New 3D printer: Bambu Labs A1 mini

For some years I've occasionally used a Creality Ender 3 printer. Worked fine and good value but when I dug it out recently during a visit from EX0AA the bed levelling drove me bonkers. Ross had recommended Bambu printers but I was a bit off them due to stories of their locked down platform. I checked the site and they had their lowest end model - A1 Mini - on sale for AU$329.

For that money it's an amazing piece of precision manufacturing. Automatic bed levelling is great but I was amazed to find that it has a camera built in so you can watch the print from your phone if desired. It takes a while to prepare itself but then prints much faster than my old Creality.

My first print is an end fed antenna winder for portable QRP operation. I design with TinkerCad but am trying to learn something a bit more sophisticated. Quite happy with the result.

There's more to learn and I'd like to be able to send print jobs to it without needing to be logged in to the internet site.

FreeDV net - excellent conditions

Ionospheric conditions were much better for local contacts this morning and we had 14 stations at least on frequency. Good reports including Stephen VK2BLQ in Sydney. VK3GTP, VK3CKY, VK3UBK, VK3BAL, EX0AA (portable VK), VK3PCC, VK2XOR, VK3SRC, VK2BLQ, VK3KEZ, VK5KVA and VK3YV. 

There were at least two others listening while visiting participating stations. One commented about how impressed they were with the audio quality. We had a storm front coming through but there was very little interference to the conversations.

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.