Wednesday, October 08, 2025

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.

Tuesday, October 07, 2025

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.

Sunday, October 05, 2025

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.



Saturday, October 04, 2025

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.

Tuesday, September 30, 2025

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);
}

Sunday, September 28, 2025

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.



Saturday, September 27, 2025

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.