Monday, November 23, 2020

WSPR Watch updates - now running on Apple Silicon

With the dawn of Apple Silicon, it's now possible to run the iOS version of WSPR Watch directly on a Mac. It works very well and looks pretty much the same as the macOS version I made with Catalyst. Here's the two side by side:

The native iOS version is the one on the left. For now, I'm leaving the Catalyst version in the App Store for people who haven't moved to Apple Silicon yet.

There have been a few bug fix releases recently. One issue was that the map stopped working on macOS Catalina, not because of something I did but because of a change in Xcode. If your map isn't showing, grab the latest version.

Sunday, November 22, 2020

Some examples of recent spam or phishing SMS messages

 Seems legit?

That's over a few months. Clearly my name and phone number is on a list somewhere.

MacBook Air M1 - great but not all plain sailing so far

As a developer, I wanted to make sure that my software runs well on the new Apple Silicon so I ordered a MacBook Air with the M1 chip as soon as they were announced.

Overall, I'm extremely happy with the battery life and performance of Apple's CPUs, but as an early adopter of both the new Big Sur operating system and the new hardware, I have run in to a few issues which I want to share.

Migration Assistant

Out of the box I tried to use migration assistant to copy over the configuration from my existing MacBook Pro. Because my existing Mac is on macOS 11.0.1 and the new machine came with the slightly older macOS 11.0, Migration Assistant said it couldn't migrate until the machine was updated. Consequently I had to complete a clean setup and do the upgrade.

Upgrade stalled

The software upgrade from 11.0 to 11.0.1 stalled about three quarters of the way through the progress bar. I left it for several hours with the mouse pointing at the progress but there was no movement. I had to long press the TouchID power button to force a reboot. On restart it seemed to finish ok but I'm a little concerned that some part of the install might not have been completed.

I fared better than some who ended up with an un-bootable machine. Apple has a support note on how to recover from this situation by making a bootable recovery disk on another machine.

External Samsung T5 SSD problems

A Samsung T5 SSD which works perfectly on other machines fails to mount or work reliably on the Air M1. I'm not alone in finding this. Heavier USB-C cables seem to help and upgrading the drive's firmware has improved, but not totally fixed the issue.

The Samsung software is terrible by the way. There is a theory that the M1 Macs are not providing enough power for some external drives but older, larger, drives are working for me so I'm not convinced that's the root cause.

Good things

The initial tasks to be done on a fresh macOS install sometimes bring a machine to its knees for a day or two. Spotlight indexing, iCloud syncing, photo analysis and (in my case), installing Xcode, are all heavy tasks. The M1 Air handled all this and stayed cool while sipping battery.

The keyboard is a big improvement over the one in my current MacBook Pro which has one of the much maligned low profile keyboards.

TouchID on a Mac is a new experience for me and is wonderful. I wish they'd do FaceID.

This MacBook Air is Apple's entry level machine and it out performs most of the current Intel based range. 24 hours in, the 8 CPU cores are mostly idle.

I can't wait to see what they do with the higher end machines.

Wednesday, November 18, 2020

After getting to 20 days of zero COVID cases, a van trip

We moved to Victoria (Australia) just as COVID was ramping up and this state has had quite a strict and lengthy lockdown which has worked. After being limited to travel within just 5km of home, that was lifted to 25km and now the state is open. I took up a kind offer from old friend Richard who has recently purchased a property in Drummond. Naturally, being a considerate guest, I slept in the van.

The van has been parked under cover for some time and a few days ago I discovered that, despite taking it for a weekly drive, the deep cycle "house" battery was very flat. It was showing 3V and at that low voltage the relay which connects it to the alternator had, correctly, declined to do that. I should have noticed.

Something must have been draining the battery slowly even though everything was off. Happily after a slow charge it doesn't seem to be too damaged.

It was sunny both days and the battery quickly charged and was able to run the fridge over night without any trouble.

I have read that connecting the house battery suddenly to the car's alternator isn't as gentle on it as being charged from solar through a charge controller so for now I'm parking it in a sunny spot and have disconnected the alternator relay.

Speaking of solar.. Richard's place is completely off grid and has an impressive solar system built over many years back to a time when panels were so expensive that it made sense to have them steered to follow the sun.

The house is wired for 48V, although it's hard to find lights for this voltage. There is an inverter to provide 240V AC as well. The fridge is gas though.

We hung out a dipole for 40m and had a tune around. Very low noise location, just the ticking of my charge controller. We heard VK7, VK4 and a bit of VK2. 

Thursday, November 05, 2020

Antenna noise canceller working well against bad switching supply noise on 40m.

HF noise is an increasing problem that plagues hams in the suburbs. Switching power supplies, solar inverters and plasma TVs are all culprits.

Here I'm plagued by occasional bad interference on 40m (but really all over HF) that I think comes from a switch mode power supply used by a neighbour. I've just built the antenna noise canceller by Terry, VK5TM and it seems to work very well.

Noise cancellers work by taking a sample of the noise, inverting the phase, matching the level with the signal and mixing them - thus cancelling the noise but leaving the signal. Here's another example where I switch it in and out:

Here's the part of the circuit that controls the phase of the noise signal that is then amplified and mixed with the main antenna signal:

I bought the board and kit of parts (AU$55) and it is a very professional package. The parts are well presented and I found none missing.

The board is excellent quality.

The kit went together smoothly following Terry's instructions. The only fault was mine, when powered up the relays didn't click even though the transmit LED came on - I had missed a solder joint on one of the coils.

I purchased a metal box from Jaycar, part HB5442, 120x61x102mm and the project fits well with plenty of room for wiring.

To effectively cancel noise you need a sense antenna that picks up the noise but not the signal. In my case I'm using a 20m dipole on the fence line as the sense antenna and an end fed for 40m for the signal. I think that having a sense antenna that doesn't pick up the band I'm wanting to receive might be a reason why it's working so well for me.

In my case the noise level on the sense antenna is very high and I have to set the gain control almost at the bottom of the range. I might try installing a smaller sense antenna on the fence specifically to pick up the neighbour's interference. The two phase controls are quite sharp and together can be used to null the noise very well. Signal strength is reduced but can be boosted with a pre-amp, the main thing is that the signal to noise ratio is greatly improved.

I was tempted to buy the MFJ-1026 for US$239.95 + shipping, but Terry's kit works well and if you can do a little soldering I recommend it.

Note that antenna noise cancellers do not work in all conditions. The best scenario is where there is a single source of noise that can be picked up close to the source. I understand that broadband noise may not be able to be cancelled but in my case the broadband noise I see between the switching supply bands are cancelled nicely.

Update: I'm having doubts

I've been playing with noise antennas and I'm starting to doubt that this is working properly. I think I get some noise cancellation but it's only when the main antenna gain is fully reduced. Bear with me while I experiment further.

Update 2: All good

It's all about the noise sense antenna. Originally I used a 20m dipole but the noise level was extremely high. Next I tried a short vertical connected via a balun - that's when things got weird. Finally I've simply clipped a meter or so of wire to the centre of the coax and the controls on the noise canceller work as expected.

Noise is reduced by playing with gain and the two phase controls.

Monday, November 02, 2020

Soldering mat using silicon baking mat

In the new shack I've been soldering on a cutting mat but it turns out this is not a good surface as it quickly melts if a hot component is rested on it. I've now purchased a low cost silicon baking mat and this works well. It's a strangely sticky material and is quite thin but it does not complain about melted solder being placed directly on the surface.

This one was purchased from Amazon Australia and cost AU$8.95 (but I notice that the price seems to vary). There are purpose made soldering mats around but they cost at least double this.

Having used it a bit now, it works well but the slightly sticky surface makes it a bit hard to pick up small components and snipped wires.

Friday, October 23, 2020

Peter, VK3YE, presents to the Melbourne Electronics and Radio Club (MERC)

One positive of the current pandemic is that many people have become familiar with video conferencing. In lieu of the regular Friday club meetup on 146.700MHz, the club has started presenting guest speakers. This week it was a great pleasure to have home brew hero, QRP advocate and prolific author, Peter, VK3YE.

Peter talked about gear, including commercial, kits and home brew, antennas, and operating to get QRP contacts. It was a great presentation. Thanks to all who organised it, and thanks to Peter for his time.

Here's the video:

Monday, October 19, 2020

ABC and the Digital Revolution: what’s next?

The ABC has historically been flexible with the technologies it uses to transmit its content to consumers. Today’s technology landscape is changing faster than ever and the ABC must continue to straddle the old and the new if it is to remain available to contemporary as well as traditional audiences.

ABC Technology timeline

The rate of change to technologies affecting ABC broadcasting has accelerated over time. New technologies have not replaced older ones but added to the technical overhead of the organisation.

Changes in broadcast technology can be painful. Some people are left behind. Old technology is often expensive but effective and is missed by many when superceded. New technology can slash costs and create new opportunities but the landscape is crowded.

The ABC’s technology usage is as follows:

1930 - Today Analog medium wave AM Radio

1939 - 2017 Analog short wave AM Radio

1956 - 2013 Analog Television

1975 - Today Analog FM Radio

1985 - Today Geostationary Satellite (Aussat)

1997 - Today Audio internet streaming

2001 - Today Digital Television

2004 - Today Internet podcast audio

2008 - Today Internet catchup video

2009 - Today Digital Radio

The switching off of analog TV in 2013 disrupted some viewers but happily low cost set top boxes were available to enable their old TVs to pick up the new digital signals.

The ending of Australia’s short wave services in 2017 has made it impossible for Australian inland communities and the Asia Pacific nations to hear ABC broadcasts unless they are served by local relays or satellite services.

Analog FM remains, for now, but the clock is ticking.

The Analog AM broadcast band continues to be used, and arguably forms a backbone for communication in times of widespread disaster such as fire or extreme weather. But AM radio is falling from favour as it is increasingly interfered with by devices such as mobile phone chargers and soon electric cars. The US FCC is considering switching AM to a digital alternative.

DAB+ (Digital Audio Broadcast) is in the largest cities and is slowly being extended. Receivers are becoming standard in new cars.

Podcasts - recorded audio, distributed via internet file feeds that users subscribe to in applications that now come with all modern phones - have emerged as an important new form of media. Smart speakers provide a convenient new way to listen to these programs in the home.

Broadcaster Video On Demand (BOVD) - which the ABC was early to deliver through the iview service via apps, web and smart TVs or set top boxes - continues to grow. During the first half of 2019, BVOD recorded in excess of 20 billion streaming minutes (Live + VOD), up 52% on the same period the previous year

Linear TV is on a long slow decline and has already been abandoned by millennials. US figures from Nielson 2020 show “In percentage terms, the amount of time 18-34-year-olds as a whole spent watching traditional TV (live and time-shifted) in the first quarter of 2020 dropped by about 15.3% from the previous year.” At the other extreme, over 65s remain loyal linear TV viewers watching over six hours a day. Nonetheless, the writing is on the wall.

The fight for attention

Media that competed for our attention in the past was divided between newspapers, magazines, radio and television. Despite fears at the time of their introduction, each new technology did not kill the earlier modes. 

Today, however, attention is more divided than ever with social media capturing reading, podcasts capturing listening, and video on demand (Netflix etc) capturing viewers.

Highly tuned recommendation systems, tailored to each consumer, are designed to keep their attention and create a fear of missing out during breaks in consumption.

Emergency broadcasting

Australians turn to the ABC when there is a fire, storm, flood, heatwave or pandemic. During times of mass disruption, internet and mobile communications may be congested or down and power may be out for long periods. Low cost, widely available, medium wave battery AM radios can reliably pick up the ABC’s high power AM transmitters located in each state.

There is a high cost to the ABC to continue to provide this network of transmitters from its existing budget, but it is a valuable resource that should be maintained just as other emergency assets are kept intact. There is a case for additional funding for the ABC as part of Australia’s emergency preparedness.

The (near) future - internet from space

Internet access direct from low earth orbit satellites to anywhere on the Earth will be commercially available from Starlink by the end of this year in the US and Canada and “near global coverage” is expected by 2021. While pricing has not been announced, it is likely that the pizza-box-sized ground unit will cost around US$300 with service costing around US$80 a month.

Starlink has registered in Australia and received ACMA permits for four ground stations in remote Australia.

SpaceX Starlink is just one of several competing systems under construction, including OneWeb, Amazon, Samsung, Boeing and others. 

Early tests of the internet performance of Starlink show latency (response time) from 20ms, download speeds of 100Mbps and uploads of 40Mbps, matching NBN speeds in capital cities. 

While internet from satellites won’t currently work from hand held or even car based terminals, it will open up the entire Australian and neighbouring regional landscape to a reliable and fairly fast internet service that can be the backbone for broadcasting and not be affected by outages from disasters on the ground.

It is conceivable that eventually technology will evolve to connect mobile phones directly to low earth orbit satellites.

Being where the audience is

As always, the ABC needs to be where the audience is. 

As long as ABC programs are clearly branded and do not have advertising embedded or surrounding them (at least for Australian audiences), there is further potential for these programs to be made available on popular platforms:

  • Social media. Facebook, Twitter

  • Social video: YouTube, Instagram

  • Video: Netflix, Apple TV

  • Smart speakers: Google Home, Apple Siri, Amazon Alexa

  • Podcast apps

  • News aggregators: Apple, Google, Twitter

The future role of “linear” broadcast

Linear broadcasts, where there is a stream of programs scheduled by time, suit consumers who favour “appointment” viewing or listening.

Traditional radio and TV continue to be valued by older consumers, but it can also serve more widely as a “showcase” for programs available by direct streaming or download. 

Rather than filling TV hours with British police shows, samples of the best of the ABC’s productions could be shown with instructions on how to access full series through digital platforms. For example, the first episode of, for example, a drama, might be shown on the linear service with the remainder available via streaming (iview).


Custom applications, such as those for iOS, Android, TVs and future platforms are expensive to create and support but provide the smoothest, most responsive experience for users.

Apps tailored to a particular device are easy for the user to understand, and particularly convenient on mobile phones which are constantly carried by the consumer.

The current ABC app catalog includes:

  • ABC News

  • Iview

  • Listen

  • Kids

  • ME

  • Triple j

  • Triple j Unearthed

  • Kokoda VR

  • Vegie Guide

Building the bond with the audience

There is much to be learned (for both emulating and avoiding) from the techniques of social media and video platforms such as Netflix, TikTok and YouTube, which monitor each individual’s viewing and use the information to make further viewing recommendations. 

To better customise ABC content suggestions to users, we need them to be uniquely identified. ABC consumers must get value from logging in. ABC systems should identify what content keeps each users attention and suggest more that might be of interest. 

Users should be able to create anonymous accounts but still be recognised. Households should have personas so that different consumers sharing a device can identify themselves easily.

Tracking should be transparent and the history editable by the consumer. Recommendations should explain why they are being made.

Future options

The Internet is rapidly becoming the dominant carrier for all content, and innovations, and with the introduction of technologies such as 5G wireless and low earth orbit satellite it will be ubiquitous.

Very little of the ABC content needs to be live, aside from:

  • Breaking news and emergency coverage

  • Sport

  • Talk back

  • Parliament (as per the ABC Charter)

Most content is more conveniently consumed on-demand in the form of catch-up or podcast subscriptions.

Smartphone penetration in Australia is approaching 80% and these devices are ideal for consumption of audio and increasingly video.

Smart TV penetration in Australia is relatively low at about 12.1% but the use of set top boxes or dongles capable of showing Netflix and other video services is increasing rapidly and ABC content should be available on these platforms.

News and other primarily text content can be delivered through web pages or news apps. The news aggregation world is changing but having ABC content prominent on aggregators such as Google News and Apple News is an excellent way to reach that audience at low cost, provided appropriate branding and non-advertising agreements can be made.

Difficult decisions

The ABC makes high quality, much loved content. Choosing the platforms on which to distribute its output is going to be tough especially as, if the past tells us anything, options will continue to proliferate.

This is the digital dilemma - which technologies to focus on in the years ahead and when to let go of the past.

Note: This piece was written for the ABC Alumni and first published here.

Worth buying an iPhone 12 with no mmWave 5G?

A recent article by Dr Stanley Shanapinda published on The Conversation warned against purchasing iPhone 12 phones because they don't include mmWave 5G outside the US has triggered some controversy.

I respectfully disagree with what he's saying for a number of reasons:

  • mmWave spectrum hasn't been auctioned in Australia yet and won't be available probably until 2022.
  • 4G LTE in Australia is already very fast
  • Future 5G modems are likely to be more power efficient
  • mmWave is a very high frequency, around 26GHz, and is suitable for very small - line of sight - areas.
Modern phones often cover different frequency bands for different countries. I understand that iPhone 12s include the mmWave 5G bands in the US because there are some places there where 5G is only available on those bands.

Stanley and I were guests on ABC Sydney Radio program "Focus" hosted by the fabulous Cassie McCullagh. You can hear the interview here.