Category Archives: Antennas

A Review of Two Medium Wave Signal Boosters

By Jock Elliott, KB2GOM

It was the survey that Thomas, our Maximum Leader, conducted that got me to thinking about this.

The survey revealed that portable radios were used 38.6% of the time by SWLing Post readers as their “daily driver.” I like portable radios, too, and use them frequently. Hold that thought for a moment.

I also like medium wave DXing (content DXing, really, I enjoy tuning around for unusual programs) because, as Gary DeBock once put it: “It’s a target-rich environment.” With that in mind, I was exploring the CCrane website and found a couple of items – the Terk AM Advantage and the Twin Coil Ferrite® AM Antenna Signal Booster that looked like they might help portable radio listeners who want to pull in medium-wave signals better. I asked the CCrane folks if they would like to review both products, and they sent them to me without charge.

Bottom line: they both work for boosting reception of medium-wave signals.

The Terk AM Advantage is a nine-inch tunable loop encased in plastic, and it requires no power supply. Simply place it near your portable receiver and just the dial to the desired frequency, and you could get up to a 20 dB gain in the signal you want to hear. The loop of the Terk AM Advantage inductively couples with the ferrite antenna inside your portable radio, although the unit comes with a direct wire connector that can be used with some radios.

I tried the Terk AM Advantage with my CCrane Skywave SSB on an AM that was coming in with a lot of static at my location. Without the AM Advantage, I had 3 bars of signal strength. As soon as I placed the AM Advantage close to the Skywave and adjusted the tuning knob, the signal strength increase to 5 bars, and the audio was much easier to hear with less noise.

With my Tecsun PL-880, which has a numerical signal strength meter, signal strength was 11 without the AM Advantage, but with the AM Advantage, signal strength increased to 14, and it was much easier to hear. The Terk AM Advantage definitely provides a modest boost in signal strength and clarity, is easy to use, and requires no batteries or external power supply.

The Twin Coil Ferrite® AM Antenna Signal Booster is more complicated. It consists of an antenna element that measures 8.5″ W x 2.5″ H x 1.25″D, a tuner unit that measures 3.25″ W x 4.25″ H x 1.25″ D, a small ferrite stick, and some patch cords. It comes with an AC adaptor and can also be powered by a 9-volt battery. For radios with external antenna connectors, package also includes a RCA female patch cord to two bare wire ends.

Set up is pretty easy: connect the tuner unit to the antenna element with a patch cord; connect the tune to the ferrite stick with another patch, and provide power through either the AC adaptor or 9-volt battery. (I used a battery).

Here are C.Crane’s directions for how to use The Twin Coil Ferrite® AM Antenna Signal Booster with a portable radio:

Place the Tuner Control in a comfortable location relative to your radio. Place the Antenna Element a few feet away. If the Antenna Element is placed too close to the radio, it will cause noise on your radio.
Place the Ferrite Stick on top of the radio near the center. Placement will vary depending on where the internal AM antenna of the radio is located.
For testing purposes, tune your radio to any weak AM station. It is important that the station be weak so you can clearly detect the improvement in reception.
Rotate the Fine Tune control, it will click on and the red LED indicator light will come on. Turn the Coarse Tune control knob slowly and you will likely notice a change in reception at some point on the dial. Adjust the control knob until you notice the most improvement on your signal. Now you can use the Fine Tune control for further refinement.
Move the Ferrite Stick around the radio to find the position that affects the signal the most. This position is the “sweet spot”, or the best position. Again, adjust the Fine Tune on the Tuner Control for the best reception possible. (I used rubber band to hold the Ferrite Stick in place, but the unit comes with some double-stick foam tape to hold it in place.)
Now you can orientate the Antenna Element for best reception. In most cases, the Antenna Element does not have to be adjusted again. When radio noise is a problem, try rotating the Antenna Element in the direction which reduces noise to a minimum.

And The Twin Coil Ferrite® AM Antenna Signal Booster works like crazy! With same station on my CCrane Skywave SSB, it boosted signal strength from 3 bars to full scale. With my Tecsun PL-880, it increased signal strength from 11 to 38.

In my view, although The Twin Coil Ferrite® AM Antenna Signal Booster costs twice as much as the Terk AM Advantage and is more complicated to use, it is more than twice as effective in boosting medium-wave signals.

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Wellbrook Communications is closing shop

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Mark Fahey’s Wellbrook antenna

Many thanks to SWLing Post contributor, Dennis Dura, who shares the following news from the Wellbrook Communications homepage:

Wellbrook Communications will cease trading at the end of April 2023.
This is due to retirement.
I would like to thank everyone for their custom over the past 27 years.

No doubt, the venerable Wellbrook loop has helped thousands radio enthusiasts mitigate RFI/QRM and make it possible to once again DX from home.

We wish Wellbrook owners a wonderful retirement!

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In which C.Crane displays a high degree of “cool”

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By Jock Elliott, KB2GOM

Okay, let’s get this straight to begin with: I’m not on C.Crane’s payroll; I get nothing for what you are about to read. I have bought two of their radios with my own money, and they sent me one for review.

Today I received an email from C.Crane, headlined “How to make a shortwave antenna.” It links to an online article, written by Bob Crane, with the same title. Here’s the link.

It explains, clearly and concisely, how to make your own shortwave antenna, and it also adds some safety warnings. Check it out; it’s worth reading and maybe home-brewing your own antenna.

What makes this a high degree of cool is that C.Crane also sells shortwave antennas . . . and yet they tell you how to make your own if you so choose. Nice.

Frankly, I’ve been a fan of the C.Crane company for years. Now I am a bigger one.

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Radio Waves: Exploring a Super Tower, Former BBC HQ, OTA Radio When all Fails, and Saving Historic Radio

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Radio Waves: Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Dennis Dura, Rich Cuff, Ron Chester, and David Iurescia for the following tips:

Exploring a 1 Million Watt Broadcast Tower (Radio World)

The father and son team of Joe and Jeff Geerling have teamed up on radio-related projects before.

Joe is a broadcast engineer, working into his fifth decade in the St. Louis market. He was market chief for CBS Radio for 20 years and today is the director of engineering for Covenant Network.

His son Jeff has spent nearly 15 years as a software architect and developer. He founded Midwestern Mac LLC and is active in many open-source software communities. Jeff recalls that one of his first web programming projects in the late 1990s was to construct an interface to display the current song on 98.1 KYKY(FM)’s initial website for his dad.

Last February, Joe appeared on a video on Jeff’s YouTube channel to install a Raspberry Pi IP KVM in a Covenant Network studio. That collaboration went so well that commenters on Jeff’s videos began clamoring for more appearances by the senior Geerling.

Over a family vacation, Joe and Jeff came to the realization that the iconic Crestwood Master Tower in Shrewsbury, Mo. — nicknamed by its original engineering community as “the Supertower” — would make for a perfect showcase for a new Geerling Engineering YouTube channel.

Given Joe’s expertise with the site, the idea for a video was a natural. In fact they ended up making two. [Continue reading…]

Amancio Ortega is testing the purchase of a former BBC headquarters in London for almost 90 million (West Observer)

The investment activity of Amancio Ortega in the United Kingdom does not stop. Pontegadea, the group that manages the equity investments of the founder of Inditex (Zara, Massimo Dutti, Bershka…) and the richest man in Spain, is negotiating the purchase of a new office building in London, as revealed on Wednesday by the specialized website CoStar News. This, citing market sources, indicates that the operation would be around 80 million pounds (89.7 million euros, at current exchange rates). The building, originally a printing press built in the twenties, is close to the BBC headquarters and, in fact, for years served as offices for the commercial division of British public broadcasting.

The property, renovated in 2015 by the construction company Kier and the firm Brimelow McSweeney Architects, currently houses a business of coworking (flexible office rental). Of the more than 3,000 meters built, 2,100 are available for rent, according to the building’s commercial brochure. Some websites advertise their tables for a price that exceeds 840 euros per table per month. It offers, in addition to parking for bicycles or changing rooms, a kitchen, private offices, meeting rooms or terraces on the upper floor (the fifth) and on the roof. To this we must add a privileged location in the center of the British capital, in the Fitzrovia neighborhood. The building is close to Soho, the British Museum and Regent’s Park. [Continue reading…]

What’s Going To Happen To Legacy Broadcast Bands When The Lights Go Out? (Hackaday)

Our smartphones have become our constant companions over the last decade, and it’s often said that they have been such a success because they’ve absorbed the features of so many of the other devices we used to carry. PDA? Check. Pager? Check. Flashlight? Check. Camera? Check. MP3 player? Of course, and the list goes on. But alongside all that portable tech there’s a wider effect on less portable technology, and it’s one that even has a social aspect to it as well. In simple terms, there’s a generational divide that the smartphone has brought into focus, between older people who consume media in ways born in the analogue age, and younger people for whom their media experience is customized and definitely non-linear. Continue reading →

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The CCrane Skywave SSB 2 and long wire antennas

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By Jock Elliott, KB2GOM

Frequently when people write about attaching a long wire to a portable shortwave receiver, readers will comment that you need to worry about desensitizing or overloading the receiver or ever harming the front end of the receiver. Clearly that can be a concern.

But recently I noticed something on the CCrane website in the FAQ section that shows clearly that CCrane has thought about and dealt with this consideration:

Q: When using the 2-wire adapter and wire attached, why am I not noticing any improvement on shortwave?

A: To see any difference using the 2-wire adapter you will need to have a wire that is more than 30 feet long (we recommend 60-100’) with a good ground wire. Insulated wire will last longer and should be stranded so it is more flexible. If you do not have a good ground, you are actually inputting noise. If you look at the 2-wire adapter (included) you will see an antenna icon and a ground (G) marking. You need to connect them properly when using an external antenna. When a plug is inserted into the antenna jack of the radio the internal rod antenna is disconnected. (See page 30 of the Instruction manual.)

If you check out my review of the CCrane Skywave SSB 2 you will read that I heard a noticeable improvement when connecting the SSB 2 to a 45-foot end fed wire.

Note, though, that if you plan to attach a wire to the SSB 2’s whip antenna, use the 23-foot reel antenna that comes with the radio.

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Loop-On-Ground Antenna Part 3: Tom’s low-noise, low-profile, portable antenna evolves

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Loop on Ground Antenna Part 3

(using multiconductor wire)

by TomL

It dawned on me recently, perhaps due to sloppy thinking or unintended distractions, that I never wrote about my modified Loop on Ground (LoG) receive antenna that I use at parks and such. For over a year now, I have been using 3-conductor rotor wire bought cheap at the local hardware store and have wired the conductors in series. Grayhat (Andrew) was the inspiration when he decided to create a folded dipole along the side of his house.

The usual construction of a LoG antenna for shortwave is a single wire of about 60 feet in circumference in order to not go above one wavelength for 20 meter band usage. If you recall, going above one wavelength will start creating weird lobes in the reception pattern. See – Loop-On-Ground Antenna Part 2.

However, I did not like this 19 foot diameter wire on the ground in public parks just waiting to be tripped over. Like, the time when a horse got loose from its owners and almost tripped over my 60 foot wire. I don’t think I would have liked the resulting lawsuit!

So out of fearful necessity I took some leftover RCA 3-conductor rotor wire, about 29 feet of it, and wired a loop with the conductors in series. This gives about 81 feet of total conductive length. But since it is folded onto itself, there is an undetermined loss of resonant length. Callum (M0MCX) of DXCommander fame has experimented and found folded dipoles need three times more length in the folded section to reach resonance, so my loop is probably around 69 feet (electrically). See – Fold the end of a Dipole Back – What’s Happening?.

In the picture below, the black wire with Ring Terminal at the bottom goes all the way around to the other side, soldered to the green wire, which goes around and is soldered to the red wire, which goes around to the Ring Terminal at the top, plus tie-wraps to hold the wires together.

The next picture is how the Wellbrook Medium Aperture preamplifier is connected to the loop with BNC cable that goes to the 12V power injector. I have had this Wellbrook unit for maybe 6+years with no signs of problems. WARNING – do NOT use the Wellbrook preamplifier in the presence of high powered RF energy like your Amateur Radio antenna pumped with 1000 watts from a linear amplifier; the Wellbrook premap might just overload and get damaged! I did use this loop and preamplifier at last year’s 2022 ARRL Field Day and was able to get away with it because we were only using 100 watts per station. Listening to the 9pm 3916-net trivia group was fun but I still needed to keep it away from the transmitting antennas. Continue reading →

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Jack remembers the Eavesdropper Antenna

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Many thanks to SWLing Post contributor, Jack Dully, who shares a link to this Eavesdropper antenna on eBay and writes:

When I had my roof top antennas, with the original building owner, I put up the Eavesdropper. There were 2 versions: this one with the twin lead-in and the second with a coax lead-in connection. I had both. One strung E&W and the 2nd N&S with a MFJ ant. switch. Both were up for about 7 years with a Zap Trapper surge protector and good cold water ground. They were pretty rugged withstanding blizzards, hurricanes and summer thunderstorms.

Back then, a company called Antenna Supermarket sold them for about 45 bucks a piece. Both worked great for me and they were only about 45′ long center fed From Yonkers, N.Y. I could pull in Madrid and Australia and New Zealand very clearly on my Eton E-1 XM. So I thought some readers might be interested in buying an eavesdropper on eBay, it works well. Take care and enjoy !

Thank you for sharing that, Jack!

I remember seeing the Eavesdropper advertised back in the day. I still believe it must have one of the best antenna names ever! The product image brings back memories of browsing radio catalogs!

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