Category Archives: QRM

DXpedition antenna testing: the Bonito Boni whip and a 240 metre barbed wire fence

 

Hi there, a few days ago I posted some reception videos comparing the performance of the Boni whip with a 30 metre longwire antenna at home, with a further check against the performance of the H field Wellbrook ALA1530 active loop. The conclusion of those tests was essentially confirmation that E field antennas don’t usually perform very well under a blanket of ‘electrosmog’ and that only on Longwave, did the Boni whip prevailed over the longwire; otherwise there was no usable difference in performance between the two.

                         Sony ICF-SW55 receiver                                     ‘Quiet’ location for Boni whip test

This prompted a number of my subscribers to ask when I would be taking the Boni whip on a DXpedition for an outdoor test against the Wellbrook and either a substantial longwire, or the 200 metre Beverage. Time is limited right now for a full test, however, I managed to throw together a kit of parts necessary to run a quick set of comparison tests with the whip, against the barbed wire fence I use for ad hoc DXing when out walking the dog! Over a period of an hour or so, I managed to copy a few stations on 31 and 49 metres and thus recorded signals using the Sony ICF-SW55 receiver with the Boni whip and barbed wire fence. Now previously, I have used that fence as an antenna for the excellent little Tecsun PL-310ET, with some nice results. However, after this series of tests, my views on the fence have changed a little. Obviously it might be somewhat directional and earthed along it’s length, neither of which I’ve checked, however, notwithstanding these performance-related factors, the performance of the whip which at home had been terrible, surprised me greatly. Text links to a set-up video and the reception videos on my Oxford Shortwave Log YouTube channel follow directly below, with embedded videos at the end of the post. 

Finally, if you’re looking for a well performing, compact and portable active antenna for outdoor use in quiet environments and of course, DXpeditions, I would definitely recommend the Boni whip. Just bear in mind that the SNR it delivers at home might not be usable for anything more than casual listening.

Thanks for watching/listening/reading 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.

Urban DXing: testing the Bonito Boni whip against a 30 metre longwire & the Wellbrook ALA15030

Hi there, if like me, you live in an urban environment, chances are QRM is having a negative impact on the quality of the signals you’re receiving at home. The presence of electrical noise makes antenna choice very important, particuarly if you’re planning to spend more than a few £££s on something more sophisticated than a length of wire. Recently I was considering the the purchase of a second compact antenna, for use at home in my shack and out and about on DXpeditions. I already had the excellent Wellbrook ALA1530 H field antenna, but at more than £250, it’s very costly and thus it seemed rather extravagent to buy a second one, if I could find something with similar performance for less expense. Space is at a premium at home and of course I take much of my equipment out on DXpeditions, so the Bonito Boni whip active antenna appeared to be an ideal choice. A wideband active antenna (from 20 kHz to 300 MHz) operating from 12 to 15V DC, with a very compact form-factor 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.

 

Now, clearly, an E field antenna such as the Boni whip is not going to match the SNR provided by the H field Wellbrook ALA1530 in a noisy, urban environment. I have uploaded a few reception videos to my YouTube channel to demonstrate this, making a direct comparison of the two. However, what about the performance of the whip versus a simple longwire in an urban environment? Is there a delta in performance? The value proposition of the whip is primarliy in it’s performance, coupled with portability I suppose, but that must be considered a secondary requirement. The whip might be 10 or 15 times more expensive than a reel of cheap equipment wire, but will the reception justify the cost delta?!

Text links follow directly below, with embedded videos thereafter; you will find 3 reception videos comparing the whip and a 30 metre longwire, on shortwave and one each for LW and MW. At the end of each video there’s a section with the Wellbrook loop, just to calibrate where the longwire and whip are in terms of a much more effective H field antenna. The result? Well, there’s not much to separate the longwire and Boni whip, except on LW, where the whip prevails. A friend told me recently, if reception is rubbish at home under a blanket of QRM, don’t blame the antenna, the noise is the real problem. He was right. So, the next tests are to be undertaken out in the field, where the whip has a real chance to shine. I’m rooting for it because to have an antenna that performs as well as, or close to my loop out in the woods, yet can be packed away into a small case would be brilliant. Thanks for reading/watching/listening.



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.

Oxford Shortwave Log: Sony ICF-SW77 vs ICF-SW55 vs Tecsun PL-310ET

Hi there, I recently posted an article regarding a couple of recent DX catches with the Sony ICF-SW77 receiver and went on to explain the background to a multi-receiver test I had started conducting, comparing it with its stablemate of the time the ICF-SW55 and, just for the hell of it, a more modern, yet modest portable in the shape of the brilliant little Tecsun PL-310ET.                                                Sony ICF-SW77

The initial results confirmed the performance of the Sony receivers to be very similar and thus the justification for the original price delta of £100 in the UK to remain in question. The first target signals chosen and in the original post were ABC Northern Territories on 4835 kHz and Radio Mali on 9635 kHz.

Sony ICF-SW55                                                        Tecsun PL-310ET

The initial results reinforced my view that the PL-310ET is a great portable for relatively small money; it managed to copy both signals, something you might not expect from what is essentially a budget receiver.

Below are links to the next 6 reception videos on the Oxford Shortwave Log YouTube channel and once again, featuring all three radios. I have used two different antennas during the testing – a 75 metre longwire and the Wellbrook ALA1530 active loop, running on batteries. The accompanying text description to the videos indicates which antenna was used.

Although the PL-310ET clearly struggled with the more ‘hard-core’ DX signals amongst those detailed below, the fact is, for less than £40 in the UK (and I’m certain even less elsewhere), Tecsun have delivered us a portable radio that really is capable of real DX. With DSP, a number of audio bandwidth filter options and great sensitivity, it’s a winner for beginners to DXing and to ‘old hands’ who want a radio in their pocket when they take the dog for a walk for example (something I do all the time – you never know when you’re going to come across the next barbed wire fence!). As for the Sonys, well I’m still not convinced one way or the other that the £100 price delta on the original price of the ICF-SW77 was worth the money – the ICF-SW55 is pretty close to it in terms of delivering discernible audio across all of the below reception videos. I’d be interested in your views and note there will be a final posting on this 3-way receiver comparison to wrap things up. In the meantime, thanks for reading/watching/listening and I wish you good DX!

Enbedded videos follow below.

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.

Fred Lundgren: “What happened to AM radio”

We all read articles about the utility and the demise of AM (mediumwave) broadcasting. In this short article via the Huffington Post, Fred Lundgren (Founder and CEO of KCAA) discusses “What Happened To AM Radio (that’s NOT a question)”:

On Christmas Eve morning, the electricity went off at our house and panic quickly spread among our younger guests.

First, the TV sets went dark. Then, the desktop computers began to die as UPS back up batteries failed. For a while, we were reassured by the sound of familiar alarms, but then suddenly, total silence. Could this be the end times? Is this the onslaught of the apocalypse?

Smart phones were quickly deployed and guests began calling each other from room to room. The panic began to subside when several millennials volunteered communal usage of their wireless data plans. The kingdom would be saved…crisis abated.

[…]As the younger generation huddled around the smart phones with data plans, I began to think of the outage as an opportunity to listen to AM Radio, so I went to my office and dusted off my old RCA SuperRadio III.

I couldn’t remember the last time I replaced the batteries but to my surprise, it came to life with its signature popcorn sound when I pushed its big silver button. “IT’S ALIVE” WOW…the AM band was extraordinarily quiet and responsive.

[…]I scanned across the dial from 610 AM to 1590 AM. All the stations were as clear as a bell. Then, I decided to press my luck. I tuned to KTSA 550 AM in San Antonio and then I moved the dial slightly to the right and heard KLVI 560 AM in Beaumont, Texas. Every station was booming in loud and clear.

I felt like a child with a new toy. I dialed up and down the band, experiencing the clear booming sound of AM Radio without any noise or interference. It was a feast for the senses. It was beautiful.

After a few minutes, one of my daughters walked in and asked about the source of my entertainment. I pointed to my SuperRadio and said joyfully, “listen”. She looked at the big black box and asked “How can you listen with the internet and electricity off?” I responded, “It’s my portable SuperRadio III.” Before I could explain further, she shrugged her shoulders, closed the door and went back upstairs, convinced that her Dad was conducting some sort of high tech experiment.

In a manner of speaking, her assumption was correct. I was listening to AM Radio in a big city without the interference of computers, wireless modems and an overloaded electrical grid. For the first time in my recent memory, the “Senior Radio Band” sounded beautiful. Sadly, my experiment ended with preordained results when the electric power was restored.[…]

Click here to read Lundgren’s full article on The Huffington Post.

The brilliant little Tecsun PL-310ET: serious DXing on a budget – part 2

Hi there, here is part two of my original post containing various reception videos for the amazing Tecsun PL-310ET pocket shortwave receiver. I continue to be amazed at the sensitivity and selectivity of this rather modest and diminutive receiver, particularly at it’s price-point of around £40 in the UK and less elsewhere! Here is the second half of the reception videos, with some nice signals from Brazil, Guinea, Ethiopia, Swaziland and India. You might notice that some of these catches involve the use of a 240 metre (approx.) length of barbed wire fence! I’m not sure how beneficial the electrical properties of the fence were, probably somewhere between not great and not good lol, but some pretty decent DX was had with the PL-310ET attached to it via the external antenna socket and a crocodile clip!

The barbed wire fence extends almost to the treeline on the horizon; about 240 metres

I hope you enjoy this set of reception videos, they certainly help to demonstrate the great performance of the PL-310ET and in addition of course, it’s ability to handle large antennas quite well. Embedded videos and text links follow below. Lastly, there are now approaching 1,200 reception videos on my YouTube channel Oxford Shortwave Log and I would like to take this additional opportunity to thank everyone for their support, friendship and advice.  In the meantime, I wish you all a very Merry Christmas, a Happy New Year and excellent 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.