Many thanks to SWLing Post contributor, London Shortwave, who recently shared his latest SDR project: a field-portable, ultra-compact, SDR spectrum recording system based on the PocketCHIP computer.
London Shortwave has built this system from the ground up and notes that it works well but is currently limited to the FunCube Dongle Pro+ at 192 kHz bandwidth. There is no real-time monitoring of what’s being recorded, but it works efficiently and effectively–making spectrum captures from the field effortless. The following is a video London Shortwave shared via Twitter:
I think this field portable SDR system is absolutely brilliant!
Homegrown innovation
London Shortwave has done all of the coding to make the FunCube Dongle Pro + work with the PocketChip computer. Even though live spectrum can’t be monitored in the field, the fact that it’s making such a clean spectrum recording is all that really matters.
All London Shortwave has to do is head to a park with his kit, deploy it, sit on a bench, read a good book, eat a sandwich, then pack it all up. Once home, he transfers the recording and enjoys tuning through relatively RFI-free radio.
A very clever way to escape the noise.
The kit is so incredibly portable, it would make DXing from any location a breeze. You could easily pack this in a carry-on item, backpack or briefcase, then take it to a park, a national forest, a lake, a remote beach–anywhere.
What I really love about this? He didn’t wait for something to be designed for him, he simply made it himself.
Thanks again, London Shortwave. We look forward to reading about your radio adventures with this cool field SDR!
Regular readers of the SWLing.com blog will be aware that I am passionate about going portable/mobile with my radio listening hobby. There’s just nothing like communing with both nature and a bunch of electrons whizzing along the wire!
As a follow-up to an article I wrote several years ago, I have now prepared two new YouTube videos entitled Preparing for Your Next DXpedition – Parts 1 and 2.
Part 1 covers:
– why we should even think about bothering to go portable with the radio
– the goals to consider when undertaking a DXpedition
– planning your listening depending on the time of day and time of year
– the all important decisions regarding location
Part 2 discusses:
– choosing the right radio for portable operations
– your options for powering the radio
– the antennas you could consider including on the trip
– handy auxiliary equipment
– references and notes to take along with you
– the importance of operator comforts while away
– developing a checklist…..so that you don’t forget to take something important!
These videos will be of interest to shortwave radio listeners and new amateur radio operators. Hopefully, they may be able to assist you in further enjoying our great hobby. They are embedded in this blog post below. You can also view these and other videos on my YouTube channel at Rob Wagner’s YouTube Channel
As always, thanks for watching and your comments are always welcome. 73 and good DX to you all,
Rob VK3BVW
Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.
Hi there, the garden at my house is pretty small and as a consequence, I am very limited in terms of what antennas I can usefully employ. You can’t position anything further than about 10 metres from the brickwork and to compound this, we are surrounded on all sides by neighbours in close proximity. All very nice people, but all very noisy – electrically speaking lol. I simply can’t get far enough away from these sources of electrical noise to achieve excellent SNR.
The solution to my problem was ultimately a Wellbrook ALA1530 magnetic loop, but prior to that I used an end-fed random wire, the performance of which deteriorated as the months went by as the ubiquitous blanked of local QRM continued to increase. Eventually, I was forced outdoors, well away from my town – effectively catalysing my forays into the Oxfordshire countryside on DXpeditions. That first experience of listening to the radio on shortwave, in the absence of any QRM was enlightening to say the least and of course, subsequently, DXpeditions have become a mainstay of my listening activities. However, despite enjoying some great DX successes out in the woods, one has to be realistic about how often it’s possible to leave the house just to listen to the radio. This led me to the purchase of the Wellbrook ALA1530 magnetic loop. It proved to be a triumph of electrical noise mitigation and an absolute necessity in copying transatlantic medium wave signals in such a noisy and compact space. A total game-changer. The brilliant performance of the Wellbrook eventually led to me purchase a second, cheaper active antenna; the E-field Bonito Boni Whip and in turn, that purchase led me to the MegActive MA305, kindly supplied by Bonito themselves for objective testing.
Have DXing kit, will travel…everything you need in a small flight case…
You might remember my initial tests at home confirmed, as expected, that E-field antennas don’t work well in electrically noisy environments (except at LW frequencies in my experience) but outdoors, away from noise, they are superb. I have a number of reception videos on my YouTube channel – Oxford Shortwave Log which clearly demonstrate identical performance of the Bonito MegActive MA305 antenna and Wellbrook ALA1530 magnetic loop out in the woods. So, what if you’ve got a large garden in a suburban area that allows you to be just far enough from sources of electrical noise…how much of a difference does it make to the noise floor of your receiving equipment? Can E-field antennas such at the Bonito MegActive MA305 do the job? Furthermore, how well does a random wire work in a larger garden?
My MegActive MA305 antenna system for mobile DXing…and another use for a washing line…
I was fortunate enough to know someone who owns a house with a large garden, quite close to my QTH (a 10 minute walk) and who was more than willing to let me set up my DXing equipment and sit around until the early hours of the morning, listening to and recording various signals on my Eton Satellit. In preparation, I set up the Bonito MegActive MA305 antenna and hung the radiating element on the washing line – sounds ridiculous but actually worked very well, placing it about 2.5 metres above the ground. I also set up a 40 metre longwire, which at its closest point, was still approximately 25 metres from the house, and 30 metres from the neighbours. This post will focus on the performance of the MA305; a subsequent post will detail the performance of the longwire.
The large garden I ‘borrowed’ for my DXing session with the Bonito MegActive MA305 antenna
Suffice to say, the MegActive MA305 performed admirably during my first listening session. In the middle of the afternoon I copied a very strong signal from The Voice of Korea around 15:44 hrs UTC on the 25 metre broadcast band, followed at 17:10 hrs UTC with a superb signal from The Voice of the Broad Masses 2, Eritrea, on the 40 metre ham band. Later on in the evening I copied Radio Mail with excellent modulation, CHU Canada with voice announcements (almost impossible at home), Myanmar Radio with an untypically strong signal and XEPPM Radio Educación from Mexico City with a signal I would normally expect on a DXpedition-proper with a large antenna.
My conclusions to this experiment are simply that E-field antennas can work in a suburban environment, if you are able to site them far enough away from adjacent sources of electrical noise. I don’t have empirical data on this, however, I can confirm that 10 metres proximity is too close at my QTH and 30 metres is sufficiently far away at this test location. One has to assume the houses nearby are similarly equipped to mine with electrical appliances that generate electrical noise. Thus, if you’re interested in a very well-priced, compact antenna and you live in an urban or suburban environment with access to a large garden/ outdoor space, an E-field Boni Whip or MegActive MA305 might well be suitable – and you’ll have a superb portable antenna for those listening sessions away from home!
Finally, I should mention the Eton Satellit. Much-maligned in certain quarters when it was first introduced into the market, it continues to demonstrate superb DXing credentials. I won’t forget some words of wisdom from a friend of mine and fellow DXer, with more than 3 decades of experience in listening to the bands on HF. He told me that Judging from his own experience with some of the original Grundig Satellit models of the 1980s and early 90s (namely the 400, 500 and 700) he was quite sure that the Eton Satellit is a considerably better DX performer than those vintage sets, that offered great sound for casual listening to international broadcasters, but didn’t perform too convincingly on weak DX signals. The Eton Satellit has been a revelation and I’m pleased to have played a small part in turning around the rather widely held view that it was less than worthy of the Satellit branding.
Fresh out of the box, the Eton Satellit has surpassed all my expectations…
Please find embedded reception videos below and text links to the Oxford Shortwave Log YouTube channel. My next post on this subject will cover the performance of a 40 metre longwire in this large garden environment. Thank you for reading/watching/listening and I wish you all great DX!
Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.
The Arecibo Radio Telescope, at Arecibo, Puerto Rico. At 1000 feet (305 m) across, it is the second largest dish antenna in the world. (Source: Wikipedia)
Many thanks to SWLing Post contributor, Ivan Cholakov, who writes:
Thomas, I did not see a story on the blog about the HF atmospheric heating experiments conducted by the Arecibo observatory a couple of weeks ago.
Indeed, I did miss posting this item. The event timing conflicted with my travel schedule in a bad way. Sadly, I only had one opportunity to tune in and I did too late (by just a couple of minutes!) that day.
Did anyone else catch the on-air experiments from Arecibo?
