Tag Archives: Antenna testing

Jock designs a Horizontal Room Loop to cope with reception issues

Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:


There’s a 50-foot antenna in this room. Can you spot it?

Got reception issues? An idea worth considering: the “Horizontal Room Loop.”

by Jock Elliott (KB2GOM)

When my radio room was in the front of the house (on the east side), it was easy to run a feedline to a large RF-hungry SWL dipole with various stubs and feeders.

Now, however, with my “shack” moved to the SW corner of the house, any attempt to mount an outdoor antenna of any significant length raised potential safety issues because of nearby electrical lines.

Monitoring VHF/UHF is no big deal because of high-performance scanner antennas. HF, however, presents challenges.

My main SWL receiver is a Satellit 800, which has the guts of a Drake R8 and also has a large telescoping vertical antenna. It works okay, but I wanted more signal. I had been looking at small loops and got some great recommendations on Radio Reference, but then I had a thought: what if I turned the 8′ x 12′ room into a giant horizontal passive loop?

Here’s a hint.

So I called a ham friend and ran the idea by him. “Sure,” he said, “give it a try.” He gave me 25 feet of 4-conductor phone wire. Before I could use it, I had to strip off the outer insulation so I could get at the four separate insulated wires inside. The better half helped. Once I had the four wires, I connected two of them together and ran the resultant 50-foot strand around the perimeter of the room by taping the wire to the top of window frames and hiding the wire on the top shelves of book cases. As a result, the horizontal room loop is near the ceiling, about 7 feet in the air, and the room itself is on the first floor.

With the loop in place, I hooked the ends to the clip-in terminals on the back of the Satellit 800.

There’s a switch on the back of the 800 that allows me to quickly compare the loop with the radio’s built-in vertical antenna. And . . . it works! It pulls in more signal than the vertical (as measured on the signal strength meter), but I have not noticed a dramatic reduction in noise. On some stations, the horizontal room loop brings the signal up to full scale, and then the sound is very agreeable indeed.

In all, I am pleased with the results.

For anyone who wants squeeze more performance out of their shortwave receiver, I can recommend giving the horizontal room loop a try. It’s not expensive; it’s relatively easy to do (and undo if you don’t like the results), and just might improve your shortwave reception.

If you are not blessed with a bunch of window frames on which you could tape the wire for your room loop, you’ll have to get creative, but with lightweight wire, you don’t need a massive support structure. Tape, map tacks, or even self-adhesive Velcro segments might work for putting your room loop in place.

I don’t claim that this is the “ultimate” SWL DX antenna, but it certainly improved my situation. Perhaps others have suggestions for improving it.

— Jock Elliott, KB2GOM

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Shortwave antenna options for apartments, flats and condos

A balcony is your friend, if you have one. Otherwise, we need to use other antenna tactics!

Many thanks to SWLing Post contributor, Tim, who writes:

I am a regular subscriber here, but until now have not formally commented. I’ve been an avid SWL since 1977.

I am intrigued by your in-depth article on understanding and setting up SDR’s. But, what about an antenna? How well will these radios work for someone who is an apartment dweller?

I live here in South Florida and am unable to erect anything outdoors. I do get pretty good reception on my Grundig Satellit 800 and Tecsun PL-880. For these, I use either an indoor slinky antenna I bought on E-Bay; or an active indoor tunable loop antenna. This is one of the models past reviewed by you. It is Australian made, and covers 6-18 MHz. Please comment if you can on antenna usage.

Thank You very much!

First of all, I’m glad you enjoy the SWLing Post, Tim!

Great question: no doubt you understand that the antenna is the most important part of your radio equation!

It sounds like you’re currently using a slinky antenna and a portable PK Loop HF antenna.

The PK Loop

You’re on the right track with a PK Loop if you live in an apartment and have no way of putting an antenna outdoors. Being a small magnetic loop antenna, the PK Loop should help mitigate a bit of the noise in your apartment building.

What I love about the PK Loop is it’s small enough that you can re-position and rotate it to tweak noise rejection and find the quietest spot in your listening room. When I travel by car and even by air, the PK Loop is a welcome companion.

Before we talk about investing in a better indoor antenna, let’s make sure we cover a more affordable option first…

External wire antennas

If you have operable windows in your apartment, even fishing a thin-gauged wire out of your window–allowing it to simply hang along the outside of the building–could improve your reception significantly. Of course, if there’s a source of noise outside of your apartment it might only make things worse, but this is at least an inexpensive experiment and the results might impress you.

I actually tested this theory once and published the following results in a previous post about the PK Loop:

I had a fantastic opportunity to evaluate how well the PK Loop would perform in a typical hotel room. My buddies Eric (WD8RIF), Miles (KD8KNC) and I stayed overnight in a hotel on Wright-Patterson Air Force Base during our mini National Parks On The Air DXpedition.

The hotel room was indeed dense with RFI.

We hooked my Electraft KX2 to both the PK Loop and to a simple random wire antenna.

Without a doubt, the PK Loop was much better at mitigating radio noise than the wire antenna we hung on the inside of the hotel window.

Unlike most modern hotels, however, this one actually had operable windows, so we tossed the random wire out the window and made another comparison. In this case, the external wire antenna consistently outperformed the PK Loop, no doubt because it had the advantage of being outside the radio noise cloud within the hotel’s walls. It goes to show that outdoor antennas–even if simply hanging from a room window–will almost always outperform comparable indoor antennas.

So, if you have a way to dangle a wire out one of your window, give this a try.

How long should the wire be? I suppose it depends on how much vertical space you have below your window. For starters, I’d try to suspend at least eight feet of wire outside. If I had the vertical space, I’d try as much as 31 feet.

Important: First you must check to make sure your wire couldn’t possibly touch electrical lines. Never lower a wire outdoors if the wind could blow it into an electric service entry point, power line or any other type of line or cable. You should do a thorough inspection of the site first.

With that said, keep in mind: Stealth is key!

Photo by jay blacks on Unsplash

Can you spot the wire antenna in this photo? Of course not.

Use a thin wire with a black or dark jacket/insulation. Only lower it when using it–don’t leave it out all day long. Check to make sure your antenna isn’t going to interfere with your neighbors below (like landing in their outdoor grill or flower pots!). One strong complaint from neighbors could shut down your operation permanently.

Now back to loops…

If you don’t have operable windows or a way to deploy a wire antenna outside–or you’ve tried a wire antenna and results were unsatisfactory–then you will be forced to stick with indoor antennas which almost always leads you down the path of larger amplified wideband magnetic loop antennas.

This is a topic I covered extensively earlier this year.

Please read the post: Indoor shortwave antenna options to pair with a new SDR.

Indoor shortwave antenna options to pair with a new SDR

Keep in mind that if you’re fortunate enough to have a balcony, this is where you should mount your loop antenna. Check out this post by SWLing Post contributor, Klaus Boecker.

Klaus Boecker’s homebrew magnetic loop antenna.

Note that there are a number of sub $100 indoor amplified antennas on the market, but I would avoid using them–click here to read my thoughts about these.

In addition, read through this post which includes practical low-to-no-cost tips and best practices for shortwave listening at home and on the go.

Frugal SWLing: Investing little, but getting a lot out of your radio

I’m plotting to write a more in-depth article about antennas in the coming months, but it will focus on external antennas and methods of mounting them. When you have no means of mounting an antenna outdoors, in my opinion, your best options are the ones mentioned above.

Post readers: Have I overlooked an indoor antenna option? Please comment if you have experience with indoor antennas!

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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.

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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.

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