The predicted rain held off this year and it was great conditions for the annual Wyong Amateur Radio field day.
As always the ARNSW Home Brew group had an excellent display of home built gear.
I cheated and showed how well I had installed a Bitx40 module in a plastic box. The best bit of my construction was the gutter guard speaker grill. Peter VK2EMU, John VK2ASU, Kevin VK2KB and others were often mobbed with enthusiastic crowds.
There was retro gear (if you don't count the 3D printed coil form):
A fascinating demo of the pulse width control of a servo motor as using in radio control planes.
Again this year I had the pleasure of assisting David Rowe on the FreeDV / codec2 exhibit.
We were kept busy with many enquiries and also people purchasing SM1000 units.
Congratulations to all involved in the field day this year, it was very smooth and seemed like a terrific turnout given the threatening weather. I can't wait until next year.
A friend I visited recently was having trouble with his computer which turned out to be an old tower machine running Windows XP connected to a CRT monitor. While he could do what he wanted to it was terribly slow and even powered itself off mysteriously at one point.
While the netbook era appears to have passed, I wondered if there was a modern alternative that would do the job without breaking the bank?
The cheapest modern laptop with Windows 10 was an HP Stream 11 R007 available at Harvey Norman for AU$238, showing as in stock. There was one on display in the store but I was told there were none actually for sale, would I consider something better?
Bait and switch perhaps? I resisted all the arguments from the sales person who was essentially suggesting spending at least hundreds of dollars more, and selected an HP Stream 11 Y009 they had for AU$248. On paper the specs seemed the same.
The sales person warned me that this was not a fast machine. I asked if it was "fit for purpose" and he said yes but he would make a note on the invoice that I had been warned.
Specifications
HP Stream 11-Y009TU
* 2GB RAM
* 32GB Flash storage
* 1366x768 display
* 1x USB2 port
* 1x USB3 port
* HDMI port
* Micro SD card slot
* Dual band Wifi
* Bluetooth
* Combined audio in/out jack
* Video camera & microphone
* Intel Celeron N3060 dual core 1.6GHz CPU
* Windows 10 Home
Appearance
Nice looking, solid construction, bright blue (there are other colours).
The keyboard is good and the display is fine for the price. The battery is built-in which I'm used to from Apple gear and I think this helps make the device seem more solid. The track pad seems very good and support two finger scrolling, tap to click and three finger gestures - unheard of a few years ago.
Initial setup
After power up and Wifi connect it was time to kick off the initial setup and Windows updates. This took a long time, it took about three hours until all was done and it's not due to a slow internet connection.
Along the way was an attempt to get me to register for McAfee anti-virus which I declined.
Cleaning up the "bloatware"
The 32GB flash disk is mostly filled with Windows and bundled software. I uninstalled: McAfee LiveSafe, Microsoft OneDrive, Dropbox, Skype Preview, WildTangent Games, Office 365, Get Office, HP ePrint, HP Support Assistant, HP Support Solutions Framework, Microsoft Solitare Collection, Microsoft Weather, HP Jumpstart (187MB), HP Jumpstart launch, HP Registration service, HP System Event utility, Mail, Calendar.
I installed: Google Chrome browser, Fldigi, WSJT-X.
The start menu had dozens of annoying things in it which I unpinned.
At this point there was 5.9GB free of 27.8GB storage. This seems small by modern standards but is actually a lot compared to my friend's XP computer.
I created a USB Recovery drive using a 32GB USB key, this took maybe an hour.
Even though McAfee was installed it turned out that Microsoft's Windows Defender was already installed so I let that scan the disk so it would stop complaining.
Chrome was set as the default browser - it's funny how Microsoft tries to talk you out of not using their Edge browser at that point and even later when you launch Chrome. This seems anti-competitive.
There was another Windows update and I got a warning that disk space was short. The Disk Cleanup utility was run and I clicked "Cleanup system files". This deleted 13.3GB of "previous Windows installations".
Is 32GB disk enough?
It was astonishing to get a low disk space warning after simply updating and removing lots of bundled software. 32GB should be enough and I've run Linux on 3GB disks in the past. Both Microsoft and HP are to blame for the bloatware that comes on these machines. At least there was only one third party anti-virus package, sometimes there are several, which slows down the machine as well as taking space.
Is 2GB RAM enough?
Machines in this class are like Chromebooks in that they are not suited to running multiple large programs together. You wouldn't run Photoshop and Office side by side. Now that the initial updates and indexing has finished I'm smoothly running Chrome, Explorer and the Atom text editor together and all is well.
The bad
Bundled bloatware needs to stop if Microsoft is to avoid losing out to Chromebooks or iOS. Initial update and messing around took a long time, don't expect to get started with real use on the same evening.
The processor is a bit slow sometimes and even Google Docs in Chrome was a bit sluggish initially.
Another USB port or two would be nice and I'm not sure about the combined headphone and mic socket - normal headphones work just fine though.
Some people might see the non-replaceable battery as a problem but I've rarely replaced a battery in a laptop - generally by the time the battery degrades it's no longer the main computer and relegated to some permanent task such as doing WSPR where it's plugged in all the time.
The good
Battery life seems excellent. After an hour's web browsing and text editing it's estimating 9 hours 38 minutes but I think 7 is closer to the truth with normal active use. Here's another probably inaccurate estimate:
The lower power processor helps battery life and I like the fact that there is no fan, which takes power and can be unreliable down the track.
Wifi seems excellent and I'm using my 5GHz network without any issues.
I really like the look of this laptop and the keyboard and trackpad are better than expected.
Ham radio applications
Fldigi, WSJT-X and SDR# all work well. SDR software typically taxes old CPUs and I wouldn't try running multiple programs while decoding SDR, but in normal use it seemed to keep up with the load.
The low res screen, just 768 lines, seems incredible to a macOS user but is typical in Windows land. It's annoying how shops don't tend to clearly display the screen resolution and you must dig into advanced display settings to find it. Some ham radio software, like the SDRuno for the SDRPlay would be difficult to run on this display but an external monitor would work well.
SDRUno works remarkably well under most circumstances, here's a video:
Provided that no other software is running, such as a web browser, and you don't zoom the spectrum in too far (no idea why that's a problem), it receives quite well and the user interface fits the screen.
I notice that WebSDR doesn't work very well, presumably not enough CPU to run the Javascript in real time, there's often repeating audio coming through.
Conclusion
A sub $250 laptop with long battery life and enough performance would be perfect for field use. I'm thinking of taking it out for QRP PSK operation and at this price it's not the end of the world if it gets a few bumps. Because of the solid state disk and fanless design it's probably pretty robust.
Screen brightness might be an issue in the field.
Prices do vary and I've seen these advertised at $299 or more. The box price at Harvey Norman is $328 so do shop around and get them to price match $248.
Update - runs better with Linux
Windows 2000 started to annoy me. It definitely got slower after a week and it kept trying to either sell me things or pop over the Chrome browser to tell me that their Edge browser was safer and faster than Chrome.
I find it hard to believe that the operating system is a sales platform, it should be a "platform" for running software.
A recovery USB key was created, so that I could go back to Windows later if I wish and Ubuntu 16.04 LTS installed easily. (To get to the boot options on the HP Stream: power off, then power on and immediately start tapping the ESC key). Installing from a USB3 key using the left hand USB3 port was really fast and soon I was up and running with 30GB free instead of 3GB.
Sound, Wifi, and the function keys for volume and brightness all worked without any tweaking. Bluetooth sort of works but not with my mouse for some reason. To get it to sleep when the lid is closed I had to uncomment a line in /etc/systemd/logind.conf
HandleLidSwitchDocked=suspend
Battery life is still excellent.
The trackpad is rather sensitive and I had to disable tap to click. Sometimes clicking with the trackpad button moves the pointer and on Ubuntu I end up opening the trash instead of clicking where I wanted. Two finger scrolling works nicely.
Here's CubicSDR receiving an FM broadcast transmission.
I recommend this low cost laptop and if you can get by without Windows then Ubuntu is a good option.
Bring your QRP gear and portable antennas to a meeting of the ARNSW Home brew group's first "QRP by the harbour" in Sydney. We'll be showing equipment and getting on air.
Date is Sunday, March 12, starting at 3pm.
Location: McIlwaine Park, Rhodes, NSW, Australia
It's a nice park with water, some shade, some trees, kids play equipment, parking and it's close to Rhodes station and the M41 bus. As an added bonus, this is a "sacred site" having been the location of the Philips factory that made transceivers.
Inspired by Peter, VK3YE, I've created a Facebook event where you can let us know you're coming and learn more.
Please let everyone know who might be able to make it. I look forward to meeting you there.
Peter, VK3YE, is a wonderful evangelist for home brew and QRP radio. As well as publishing videos and books, he organises a twice yearly home brew QRP meet up at Chelsea beach near his home in Melbourne, Australia.
This year, I travelled from Sydney and Peter kindly met me at the iconic pier that is often seen in his videos.
Although quite hot, we eventually took over a shady spot and various home brew radios were displayed and discussed.
Lots of Bitx40s as you might expect. I brought an MMR40 which I like for its compact size and interesting permeability tuning.
There's an audio description of the event here including a description of the rig below.
Conditions on the day were not good on 40m but Peter did have a few contacts.
Peter moved to the beach and had some pedestrian mobile contacts at the waterfront much to the bemusement of the simmers.
After a great day in the sun we went to a local restaurant for a lovely meal.
My thanks to Peter for his hospitality and it was great to catch up with old friends from Melbourne. QRP by the bay is a great idea that could be replicated in other locations. Peter has made a video about running this sort of event.
Thanks also for the gift packs containing ceramic resonators on 4.92Mhz and 7.20Mhz, the former useful for Peter's VFO stability mod for Bitx40's and the latter for 40m oscillators.
Like, it seems, everyone on the internet, I have added a digital VFO to the Bitx40 board.
The Bitx40 board is a great base for experimenting with a 40m QRP SSB radio.
The code for the Arduino is based on code from AK2B who based it on code from Jason Mildrum, NT7S and Przemek Sadowski, SQ9NJE.
I slightly modified it to use the Etherkit version of the Si5351 library (which can be installed from within the Arduino Library manager).
Other changes were to strip out some things not needed for the Bitx40, enforce 40m band edges and improve the display of the step size a bit. Here's a video of it in use receiving.
I did run into insufficient space on one of the Arduino I had in the junk box but another worked fine. My fork of the code is available on github here. Having done all this, I'm now having second thoughts and am considering doing what Peter VK3YE did and using a ceramic resonator for the VFO.
Great to catch up with some real pros this morning Terry and Paul.
The cyclist on the right who you see briefly in this video told us that he'd attempted a height record with a kite. The kite's angle could be remote controlled and got to about 13km of string.
Update
I'm now using an SDRPlay receiver with their excellent SDRUno software and hearing Peter this morning.
Click on the screen shot to see it in its full magnificence. The trick for sending the audio output from the SDR software into the input of the WTJT-X application (or whatever you use) on Windows is the free VB-Cable.
I've found VB-Cable works better than expensive commercial software I've tried in the past. Note that after changing settings it's necessary to stop and start the sending and receiving software.
Here is a plot of the signal to noise ratio of received spots plotted against time of day over about three days.
It might be that the better S/N in the early hours of the morning is more to do with lower noise from the neighbourhood than propagation.
My favourite digital modes are PSK31 and WSPR, both on 20m, but there are a large number of other modes. Recently tuning around I saw the mode pictured on the right but despite reviewing some excellentsites that show all the modes and provide both images of the waterfall and audio recordings I was unable to decode the signal using fldigi.
Machine learning has improved enormously in the past few years and the ability of trained models to recognise new images as being things like a cat or sunset are amazing.
It might be possible to train a neural network with a collection of screen shots from the waterfall of each digital mode so that a new screen shot could be automatically identified.
An internet search for some existing software that does this turned up something that looked hopeful - a windows application called Artemis: Free Signal Identification Software, but (after navigating through a truely evil free hosting Windows malware attempt) the downloaded utility is just a GUI for searching the collection of waterfall images so that the user must decide.
Google has open sourced TensorFlow which is a system which can be trained with sample images and then when given a new image will classify it for you. They ship a pre-trained model called Inception v3 that has been trained with 1,000 different classes of images from ImageNet.
There is a really excellent introductory tutorial called "TensorFlow for Poets" that I followed.
The tutorial shows how to re-train this model with additional flowers that it doesn't know including daisy, dandelion, roses, sunflowers and tulips. Here's some of the sample daisy images.
Thanks to docker, it's very easy to get TensorFlow running. The sample images are in a directory that is mounted as a volume in the docker container.
After getting all this to work - and very reliably recognise flowers, I captured and hunted down sample images of two digital modes, BPSK and RTTY. I chose these two because they are common and also rather similar to the eye. Here's some of my psk sample images.
One trap to note is that you do need a decent number of sample images, 30 - 40 or more or you'll get this mysterious error during training.
CRITICAL:tensorflow:Label rtty has no images in the category validation.
Traceback (most recent call last):
File "tensorflow/examples/image_retraining/retrain.py", line 1012, in
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/platform/app.py", line 43, in run
sys.exit(main(sys.argv[:1] + flags_passthrough))
File "tensorflow/examples/image_retraining/retrain.py", line 839, in main
bottleneck_tensor))
File "tensorflow/examples/image_retraining/retrain.py", line 480, in get_random_cached_bottlenecks
bottleneck_tensor)
File "tensorflow/examples/image_retraining/retrain.py", line 388, in get_or_create_bottleneck
bottleneck_dir, category)
File "tensorflow/examples/image_retraining/retrain.py", line 245, in get_bottleneck_path
category) + '.txt'
File "tensorflow/examples/image_retraining/retrain.py", line 221, in get_image_path
mod_index = index % len(category_list)
ZeroDivisionError: integer division or modulo by zero
In the end I got past this by simply duplicating my sample images which of course doesn't help improve recognition but gets past the fatal error. It is quite hard to find 40 sample images of a digital mode.
Identifying images of modes
As a first test I fed the system two images which were part of the training images.
As expected, not quite as sure but still very good.
I think there is a good prospect of using machine learning image recognition for guessing digital modes. Ideally this would be built in to clients but it might make a good app (using the phone camera to capture the unidentified signal) or a web site where you upload a screen shot.
The main thing I need to expand this is lots of sample waterfall images.
There's some interesting discussion in a thread in the Reddit amateur radio subreddit.
The end of an era. I talked about the value of shortwave broadcasting this morning on ABC Radio National. You can hear the audio here. (Technical friends please forgive my simplistic explanation of the ionosphere).
Here she is in a radio play "East Lynne" episode 7, as always she played a young boy. (About 2:30 in s/he appears as Bobby).
I've just celebrated ten years as a commentator on ABC RN Breakfast. That's nothing compared to the length of Peggy's career. On Saturday we talked about the excitement of doing live radio.
Update
Next Saturday at noon ABC Local Radio will air this tribute edited from the audio on DAB+ and streaming as part of Editor's Choice. Thanks James O'Brien for a lovely job.
My thanks to the wonderful National Film and Sound Archive who helped me find performances by Peg a few years ago. She was amazed that some had survived.
DELIA OF FOUR WINDS
Series: 238366
Summary: The story of the Markham family set around family house ‘Four Winds’. The story centres around Gilbert Markham, his four children and his second wife, Anne.
Contributors: Madge Thomas (SCR), Broadcast Exchange of Australia (PDC), Grace Gibson Radio Productions (DSR), Athol Reilly (PDR).
Cast: Beverley Dunn, Mary Disney, Douglas Kelly, Carl Bleazby, Noel Ferrier, Peggy Marks. Label: BEA
Episode duration: 15 mins
Episodes produced: 520
Broadcast details: Broadcast nationally in Australia over the Major Network, and in New Zealand over the New Zealand Broadcasting Corporation.
Notes: Sequel to ‘Stepmother’ and is followed by ‘The Markhams of Four Winds’.
---
EAST LYNNE
Series: 238597
Summary: Adaptation of Mrs Henry Wood’s early Victorian novel of romance and intrigue. Contributors: Mrs Henry Wood (AUT), Marcus Clark, McDowell’s Ltd (SPO), George Matthews (PDR).
Cast: Queenie Ashton (Lady Isobel), Harvey Adams (Archibald Carlyle), Lola Kelly (Barbara Hare), Leonard Bennet (Lord Mount Severn), Ronald Morse (Francis Levison), Nellie Ferguson (Cornelia Carlyle), Margaret Johnson (Emily), Peggy Marks.
Label: BAP
Episode duration: 15 mins
Episodes produced: 52
Broadcast details: 1939- ; Sunday to Wednesday on 2HD at 8.45pm ; Monday and Wednesday on 2CH at 9.00pm
References: ‘Once upon a wireless’ oral history interview.
---
LAVENDER GROVE
Series: 239090
Summary: Cheerful story which approaches the problems and pleasures of everyday life about the Grant family. Lavender Grove is a pleasant tree-lined street in a better-than-average suburb.
Contributors: Warren Glasser (PDR), Rae Clye (SCR).
Cast: John Bhore, Robert Peach, Peggy Marks, Mary Ward, Beverley Dunn, Monty Maizels, Bettine Kauffman.
Label: BEA
Episode duration: 15 mins
Episodes produced: 1452 (At least)
Broadcast details: 1955-1960 ; Major Network.
References: ‘Once upon a wireless’ oral history interview with Monty Maizels.
NFSA Holdings: Eps 15-40 (incomplete)
---
POLLYANNA
Series: 239427
Summary: Radio serial based on the children’s novel, Pollyanna. Contributors: John Hickling (SCR).
Cast: Ngaire Thompson, Peggy Marks.
Broadcast details: 3DB
References: ‘Once upon a wireless’ oral history interview.
---
SIMON MASTERTON
Series: 239609
Contributors: Madge Thomas (SCR), Broadcast Exchange (PDC).
Cast: Beverley Dunn, Peggy Marks
Label: BEA
Episodes produced: 832
Broadcast details: 1940s-1950s
Notes: Final series in the Markham family saga. Other include ‘Stepmother’, ‘Delia of Four Winds’, ‘Markhams of Four Winds’, ‘Markhams’ and ‘His Heritage’.
References: ‘Once upon a wireless’ oral history interview.
---
Seems to be a program called "once upon a wireless"
And from: http://nfsa.gov.au/site_media/uploads/file/2011/12/12/NFSA_OH_Sound_recordings_radio_amended.pdf
[MARKS, PEGGY : INTERVIEWED BY BEVERLEY DUNN : ORAL HISTORY]
Record No. - 271769
Peggy Marks (Glasser), radio drama actress, discusses her career in radio. Marks tells how she started in radio while still at school and won a part in the popular "Pollyanna". She recalls how she often won boys' parts and played Fatty in The Blytons. Marks talks about her involvement in many of her favourite shows including Lavender Grove, Simon Masterton and The Fakamagangees. (00:41:39)
Wow, Apple got some heat when they announced the updated MacBook Pros with just USB-C ports. They're feeling that heat too, I can't remember a time when they have responded to criticism by cutting the prices of products like this.
Rather than focussing on the annoyance of needing dongles to convert from USB-C to USB-A, HDMI, DisplayPort, SD Card, and many others; I propose that we marvel in the genius of this new standard.
The USB-C connector is slim and strong. You can plug in either way up. The same socket can charge, output video, connect to a wired network, and even extend the PCI bus outside the box potentially to cards in a rack. One laptop can even charge another (the first one you plug in supplies power to the second). The monitor can charge the laptop via the cable being used for video and extend USB.
When I told loyal PC guy Theo on the bus that the new MacBook Pro could drive four 4K monitors he flat out didn't believe me.
We are in a transition. For a period of time we'll need either dongles or docks but soon peripherals with USB-C cables or sockets will take over and the dongles will disappear. Wireless from cameras needs to get better (maybe Apple should license a form of AirDrop?).
Apple said that they showed "courage" in removing the headphone jack from this year's iPhone. I think the real courage they're showing is going all in with USB-C. The next step would be to put USB-C on the iPhone.
I've built a couple of Bitx rigs in the past but when I heard a company had been formed to supply pre-built radios for 40m I couldn't wait to get one. Thanks to my Indian colleague Thalha I was able to order one in India and then have it shipped to Sydney. Thanks mate!
On the right you can see what you get. The board is fully constructed with very nice surface mount design. In the bag are all the connectors and pots you need, even a microphone is there.
The quality of components and construction is excellent.
I boxed it up in a $5 Woolworths "world explorer" box - which seems somehow appropriate.
Plenty of space for a DDS VFO in the future...
Tuning is very sensitive and I'm ultimately planning to install a DDS to replace the onboard (rather drifty) VFO.
Having said that, the receiver is very sensitive and signals sound great. My first contact was with a station in Melbourne - about 1,000 Km away.
The receiver is very sensitive and there's plenty of audio output to drive a speaker. Carrier was well nulled and I've had good reports of the audio using the supplied mic insert.
90mA is drawn on receive which makes this a great trail radio. My unit puts out a solid 6 watt but the availability of the option to supply a higher voltage to the final means you can get more if you wish.
Mine gets a tiny bit of broadcast band break through into the audio stage (when the volume is down) and it doesn't like noise on the power line (I have a solar charger that sometimes pulses).
This is a great rig and I recommend it to anyone who would like to play around with an easy to get going QRP 40m SSB transceiver. At about AU$50 it's an extraordinary deal.
I also enjoyed the newspaper that the board was wrapped in - lots of celebrity gossip there.
Update: Re-boxed with VK3YE's resonator mod
This is for commenter Alex who asked about the interior view. Since the article above, I decided to re-box in plastic and having found the VFO annoyingly unstable (by modern standards) I applied Peter VK3YE's ceramic resonator mod to give three small ranges of tuning. Here's how it looks now (click image to enlarge).
Ross, VK1UN (aka 6O0O) is visiting this weekend and has been sharing a nifty technique for making magnetic loop antennas using a tubing normally used for pressure gas pipes called Pexal.
The loop is very simple and is fed with a toroid transformer coupler.
We purchased two diameters of Pexal, "Gas-TITE", polyethylene cross linked aluminium, 20mm and 16mm. The idea is that by shaving down the thinner tube, used for most of the loop, the thicker pipe can be slipped over both ends and works as the capacitor.
Pexal is easy to cut and Ross recommends using a box cutter as shown here. (No blood was spilled in this video).
Here's how the pipe looks. It is insulated on the inner and outer surfaces and has aluminium in it. This works up to hundreds of watts if required as the breakdown voltage for this material is 19KV.
To get the smaller tube to slip in to the larger tube we had to do a considerable amount of shaving with the knife. We also tried heating the outer tube but it didn't seem to help much.
There are some excellent calculators for computing the size of magnetic loops and figuring out the capacitance of the run of tube within tube. Here's the windows app called "Magnet Loop".
We ran a WSPR receiver with a Raspberry Pi decoding over night and here are the received spots.
We also made a larger loop for 30m but it's a little unwieldy.
Some tuning can be achieved by sliding the smaller tube in and out of the larger linking part. Note that because this section is two capacitors in series the value is halved so you need to double the amount of capacitance needed to resonate.
Another way to tune is to use aluminium flashing tape over the ends of the thicker tube which can be trimmed to adjust.
We used between 2 and 4 turns on the toroid and this affects the SWR you can get. You'll need to use a minimum of 850 initial permeability. We used a toroid from Jaycar marked as L15 but we're skeptical.
Thanks Ross for sharing this interesting technique. Ross is well known as the "loop meister" on wsprnet.org, here's a few of his past loops.
