Category Archives: QRM

Hi there, you might remember my post from last month focussing on the Bonito MegActive MA305 E-field antenna, kindly supplied to me for testing, by Bonito themselves. That post was essentially a report on my experiences travelling to Crete with the MA305, navigating through security at London Gatwick and Heraklion airports (mostly with relative ease), but more importantly, how well it worked with the equally excellent Eton Satellit portable receiver. Whilst in Crete I managed to copy a number of personal firsts, including CRI on 7295 kHz, via their relay in Bamako, Mali, The Voice of Beibu Radio on 5050 kHz, Nanning, XSL ‘Slot Machine’ on 6251 kHz USB, Ichihara, Japan, S32 ‘The Squeaky Wheel’ on 3828 kHz and NHK World Radio Japan, 11910 kHz. I also copied RTM Wai/Limbang FM on 11665 kHz from Kajang, Myanmar Radio on 5985 kHz and AIR Bhopal on 4810 kHz, amongst others – all of which I would certainly consider to be difficult catches in Europe.

The USB-powered MegActive MA305 is perfect for DXing on the move…

Despite excellent all-round results from the ultra-portable USB powered MA305, there was one signal I copied, which more than any other, demonstrated the DXing credentials of this antenna; Radio Tarma from Peru on 4775 kHz. With a TX power of 1 kW, this is a very difficult station to hear in Western Europe, even with a longwire. To catch this station in Crete, with a 22 cm antenna was incredible and it was at that point during my trip that I realised E-field antennas really can work superbly well for hard-core DXers on the move.

Upon my return to Oxford, I immediately started thinking about a DXpedition to the local woods I use for what I consider serious DXing. For obvious reasons, E-field antennas require an electrically quiet environment to ensure maximum SNR performance. In noisy environments, these types of antennas amplify the signal of interest and the background ‘electro-smog’, thus increasing signal levels but critically, not signal-to-noise. Fortunately, the Oxfordshire wood I have been using for a couple of years is only a 10 minute drive from my QTH as I sort of live in the countryside anyway and the QRM levels there are just about zero. Now, given that this was essentially an experiment to determine the best possible performance from the MA305, I decided to use my best portable radio. It was quite tempting to pack up the Elad FDM DUO which running on a home-brew battery pack has proven itself to be my best (pseudo) portable radio. However, this is supposed to be a real-world test and in this type of scenario, DXpeditions with the Bonito antenna are much more likely to be undertaken with a portable radio. For these reasons I decided to conduct the test with the venerable Sony ICF-2001D. Having proven to be a superb receiver over many, many dxpeditions (check out the evidence on my YouTube Channel Oxford Shortwave Log) and still regarded by DXers as one of the best ever portable radios – possibly the best – it was the obvious choice.

My portable DXing kit comprising the Bonito MegActive MA305 antenna and the Sony ICF-2001D…a bit of a legend in DXing circles…

I ventured out in early June around 23:00 hrs BST (22:00 hrs UTC), parked the car on the edge of the wood and proceeded to set up my cheap camera tripod, slightly modified to accept a 2 metre-long stainless steel tube, into which a slightly thinner 1 metre tube was mounted, topped off with my partially disassembled ‘Selfie Stick’ – which made it back from Crete lol. The antenna was set up in less than 5 minutes and approximately 4 metres above the ground – much quicker and easier than de-spooling 100 metres of wire! With fresh batteries in the Sony and the MA305 powered up using the USB power brick supplied by Bonito, I was ready to start listening. Almost immediately I heard and recorded a personal first; Lao National Radio, Laos, signing on 6130 kHz, with an excellent signal. Hearing them in the UK was only made possible by the annual two week shut down of the PBS Xizang transmitter in Lhasa, Tibet, but hey, I’ll take it. A brilliant start to my listening session.

Over the next two hours I was amazed at what could be heard using this 22 cm amplified antenna. Bearing in mind I have spent many hours at the woods previously, listening via various 100 metre longwires and a 200 metre Beverage, my expectations were, I thought, realistic in that the MA305 coupled to the Sony would catch some very good DX. However, I did believe there might be an absence of at least some of the more exotic low power stations on the Tropical Band – afterall the MA305 is a very short antenna. Clearly I was wrong, because what transpired during the session surpassed anything I thought possible with this set-up. A list of reception videos follows below and further below, a selection of embedded videos. Some of the entries on this list simply stunned me at the time. Rádio Educação Rural for starters is such an incredibly difficult signal to hear in Europe, even with a very large antenna. Thus, to hear them on an ultra-compact set-up felt very special. Radio Mali is another station that is very difficult to catch with any modulation, except on a large antenna and yet there they were – at the first time of trying. Similarly, Rádio Nacional de Angola and Alcaravan Radio are exotics that at best deliver very weak audio – and most of the time no audio. Furthermore, the signals from Emisoras Pio XII, Myanmar Radio and Rádio Clube do Pará were verging on what I would call superb…I’d never heard anything like it previously except via 100 (or more) metres of wire.

The ICF-2001D and MegActive MA305 Rádio Educação Rural transmitter site in Tefé, Brazil

So what’s next? Well it would certainly be an interesting experiment to compare the performance of the MegActive antenna with the Wellbrook ALA1530 active loop in a similar environment. I have used the Wellbrook on DXpeditions several times, with often excellent results, however, it’s not designed to be portable and if SNR performance could be demonstrated as similar between these two products, given a very favourable price delta, the Bonito antenna would add up to be a very compelling purchase decision. More on that to come. In the meantime, thank you very much for reading/watching/listening and I wish you all excellent DX.

Please click on the links below for the reception videos on the Oxford Shortwave Log YouTube channel.

Selected embedded reception videos from the list above:

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.

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Travelling and DXing with the Bonito MegActive MA305 antenna

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Ok, so officially it wasn’t a DXpedition; it was a well needed vacation in the sun after several hectic months of work, some of which involved travel to slightly more exotic locations. However, these days, I view any travel, whether it be for business or pleasure as a ‘DXpedition’ opportunity! Some of you might remember that I purchased a Bonito Boni Whip at the beginning of 2017 because (a) I needed another antenna and (b) a second Wellbrook loop felt like too much of an extravagance. They’re excellent antennas for sure, but at around £300, I couldn’t justify buying another. Thus, for about a third of the price I bought the Boni Whip. It proved to be an excellent choice – very compact and so perfect for my regular DXpeditions, quick to set up and capable of really excellent DX. There are many videos on the Oxford Shortwave Log YouTube channel that are testament to this. I wrote a couple of articles, published here on the SWLing Post which were seen by Dennis Walter of Bonito, who subsequently contacted me and offered to send over their MegActive MA305 E-field antenna for testing. Dennis made it crystal-clear that I was to ‘do my own thing’…test the antenna in any way I saw fit and publish my findings so DXers/radio enthusiasts could learn more about the capabilities of the antenna – from another DXer. I was happy to agree to this arrangement and the MegActive MA305 duly arrived, complete with two lengths of (bayonet BNC terminated) high quality H-155 coaxial cable.

My portable Dxing kit with MA305 antenna The MA305 power inserter and USB power ‘brick’

The specifications of the MegActive MA305 are very similar to the Boni Whip; they both offer a Gain of +3 dBs, second and third order intercept points of greater than +30 and +50 dB respectively and both tune to 300 MHz. The MA305 is supplied with a longer radiating element and tunes down to 9 KHz (versus the 20 kHz lower limit for the Boni Whip). Obviously this isn’t a specification that is going to concern most radio enthusiasts; both offer fantastically wide operating bandwidths. The way in which these antennas do differ quite significantly however, is in how they are powered. The Boni Whip operates from 12 to 15 V, whilst the MA305 operates from 5 to 15 V. Bonito’s design philosophy regarding this feature is based on the increasing difficulty in procuring reasonably priced analogue external plug-in power supplies (they are no longer allowed to be produced due to power consumption restrictions).

Interestingly, when the power supply for my Wellbrook ALA1530 packed up, I called them to purchase a replacement and was told they only have limited stocks remaining. Thus, a solution for powering active antennas with a suitable low-noise supply is an issue that needs resolving. The guys at Bonito figured a USB power source was suitably quiet and with USB ‘power bricks’ almost ubiquitous these days for charging mobile phones and other portable electronic devices on-the-go, the idea could be applied to their active antennas. The result is the MegActive MA305, designed to operate at 5 Volts with no loss of performance. As a DXer who probably spends more time listening on DXpeditions than I do in my shack at home, the USB power solution was perfect. I myself often carry a cheap Chromebook laptop to use as an additional power source for my camera phone when I’m DXing, so Bonito’s design approach resonated with me completely.

Travelling with the MegActive MA305

Ok, so the MA305 is very compact and very light indeed – perfect for a trip to Crete! However, I know from many conversations with my YouTube friends and followers that some of us feel a slight sense of trepidation carrying shortwave radios and antenna systems on board flights, be they national or international. I myself wasn’t really concerned other than if my bag got pulled from the X-ray machine, there’s often quite a long wait whilst the security staff work through the queue of luggage requiring er…human intervention! Predictably, my rucksack did get pulled and I waited patiently until it was my turn to explain the contents! Looking back on this retrospectively, it’s hardly surprising. Other than the usual holiday paraphernalia, my rucksack contained:

A 10.0 metre length of H-155 coaxial cable
A 1.0 metre length of H-155 coaxial cable
Eton Satellit receiver
MA305 Coaxial Power Inserter
MA305 Antenna Amplifier
Bonito USB ‘Power Brick’
Bonito USB Power Cable
NooElec RTL-SDR dongle
NooElect ‘Ham It Up’ upconverter
Various screened cables and connectors
10 metres of equipment wire

I explained to the (friendly) security chap that I was a shortwave radio hobbyist and identified the various pieces of equipment for him, as he removed them from my rucksack. He confirmed my X-ray had ‘lit up’ (in blue as it happens) with metallic/electronic items and was even kind enough to swivel his monitor to show me the mess of items strewn across the screen – just as I had thrown them all into my rucksack! However, after quickly swabbing some of the items, he said all was fine and hoped that I enjoyed my holiday and listening. Service with a smile at Gatwick Airport – and I was on my way. My outbound experience got me thinking whether it would be possible to pack my DXing kit in such a way that it wouldn’t alarm airport security. Thus, for the trip home, I packed all of my cables into my (checked-in) suitcase. I figured it would be obvious there was no security risk associated with cables alone. I then packed my RTL-SDR, upconverter and all of the MS305 components very neatly into a single box and put that in my carry-on rucksack. Now, some might argue that security measures at Heraklion International Airport in Crete differ a little from London Gatwick, but I observed staff at the X-ray machine very carefully monitoring every piece of luggage passing through it – including my own and I passed straight through without a problem. All I did was take my laptop out as usual, and put it in a separate tray. Job done.

DXing with the MegActive MA305

My listening post in Crete, with the brilliant Eton Satellit receiver

My apartment in Crete was on the second floor and a large balcony provided a decent outdoor location for DXing. As regards electrical noise, the location was much quieter than my shack at home, but it certainly wasn’t perfect, thus a good test of the MA305 in a real-world pseudo-urban environment. in an attempt to improve SNR, I bought a cheap ‘Selfie Stick’ and some tape and managed to construct a mount for the amplifier, increasing the overall height above ground by about 1.5 metres and displacing the radiating element an additional 2 metres thereabouts from the building. I’m not sure whether it made much difference, but it seemed like the sensible thing to do for less than 10 Euros.

During my week-long stay, I managed to fit in several listening sessions and copied some really excellent DX from this ultra-compact, USB-powered set up. In fact, the MA305 coupled to the Eton Satellit performed so well, I managed to copy a number of personal firsts, including CRI on 7295 kHz, via their relay in Bamako, Mali, The Voice of Beibu Radio on 5050 kHz, Nanning, XSL ‘Slot Machine’ on 6251 kHz USB, Ichihara, Japan, S32 ‘The Squeaky Wheel’ on 3828 kHz and NHK World Radio Japan, 11910 kHz. I also copied RTM Wai/Limbang FM on 11665 kHz from Kajang, Myanmar Radio on 5985 kHz and AIR Bhopal on 4810 kHz, amongst others – all of which I would certainly consider to be difficult catches in Europe. To hear them with an 18 cm antenna felt pretty special. African shortwave stations were also very well represented and I managed to copy a number of them including Radio Hargeysa on 7120 kHz, Voice of Tigray Revolution on 59150 kHz, Radio Oromiya on 6030 kHz, Radio Fana on 6110 kHz, Radio Ethiopia on 7235 kHz, Radio Sonder Grense on 3320 kHz and Radio Guinée on 9650 kHz. I expected to hear all of these stations, except for Radio Guinée, which is farther away from Crete than the UK. So, all-in-all an excellent result.

Despite hearing a lot of excellent DX whilst in Crete, there is one signal I copied, which more than any other, demonstrates the DXing credentials of the MA305 – and Eton Satellit for that matter. In the early hours of the morning (00:59 hrs UTC) I copied and recorded Radio Tarma from Peru on 4775 kHz. With a TX power of 1 kW, this is a very difficult station to hear in Western Europe, even with a longwire. To catch this station in Crete, at all, was incredible on an ultra-compact set-up. It was at this point during the trip that I realised E-field antennas really do work superbly well for hard-core DXers on the move. It inspired me to conduct further tests back home in the Oxfordshire countryside, where electrical noise is absent. This I did a few days ago, with some quite amazing results on the Tropical Band. More on that to come in my next post. In the meantime, please find text links and embedded videos for selected reception recordings, below. Many more recordings are available on the Oxford Shortwave Log YouTube channel and please don’t hesitate to contact me if you require further information on the MA305 or the Eton Satellit. Thanks for reading/watching/listening and I wish you all excellent DX.

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The Bonito Boni Whip goes from strength-to-strength: hardcore DXing in compact package

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Hi there, subscribers to the Oxford Shortwave Log YouTube channel and regular readers of this excellent website will be aware that I have been using a Bonito Boni whip E-field wideband antenna for a couple of months now. You may have seen my previous post here, detailing some excellent initial DX results achieved with the Boni Whip. What makes this antenna so compelling for a DXer such as myself is simply that it’s so light and compact; I can literally take it anywhere. Currently it lives in a small flight case (see above & below) on the back seat of my car, with either my Sony ICF-SW55 or Eton Satellit, a home-brew battery pack (that literally cost pence) and some peripheral bits and pieces; spare batteries, cables etc. I think it’s probably already clear that if you consider the Boni Whip’s performance as a function of portability and price, it’s out there on its own – I’m not aware of another antenna that can match it. Of course, there are H-field antennas, such as the excellent Wellbrook active loops that will effectively reject QRM, if that’s an issue for the user, but at a significant cost delta.

Since my last posting, I have continued to use the Boni Whip regularly on my DXpeditions and upload the reception videos to my YouTube channel. I have been nothing but totally impressed with this antenna, to the point that I’ve actually been surprised by the signals I’ve caught and recorded with it. Recent catches include a number of low-power stations from Brazil, including Radio Bandeirantes – Sao Paolo, Radio Voz Missionaria – Camboriu (on the 49 and 31 metre broadcast bands) and Radio Aparecida. Some of these signals are incredibly difficult to hear in Europe at all, let alone well and yet the ultra-compact Boni-Whip running off AA batteries, coupled to the (equally brilliant) Eton Satellit managed it with aplomb. Other catches include Zambia NBC Radio 1 – Lusaka and a signal from Bangladesh Betar that sounded as if the transmitter was 5 miles down the road!

All-in-all, I’m extremely satisfied with the performance of the Bonito Boni Whip and highly recommend it to those DXers requiring a high-performance, compact antenna, for use at home in electrically quiet environments or on any DXpedition. You certainly won’t be disappointed.

Please find embedded reception videos below and text links that will take you to the Oxford Shortwave Log YouTube channel. Thanks for reading/watching/listening and I wish you all great DX.

Click here to watch on YouTube

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The Panasonic RF-B65: the legendary portable with a cult following amongst DXers

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Hi there, back in 1990 I was given a Panasonic RF-B40 for my birthday (I think it was my birthday…1990 was a long time ago!). I found that radio to be very sensitive on shortwave, more so perhaps than my Sangean ATS-803A, but ultimately it didn’t really add much value to any serious DXing because it would only tune on shortwave in 5 kHz steps. This rather course tuning arrangement was very limiting in terms of tuning out adjacent noise and copying tropical band – and other signals that weren’t quite on-frequency etc. Frustrated, I lent my RF-B40 to my brother a few years ago and serves me right; following a house move, he managed to lose it! Quite a shame really because almost three decades later, I would have been very interested to put the RF-B40 through it’s paces on a DXpedition or two. You really don’t see them in action very often at all these days.

Above: the Panasonic RF-B40 (not mine – unfortunately) and the RF-B60, mid-DXpedition!

At that time, which was around the beginning of the 1990s, I read a review somewhere and it became clear that the better receiver was quite obviously the RF-B65. Upon it’s introduction into the market, the RF-B65 was immediately recognised as an excellent receiver, however, in the intervening years it’s reputation has continued to grow to the point today where it enjoys legendary status amongst DXers and bit of a cult following. There’s a lot of information on the RF-B65 to be found on the internet, so I won’t go into huge detail, but the obvious question is: what makes thsi receiver so special? Well, it’s a quite compact PPL double conversion receiver, covering 153 kHz to 29,999 kHz AM and 87.5 to 108 MHz, FM. It has a keypad for direct frequency input, although you have to press either the ‘FREQ’ or ‘METER’ buttons prior to punching in the numbers to define whether you wish to access a particular frequency, or band. I actually find that slightly annoying, but you easily learn to live with such trivial matters when using a radio of this quality and performance.

Furthermore, there’s an electronic signal strength meter, a DX/local attenuation switch, external antenna jack, SSB reception mode, 1 kHz tuning steps on shortwave (unlike it’s little brother the RF-B40) and fine tuning. The single bandwidth filter is 6 kHz wide and thus limits selectivity a little, although the SSB option and fine tune helps offset that somewhat. It would have been nice to have a couple more filtering options, particularly narrower for serious DXing in crowded bands, to combat adjacent channel QRM. Build quality is generally excellent as you would have expected from a high-end Panasonic portable and with a very compact form-factor – roughly the size of a paperback book and weighing in at just 1.4 Ibs, it is eminently more portable than a Sony ICF-SW77 or the iconic ICF-2001D/2010.

Ultimately, the RF-B65 continues to enjoy an excellent reputation today, nearly 30 years after it was introduced because it is a wonderfully sensitive receiver and arguably the best-ever performing shortwave portable in the paperback book size category – often touted as ‘travel portables’. I managed to acquire an example in as-new condition from eBay, although mind you, I paid through the nose for it lol – that cult following ensures prices remain very robust! I have tested my example against the equally legendary Sony ICF-2001D, still considered by many to be the benchmark for shortwave portables, and in my experience the Panasonic is right up there with it. There’s virtually no difference whatsoever in sensitivity. Where the Panasonic comes a little unstuck is the lack of bandwidth filtering and SYNC, leading to lower selectivity. However, clever use of SSB and fine tuning does provide quite good compensation for these shortcomings. Overall though, given it’s size, sensitivity, build quality and audio, as a complete package, in my opinion, the RF-B65 is equal to the ICF-2001D, and this is why today, it remains so highly sought after.

Below are embedded reception videos and text links to the Oxford Shortwave Log YouTube channel, with various DX catches on the RF-B65. Some of these are considered quite rare in Europe, for example EXPPM Radio Educación’s 1 kW signal from Mexico City, the now defunct ABC Northern Territories on 120 metres and Radio Bandeirantes from Sao Paolo, Brazil, amongst others. Please note; right at the bottom of this post is a link to some very recent comparisons with the brilliant Eton Satellit – one of the very best portables currently on the market today. The vintage Panasonic holds its own, despite 30 years of supposed technical innovation in electronics. Thanks for reading/watching/listening and I wish you all great DX.

Click here to view on Oxford Shortwave Log

Click here to view some comparison videos of the RF-B65 and Eton Satellit

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The Bonito Boni whip: proving to be excellent portable antenna for DXing

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Hi there, if you’re a subscriber to the Oxford Shortwave Log YouTube channel, you will be aware that I have been using a Wellbrook ALA1530 H field antenna, for 15 months or so, with (at times) excellent results. A while back I was on the lookout for a second antenna, however at more than £250, I couldn’t justify purchasing a second Wellbrook. Ultimately I splashed out on the Bonito Boni whip E-field wideband active antenna (20 kHz to 300 MHz) and with a very compact form-factor suitable for DXpeditions/portable operation in general, the Boni whip definitely ticked all the boxes. Furthermore, with reasonable second and third order intercept points of +55 and +32.5 dBm respectively, the Boni whip, on paper at least, looked like a pretty good buy at around £100.

Initial testing at home confirmed, perhaps not surprisingly that the Boni whip could not match the SNR provided by the Wellbrook ALA1530 in a noisy, urban environment. However, less predictably, the Boni whip has proven to be a truly excellent antenna away from the ubiquitous blanket of ‘electrosmog’ at my QTH. Furthermore, it really is so compact, I simply leave it in the car in a small flight case, with a portable and connectors etc. for ad-hoc listening sessions. Since returning from my most recent trip to Brazil, I have had a chance to review my most recent catches with the Boni whip, some of which are realy pleasing and most definitely underline the excellent performance of this diminutive antenna. In particular, signals from Radio RB2 on 11935 kHz and Radio Aparecida on 11855 kHz, both low power Brazilian stations, are testament to how sensitive the Boni whip is in an electrically quiet environment. Check out also the quality of longwave signals from Poland and the Czech Republic – simply amazing for such a physically short antenna. Finally, there’s a personal first from Lusaka, Zambia, Voice of Hope Africa on 13680 kHz. All the more rewarding that this was actually copied in my work office!

I hope you found this article interesting. There are embedded reception videos below and text links for all, which will take you directly to the relevant video on the Oxford Shortwave Log YouTube channel. Thank you for reading/watching/listening and I wish you all excellent DX!

Click here to watch on YouTube

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North American and European medium wave signals into Oxford, UK

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Hi there, I’ve been rather preoccupied of late, initially with the brilliant Tecsun PL-310ET and latterly with the even more brilliant Eton Satellit. However, in the background (as always), I’ve been trying to catch transatlantic medium wave DX. My listening schedule is broadly based on shortwave DXing during daylight hours – when I’m not at work of course, typically a Friday afternoon or at weekends – and always with a portable. Evenings usually start off with a tune around the tropical bands, followed by setting up the Elad FDM DUO to run some medium wave spectrum recordings overnight. In the past few days though, my daylight DXing has been bolstered by my NooElec RTL-SDR and ‘Ham it up’ upconverter. I bought the device over a year ago and after some initial exceitement, it quickly became quite obvious that I needed a reciever with a bit more ‘oomph’! However, it’s actually proving very useful to view signals on a spectrum, even when I’m conducting most or all of my listening on a different (i.e. higher performing) receiver. Ultimately, the RTL-SDR is always going to be a compromise, with relatively limited sensitivity, but because by it’s very nature it has excellent selectivity, overall it’s a reasonable performer. My particular RTL-SDR performs quite well if a decent antenna is employed with it, such as a longwire or the Wellbrook ALA1530 active loop.

Anyway, back to the medium wave DX. In the past month or two, I’ve copied a number of stations from North America, with really nice signals, including WRCR Rampano – New York, WFED Federal News Radio – Washington DC, WENE – Endicott and WUNR – Brookline from Newton, Mass. I’ve also recorded a lovely interval signal from RAI Radio 1, Milano and further European signals from Magyar Radio, Budapest and Radio Slovenija 1, from Ljubljana. During the past 18 months or so of DXing, I have been mostly ignoring signals coming into Oxford from the continent. However, that changed a little after I stumbled across the RAI Radio 1 interval signal, which complete with the rather rousing Italian National Anthem, inspired me to dig out some more European DX. I’m actually finding European DX quite rewarding, particularly because it feels new again – not surprising since I haven’t listened to Europeans on medium wave for any length of time since the 1980s. I hope you enjoy the reception videos – embedded video and text links follow below and I wish you all the very best DX.