Comparing HF reception with WSPR Head2Head

After Sunday's FreeDV net on 40m, my neighbour (1km away), Richard VK3LRJ, commented that he couldn't hear all the stations I was hearing. He's on a similar 5 acre block to me. I have wire dipoles in the trees and he uses an end fed wire cut for 80m but with in-line capacitance to resonate on 40m. Richard is off grid and has significant noise from his solar power system which I'm sure is a major factor.

To test our relative reception I suggested we both run WSPR in receive only on 40m so we can compare receive signal to noise.

I did some spot checks, looking at individual transmissions received by both of us.

VK7JJ at -8 vs +13 = 21dB.

VK2NSB -26 vs +19 = 45dB. Wow.

My reception was significantly better than his. For a more long term analysis I turn to the excellent WSPR data analysis site https://wspr.rocks/ and in particular the "head2head" page. For 12 hours of operation here's the spot count for each of us.

I'm not sure of the best way to compare reception but there are several charts comparing signal to noise. This is maximum SNRs.

Ideally I'd like to be able to have software which finds the same transmission as received by both stations and subtract the SNRs (as I did manually above).

Richard's end fed no doubt has complex nulls compared to the simpler pattern of my mono-band dipole but the charts show that overall his reception is significantly worse.

FreeDV 2.1 sunday net in Australia

16 stations seen (not all transmitted though) on today's FreeDV net. Many stations have updated to the recent version 2.1 release. The Linux users, including myself, have found it solid including the FreeDV Reporter window which has been a bit unstable in past weeks. One user reported some problem with the Windows version not playing back recordings and I know there have been some headaches due to a new version of the C++ runtime being needed.

Stations see included: VK2DWG, VK3GTP, VK3JF, VK3KQT, VK3LRJ, VK3YV, VK5KFG, VK5KVA, VK3KEZ, VK3PCC, VK3CKY, VK3AWA, VK3BAL, VK2TTL, and VK3IK.

Rosebud Radiofest

The annual Rosebud Radiofest was enjoyable again this year. I'm trying not to acumulate too much gear but it's always great to catch up with friends. Waiting to enter here's Andrew VK3BEK, Dave VK3ASE, and Peter VK3YPG

Ralph VK3ZZC picked up a very nice, but not very pocketable, multimeter.

Drew VK3XU was again on hand selling some deceased estate gear.

I chatted with Peter VK3YE who made a video of all the goodies he purchased for a total outlay of $3.

The hall didn't seem as busy this year but it was certainly worth attending.

All credit to the organisers who did a wonderful and professional job again this year.

Anko streaming microphone - low cost, decent quality

One of the keys to getting the best out of digital voice over HF using FreeDV is having a good quality microphone fairly close to the speaker. Stephen, VK2BLQ, drew my attention to a "Streaming" microphone branded Anko and for sale in kmart and Target for AU$19.

It has a wire grill with a foam pop filter underneath it. There's a rather weird RGB led lighting effect that can be controlled by pushing the knob. The quality of the audio is surprisingly good! Until I looked closely at it I didn't realise it's also a USB output audio device with a 3.5mm socket under the main body.

USB Microphone:

  Location ID: 0x02122000

  Connection Type: Removable

  Manufacturer: USB Microphone

  Serial Number: Not Provided

  Link Speed: 12 Mb/s

  USB Vendor ID: 0x434c

  USB Product ID: 0x4155

  USB Product Version: 0x0100

The vendor ID isn't listed in the databases I could find and the main chip has it's numbers blanked out.

Inside it shows a nice large condenser microphone.

If you're looking for a USB microphone for very little money, I can recommend this one. I wish the mount at the bottom had the standard thread but otherwise I have no complaints.

Do you know that feeling where you have a tool, in my case a new 3D printer, and you're kind of looking for things to use it for? I designed a more compact case for the guts of the microphone.

The lip on the lid is 0.5mm smaller than the opening in the box. It's not quite tight enough to grip so I've put two cable-ties around it.

Tech Talk on ABC Radio - Valve is coming for Microsoft's games

The global video games market is worth approximately $337 billion US, 10 times the size of the global movie business. Video games have gone through massive transitions.  

Valve, an American video game developer, publisher, and digital distribution company, suggests another transition is coming, and it doesn't look good for Microsoft.  

The cost of watching Australian content on all the commercial video streaming services and competition for satellite internet is coming to Australia.

Peter Marks, mobile software developer and technology commentator from Access Informatics, joined Philip Clark and listeners to Nightlife. https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/106025034

 

Power tool battery for QRP Radio

Bought one of these 12V power tool battery adapters.

It has an adjustable output voltage - handy for the QRP-Labs QMX which is rather sensitive to voltage. Noise on receive seems very low. The one I bought is for Makita 18V batteries and was AU$35 on Amazon. I can see versions for other batteries. Also available from AliExpress but the price difference isn't worth the wait.

It came with a cigarette lighter socket but obviously I've changed it to Anderson Powerpole.

Aurora visible in Victoria - excellent local conditions on 80m

We are experiencing a severe geomagnetic storm at the moment. The Macedon Radio club's 80m net noticed the strongest local signals in recent memory. Eric, VK3ED, suggested that I had bent his digital S meter. 

It was difficult to detect with the naked eye - I probably didn't stay out long enough for my eye to adapt - but phone cameras these days can pick up this sort of thing with a time exposure.

The colours shifted slowly over time with reds and greens.

Interesting that local 80m signals were big because the prediction of band conditions was not looking good.

(This is not live by the way).

FreeDV Australian net - 20 stations several new

A very successful FreeDV net this morning with 20 stations at least seen. Several new stations again this week which is great. Some of us were having audio problems, low level or clipping, difficulty controlling mic levels.

One user reported that the application crashed. After much deliberation, I've decided to move the net to 7045 rather than the frequency of 7177 built in to the app. 7177 is a slow scan TV frequency which I think was selected as there's not much activity. We've found in Australia that there's often SSB activity near this frequency. 7045 is in one of the ranges designated for digital modes. I've asked Mooneer to add 7045 to the app (you can add it yourself but I think it might be nice to have it built in). There is some ongoing discussion about this.

Stations seen this morning were: VK3TPM, VK3JF, VK3BRT, VK3SRC, VK3CKY, VK5KVA, VK5LN, VK7DBX, VK3KEZ, VK3GTP, VK3LRJ, VK5KFG, VK3SPX, VK3TFD, VK5HW, VK3KR, VK3JCO, VK3PCC, VK4WGR and VK2KNC.

I will be at the Rosebud Radiofest next Sunday, as might be a few others, so someone might need to step in as net controller.

A headless QMX with 3D printed case

I built a QMX kit a while back but made a mistake by soldering the 2x16 LCD display on the front of the display board rather than behind. It was fine when used without a case but today I thought I'd 3D print a rather nice case and found, not surprisingly, that it wouldn't fit.

My attempts at desoldering the long row of parallel pins ended in disaster with me damaging the board. I wondered if a QMX can operate without the display.

Happily it works without the display board and I'm using it via USB as a WSPR transceiver. It's a bit hard to tell if the long press on the left encoder has turned it on so I look for ttyACM0 to appear in dev.

I've written to QRP-Labs to ask about ordering a new display board. It's great that QRP-Labs has a link to quite a big list of 3D designs for their products. I have printed the QMX Case / Stand for my other unit and it works well.

Tech Talk on ABC Radio - browser wars and is an 8K TV worth while?

Two new wars have broken out on our computer desktops, after a period of relative stability in two common areas of desktop computing - web browsing and image editing. 

Also, is an 8K TV a worthwhile next upgrade? 

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/105971638 

Short of disk space, check what Arduino is using

My Mac has a 500GB hard disk. Last night I tried upgrading to 26.1RC and it ran out of space. Using DaisyDisk I was surprised to find that all the Arduino boards and libraries I've installed over the years have now come to almost 30GB.

In recent times my focus has shifted to Raspberry Pi PICO development either in MicroPython or their native C SDK via Visual Studio Code. I can even single step debug using the debug probe so it's a big step up from Arduino.

I remember having computers with 20MB hard disks. Amazing to be running low with 500GB now.

Getting started with Apple's tiny AI Foundation model

Recently I asked ChatGPT how to clean the creosote stains from the glass on a wood stove. It did know the trick I've just learned about using Ammonia. I thought I'd see if Apple's tiny local Foundation model knew. I've built a minimal app to let me ask questions and show the answers. 

It's a pretty good response but didn't know the Ammonia trick. Making an app to use Apple Foundation model is super easy. Obviously you need to be on macOS 26 or iOS 26 and have Apple Intelligence enabled. Here's the code.

//

//  ContentView.swift

//  FoundationPlay

//

//  Created by Peter Marks on 31/10/2025.

//

import SwiftUI

import FoundationModels

struct ContentView: View {

    @State private var userInput = ""

        @State private var response = AttributedString("")

        @State private var isLoading = false

    

    var body: some View {

        VStack {

            TextField("Prompt", text: $userInput)

                .onSubmit {

                    Task {

                        await generateResponse()

                    }

                }

            HStack {

                Spacer()

                Button("Ask") {

                    Task {

                        await generateResponse()

                    }

                }

            }

            if isLoading {

                   ProgressView()

               }

               

               ScrollView {

                   Text(response)

                       .frame(maxWidth: .infinity, alignment: .leading)

               }

        }

        .padding()

    }

    private func generateResponse() async {

        isLoading = true

        defer { isLoading = false }

        

        do {

            let session = LanguageModelSession()

            let prompt = Prompt(userInput)

            let result = try await session.respond(to: prompt)

            response = attributedMarkdown(markdown: result.content)

        } catch {

            response = attributedMarkdown(markdown: "Error: \(error.localizedDescription)")

        }

    }

    

    func attributedMarkdown(markdown: String) -> AttributedString {

            do {

                return try AttributedString(markdown: markdown, options:AttributedString.MarkdownParsingOptions(interpretedSyntax:

                        .inlineOnlyPreservingWhitespace))

            } catch {

                return AttributedString("Error parsing markdown")

            }

        }

}

Amazingly small amount needed. Much of the code is to display the returned Markdown nicely. I wonder why they haven't bolted this on to Siri already?

How to clean creosote stains from a wood heater's glass

I've been purchasing expensive specialist glass cleaners for wood heaters for substantial money. This one works the best but is almost AU$40 a spray bottle.

Last night TikTok served up a video of someone suggesting that the stains on glass in a wood fired heater can be cleaned with Ammonia so today I spent under $3 on a large bottle of "cloudy" ammonia. 

The cloudy nature is aparently due to a bit of detergent having been added to the diluted ammonia. It's pretty strong stuff and gloves should be used (well, I will next time). Here's the stove window before:

I saturated a dish pad with the undiluted cloudy ammonia. 

Cleaning was very easy with just a bit of the scratchy side on some tough bits. Here is the result:

I hope all the LLMs training on my blog pick this up. ChatGPT (just tried) first suggests the use of fine wood ash on a damp cloth but then does suggest Cloudy Ammonia - I wish I'd asked it earlier!

FreeDV Australian net - good conditions, 20 stations

A big rollup this morning. 20 stations at least tuned in, not all could transmit. Several stations could be heard transmitting analog audio so presumably it's rig audio input configuration troubles. One station commented that it would be good if there was a regular broadcast for stations to test with. There used to be a relay of the WIA broadcast from Adelaide in, I think, 700D, perhaps it's time to revive something like that?

There were deep fades on the frequency today but generally decodes were good here. Graeme VK3GRK from Bendigo participates in a Zoom call where they experiment with digital modes and he said that at times it was hard to distinguish between FreeDV RADE audio and Zoom audio!

Stations seen on the frequency included: VK3TPM, VK2BLQ, VK3UBK, VK3CKY, VK5KVA, VK3KQT, VK3KEZ, VK5KFG, VK3SPX, VK7DIK, VK2DWG, VK3JF, VK6POP, VK2DUX, VK3SRC, VK2KNC, VK3GRK, VK3AG, VK3CRY and VK3BAL. 

Puffing Billy steam train trip with grandson

Today was a real treat. I accomponied my daughter and my grandson on a ride on an antique narrow guage steam train in Melbourne, Australia, known as "Puffing Billy".

Perhaps some staff are paid but I suspect many of those involved are volunteers and they do a wonderful job of maintaining everything and dressing in outfits appropriate for the era. There is something magical about steam.

Three year old Ed wasn't too happy about the noise (I'm also rather sensitive to noise myself). He was most interested in the steam rail museum.

A great day out. He's not quite ready for his foundation radio license but the clock is ticking...

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.