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 .
A little video from a few years back for those who like playing with small cheap electronics. In this case an MP3 digital audio player module. Watch and find out what uses they could have around the ham shack.
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.
A video from a few days ago of portable operating one warm afternoon from the beach.
PS: Enjoy building antennas? Many hams do. Hand-carried QRP antennas, my first antenna book has been very popular. That concentrated on basic concepts and the lower HF bands. Anyway here's the follow-up. Called More Hand-carried QRP antennas it describes more than 30 antennas and accessories that you can easily build. And there's more of an emphasis on upper HF, VHF and UHF antennas that the previous volume didn't have so much on.
The ARRL makes some free articles, mostly from QST, on its website. They are handily arranged by topic. Here are some ones about QRP or low power amateur radio.
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.
Quite a few people have asked about paperback copies of my books. Especially Australians. They're dearer to buy here as Amazon publishing here is ebook only. This has been a particular issue with my Australian Ham Radio Handbook due to its targeted audience.
Anyway I've got some good news. Australia's own ham radio handbook is now locally available in paperback. So there's no expensive postage from overseas to pay. It's all thanks to Jaycar who now make the book available via their website (Cat No BM2492).
Where does the Australian Ham Radio Handbook fit if you wanted to assemble reasonable collection of books?
Right at the start is the WIA Foundation Manual. That gets you started. Enough to pass the basic Foundation test. But it's a slim volume limited to the licence syllabus.
Then there's Ron Bertrand's amateur radio theory handbook. You need that for Standard and Advanced. Solid for knowing more about how electronics and radio work. But not so much a practical manual. Ditto for Fred Swainston's theory book.
The ARRL Handbook covers a bit of everything with lots of theory and a bit of operating. But the latter is (understandably) US-based. Not so useful for Australia where our licence conditions and frequencies are different. You should buy one anyway (doesn't have to be the latest) especially if you can find them going cheap at a hamfest etc. Also get at least one of their antenna handbooks if you can.
The gap (for us in VK) is locally relevant practical and operating information. That's where my Australian Ham Radio Handbook comes in. Especially if you're starting out you'd rather it in an easy to refer to paperback as you'll be using it all the time. So this is why I think this book is so significant.
It's not in the stores yet - that is probably a few weeks away. But there's stocks at their warehouse so an online order will get it to you fastest.
Interference is a major reason for amateurs not to be active from home as they could be.
Most homes (including hams' own) are filled with electronic stuff that radiates RF over a wide frequency range. Offenders include solar power inverters, switch mode power supplies, computers and more. The result is a high noise floor on HF that allows only the strongest signals to be heard.
A group of amateurs here in VK3 has put together some information resources for diagnosing and resolving interference.
For a specialist self-help guide on getting your bands back by tackling interference to your amateur station head over to the QRM Guru website. On it you will find many helpful articles and videos on diagnosing and treating RF interference. There are also things you can buy like DF loop and ferrite kits.
What have been your experiences with interference to your station and how have you go around it? Please share them in the comments below.
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.
CB radio is a little different in Australia than elsewhere. The term 'CB' here is officially used to refer to either our 27 MHz or 477 MHz bands. And it's the latter where we're significantly different from elsewhere. There is no limit to the antenna gain you can have and there are repeaters in many parts of the country. And our power limit is five watts with both mobile and handheld units available.
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.
Lovers of vintage gear or 'boatanchors' will enjoy this recent video from VK3ASE.
It features an Australian made general coverage receiver - the AWA AR8 from WWII.
Dave's video takes you on a tour inside and tests reception on AM, CW and SSB signals.
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.
But I know some out there collect or at least interested in older solid state QRP gear, say from the '70s or '80s.
Japan had millions of people go through its basic amateur radio licence, which has a ten watt power limit, in the 1970s and 1980s. It had a substantial industry producing QRP rigs for this market. Some made it outside Japan but I suspect not many were sold.
Names like Mizuho and (ironically) Tokyo Hy-power spring to mind. Because many people don't have a lot of space for antennas a fair lot of gear was produced for the higher HF and VHF bands. Especially, it would seem, 21 and 50 MHz. And if you were in an apartment or small house you could put up a small vertical or dipole and get some long distance contacts on those bands.
How do you get some of this stuff?
You can import it.
But how? Especially if the seller will only ship domestically.
The answer is you use an intermediary company who buys it locally, charges you a fee and sends it to you.
Techmoan explains how all this works (he specialises in audio gear, particularly obscure recording formats). Sounds like it's more trouble than it's worth but where there's a will there's a way.
Anyway I looked on the Jauce website (one of the middleman websites) to see what ham gear you could find. Searching 'QRP' didn't produce much. But 'Mizuho' did. For instance some 6m AM rigs and small handheld HF transceivers. Have a look here for yourself. Also try Tokyo Hy-Power. And other websites and brands.
There's obviously costs and risks, the gear may be old and there may be less recourse if there are problems. But if an FT817 is too plain for you and you absolutely have to have vintage Japanese novelty gear then you now know where to start looking.
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.
This is about the most basic setup you could have. Five watts of 144 MHz SSB only with a 2 element yagi at not much higher than sea level. Nevertheless contacts up to nearly 200km were made.
Here's the video.
PS: Enjoy building antennas? Many hams do. Hand-carried QRP antennas, my first antenna book has been very popular. That concentrated on basic concepts and the lower HF bands. Anyway here's the follow-up. Called More Hand-carried QRP antennas it describes more than 30 antennas and accessories that you can easily build. And there's more of an emphasis on upper HF, VHF and UHF antennas that the previous volume didn't have so much on.
There's no doubt that building antennas is a popular activity amongst hams. This is reflected in the sales of my books; Hand-carried QRP antennas consistently ranks as the most popular with thousands sold.
We're overdue for another volume. Not because anything in the first book is out of date but because the antenna field is so wide that only a small fraction can be covered in one book.
Hence the new release: More Hand-carried QRP antennas. With the basics covered in the first volume, this gets straight down to business with descriptions of over thirty antenna projects. There are also some background articles and ideas for the antenna experimenter.
More Hand-carried QRP antennas devotes more attention to upper HF, VHF and UHF antennas, complementing the lower-HF focus of the first volume. But you'll still find projects for bands down to 1.8 MHz, including some exciting loop and loaded pole ideas.
Everything presented has been built and tested by the author over almost 30 years of successful QRP activity.
More Hand-carried QRP antennas is available in ebook format with a paperback edition coming soon. It's the author's seventh book, following on from popular previous titles for QRP operators, antenna builders, radio beginners and more.
The price is the same as with the first book; under five US dollars or five euro.
To learn more watch the summary video below, search the title in Amazon or head over to the book's page on my website.
John KC0KBG very generously mailed me this frameless kite. The good thing about it is it has no bulky poles. Hence it can scrunch up into a small light package ideal for portable QRP.
In this video I take it for a fly. It probably isn't great for very light winds but in a moderate wind it held up, even supporting 20 metres of thin hookup wire for an antenna. The video below is my test of it.
You'll be able to buy it via Walmart stores in the US later this year. Or you can order it via Amazon. Link is here (note that it's an affiliate link so I get a small commission on items sold - no extra cost to you).
If you do get one please let me know how you go in the comments below!
ARRL has launched a new magazine for beginners to amateur radio. It's called 'On the Air'.
I like it. The first edition includes articles on propagation, using repeaters, extending your transmitting range, public service communications, buying a handheld transceiver and more.
The first edition is available as a free sample by clicking here
PS: More detail on operating, also suitable for new hams, is in Minimum QRP. It's the top-selling manual on the equipment, antennas, operating and strategy of successful low power amateur radio operating. And its techniques work for 100 watts as well. 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.
We don't often get thunderstorms here in Melbourne. But they're much more common in the tropics further north. And apparently also in places like the USA deep south.
Anyway here's some videos and links that discuss how amateurs can prepare against them and save their gear from being blown up. Not surprisingly they're all American.
PS: I've now written six books on various aspects of amateur radio. Whether you experiment with antennas, enjoy QRP or are starting out in radio there's a book for you. Find out more here.
The latest Ask Me Anything. Discusses a range of topics with questions from viewers.
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.
Something I've 'known' but never, until today, seen described concerns how much current you can draw from rechargeable batteries. Especially when what you're drawing is a high percentage of a a battery's amp hour rating.
For instance supposing you had an FT817 that draws something like 2A on transmit. You might think that a 2AH sealed lead acid battery is sufficient to keep you transmitting for 2 hours (I'm assuming a continuous duty cycle mode like FM).
But in practice you'll get less. Why? It's something called Peukert's Law.
I hadn't heard of it up to today (where I was researching a question I got asked).
To summarise you need more battery capacity than you might have calculated when you're drawing lots of current, eg when using a radio transmitter, particularly on a high duty cycle mode eg FM, SSTV or WSPR.
PS: I've now written six books on various aspects of amateur radio. Whether you experiment with antennas, enjoy QRP or are starting out in radio there's a book for you. Find out more here.
I've had great results with 50 ohm oblong loop antennas for 144 MHz. But what about 28 and 50 MHz? Today I built one for those bands. Watch the video to see how it performed.
PS: Want to learn more about portable antennas? You'll find many ideas and projects in the top-selling Hand-carried QRP antennas.
The fires are far from over and the above good work amateurs are doing is continuing. In fact VKs have been assisting with communications not just in the last few weeks but going back several months at least.
Information on various bushfire appeals appears here if you wish to donate.
Accounts of Australian amateur involvement in bushfire communication (going back to 1939) can be found in these issues of Amateur Radio magazine:
We're always told that if you used a balanced antenna, such as a tuned feeder dipole, one should use a balanced antenna coupler rather than something that's simple and unbalanced eg a single L-match.
In this video I do some tests on WSPR with a tuned feeder dipole (20 metres end to end, 8 metres feedline) on 14, 18 and 21 MHz. I swap between a balanced antenna coupler and an unbalanced coupler. Are there differences in signal reports? Watch and find out!
PS: Find hints and tips for working DX in Minimum QRP. It's the top-selling manual on the equipment, antennas, operating and strategy of successful QRP operating. And its techniques work for 100 watts as well. 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.
Most will have heard about the still-raging bushfires in much of south-east Australia. There have been fatalities, many have lost their homes and thousands have been forced to flee. Roads are cut and the navy has been evacuating some by sea. Air quality in Australian cities is currently amongst the worst in the world due to the smoke.
Communications is important. Mobile communication sites have been destroyed and emergency satellite phones have been dropped. ABC Radio has been covering the fires on its AM and FM frequencies, providing vital advice to residents and travellers in the area.
It is at times like these that the capabilities of technology some would think as 'old hat' (such as AM radio) shine. A 50 kilowatt AM transmitter, particularly on the low frequency end of the band, can provide day and night blanket coverage out to 400 or more kilometres. And even 10 kilowatts in the middle of the band can reliably cover 200 or more km.
A good receiver can help with fringe area AM reception. Failing that a good antenna with a mediocre receiver can do wonders. Especially if it's a multi-turn tuned loop such as demonstrated below:
