Radio - Internet outage due to Amazon

Flickr, snapchat, PlayStation and Amazon were among the businesses that suffered an outage due to a failure at Amazon Web Services in the US. 

What caused this major disruption, and what did all these popular services have in common? 

Windows 10 support has ended, what happens if I can't run Windows 11? Also, China's robot lead in manufacturing.

Peter Marks, mobile software developer and technology commentator from Access Informatics, joined Philip Clark and listeners to Nightlife with a comprehensive discussion. 

https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/105918668

USB C PD power for QRP radios

An idea mentioned to me by Ross, EX0AA. USB C Power Deliver (PD) lets the powered device ask for certain voltages and the power supply can adjust. It turns out you can buy cables or adapters with the PD negotiating chip in them so I purchased a USB C to 2.1mm plug. Mine is configured for 12V and seems to power my QMX very nicely.

There's no particularly noticible noise from the battery (which presumably has a buck converter) but I'm sure the noise floor is higher. One thing to watch is that not all battery packs are capable of 12V, my others only do 5V. The no-load voltage is very close to 12V. 

As well as cables there are adapters with a USB C socket on them.

 It would be great if the USB C socket on a QRP radio used PD to be at least optionally powered this way.

The powerbank I bought is the UGREEN 100W Power Bank 2000mAh. (I think the trick is to get one that can charge laptops and not just phones. The cable is described as "USB Type-C PD to 12V DC 5.5 * 2.1mm"

Pi PICO Debug demo

With the uncertain future of the Arduino platform I've decided to look more deeply into the Raspberry Pi PICO platform. I ordered a Raspberry Pi Debug Probe and it arrived today. It plugs into three pins on the end of the board and also to the serial port pins.

I had previously installed the official extension for Visual Studio Code.

By some magic it automatically found the board and the debug probe and "just works". The marvellous thing is that this lets me set breakpoints and single step through a program while inspecting variables. 

I had a bit of trouble the first time I added a variable which didn't show up in the Locals area. Turns out the compiler optimises out variables you don't actually use. Presumably this can be turned off but it's for the best. Anyhow, this is a very nice improvement over lots of print statements to figure out what's going on.

 The Pi Pico software development kit is extensive and well documented. 

FreeDV Sunday net - very poor conditions

There is a G1 Geomagnetic storm at the moment and local contacts were very difficult on 40m. We started the net there and I had contacts with VK2BLQ and VK5KVA. Later we QSYd to 80m and was able to talk with some local stations. All up 11 stations were at least seen.

VK3KEZ, VK5APR, VK3UBK, VK2BLQ, VK5KVA, VK5LN, VK3SRC, VK6KR, VK3PCC and VK3CKY.

Thanks everyone for joining in and hopefully conditions will improve in the near future.

73 VK3TPM

QRP AM transmitter from AliExpress

A low power AM transmitter kit from AliExpress caught my interest. It was AU$30 and is crystal locked to 21MHz.

The board is good quality and went together easily.

Component values are marked on the board, which is handy because the supplied documentation is a bit different to the actual board. One ceramic capacitor and 4x 47uF electrolytic capacitors were missing but easily found in the junk box (although rather bigger than the space on the boar). There was a handful of extra small value components along for the ride.

It does work but sounds a bit rough.

Tuning the two metal tin inductor slugs increased RF voltage significantly. Fed into a non-resonant dipole and it gets out very well. This recording is at about 100m away.

 

An excellent end fed unun from bh7jyr

It's been very windy here and I worry that my main dipole for 40m might come down so as a backup I recently purchased a 1:64 unun for an end fed antenna from AliExpress for AU$27. (The price varies a bit). I'm very happy with the quality and performance of it and can recommend this one.

Externally it's very solid and seems to be quite weatherproof and easy to hang.

From the seller's page, the internal construction seems good too.

I have it hanging on the wall of the shack with a thin wire running up in to a near by tree. This wire is very hard to see and would suit stations who wish to not attract attention.

Adjusting the length of the wire got it on to 40m very nicely.

Or via nanovna saver:

So SWR of 1.07 on 7.140Mhz looks very nice. Under 1.5 across the band. On air reports have been good. I haven't tried sustained 100W but I can believe SSB could be ok given the size. This design is described in various places and could easily be home built.

FreeDV Net - good rollup, terrible conditions

14 stations were tuned in but few of us could hear each other. I'm in VK3 and could only talk with VK2 and VK5 so, like last week, no local propagation. VK2KNC, VK5KVA, VK3CKY, VK3GTP, VK3KEZ, VK3KR, VK3PCC, VK3SRC, VK3UBK, VK6KR, VK3AG, VK3IK, and VK2BLQ. 

Running WSPR clearly shows the lack of local propagation:

As suggested by Joe, VK3SRC, I'll keep an eye on conditions through the day. Perhaps there's a better time for the net?

Tech Talk on ABC Radio - Has social media peaked?

Have we passed peak social media? Facebook would be the biggest platform amongst the 55+ crowd. Are you still on it, using it frequently? Or have you gotten over it? 

Also, your home security is getting smarter, but what does it mean for privacy? 

Peter Marks, mobile software developer and technology commentator from Access Informatics, joined Philip Clark and listeners to Nightlife with a comprehensive discussion.

https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/105863852

I'm pretty happy with my audio these days. My objective is to sound as if I'm in the studio with Philip when in fact I'm in country Victoria connected via Starlink. My mic is a Sure SM7B and I'm using a Rodecaster Duo with the Aphex effects set to the Natural preset. It nicely gets rid of my popping, de-esses, does some compression and a few other magic things that makes my voice sound better than it is.

Blog traffic up - or is it AI training?

There have been reports in recent months that web site traffic decreasing presumably because people are either using LLMs to answer their questions of Google is giving the answer without the reader needing to click through. This is a problem for sites that earn money through ads or other visitor based streams.

Recently I've noticed my traffic increasing and was pleased this morning to see that my all time page views has just exceeded 3 Million.

I doubt that the site is really getting more "organic" viewers so my theory is that this traffic is lots of AI Large Language Models training on blog posts. Bill at the great Soldersmoke blog notes a similar increase. 

Another annoying trend is comment spam. Random comments on posts from any time with something nice and a link to a business. Often these are car repair, skip bins or small builders. My theory is that someone has been hired to do Search Engine Optimisation (SEO) by generating links to the business on web sites around the place to increase the ranking. They look like this:

I click the "mark as spam" every time but it doesn't seem to do anything. I wrote to several of the businesses, via their contact us form. One replied and didn't seem aware of what was being done in their name.

FreeDV net - good rollup, terrible conditions for local

This morning's South East Australian Sunday 10:30am FreeDV net on 7.177 had a good rollup of 15 stations, including several first timers, but conditions were such that local stations couldn't hear each other. On frequency were John VK2DUX, David VK2VJ, Barry VK3BRT, Graeme VK3GRK, Stephen VK3SPX, Joe VK3SRC, Tony VK3YV, Peter VK5APR, Jack VK5KVA, Michael VK5LN, Bob VK6POP, Dick VK7DIK, Rob VK3CQK, and Dave VK1KV.

AWA Forestphone - shack addition

I mentioned to Don, VK3BIG, that I've been hunting for an AWA Forestphone for some time. He kindly passed on his which has been put on to the 80m amateur band. It's a portable AM transceiver in a beautiful rugged enclosure. Built for the Forests Commission in Australia. Modulation isn't great but it's a lovely thing. Here I listen to it on the excellent Shepparton SDR.

And here's a real first contact with Richard, VK3LRJ:

From the Victorian Collections site:

"Historical information

In the mid 1960s, Amalgamated Wireless Australasia (AWA) was asked to design a solid-state replacement for the PYE TRP-1 in collaboration with the FCV. The new transceiver was to be more powerful than the TRP-1, with an output power of about 10-12W (compared to 1.5-2W).

The set also had to be capable of being used as a walkie-talkie, as well as being suitable for use in a vehicle

The FP-1 is a single channel radio that has a crystal for each channel, and an IF frequency of 45 5khz. The receive crystal is 455khz higher than the transmit crystal.

It is completely transistorised, and uses AWA and RCA brand transistors.

A later version was called the FP5 and had five channels."

From the RAN Technology site: 

"This short article about the AWA Forestphone was the last one put on the Midwest Classic Radio Net website by for former webmaster George K9GDT before he unfortunately became a Silent Key.  

MCRN article

Now that a longer version has been published in Electric Radio magazine I thought I'd include it here as well.

Throughout most of the 20th century AWA was Australia's leading electronics company, providing a wide range of radio, television, and audio equipment as well as broadcasting services. Over that time period the company partnered with other companies including RCA, Thorn, Rediffusion, and others to broaden it's product offerings. But as an Australian company, the Forestphone FP-1 no doubt was it's own creation, a small, easy-to-use, portable transceiver designed for use by forestry crews and similar commercial endeavors back when HF radio was the primary means of communication beyond line-of-sight. According to the seller, the FP-1 I recently acquired was "Originally built for the Forestry Commission in the state of Victoria, the last user of this rig was a gliding club, before gliders and balloonists were compelled to move to the VHF air band in the 1980s. They were also used by mobile bee-keepers, inland waterways craft such as houseboats and dredgers, and local government operators in the inland."

The FP-1 is all solid-state, a big plus for battery operation in the field, and being a mid-1960s design uses germanium transistors, including a pair of 2N301As as the modulator, a transisitor I remember scavenging from hybrid car radios as a young ham! The PA uses two 2N3879 transistors in a push-pull neutralized output stage which uses a toroidal inductor having 11 taps and a second inductor for antenna tuning/matching. Two output connectors are provided with a switch to select between taps that have been set for mobile (presumably close to a 50 ohm load) and as a loading coil for a portable whip. Unlike some similar sets, the FP-1 uses an external battery, which I see as a plus given how often battery leakage causes damage to portable radios. As the pics show, the interior of the FP-1 is very clean and quite interesting to look at, since many of the locally-sourced components look a bit different from the ones we're more accustomed to seeing. The frequency range is 2-5 Mhz

The receiver is a single-conversion superhet that requires a crystal 455Khz above the desired operating frequency and is very sensitive (Under 2µV). Fortunately for me, the radio came equipped with transmit and receive crystals for 3888 Khz, which the seller said was outside the AM allocation in Oz and thus he never was able to use the radio on the air. It took only a slight tweaking of the IF cans to peak it up 3Khz away, on 3885. For transmit, I merely substituted one of the inexpensive HC-49/U crystals from N4ESS, which did not oscillate to begin with. Fortunately again, the radio came with a complete technical manual where I saw that a 33pF cap had been placed in series with the crystal in the Colpitts oscillator, and which was reducing the feedback too much. Bypassing this cap brought the oscillator to life with full output of 12-15 watts with 13.8V supply, or a solid 10 watts from a 12 volt battery. Transmit current drain is as high as 3.8A but the receiver draws only 20ma in standby yet produces lots of audio. For this reason we plan to have the Forestphone "guarding 3885" during next year's Hamvention at Xenia, OH ? so calls on 3885 AM might just be heard!

I found little information about the FP-1 online but the pic shows one with the cover and canvas carry bag which I do not have, as show in photos here with permission of Ray Robinson who was more than a little surprised to see mine at the Dayton Hamvention!

Small AM (and later SSB) field radios like the Forestphone were the mainstay of the Forests Commission in Australia until the mid-70 when VHF took over. But HF still plays a role in remote regions of the world, and when used with a decent antenna, radios like this are still capable of communication over several hundred miles.

In the modern era when satellite communications are available virtually anywhere on earth, it is still fun to remember when HF radio was really the lifeline for anyone more than line-of-sight away from civilization and to recognize the trials and tribulations of that form of communications by restoring and using this equipment on the ham bands."

Here's a schematic kindly passed on to me by Dave VK3ASE.

FreeDV 2.0.2 release getting good reviews

FreeDV GUI 2.0.2 is out with a microphone AGC and level controls in the main window. This helps people to set their mic level. Reviews so far are good. I just had a contact with Joe, VK3SRC which I captured as an example of the audio quality.

Also of interest is the fading you can see on his signal which has virtually no impact on the decoded audio.

Arduino controlled Useless box

Recently I purchased a "useless box". You turn on a switch and an arm immedietly pops out and turns the switch back off again. It was a bit boring so I bought an L298N DC motor controller and use an Arduino Nano. The motor controller is an H bridge which can switch the polarity going to the motor. I didn't bother with the protection diodes and so far it hasn't died.

It's built on strip board.

Here's how it behaves with a random delay.

The code has to read the main switch and a limit switch which is closed when the arm is "home" inside the box. I implemented the logic as a little state machine. To get a random number on an Arduino for the delay, an unterminated A/D pin is read to provide the random seed.

Here's the final form boxed up. I power it from a USB power bank. Amazingly the Arduino is able to power the motor just fine.

I tried to vary the speed of the motor by driving it with pulse width modulation but this motor doesn't seem to vary with PWM.

My head hurt writing the code for the required logic until I rememberd the state machine. This is the way.

// Switch connections

const int kMainSwitch = 2;

const int kLimitSwitch = 4;

// Motor A connections

const int kIn1 = 8;

const int kIn2 = 7;

// switches are pulled LOW when on

int gMainSwitchValue = HIGH;

int gLimitSwitchValue = HIGH;

// on the first go, don't delay

int gFirstGo = true;

enum State {

eStopped,

eForward,

eBackward

};

enum State state = eStopped;

void setup() {

pinMode(LED_BUILTIN, OUTPUT);

// Set switch inputs

pinMode(kMainSwitch, INPUT_PULLUP);

pinMode(kLimitSwitch, INPUT_PULLUP);

// Set the motor control pins to outputs

pinMode(kIn1, OUTPUT);

pinMode(kIn2, OUTPUT);

// Turn off motors - Initial state

digitalWrite(kIn1, LOW);

digitalWrite(kIn2, LOW);

// read an unterminated analog pin for the random seed

randomSeed(analogRead(0));

}

void loop() {

gMainSwitchValue = digitalRead(kMainSwitch);

gLimitSwitchValue = digitalRead(kLimitSwitch);

switch(state) {

case eStopped:

stop();

if(gMainSwitchValue == LOW) {

state = eForward;

if(gFirstGo == true) {

gFirstGo = false;

} else {

delayRandom();

}

}

break;

case eForward:

forward();

if(gMainSwitchValue == HIGH) {

state = eBackward;

}

break;

case eBackward:

backward();

if(gLimitSwitchValue == LOW) {

state = eStopped;

}

break;

}

}

void delayRandom() {

int seconds = random(5);

delay(seconds * 1000);

}

void forward() {

digitalWrite(kIn1, HIGH);

// Tried slow motor with PWM but doesn't have much effect

//analogWrite(kIn1, 120); // 0 - 255 PWM

digitalWrite(kIn2, LOW);

}

void backward() {

digitalWrite(kIn1, LOW);

digitalWrite(kIn2, HIGH);

}

void stop() {

digitalWrite(kIn1, LOW);

digitalWrite(kIn2, LOW);

}

FreeDV Sunday net - 18 Stations

Another active FreeDV RADEV1 net in South Eastern Australia this morning on 7.177Mhz. Some stations were not in a position to transmit but I've counted them all. VK2DUX, VK3BRT, VK3CKY, VK3KQT, VK3SRC, VK4WGR, VK5KVA, VK5LN, VK6KR, VK6POP, VK3KEZ, VK2TLQ, VK5JSA, VK3JF, VK3YV (Portable!), ZL2TJM.

Improved my 40m dipole using a DJI Neo drone

I'm lucky to have lots of space and some nice tall trees. In the past I've raised antennas with a squid pole,  thrown weights and drones but my new drone, the DJI Neo has propeller guards which avoids the string getting tangled in the prop. Here I show how high I've got my 40m dipole.

Web GUI for the QRPLabs QMX

An interesting project spotted on the QRPLabs group by Paul DJ0CU/G4ADF. It's a pure web page app that connects to a QMX via USB and lets you control it. Also supported is audio streaming and it draws a little spectrum display. https://github.com/Sparks72/QMX-new-GUI Very clever! 

It uses serial from the web browser for control and captures the USB audio device.

Guest appearance on ABC Download This Show

The Australian Finance Industry Association has modelled AI's contribution to economic growth in the years ahead. It found that "scaling", or expanding, the use of AI could add up to $60 billion to GDP over the next decade. But who is actually going to benefit from this, and where are we getting these numbers from?

Also, we explain the blossoming $100 billion bromance between Nvidia and OpenAI, and how Gen Z elected their new PM via the gaming app Discord amidst a wave of protests.

Plus, the latest on the teen social media ban.

GUESTS: 

Mark Serrels, Editorial Director at CHOICE

Peter Marks, software developer at Access Informatics

This episode of Download This Show was made on Gadigal land.

Technical production by Craig Tilmouth and John Jacobs. 

Listen here: https://www.abc.net.au/listen/programs/downloadthisshow/ai-boosts-economy-nvidia-openai-investment-nepalese-election/105764962 

Notes on my weird audio. I was remote and they couldn't get the normal iPDTL audio stuff to work so we connected using FaceTime Audio. Additionally, I've started using a RODECaster Duo and I had enabled the Aphex effects including the "Aural Exciter". It certainly makes me sound more punchy and nicely suppresses my microphone popping but on listening back I think I'll dial it back in future.

Tech Talk on ABC Radio - Mobile Phones

Tech Stuff - With the Optus outage over the weekend leading to the deaths of multiple people, it showed the network and technology we now rely on to survive is not infallible. But how did we get to this point? Nightlife takes a look at the past, present and future of mobile phones and their place in our lives. 

Peter Marks, mobile software developer and technology commentator from Access Informatics joined Philip Clark and listeners to Nightlife with a comprehensive discussion. https://www.abc.net.au/listen/programs/nightlife/nightlife/105786510  

FreeDV Sunday net 10:30 eastern time 19 stations

Another well attended Sunday morning net. Seen were VK3AWA, VK3KEZ, VK3SRC, VK3YV, VK5KVA, VK3PCC, VK2KNC, VK6KR, VK3AMO, VK3BRT, VK3SPX, VK7DIK, VK5APR, VK4WGR, VK5IS, VK2TTL, VK2BLQ.

FreeDV reporter was experiencing some issues but I decided to work from a list in my log book which saved my bacon.

Thanks to all those who tuned in.

Peter, VK5APR, (a net regular) has sent the following useful links for new users:

FreeDV User Manual, which is very comprehensive

Ham friendly introduction to the concepts of RADE:

https://github.com/drowe67/radae/blob/main/doc/rade_intro_waveform.pdf accessed from https://freedv.org/davids-oct-2024-update-real-time-rade-bbfm/ 

Davids presentation to the AREG ( areg.org.au ), a local amateur radio club in Adelaide, March 2025 meeting:

https://youtu.be/LxjcAF7Vy0Y accessed from https://freedv.org/rade-ham-club-presentation/ on the FreeDV blog dated March 22, 2025

For the technically inclined:

https://arxiv.org/abs/2505.06671 accessed from https://freedv.org/david-july-2025-waspaa-paper-papr-rade-v2-snr-bbfm-otc-demo/

As always the main site is https://freedv.org/ and also keep an eye on the blog posts.

Enjoyed the Radio Old Timers Club lunch in Melbourne

Always a pleasure to attend these lunches. An efficient annual general meeting (I've joined the committee). Lovely to catch up with many old friends.

The multi-talented VK3YE was on tonight's ABC TV news

Watching the local TV news tonight and was pleasantly surprised to see a familiar face, home brew hero, Peter, VK3YE:

Seeing him described as "Bus Expert" leaves too much unsaid. Here's my touched-up version:

The story showed a chart of expendature on buses by each state with Victoria coming last.

I'm told that VK3YE was also active on 774kHz AM in the morning running very high power.

Great stuff Peter.

 

Morning walk in the Australian bush with a DJI Neo drone

Almost every morning I go for a walk in the state forest opposite my house. It's very peaceful. This week, I purchased a little drone for antenna hanging activities and it turns out to have a "follow" mode where it will fly along behind you recording video. 

Here's another walk, and a bit of a jog!

Later in the day I got my 40m dipole suspended higher in the trees. I tied flourescent bricklayer's string around the drone and flew it right over a near by tree and used it to pull a heavier rope over.

The Neo drone is better for this than my normal drone as the propellers have guards around them so the string doesn't get caught up when decending on the other side of the tree.

Installing FreeDV on Linux

In this video I walk through downloading, installing, running and doing the initial configuration of FreeDV on Linux. In this case I'm using Ubuntu 22.04 but it will be similar on derived distributions and I know it also works on Fedora based distributions.

FreeDV Sunday net - 19 stations

The biggest Sunday morning south east Australia FreeDV net so far this morning with 19 stations. Not everyone could transmit but I'm counting them anyway.

VK2DWG, VK2KNC, VK3AWA, VK3JF, VK3KR, VK3KEZ, VK3PCC, VK3SRC, VK3YV, VK1EJ, VK5LN, VK4BAP, VK5RM, ZL2TJM, VK2BLQ, VK3KVA, VK7DIK, VK3IK.

Great to talk with everyone and sorry I'm such a clutz at running the net. I need to figure out a better to run it than working through a changing list.

Installing FreeDV on macOS

To help newcomers I've made a video showing download, install and initial configuration of FreeDV on macOS.

My plan is to make a similar video for Linux but it would be wonderful if someone else could make the equivalent video for Windows users.

Tech Talk on ABC Radio

Atlassian is a hugely successful Australian software company that makes tools for software teams. Last week they surprised everyone by announcing the purchase of "The Browser Company" for almost one billion Australian dollars. 

Founders Mike Cannon-Brookes and Scott Farquhar financed the startup of Atlassian with $10,000 of credit card debt. Today, their market capitalisation is $45 billion US dollars. 

Peter Marks is a software developer and technology commentator from Access Informatics, joined Philip Clark on Nightlife to discuss the acquisition and other tech news. Listen here: https://www.abc.net.au/listen/programs/nightlife/tech-talk-with-peter-marks/105755424 

This morning, after the Apple announcements I had several requests for comment including ABC Radio Darwin. My bit starts at 1hour and 6 minutes here. Host Adam Steer is a bit of a skeptic and has nostalgia for his old Nokia tradie's phone.

FreeDV Sunday net - 14 stations

The weekly FreeDV net on 40m in South Eastern Australia was excellent this morning despite wet weather here. Mark, VK5QI had planned a balloon launch that had to be delayed for the same reason.

7177 was busy so we moved to 7197 which caused a bit of confusion for a few minutes.

Stations on the frequency included VK2ATW, VK2TTL, VK3AWA, VK3BRT, VK3KEZ, VK3SRC, VK3YV, VK5GY, VK3KVA, VK5LN, VK5QI, VK5RM and ZL2TJM just listening but said "hi".

Thanks everyone for participating.

Is high octane fuel worth it in a Toyota Corolla Hybrid?

I was wondering if high octane petrol was worth the extra price. I asked two car oriented friends recently and they both said “absolutely - wouldn’t not use it”. Another friend said it has no effect except on high compression engines which modern cars are not.

Anyhow, I’ve been doing an experiment. I let my Toyota hybrid run very low on fuel and filled it with 98.

Here's what I see after a tank of Unleaded 91 fuel:

Here's what I'm seeing after a fair amount of a Premium 98 tank:

Normally I get 4.3 l/100 km. On high octane I’m getting 4.1 l/100 km. So it seems to make a small difference but not enough to justify an extra 20c per litre.

Here is where I fill up locally:

As is normal for a headline that is a question, the answer is no.

FreeDV with VK3SRC and VK3CKY

Just a little off air recording of some local stations talking with FreeDV RADEV1.

Joe VK3SRC asked about those "wings" (as he called them) on either side of the main carriers. He hypothosised that they were extra error correction signals. In fact they are an unwanted side-effect of the current RADEV1 code that will be removed in a future version.

To test this he used filtering in his transmitter to nicely remove them. You can see a "normal" signal at the bottom and his frequency limited signal above:

The resulting signal was perfectly decoded and has less wasted transmitter power.

Tech Talk on ABC Radio

Google has shown their new Pixel 10 phones ahead of Apple's expected launch of their next iPhones in two weeks. What are the big new features? 

Also, the buzz surrounding the launch of OpenAI's ChatGPT5 did it live up to the hype? 

Peter Marks, software developer and technology commentator from Access Informatics, joined Philip Clark on Nightlife to discuss the latest news in technology.  

https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/105700240 

FreeDV RADEV1 compared to Sideband at reducing power levels

Jack VK5KVA kindly tested analog single sideband against FreeDV RADEV1 at a series of reducing power levels. We are 560km apart and this was recorded in the middle of the day on 40m. You'll hear how much easier digital voice can be to listen to compared with analog radio.

I think we could go to even lower power levels and still have a good conversation on FreeDV RADEV1.

FreeDV Sunday morning net - 14 stations

An entertaining FreeDV net here in south eastern Australia this morning. I had, unfortunately, changed my microphone from a desktop with a preamp to a cheap headset and got universal feedback that I sounded much worse. In the end I unplugged the headset and just used the microphone in the monitor and it was reported to be vastly superior!

Amazingly there were two stations running QMX QRP radios. They seem to work amazingly well transmitting (and presumably receiving) FreeDV. 

Stations seen on air (not all transmitted) were VK5KVA Jack, VK3YV Tony, VK3BRT Barry, VK3KR David, VK3KEZ Bryan, VK3GTP, VK3AWA Daryl, VK5LN Michael, VK4APF Robert, VK6KR, VK2XOR Max, and VK5VC.

Note that I'll be away next Sunday so Jack VK5KVA has kindly offered to be net controller.

Later today, lots of activity in Australia:

The Power of Shortwave Radio. And, What Gets Lost with Voice of America?

A terrific edition of the "On the Media" program from WNYC Studios about shortwave radio and what we've lost, not just from the cuts to the Voice of America but also, of course, previous cuts to Radio Australia.

https://www.wnycstudios.org/podcasts/otm/articles/the-power-of-shortwave-radio-and-what-gets-lost-with-voice-of-america

A chat about FreeDV with Ben from Amateur Radio Channel

Last week I had a chat with Ben, VK3TBS, from the popular Amateur Radio Channel YouTube channel. He's put what I said together with some illustrations of the use of the FreeDV app.

My thanks to Ben for all his work in putting this together.

FreeDV Sunday morning Australian net - 15 stations!

A record rollup for the Sunday morning net in eastern Australia this morning with 15 stations.

VK3PCC, VK5KVA, VK5RM, VK2DWG, VK2HJW, VK2DWG, ZL2TJM (rx only), VK5LN, VK3BRT, VK2JXB, VK3KR, VK3RV, VK3YY, VK5QI (the famous Mark Jessop!).

Really great to talk with everyone.

The net begins each Sunday morning at 10:30 eastern time and Jack, VK3KVA hosts an evening net from 20:30.

Some people have used FreeDV in the past and are experiencing the sonic goodness of the new RADEV1 mode for the first time.

New shack Mac and first FreeDV contact with ZL2TJM

Just brought an unused old Intel iMac up from Melbourne. These feel very slow compared to the current M series CPU Macs but they do have a beautiful screen and it seems a pity to sell for just a few hundred dollars.

Anyhow, plugged it in, installed FreeDV and immediately heard a New Zealand station, ZL2TJM making his very first FreeDV transmission. I asked Rob what prompted him to try FreeDV and here is his reply:

Sounding pretty good on 40m from across the ditch from New Zealand. "You won't believe how good eighty meters is on FreeDV".

Upgraded to macOS Sequoia 15.6 by installing OpenCore Legacy Patcher

The iMac is 11 years old and was stuck on macOS Big Sur 11.7.10. While everything worked OK some software for the old OS is no longer being updated including the Chrome browser and, of course, tools like Xcode.

There is a thing called OpenCore Legacy Patcher that will take a macOS installer, modify it so it will install on the unsupported hardware and add the drivers needed to support the older hardware.

It's not for the faint of heart but after a few hours I got through the process and now have the configuration you see in the About this mac window shown on the right.

One, pretty major, problem I encountered is that it recommended Sequoia 15.7 but when it booted the software couldn't find the drivers and not much was working. It didn't draw the desktop properly and there was no dock.

A bit of searching and I found that one should go back a version to 15.6. I tried downgrading over the working system but that failed so I ended up doing a clean install of 15.6 which is now working very well.

A few small things don't work - I think. One is Watch unlock but that's a bit flakey in normal use. Overall I feel like this machine is getting a second life. It's a wonderful 5K screen and as you can hear from the FreeDV audio above, the speakers are very good.

An 11 year old computer being this good strikes me as excellent value. Congratulations to the good folks behind OpenCore. Make sure you back up your data before attempting this (I did).

Tech Talk on ABC Radio

Some GPs are using artificial intelligence to record patient consultations. Just how safe is our personal data?

Also, Google is running an attack ad against Apple in the lead up to both companies announcing their next phones.

Peter Marks, software developer and technology commentator from Access Informatics, joined Philip Clark on Nightlife to discuss the latest news in technology.

https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/105644976

FreeDV Sunday morning net - 8 stations

We had a good Sunday morning 40m net here in Australia with VK3BRT, VK5KVA, VK2DWG, VK2ATW, VK2BQL, VK5LN and VK7MB.

Two of the stations were first time users of FreeDV. A few problems with audio devices and mic levels but sorted in the end.

There is also a Sunday evening Australia net too starting at 8:30pm eastern time run by VK5KVA.

Getting a zBitx on Wifi without USB OTG

Just bought a zBitx radio from HFSignals. The attraction is for portable use on digital modes without needing a computer as it has a Raspberry Pi built right in.

Mine arrived, unfortunately, without the microUSB OTG adapter. I've ordered one but thought I'd try to get it connected to Wifi without needing an external screen, keyboard, and mouse.

Following the disassembly instructions (which are excellent) I removed the battery compartment.

The micro SD card is visible and you'll need tweezers or pliers to pull it out (it's not a push to eject style holder).

I plugged the card into a mac and opened the boot directory. The trick is to create a text file called wpa_supplicant.conf in the following format:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev

update_config=1

country=<YOUR_TWO_LETTER_COUNTRY_CODE>

network={

    ssid="<YOUR_NETWORK_NAME>"

    psk="<YOUR_NETWORK_PASSWORD>"

    key_mgmt=WPA-PSK

}

Also, a file simply named "ssh" should be created to enable ssh. (I did this as a matter of course and am not sure if it was required).

After putting the SD card back and powering up, the device, named "sbitx" appeared on my network. I was able to ssh in as pi@sbitx.local:

The default password is hf12345

Once on the network the zbitx was able to synchronise its clock so FT8 works.

The web interface at http://sbitx.local is quite impressive. It streams audio to the browser so can be used remotely. Default password is 123

I really like that it runs on 2x18650 batteries attached to the side. I wish other QRP radios could work like this.

The radio has both a Pi Pico and a Raspberry Pi. The source code is here.

VNC was enabled by using the ssh terminal and we get the following view:

This is the most network connected radio I've ever experienced.

I am impressed by the quality assurance card that came with the radio. Great stuff!

One thing that I found disturbing is that I searched high and low for the off button. Being a linux computer I have a strong feeling about just yanking out the power chord but that seems to be the recommended approach.

FreeDV Sunday Morning Australian net - 10 stations

We've just had the FreeDV Sunday morning net (starts at 10:30am eastern time) and 10 stations were at least seen.

We had VK3TPM, VK3RV, VK5KVA, VK2BLQ, VK3LRJ, VK2GTS, VK5APR, VK3KR, VK7DBX and VK2XOR.

Some stations were receive only and I think some are still getting audio issues sorted out.

It was great to welcome David VK3KR who was using FreeDV for the first time running 5W on a QMX.

Richard, 3LRJ, and I were running an early build of 2.0.2 which includes a handy mic gain slider in the main window.

Tech talk on ABC Radio

Could the iPhone end up looking a lot different from what it does now? By September, it could feature a larger screen, upgraded selfie camera, and possibly a thinner design.

Also, Australia will require age verification for social media by the end of this year.

Peter Marks, software developer and technology commentator from Access Informatics, joined Philip Clark on Nightlife to discuss the latest news in technology.

https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/105587888

Quick Wordpress testing using Docker on Linux

Recently I've been investigating how to migrate from Google Blogger to Wordpress. The best solution for me so far is by using Google's takeout to get a feed.atom file and use a python script to copy over posts, comments and images.

Along the way, I needed to run Wordpress and my normal approach to this was to install Ubuntu Linux and manually set up mysql, nginx, php, and wordpress. This gets tedious. I've played with docker in the past but was very pleased to find that there is an official wordpress compose.yaml and this makes it very quick to get up and running. (Ubuntu 24.04.2 LTS)

curl -fsSL https://get.docker.com -o get-docker.sh 

sudo sh get-docker.sh 

sudo usermod -aG docker $USER

# log out and back in then test

docker run hello-world

docker info

mkdir wp-docker

cd wp-docker

# save the compose.yaml file

# from https://hub.docker.com/_/wordpress

docker compose up

Then visit the machine's web port 8080 like http://latitude.local:8080/ 

The first time you get this:

The two docker containers, one for mysql, the other for the apache web server, already know how to talk to each other. After just a little config we have Wordpress:

The terminal that you did the 'docker compose up' in can be gracefully shut down with Control-C.

To wipe it all, so you can start fresh or get some space back:

docker compose down --volumes

Note that docker is extremely efficient and takes much fewer resources than running a full vitual machine.

macOS?

It's even easier and nicer on macOS. Install OrbStack which provides VMs and Docker and is free for personal use. I'm on Apple Silicon and it all "just works". The UI has a link to click to go to it in the browser.

Amazing.