Tag Archives: Longwire antenna

Wire antennas vs. mag loop antennas

In the past few weeks, I’ve gotten a lot of questions from readers who are trying to decide if they should install a magnetic loop antenna or a simple wire antenna at their home. Obviously, most of the questions come from shortwave radio listeners, but some have come from ham radio operators as well.

I realize that there’s a common theme to my answers and I thought it might be useful to share it here on the SWLing Post for future reference. I started to write a slightly more comprehensive article about this, but I quickly realized I want to keep my advice as short and clear as possible. I’ll be painting in broad brush strokes, but here you go:

If you live in an environment with a lot of radio interference…

Magnetic loop antennas are your friend.

By design, mag loop antennas are some of the best antennas for mitigating the radio frequency interference (RFI) that plagues so many of our homes and neighborhoods. When oriented vertically, mag loop antennas can also be rotated to null out unwanted signals on lower frequencies.

Mag loops come in a wide variety of configurations:

  • The most popular among SWLs are wideband amplified loop antennas manufactured by companies like Wellbrook, Chameleon Antenna, MFJ, DX Engineering, Cross Country Wireless, Bonito, and a number of manufacturers in China. Unlike passive loop antennas, wideband amplified antennas require no manual tuning. These loops do require a power source, typically fed through a Bias-T or batteries.
  • Passive loop antennas are popular among ham radio operators because they’re easy to build and, unlike amplified loop antennas, one can transmit into them if designed correctly. They’re less popular among radio listeners only because they typically have a very narrow bandwidth and need to be re-tuned (via a variable capacitor) each time you move frequency even a few kilohertz. The NCPL (Noise-Cancelling Passive Loop) which is also known as the Moebius or YouLoop is a bit of an exception and doesn’t require tuning, but does require a receiver with a very high dynamic range.

Loop antennas can also be very stealthy. In fact, Loop on Ground (LoG) antennas are essentially invisible and could be deployed (under the cover of darkness, of course!) in the most restrictive of neighborhoods. Note that since LoGs are horizontal, they are essentially omni-directional. [13dka corrects this in the comments: “This is somewhat ambiguous and not entirely correct: LoGs are horizontally oriented but (somewhat surprisingly) vertically polarized, and even more surprisingly they have the trademark property of verticals”]

We’ve also featured other stealthy loop designs like this porch loop.

As with any antenna, mag loops prefer to be outdoors but can be effectively used indoors if that’s the only option.

If you live in an environment free of radio interference…

Outdoor wire antennas are very hard to beat.

I am a case in point, in fact: I live in a rural, remote location without any meaningful RFI. All of my external antennas are homebrew wire antennas and they serve me incredibly well.

If you’ve been a reader for long, you may note that I don’t personally review amplified magnetic loop antennas often–these are typically published by some of our amazing contributors. This is because I like to do “apples to apples” comparisons and usually don’t have a second compact magnetic loop antenna for comparison here at SWLing Post HQ.

Almost without exception, my cheap homebrew wire antennas outperform wideband amplified mag loop antennas…sometimes, by orders of magnitude.

Many years ago, I tested a Pixel Loop amplified mag loop antenna (now under a different name and sold by DX Engineering) specifically for use on the mediumwave band to null unwanted stations. It was a very capable amplified mag loop antenna, but other than its MW nulling abilities, all of my homebrew wire antennas outperformed it on the HF bands. Reception was, at times, dramatically better on my wire antennas.

Of course, for a wire antenna to perform properly, it needs to be deployed properly. There are excellent resources out there that describe ideal heights and configurations for any given wire antenna design.

Keep in mind that wire antennas can be incredibly stealthy as well. It’s very difficult to see a wire antenna among or in front of a patch of trees, for example. At a previous home, I deployed a horizontal delta loop antenna on my property that–if you knew where to look–was easy to spot from the road. In all of the years we lived there not one neighbor took note, though, because the antenna wire had sky blue jacketing and I deployed it while no one was looking.

Summary

Experiment!

This isn’t an either/or choice for most of us. There’s no harm in building a simple wire antenna and trying it at home first. If the local noise floor is high, then consider adding a magnetic loop antenna to your arsenal as well.

You might find that the wire antenna has an advantage on frequencies where you have less radio interference, and the mag loop serves you well in those portions of the band with thicker RFI and QRM.

Find the best antenna system that works for you at home, but always remember that hitting the field with your radio has advantages as well!

What did I miss?

I omitted numerous antenna designs that aren’t straight-forward loop or simple wires. Check out some designs by our contributors Grayhat, , TomL, and many others here on the SWLing Post. As always, please feel free to comment!

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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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Your support makes articles like this one possible. Thank you!

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The WDX2RADIO Timeless Classic longwire antenna

Mike (N1YKH) writes:

Hi Thomas, Just wanted to promote an antenna I sell for a fellow HAM, It sells via http://www.dipolesusa.com/shortwave.html

WDX2RADIO Timeless Classic. 50′ foot longwire antenna kit w/ 25′ foot lead in, quick clip (to click onto a telescoping antenna), wire connector ends to radio, twine, shrink tube for sealing connections, tape, and insulators. Includes instructions. This is very similar to the Shortwave Antennas that were sold at every radio store (incl Radio Shack). Now hard to find. Works with any Shortwave Radio, desktop or portable, new or vintage. I supply all of the clips and lugs necessary.

Perfect for Shortwave, LW, AM DX and General Communications Reception, .05khz to 54 Mhz.. Simple, classic design and installation. Excellent Performer, Big Bang for the Buck and a Super Value. Nothing beats a Longwire Antenna for Shortwave Reception.

Ready to connect to antenna screw on back of set, or to clip onto telescoping antennas on most portables. Everything you need to Mount Outdoors, or in Attic. Easy to follow instructions included.

73 Mike N1YKH

This is certainly a classic wire antenna design–indeed the first wire antennas I ever used for SWLing. And, yes, I purchased it at RadioShack way back when!

Click here to view at Dipoles USA.

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The brilliant little Tecsun PL-310ET: serious DXing on a budget – part 1

tecsun-pl-310etHi there, a good friend of mine Mr Thomas Brogan mentioned to me recently that his little Tecsun PL-310ET was proving to be an excellent receiver and that it would suit my DXpedition activities. Now, as someone who likes to push the envelope of performance with sophisticated portables, usually coupled to very large antennas, a cheap little Tecsun might not have been an abvious choice for my next purchase. However, Mr Brogan (who has an excellent Youtube channel by the same name – check out his wonderful collection of vintage and modern receivers) previously suggested I buy, for similar reasons, the Sony ICF-SW100. That little masterpiece of electronics turned out to be one of the best receivers I’ve ever owned. I felt compelled to take notice because Tom never gets this stuff wrong! A few days later I found myself in Maplins – again – and there it was on the shelf at just under £40, so I bought one.

I got back into shortwave listening about 18 months ago, after many years of inactivity whilst my poor Sangean ATS-803A rotted away in the garden shed and Sony ICF-7600G long-gone via eBay. To start all over again, I bought a Tecsun PL-360.  What a great little portable that turned out to be – there are over 100 reception videos on my YouTube channel demonstrating how it continually performed above and beyond the very modest price tag. I even managed to hear ABC Northern Territories 4835 kHz on it once –  simply amazing for a receiver under £30. Given my extensive experience with the PL-360 and having learned the PL-310ET shared the same DSP chip, I was expecting the same, or at least very similar performance and the only real benefit to upgrading to the PL-310ET was the direct frequency access.  However, I was wrong about that!

pl-360

The brilliant Tecsun PL-360 got me back into shortwave radio for less than £30

About a week after buying the PL-310ET,  I managed to get out on a DXpedition and with 30 metres of wire attached to it via the external antenna socket, I started tuning around the SW bands. Quite simply, I was amazed at the sensitivity and selectivity of this diminutive little portable. With the proven DSP receiver chip and a number of audio bandwidth filter options  from 1 to 6 kHz, coupled with direct frequency access via the keypad, it was a joy to use and listen to. In just over an hour I had  copied signals from North Korea, including their internal service KCBS Pyongyang, Zanzibar BC, ABC Northern Territories (at the first attempt!), Zambia NBC Radio 1, Radio Oromiya and Radio Amhara from Ethiopia, amongst others. Brilliant stuff and clearly demonstrating that the overall hardware/software package with the PL-310ET is a step up in performance over the PL-360 and capable of proper DX for a very modest outlay. Interestingly, in a conversation with Thomas Witherspoon regarding the PL-310ET, he reminded me that it was one of his go-to radios for travelling and confirmed it’s excellent performance.  I would definitely recommend this radio to novices and experts alike.

Reception videos follow below, with more to come in part 2; I hope you enjoy them. Thanks for watching/listening and I wish you all 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.

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Myanmar Radio, Yangon, heard in Oxford UK on 49 and 41 metres

Myanmar

Hi there, I thought some of the readers of SWLing post might be interested in my reception of Mayanmar Radio, Yangon, during a late-night DX’pedition in Oxfordshire, UK. I managed to catch them on 5985 and 7200 kHz; the latter was a personal first and perhaps further confirmation that my 200 metre longwire is contributing in a positive way to my mobile listening post. Subscribers and regular visitors to Oxford Shortwave Log on YouTube will know that I am forever trying to push the performance of my vintage portables to the limit of what’s possible, in the hope that I might hear something very exotic. it’s happened once or twice and thus worth all the effort in the small hours. Thanks for watching/ listening.

Direct link to Oxford Shortwave Log for Mayanmar Radio reception video 5985 kHz

Direct link to Oxford Shortwave Log for Mayanmar Radio reception video 7200 kHz

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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