Amateur radio antennas, circuits, techniques and related topics. By Peter Parker VK3YE/AK3YE.
Newer material appears at https://vk3ye.com and https://youtube.com/vk3ye .
Equinoxes often bring good DX conditions, even during solar lows. And the Corona virus is keeping more and more people in. So now might be a good time to turn on the rig and work DX. Here's me a couple of weeks back at the beach.
Now's a great time to be reading books. Especially with not much else to do.
The BERU CW contest was nearly 2 weeks ago. It's a contest for stations in the British Commonwealth to work each other. It's not the high pressure of the big DX contests but still brings out stations from interesting parts of the world.
This year I took the linear amplifier to the park at the end of the street. I was using a T vertical antenna with each leg 5m long. Contacts were made on 40 & 20m. There was also some European DX on 30m worked (not part of the contest). Also notable was the strong signals from US-based Reverse Beacon receives on 40m. This will definitely be a site I'll return to given the results.
I was also active last year but as a QRP station from the beach. Here's my video from then.
PS: Want to read about antennas? Consider this selection of antenna books. They are affiliate links meaning that I receive a small commission (at no extra cost to you) if you decide to purchase.
Many will be aware that Radio Australia ceased its shortwave transmissions a few years ago due to government cuts. This video shows reception during its last days.
A pirate (using SSB) came up to mock this decision. I caught snippets here.
The site has been idle for a while. But the Shepparton Amateur Radio Club was able to get access to it to give the antennas one last use, but this time on the amateur bands under special event callsign VI3RA a week or so back. The antennas were pointing the wrong way for Melbourne and short-distance propagation was unfavourable so I didn't hear them very strongly (or at all) on 7 and 14 MHz. But they were good signals on 160m. Here's some recordings I made.
PS: My latest antenna book, More Hand-carried QRP antennas, is now available in both ebook and paperback formats. More details here.
A few days ago I described pedestrian mobile APRS. Results were patchy. This time I go longer distances on a bike with an improved antenna. Watch the video to see how it worked.
Now's a great time to be reading books. Especially with not much else to do.
Many of the popular low earth orbiting amateur satellites are basically a very high FM repeater. They work well and signals are strong. And not much frequency adjustment is required to compensate for Doppler. However they only allow one contact to happen at once.
A little harder to receive are satellites with linear translators. However they have the advantage of allowing multiple CW, SSB and other contacts within their 20 kHz or so bandwidth. And low earth orbiting type, like the Chinese CAS series, can still be received on simple antennas.
Watch this video for a demonstration. Signals were audible from three satellites within a few minutes of each other making it a bumper evening of reception.
Here's an earlier video I did where I used a handheld transceiver on 70cm to transmit a carrier which was received.
PS: Into low power amateur radio? Minimum QRP is the top-selling manual on the equipment, antennas, operating and strategy of successful QRP operating. It's available for under $US 5 each in electronic form. Or you can get a paperback version. Visit VK3YE Radio Books to find out more.
Sometimes what you intend and what happens can be different things. The idea was to work some US DX during their SSB contest. But I'd got to the pier too late for best signals on 40m and 20m was producing only weak signals.
Rather than go home I stuck around and had some within VK contacts on 40m. Mostly the usual news broadcast callbacks, park activation and holidaying ham (it was a long weekend).
The antenna I used was different to usual - a 1/4 wavelength vertical. This probably helped with good reports into VK2 (around 800km distance). Watch the video to see how I went.
The moral of this is that with QRP under the current conditions you should be flexible. Change your aims to meet conditions. And don't expect to work DX every time you go portable.
For more on portable QRP my book Minimum QRP could be worth getting. Available in paperback or ebook details are here.
Last week I reviewed a pack of six amateur band crystals available on eBay. The beauty of them is they are on popular digital frequencies. More precisely 7 and 14 MHz WSPR, FT8 and JS8 frequencies.
While you could get an SI5351 for less for more frequencies, there's a certain elegance about crystal control when it comes to simplicity and low current consumption. Eg a simple direct conversion receiver needs just three transistors and draws just a few milliamps. More in the video below.
Later I tried 14 MHz FT8 reception. Here's the results I got.
Then I took the receiver out portable, mainly receiving FT8 signals. But this time I had put in a rotary switch to select between 7 MHz WSPR, 7 MHz FT8, 7 MHz JS8 and 14 MHz FT8.
PS: Want to read about antennas? Consider this selection of antenna books. They are affiliate links meaning that I receive a small commission (at no extra cost to you) if you decide to purchase.
Want to track something by radio independent of the mobile phone network? APRS could be handy.
You basically need a 2 metre FM transceiver with VOX (voice operated transmit), a mobile phone with GPS, the APRSDroid app and an interface cable. It's best to get used to all this from home with a good antenna.
Then once you've had success with that you could go for a wander to see if there are any receiving stations near enough to receive your signals. Sometimes there are, sometimes there aren't. My experiences, using a 5 watt handheld transceiver with small antenna, are in this video.
After I made that video I did more APRS. That involved an outing with friends. We were in buses and walking through sometimes hilly forest. The longest distance a position from me was decoded was 100 km (from the bus) while from the handheld in scrub the distance was nearer to 4 or 5 km.
This is the book for those returning to amateur radio. Available as a low-priced ebook or in paperback. More details including links to reader reviews here.
Not only am I VK3YE but I'm also now AK3YE. More for curiosity than anything I did the US ham tests last month. They're regularly conducted fairly close to here and you could do all exams in one go for a small fee. This video goes through the six steps required. It should be particularly useful for those outside the US. A US callsign can be handy if you're using a US-based remote station or for some overseas trips to countries that recognise the US ham qualifications.
Interested in exploring various facets of amateur radio? This is the book for you! Learn more here.
You can do a lot with 20 metres of wire. You could cut it in two, feed it in the middle and have a dipole. Put breaks along it and make it a link dipole for a couple of extra bands. That works fine with coax cable and no antenna coupler. Or you can feed the whole 20 metres at the end via an L-match coupler.
Which works better? I did a midday test on 40, 30 and 20m WSPR. How I did that and the results achieved are in this video.
Something to note is that there are errors on the 30m slide. The numbers are right but the conclusions are not. The dipole was mostly worse not better. You'd need to do more comparisons at various times and over more paths but the learning here is that a non-resonant length of wire can do OK.
PS: My latest antenna book, More Hand-carried QRP antennas, is now available in both ebook and paperback formats. More details here.
My newest book, More Hand-carried QRP antennas, has been quite popular. It came out in January but was only available in ebook form. Anyway that's now changed with a paperback edition now available via Amazon in many countries. The price is the same as for my other paperback books. Details here.
I've been away so no posts for a while. Anyway I'm back, although with some extra activities don't be surprised if there's sometimes a few days between posts. One of the places I went to was Hobart, Tasmania where I spoke to the REAST (local radio club) on QRP. Here's a video of the event, produced by Hayden VK7HH. If you want a general guide to portable QRP this video could be worth watching. And more care has been taken in its production than most of my videos!
There's only so much you can say in an hour or so. For much more detail my book Minimum QRP could be worth getting. Available in paperback or ebook details are here.
