Monday, June 19, 2017

Lo-Key features QRP by the harbour

Thanks Lo-Key for featuring QRP by the harbour on the cover and in a feature article. It's a great newsletter of general interest beyond just CW operators. More info at http://www.vkqrpclub.org

Thanks to editor Terry, VK2KTJ, for promoting the event and giving us this coverage in such an auspicious journal. I encourage readers to subscribe via this page.

Future of Radio Australia Shortwave broadcasting - Senate Committee Hearings begin

Last Friday the Senate Committee hearings into a bill by Senator Xenophon to compel the ABC to resume short wave broadcasting began.

The SWLing Post reports that former RA transmission manager Nigel Holmes appeared. He jovially described being "grilled like a breakfast kipper" but I'm confident his encyclopaedic knowledge would have served the committee well.

I think it's important that there is a discussion about the value of short wave broadcasting at this time,  there have been many interesting submissions, in my submission I argue that it's not the archaic technology as it has been presented and in times of conflict or natural disaster it's the only thing that gets through.

Geoff Heriot has written that abandoning shortwave is just one more step in the winding down of Australia's engagement in the Pacific. Graeme Dobell describes the end of our shortwave service as "technical bastardly".

The inquiry has been granted an extension of time and will report on 9th August 2017.

Sunday, June 18, 2017

Switched to the NBN - seems good

We've been receiving letters for months from ISPs offering to be the ones to connect us to the NBN which has just arrived in our area.

As we were already on Telstra cable we decided to switch with them. I chose to self install the modem and a router arrived a week ago. It was puzzling because it didn't have a cable connection on the back.

Today the missing piece, the black box shown at right, appeared and it connects to the cable and to the router.

The router is a white box titled "F@st 5355TLS" made by Sagemcom Broadband SAS, not a company I was previously aware of. It seems like a competent device with 2.4GHz and 5GHz radios, two ethernet ports (not counting the WAN port), USB file sharing, and a telephone line port which we don't plan to use.


In the past I had put the Netgear modem into bridge mode and used a TP-Link wireless router which served us well and I may well switch to that again if the Sagemcom box proves unreliable. So far all seems good and the measured speed is more than I was expecting (I'm paying for 50Mbps down and 20Mbps up).


Ping time is better than reported there, normally around 10-12ms. I'm not clear if the Sagemcom box is actually needed given that I have other routers here I'm happy with.

I had a few problems getting ethernet connected devices going, in the end connecting them one by one did the trick, there was some sort of network storm going on possibly triggered by the change in IP address range.

It's weird that when switching to the NBN you are compelled to get a landline phone - something we have not had for some years. Here's the bit of the signup form that forces you to get a phone:


I tried putting my mobile phone in there but it wouldn't let me. (Probably a bad idea anyhow). A few more tests tonight:



Friday, June 02, 2017

Good value laptop for linux - not what you might expect


There are very low cost laptops around but they're often unsatisfying in the end. The family is down one Mac laptop at the moment due to a fault in the keyboard and I had a look at what's available second hand.

Generally Apple gear holds its price very well, which is great if you want to sell to upgrade but not so good of you want to get a cheap Mac.

There is a regular trickle of Mid 2012 MacBook Pros appearing on eBay. This model is the last one before they went retina.

With a 2.5GHz i5 CPU, they are built like a tank but are very easy to open and work on. Some people even say "The 2012 Non-Retina MacBook Pro Is Still the Best Laptop Apple Sells" and while that's not really the case if you value a high resolution screen and light weight, they are attractive at the right price.


I was pretty lucky and got one for AU$415. The battery wasn't great, a few key caps had been substituted, it had 4GB of ram and a slow spinning 500GB disk. Otherwise it's fine.

A few standard cross head screws aside and you're in and able to upgrade the machine.


As it came, and as they were at the time, the machine felt pretty slow. I added the following enhancements:

  • 120GB SSD
  • Extra 4GB RAM to take it to the maximum of 8GB
  • New battery
The SSD makes a huge difference and if you are still running a spinning disk I can't recommend this upgrade enough. Four or five bounces to launch Safari is now just one.

These machines will run the latest edition of macOS, Sierra, and support AirDrop and Handoff.

A non-retina screen is a shock after getting used to it on every other device I look at. Apple's switch to the San Francisco font actually makes a non-retina screen look worse. There is a utility to switch the system font back but I found the font metrics are so wrong that you see lots of glitches running like that so I don't recommend it.

Linux

It turns out that dual booting Linux on a Mac does not require Boot Camp or any of those fancy EFI boot tricks.

To install boot into the recovery system by holding Command-R during power on and use Disk Utility to resize the main partition down to leave free space for Linux. Hold option during power up to boot from a Linux USB install drive.

Fedora Linux was installed into the free space on the disk. To choose which OS to boot into you simply hold the Option key down during power on and you get this nice menu.


Wifi doesn't immediately work after a clean linux install due to proprietary drivers but happily this machine has an ethernet port and I simply followed this recipe to get the driver installed and now Wifi works well. 

Everything else just works including volume, screen brightness keys and sleep on close.


It makes a very respectable Linux laptop. One thing to note that after the install you should boot into macOS and set the startup disk in System Settings so that by default it will boot into macOS (if that's what you want).

Saturday, May 20, 2017

YouKits SK-1A QRP 40m transceiver review

YouKits is getting a good reputation for low cost amateur radio gear. Their antenna analyser is well regarded. When I saw a new mono-band 40m SSB / CW transceiver for US$189 including postage I couldn't resist. It's called an SK-1A.

It arrived very quickly and was easy to figure out even without reading the user manual.

While it comes with a Yaesu branded speaker / microphone, it's not wired to use the speaker in it so you must use headphones or an external speaker. Note that this transceiver does not have a built-in speaker which probably isn't a bad thing given the small size of the case.


I've had two contacts so far, one local and another VK2 to VK3. Both reported good audio from me and I found reception at my end pretty good. Disconnecting the antenna shows that the receiver is sensitive enough to hear band noise which is all you need on 40m.

The display is clear and the backlight is bright. The manual includes instructions for adjusting the display but it's not brightness or contrast, it lets you switch the backlight on, off, or auto.

Internally, construction seems good with lots of surface mount components used throughout. There's no circuit diagram in the manual, which is a pity, but you can see that the 6 crystal IF is on 4.9152Mhz and there are a few SA602A balanced mixers in there along with an LM386 audio amplifier.


The VFO board behind the front panel is compact and the software works well although I find the way pushes on the knob change between going up and down in step size a little weird. The soldering on the PIC microprocessor looks a little rough on my unit but all seems to work reliably.


The final is an IRF510 and I get about 4W peak output. I like the way they use shielded coils.


Main board soldering is good but clearly done by hand rather than machine.


Internally there's a socket for the 18650 Lithium battery pack which they supply with a charger but it looks like you'd need to open the case to charge the battery.

This radio is lower sideband only (along with CW), which is perfectly fine for voice contacts but I was rather hoping to use it for digital modes which normally need USB.

While a traditional SA602 based design, this radio works well enough and is more compact than even an FT-817. 40m is a good choice for a mono band QRP radio. There's no deafening thump during receive / transmit switching like I get on some other designs and audio output is more than enough for headphones but a little low for an external speaker.

Wednesday, May 10, 2017

Radio Australia's Shepparton broadcasting site for sale

For the ham who has everything... a lovely 500 acre vacant site at Shepparton, Victoria, Australia complete with short wave antennas (I assume).

More details here.

They say it's a significant "land banking" opportunity, whatever that is.

Close to a highly regarded school and just "moments" from the Shepparton Town centre.

But seriously, the site is up for sale while there is a pending bill before the senate calling for the restoring of shortwave radio.

There have been 40 submissions received (including one from your humble blogger). The inquiry is due to report on 9th August 2017.

Lovely cabinet work on site:


I'm advised that the property will be sold with buildings only, antennas and feed lines above ground will be removed.

The local Shepparton News is reporting that not everyone is happy with the shut down of the shortwave service.

Sunday, April 23, 2017

rtl-sdr direct sampling on linux

There's a nicely put together rtf-sdr receiver box available on Ebay from China for about AU$45 with the direct sampling modification for HF already done for you and separate inputs for HF and VHF+.

There are several sellers so shop around.

You can see it on the right here and the box above it. (Click to enlarge)

Internally, it's an RTL2832U.

On my recent weekend visit to Kevin, VK2KB, I helped to get it going under Windows using SDR# software and this prompted me to get mine going at home under Fedora linux.

One mistake I've made before is that some USB cables seem to come wired only for charging and don't wire up the other USB connections. I wasn't seeing the device in lsusb and when I tailed the log (which, incidentally, has changed under Fedora since I last looked, to be sudo journalctl -f), there was no chatter as the device was plugged in. Trying alternate cables fixed this.

It turns out that GQRX finds the device just fine. To switch on direct sampling from the Q input, you set it like this:


CubicSDR saw the device but couldn't receive until I blacklisted the built-in TV reception driver by creating a file /etc/modprobe.d/blacklist.conf and entering blacklist dab_usb_rtl28xxu in it. Then I rebooted.

After that, the CubicSDR device config looks like this:


And it receives 40m SSB like this:


(There's not much on at this time of day).

Google reader alternative - tt-rss review

I still miss Google Reader which went away in 2013. It was an efficient way to catch up on all the RSS/Atom news feeds I subscribe to in a web browser.

The key feature I need is that whatever I use remembers what I've read and can be accessed from multiple devices that stay in sync.

When Reader went away I subscribed to FeedWrangler which works well but lacks a decent web interface so must be accessed from a macOS or iOS app such as Reeder.

Recently I've installed Tiny Tiny RSS, also known as tt-rss on a Fedora linux computer in my home network. The installation guide is good but I ran into a few things that were not right on Fedora 25.

I chose to use mariaDB (mysql clone) as the database although they recommend Postgresql.

From memory, the issues I encountered were:

  • PHP couldn't connect to the database due to secure linux. 
  • httpd couldn't write to the tt-rss web directory for config and cache writing. Needed # setsebool -P httpd_unified on
  • The name of the mysql driver for php is different, I needed # dnf install php-mysqlnd
  • # dnf install php-pdo php-gd php-mbstring php-common php-apc
To get my feeds imported, I exported the OPML file from FeedWrangler and imported it into tt-rss by going to Actions, Preferences, Feeds tab and there's a long horizontal panel called OPML that's a button for choosing the file to import.

The user interface is nice and clean and I particularly like how it responds to up and down arrow keys to roll through the stories in the scrolling panel.

Updating feeds


The authors suggest leaving a process running to do the updates (it sleeps periodically) but I prefer a cron job as follows:

*/30 * * * * /usr/bin/php /var/www/html/tt-rss/update.php --feeds --quiet

Anyway, so far I like it a lot and my plan is to eventually move it to a virtual server in the cloud. It looks like you can aggregate all of your unread items into a new feed and presumably read that from an app while out - this could possibly replace the commercial service I'm using at the moment.

Friday, April 14, 2017

QRPver pocket sized transceiver review

The QRPver is a US$80 1W QRP transceiver that is perfect for running digital modes such as PSK31. It connects to a computer via analog audio cables and has internal VOX so there's no need for an interface box or serial rig control.

It's about the size of a pack of cards as you can see in the photo on the right. 

I'm using it with Fldigi running on Fedora with a generic USB audio dongle. I did need to use the Sound application to increase the audio level a bit to get the VOX to trigger when I transmitted.

Note that the audio sockets are stereo sockets with left and right tied together so you do need to use stereo leads or you'll short audio to ground.

I ordered my QRPver for 14.070 (there are a range of bands and frequencies to choose from). 20m PSK31 was very lively a few years ago but at the moment seems rather abandoned for some reason, perhaps everyone's running JT65?

First contact was pre-arranged with Stephen, VK2BLQ who is pretty near by. Today VK5WOW popped up being operated by Grant, VK5GR who made a few comments about the signal not being all that clean and also it drifted about 20-50Hz during a longer over.


The QRPver draws just 20mA on receive and 650mA or so on transmit so it would be great for portable digital operation. The receiver seems sensitive enough and while not a perfect signal on transmit - something that might be because I need to tweak the level a bit or possibly there's some RF getting in to the audio - I think it's a great gadget for the travelling ham.