Tech news spot on ABC Radio

Peter Marks, software developer and technology commentator from Access Informatics joined Dom Knight with all the latest in tech news. It's been 40 years since Microsoft Excel was developed, touchscreens are out and buttons are back! listen at: 

https://www.abc.net.au/listen/programs/nightlife/nightlife-technology-peter-marks/104564546

HF FM transmitter with Franklin oscillator

Recently I've been working on an AM transmitter for 40m. It occurred to me that FM should be much simpler to produce. I had ordered some varactor diodes recently and first tried to FM a crystal or ceramic resonator. I can't get much deviation and the audio did not sound good.

Then I remembered a post on Soldersmoke about a largely unknown but surprisingly stable oscillator called a Franklin oscillator. It has two transistors and has a very light load on the tuned circuit.  

Rather than the variable supply transistor I fitted a 5V three terminal regulator. Coupled to the tuned circuit is a varactor diode with an electrolytic capacitor through which line audio is inserted. There's a trim pot to set the DC to the diode.

Initial results are quite promising.

The brilliant Charlie Morris, ZL2CTM, has an excellent video on the Franklin oscillator.

Thanks Stephen, VK2BLQ, for the tip.

Tech news spot on ABC Radio

A new online safety code of practice to protect children online has been released by the Digital Industry Group for public consultation. The key principles of the codes is to protect and support children and provide all end users, including parents, with more control over what their children see, read and hear while protecting privacy. Nightlife Tech Guru Peter Marks, a software developer and technology commentator from Access Informatics, joined Philip Clark on Nightlife to discuss the latest news in technology. Listen here

3LO turns 100

The (now ABC) station called 3LO turned 100 last week. The ABC pulled out all the stops to put on a wonderful live broadcast followed by an ex-staff party in Melbourne. 

I've heard that everyone who was asked to perform was more than keen to be there. Aside from amazing musicians there were many notable celebrities in the crowd.

The first guest was no less than the Prime Minister, Anthony Albanese, who was wearing ABC Sox.

Some names that stood out for me included: Brian Nankervis, Colin Denovan, David Anderson, Deborah Cheetham Fraillon, Jacinta Allan, Jacinta Parsons, John Pesutto, Jon Faine, Mark Seymore - (hunters & collectors), Paul Higgins, Pete Smith, Peter Couchman, Raf Epstein, Red Symonds , Sarah Blasco, The Teskey Brothers, Tina Arena, TISM, Vicka & Linda Bull, and Virginia Trioli.

Danny Tran was there doing interviews for a TV news spot. Daniel Ziffer was sitting behind me. (I wanted to tell him how much I enjoyed his coverage of Sam Bankman-Fried's hair).

The show opened with the ABC news with the theme played live. Here are a few clips:

The Athenaeum Theatre was a wonderful venue for all this.

WIA historian Peter Wolfenden, VK3RV, kindly sent me this list of the first stations:

Warm thanks and congratulations to the team that put all this together. A memorable event.

As well as those of us who've worked at 3LO in the past, the current staff gathered for a photo:

John Amies wants to know why Peter Evans wasn't there.

Comms Connect Show in Melbourne

Today I joined some other amateur radio operators at the Comms Connect trade show at the Melbourne Exhibition Centre. Check in was efficient. Ralph VK3ZZC, Peter VK3YPG and Nigel VK3DZ were there too.

It was mostly pretty dry commercial stuff but Icom was there and even had some amateur equipment on display. Knowledgeable Craig Norris was there with all the Icom news.

Kenwood had a stand but there was no amateur gear, mostly DMR commercial stuff.

Telstra had some sort of life-saving drone idea but "it's going to have to be at least three times bigger than this" to be useful.

After the show we went for a very nice Yum Cha and then headed for one of Nigel's family bars "The Sherlock Holmes Inn".

Very nice. My thanks to Ralph for the bag of semi-conductors and happily I had a bag of NE602s for him.

On the train home I ran in to Ray VK3ACR, the world if full of Amateur Radio operators if you pay attention.

QRP Kits Easy Receiver

As a refreshment after all my recent home brew activity I built a nice little direct conversion receiver kit from QRP Kits aka "Pacific Antenna".

It's a classic NE602 + LM386 direct conversion receiver as described in Experimental Methods for RF Design. I've built these before. This version ads an RF bandpass filter to the front end and has an unbalanced audio chain to the LM386. It drives headphones just fine but is a little soft into my bench receiver.

Even though it only covers a small portion of the band - you move that portion with the trimmer capacitor - tuning is very sensitive and they do suggest that a multi-turn pot would be a good idea. I find it drifts a bit. Some of the supplied capacitors had very tiny and indistinct markings but the kit went together well and it worked on first power up.

Here it is receiving a parks operator:

The documentation is good and available on the web page. My kit arrived here in Melbourne, Australia, three weeks after ordering. Pretty good.

With a bit of board trimming I was able to fit the receiver into a low cost compact case.

"Socketry" this is called.

It seems more stable now that it's boxed up securely.

Tech news spot on ABC Radio.

I was a guest on ABC radio's "Nightlife" program talking about the amazing "audio overview" feature of Google's NotebookLM that generates a conversation about a topic you give notes on. 

Also Pig butchering scams are targeting Australians and are social media platforms really biased against conservative users? 

Listen here:

https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/104446916