tag:blogger.com,1999:blog-359018252024-03-19T08:57:19.431+10:00marxy's musing on technologyA bloke with too many hobbies.Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.comBlogger1329125tag:blogger.com,1999:blog-35901825.post-8568144237820967912024-03-15T15:55:00.000+10:002024-03-15T15:55:54.728+10:00Handy breakout board for Raspberry Pi PicoJust picked up a few of these breakout boards. I'm not sure that I like the screw terminals but it is handy having LEDs on each GPIO pin. I'm really getting in to the RP2040 and recently ordered some boards with USB-C connectors.MicroPython is great for most things, there is support for the Arduino runtime library and I can drop down to the native toolchain if required.Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-39233479798953036592024-03-10T11:50:00.006+10:002024-03-19T08:56:47.624+10:00A pleasant trip north via "The Dish"A friend had some boxes of yachting gear left in Melbourne and I kindly agreed to drive it up to him at Dorrigo NSW. Along the way I visited John, VK2ASU, Merv and Dallas, VK3EB. On the way back I dropped in a Parkes and took another look at the CSIRO Dish.It was a long drive in the Jimny and to avoid the high noise level I listened to podcasts in noise cancelling headphones.I stopped for Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-63685104377269934692024-02-26T12:32:00.007+10:002024-03-11T16:32:25.619+10:00Simple Arduino rotary tuning knob for SDRI like using SDR++ to remote control my AirSpy receiver but I was missing the tuning knob. SDR++ can be tuned with the mouse wheel but I find it a bit difficult.Using an Arduino UNO R4 Minima I've made a very simple Rotary encoder that sends left or right arrow keys to the computer. I can't get the interrupt driven encoder code to work so I'm just polling but it seems fine for me. Soon I'll Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-10942397357842180492024-02-25T16:01:00.000+10:002024-02-25T16:01:00.875+10:00Wyndham Amateur Radio Club radiofest a good showIt's only a few short weeks since the Ballarat hamfest but as I live pretty close it was a no-brainer to head over. There was an excellent turnout and the new venue, Rowsley Hall, wasn't really spacious enough for everyone to get in.Lots of interesting older gear to look at. I was tempted by the high voltage variable capacitors.In the end I came away with a 1994 edition of the ARRL Antenna Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-20661188273389881652024-02-23T06:55:00.004+10:002024-02-25T14:02:05.988+10:00New radio streaming iOS app - Sound SalvationThe name is inspired by a line from Elvis Costello's song "Radio Radio". I like to listen to radio in an earpiece when I wake during the night. Where I live there is no FM (or DAB+) and the house interferes with AM reception so I've been trying various radio streaming apps.The apps I've tried are often very annoying in one way or another. Some force ads on the listener - one even made me watch a Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-49844225516531625122024-02-15T06:48:00.001+10:002024-02-15T06:54:16.171+10:00Listening to shortwave on my 80m loop antennaRecently I strung 80m of wire up in a loop attached to trees. It's not as good as my dipole for transmitting but it makes an excellent receive antenna. I've got an AirSpy HF+ SDR running with SDR++ in server mode so I can tune from the house (which is separate from the shack). This is running over two Wifi links but as you'll see it's a pretty good experience.I'm currently reading Geoff Heriot's Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-39387100222119482802024-02-10T10:03:00.000+10:002024-02-10T10:03:46.998+10:00WSPR Watch 4.10 - fixed a long standing thread crashWSPR Watch, my iOS app for quickly looking at spots on WSPRnet, is 12 years old. During that time it has been updated as the software tools and frameworks have changed.First it was Objective C and UIKit. Next came the move to Swift. Version 4 was a move to SwiftUI.I've always used background threads for doing the time-consuming requests to the different data sources. Most recently I've been usingPeter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-7898966988483507402024-02-04T16:38:00.003+10:002024-02-04T16:38:37.776+10:00Enjoyed the Ballarat Radiofest 2024A few friends came from around the state including Shepparton, Bendigo and Melbourne. We stayed at a local motel and had a nice dinner and walk the night before to check on shortwave reception.It was a warm day but thankfully there was a very pleasant breeze to keep things comfortable. By opening time, 10am, the crowd was keen to get in to see the gear for sale.There were lots of older generationPeter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com2tag:blogger.com,1999:blog-35901825.post-21981469733772945282024-01-31T11:25:00.000+10:002024-01-31T11:25:01.548+10:00LiPo Battery box - a modest projectI have a 12.8V 12Ahr Lithium battery but I wanted to avoid a mess of wires when using it in the field so went looking for a box to house all the bits.Annoyingly hardware stores don't seem to list the internal dimensions of these boxes on their web sites but I found one at Bunnings for $35 that is perfect.Not much to this project. There's an in-line automotive fuse holder, I've fitted a 30A fuse Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-73204605274097036692024-01-26T15:19:00.006+10:002024-02-06T10:39:53.895+10:00Raspberry Pi Pico RF transmitSome great work by Jon Dawson on his 101 Things project "A collection of cool projects to make!". Jon clearly describes how he has built:SDR ReceiverSDR Transmitter, including SSB, AM & FMA Class E (and D) power amplifierMulti-effect Guitar unitSource code is shared on his Github repository. He has a video about the transmitter:I set up the native C++ build tools for the Raspberry Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-63522667566932673382024-01-24T14:28:00.003+10:002024-01-24T15:17:24.970+10:00Tried a raspberry pi pico WSPR transmitter with no external oscillatorSomeone mentioned that it's possible to generate RF with a Raspberry Pi PICO with no external oscillator. There is a library by Roman Piksaykin, called pico hf oscillator and it's used in a simple WSPR transmitter available here.To build this project you need the native C/C++ toolchain. There are good instructions around for getting this going on a Raspberry Pi, but I did run in to a few issues Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-12822503472536986052024-01-24T08:43:00.003+10:002024-01-24T08:43:28.536+10:00World Economic Forum lists AI as the second top riskThis week I discussed the World Economic Forum's risk report which lists AI as second only to climate change.You can listen here if you wish.I'll be back again next Tuesday evening for more tech talk.Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-77833650798091688662024-01-21T11:37:00.001+10:002024-01-21T11:37:12.621+10:00AI noise reduction on sideband radioDavid, VK3KR, drew this to my attention. There is amazing work being done to remove radio noise from sideband signals. Check out the demonstration on the RM-Noise Video page. RM-Noise only has a Windows client and does the work in the cloud. I look forward to the day when this is built in to HF radios.Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-73724510873962769372024-01-16T14:35:00.004+10:002024-01-16T14:35:49.187+10:00Powering a QRP radio for portable operations with a Powertech battery inverterI was looking around for a nice way to power a small radio when operating in the field. I have various batteries but nothing in a convenient box. A solution was right under my nose! I have a little (155Whr) Powertech rechargeable battery. It has USB outputs and a 240V "modified" sine wave inverter. This will run a Dometic fridge in the car during a trip to the supermarket to get frozen food.It Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-44484702380434511802024-01-13T16:00:00.006+10:002024-01-17T20:25:58.665+10:00Full wave loop for 80mFortunate to have space for this, I have put up a horizontal full wave loop for 80m. I cut 82m of wire, put up the loop and trimmed it down until it's resonant in the band. The resonance is quite sharp though.I initially used a 1:1 balun to feed the loop and it matches quite well.Now I can switch between the full size dipole for 80 and the full size loop for 80m.Noise, and signals are lower on Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com2tag:blogger.com,1999:blog-35901825.post-17111801694649160622024-01-11T16:17:00.003+10:002024-01-11T20:37:46.668+10:00Antenna performance makes more difference than anything elseLast night I joined the weekly Macedon Ranges Amateur Radio Club 80m net on 3685 for a chat with the group. I called in as usual and was acknowledged. Net controller Joe commented that my signal was a bit down but I was fully readable. After my first over I had a look and noticed that my transmitter was transmitting just 2% of the normal 100W as I'd been using it for WSPR earlier in the day!Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-38024891430793248602024-01-03T06:41:00.003+10:002024-01-03T06:41:51.377+10:00Talking Tech on ABC RadioI joined Lisa Pellegrino last night to wrap up the past year in technology and look at what I expect for the new year.Topics included:Twitter X train wreckWearable health sensorsCrypto's bad yearHome automation still a messUSB-C wonIt's amazing to me how much the radio audience interacts with the Nightlife program.My audio this week was via a Sennheiser USB mic. We used Zoom and I set the audio Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-91386057450386135242023-12-22T08:34:00.001+10:002023-12-22T08:34:40.220+10:00Olivia experimentsThere seems to be increasing interest in Olivia. It's a keyboard chat digital mode built in to Fldigi that gets through when signal to noise is poor. The Olivia Digital Mode website gives some useful information including suggested calling frequencies and sub-modes. Because Olivia can be decoded well in to the noise you can't always see the calling station on the waterfall so knowing where Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com1tag:blogger.com,1999:blog-35901825.post-18715238298793637722023-12-20T08:20:00.002+10:002023-12-20T08:20:40.254+10:00Talking Tech on ABC RadioThis week I was a guest on the national ABC radio program Nightlife with Philip Clark. My tech topics are:EU investigating Twitter under the Digital Services Act which could lead to a fine that is up to six percent of global turnoverApple moving to protect iPhone owners who have their phone and PIN stolen.Vodafone turned off their 3G network last week. Telstra and Optus will follow in 2024. What Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-12037560973067321092023-12-17T07:56:00.002+10:002023-12-17T07:56:25.976+10:00Join an Amateur Radio club to build a real social networkIt's now two years since I moved to country Victoria. One of the first things I did was find the local amateur radio club. For me it's the Macedon Ranges Amateur Radio Club.During this relatively short time I feel like I've made some significant new friends and I have no feeling of isolation which I imagine might affect people who've made a move like this.We had our annual Xmas meeting this week Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-85625467796211469142023-12-08T07:29:00.001+10:002023-12-08T07:29:24.640+10:00WSPRnet down with database errorUsers of my WSPR Watch app have been reporting problems over the last day. It looks like WSPRnet.org is down with a database error. "PDOException: SQLSTATE[HY000] [1040] Too many connections in lock_may_be_available (line 167 of /data/var/www/drupal-7.98/includes/lock.inc)."Unfortunately, my error handling code is looking for a connection error but is failing to pick this up and fails silently asPeter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-25154520429686548602023-12-06T06:38:00.002+10:002023-12-06T06:39:23.954+10:00Talking tech on ABC RadioAnother chat with Philip Clark last night on ABC Radio across Australia. If you like, you can listen here.I've purchased a new microphone, a Sennheiser Profile USB. Frequency response is mostly flat but it has a nice peak in the high frequency which I think makes it sound clear.Knobs on the front make it easy to set mic gain, headphone level and the mix between return audio and local foldback. Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-37707279910964274572023-12-05T08:02:00.003+10:002023-12-05T08:02:52.164+10:00Five acres and antenna blissAfter a life in dense suburban settings where HF reception is poor, I am enjoying the benefits of five acres in the bush. The radio shack is in a shed somewhat distant from the main house (which does generate a bit of HF noise). Happily there is a convenient dead tree next to the shed that I use to support my antennas. Other trees hold the ends of dipoles up.Getting lines up over these Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0tag:blogger.com,1999:blog-35901825.post-85630743278236503852023-11-22T11:13:00.002+10:002023-11-22T11:13:58.861+10:00Adapting Ozito battery for ham radio powerWe have quite a few low cost Ozito (Bunnings) battery powered tools around here even though I've been transitioning to Makita. The battery packs put out about 20V when fully charged which is too much for nominal 12V radios. I purchased a variable buck converter that can regulate this voltage down. To get power from an Ozito battery I butchered a spare single battery charger with pins like Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com2tag:blogger.com,1999:blog-35901825.post-44017574736705648032023-11-22T05:48:00.001+10:002023-11-22T05:48:34.364+10:00Talking tech on ABC RadioAfter contributing technology commentary for many years on ABC radio, I've had a break this year but now I'm back. This week I did a spot with Philip Clark on ABC local radio's Night Life program.You can stream it here.ABC Radio Sydney is turning 100 about now although NightLife is a national program.It looks like I'll be a regular contributor to the program presented by Philip Clark.Peter Markshttp://www.blogger.com/profile/13007012724570360389noreply@blogger.com0