Wednesday, June 04, 2025

Tech Stuff on ABC Radio

Do you feel that AI is advancing faster than anything else you've seen in history? And the pace at which AI is developing is overwhelming? 

New analysis from Mary Meeker finds that we are in the AI boom. 

Also a look at the merger between OpenAI and ex-Apple head of design Jony Ive's io.

GUEST: Peter Marks, a software developer and technology commentator from Access Informatics.  Listen here.

Tuesday, June 03, 2025

Built the QMX kit - watch out for enamelled wire joints

Like many people I was very excited by QRP-Labs work to bring sideband to the excellent, compact, high performance, digital rig, the QMX. I ordered a built version and have been using it in the field.

My setup, in a small waterproof box is quite compact but I plan to put together a portable radio with a QMX, rechargeable battery and some sort of antenna tuner. For this project I ordered the kit version and have now completed construction. It's a dense six layer board. The surface mount components are all pre-soldered so most of the work is toroids and connectors.


The QMX has built-in diagnostics, including RF bandpass and low pass filters. After my build I could see some problems all of which were due to me not managing to solder to enamelled wire. At times, inspection under high magnification revealed a solder joint where the solder seems strongly repelled by the wire. After a bit of debugging the radio is working well.


On the bench I run it from 12.0V via a linear regulator (I built the 12 not 9V version). (My bench supply of 13.8V is too high. I get 5W out on 80m and about 4W on 40 and 20m. Performance as a WSPR transceiver is really excellent.

If you run in to trouble there's some great resources including Hans' troubleshooting guide which includes a faultfinding log of fixes he's needed. 

Also there is an active QRPlabs discussion group where people help each other.  I've enjoyed this kit very much and it's a really wonderful radio.

I've been running it receiving and transmitting WSPR almost continuously for about a week. Rock solid. Sometimes reception of my signal is amazing (when there aren't solar flares that kill the bands). Here's a single transmission on 40m reported by 94 stations:


It also receives exceptionally well.