Tag Archives: Mediumwave

Valentino experiments with a ferrite sheet loop antenna

Valentino’s homebrew ferrite sheet antenna.

Many thanks to SWLing Post conttributor, Valentino Barbi (I4BBO) who writes detailing a novel approach to FSL antenna design.

Please note that I translated Valentino’s message from Italian to English via Google translate so please forgive any errors. Valentino writes:

FSL antenna radio enthusiasts typically use numerous ferrite bars with high cost, weight and scarcity,

Ukrainian ferrite bar producers have now finished stocks and have raised their prices.

Normally you use this site to build FSL antennas:
http://www.am-dx.com/antennas/FSL%20Antenna%20Design%20Optimization.htm.

I’ve been experimenting with a new antenna design for about 10 days comparing it with a classic FSL with 20 ferrite bars.

Listening to the audio signals are the same, only instrumentally the antenna FSL in ferrite film
Loses -2dB.

The construction is very simple in that the two ends overlap 5 mm.

I did this:

  • I took a sheet of A4 paper, I cut 5mm paper at one end.
  • I laid this sheet on a 10 cm (10 cm) diameter PVC tube.
  • The uncovered part of the tube is cut, now we will have exactly the exact diameter to fix the A4 sheet of ferrite with the overlap of 5 mm.

As for where to source a ferrite sheet, after much research I discovered this supplier almost by accident:

Click here to view the product page and ordering information.

In summary, the main advantages of this antenna design is weight, cost and availability of A4 sheet of ferrite.

Click here to follow Valentino’s antenna project on his website.

Fascinating, Valentino! Please feel free to share any further information about this FSL antenna as you experiment. It’s true that ferrite bars are becoming difficult to source. Sounds like this is an affordable alternative antenna design for ultralight DXing.

How to build a Milk Crate AM Broadcast Loop Antenna

Many thanks to SWLing Post contributor, James Townley, who shares the following guest post originally posted on his Shortwave/Medium Wave blog:


540 kHz to 1700 kHz Loop Antenna (Click to enlarge)

AM Broadcast Loop Antenna

by James Townley

Several years ago, I became interested in medium wave DXing. One of my limitations was the size of my yard, so I developed an interest in tuned loop antennas to compensate, because setting up a beverage antenna was out of the question. I experimented with different sizes of loops, and found that the bigger the aperture, the more gain the loop would have. The tuned loop antenna is also very directional, which allows you to reject, or null out interference from either noise or other stations. Loops are considered bi-directional in that they receive to the front and back, but not to the sides. The tuned loop antenna quickly became my weapon of choice for medium wave DXing.

Recently when the weather began allowing me to enjoy the outdoors, I decided to make another smaller loop antenna from a plastic milk crate I had lying around. I saw the idea on the internet when I observed that someone had used a milk crate for their loop. Click here to see a variety of tuned loop antennas that others have made. Whichever material you decide to make your loop antenna from, just make sure that it is not a conductive material. Wood, plastic, and cardboard seem to be popular materials for loop making. In the photo above, I am using my Sony ICF-2010 to listen to WCCO on 830 kHz. This station is nearly 200 miles south of me, but I am able to receive it with 9 LEDs lit on my signal strength meter while using the loop. There is no direct connection of the loop to the radio, it is inductively coupling with the radio’s own ferrite rod antenna.

If you are interested in making a loop antenna like mine, here are the materials you will need:
120 ft of 18ga insulated wire (I bought a 100 ft spool of cheap speaker wire and pulled the 2 conductors apart):

1 – Plastic milk crate
1 – 15 to 365 pF air variable capacitor (found in many old radios, or a google search to buy one from an internet store)
1 – Tuning knob. Any knob will do as long as it fits the shaft on the variable capacitor.
1 – Tape or wire ties. I used tape to secure the wire while winding, then hot glue when finished.

When you begin to wind your coil, use tape or a wire tie to secure the wire, and leave about a foot of wire. This extra foot of wire will later be soldered to the frame on the capacitor. As you wind your coil, pull the wire snugly and with each turn leave about a quarter inch spacing between each turn. The spacing isn’t critical as long as the spacing is consistent.  I wound 21 turns on my crate. This may differ for you, depending on the size of your crate, or the value of you capacitor. If you find that the bottom frequency isn’t low enough, you can add more wire to make a few more turns. This will lower the bottom frequency for you.

After winding the coil, you can solder each end of the coil to your capacitor. The beginning of the loop gets soldered to the frame of the capacitor, and the other end of the coil to the rotor solder lug on the side of the capacitor. If you do not have a soldering iron, you can use alligator clips to connect your loop coil to the capacitor as well. I secured my capacitor to the inside corner of the crate with hot glue. I put a generous amount of the hot glue onto the bottom of the capacitor frame, and held it to the crate until the glue cooled enough for the capacitor to stay on it’s own. I used enough to get the job done, but not so much that it interfered with the plates in my capacitor. The hot glue seemed to adhere very well. I then checked the spacing of my coil turns, and secured them with the hot glue as well.

I was very impressed with the results after spending some time with the loop. It’s small enough to maneuver around easily, but big enough to give it some gain, so I can listen to daytime DX. I may make another tuned loop using two crates to see how much more gain I get with the larger aperture.

Happy DXing,
James Townley


Many thanks, James, for sharing your project with us! This loop appears to be relatively simple and accessible even to those with little knowledge of soldering or homebrewing. I’m now wondering how a loop made of four milk crates might perform!

Click here to view James’ Shortwave/Medium Wave blog.

DK’s Barn Find: A GE Super Radio II

My good friend, David Korchin (K2WNW), has a knack for finding diamonds in the rough.

He’s been known to find a radio that needs TLC, take it home and restore a bit of its former glory. He’s had some amazing luck in the past.

Recently, DK sent a video of of his recent acquisition: a beat-up GE Super Radio II he purchased for two dollars. This radio will win no beauty contests, but it still plays well.

Check out DK’s video:

Click here to view on YouTube.

Many thanks, DK, for allowing me to post this video. It goes to show you that you should never pass up an opportunity to adopt a Super Radio. Even if the telescopic antenna is all but missing, the internal ferrite bar is where the money is!

Play on!

Arctic Radio Club special mediumwave broadcast May 6 & 7

The Arctic Radio Club Radio Van (Source: Arctic Radio Club)

Many thanks to SWLing Post contributor, Mick Holland, who shares the following:

This popped up on my Facebook news feed this week. Posted by Giampiero Bernardini in the WRTH – World Radio Tv Handbook Facebook Group:

Arctic Radio Club in Sweden celebrates the 2017 Convention in Jönköping, Sweden May 6 & 7th. Our radiostation ( the radiovan above) will be on the air with many different type of programs, mostly in Swedish. The transmitter will have a power of 250 W (ERP) on 1593 kHz and the antenna is located on a high hill near lake Vättern. In the evening of May 5th we will start tests. There will be station identifications in English, too.

The official start will be May 6th at 1900 UTC and the programs will be running until 1100 UTC on Sunday noon

On the 7th there will be a program dedicated to the local SR P4 Radio Jönköping that celebrates its 40th year of broadcasting. this year. This program starts at 1000 UTC and will be in Swedish. Until the station signs off at 1100 UTC.

Reception reports are appreciated and a special QSL-card is issued, if you enclose return postage in your letter. Reception reports by e-mail will be answered by an e-QSL. Address: Ronny Forslund, Arctic Radio 1593, Vita Huset, SE-17995 Svartsjö, SWEDEN. E-mail: info(AT)rock.x.se”

Readers of the SWLing Blog might be interested.

Indeed we are!  Thank you for sharing, Mick!

Standing Inside a Broadcast Transmitter While it’s ON!

I stumbled across a video from the fabulous Mr Carlson’s Lab YouTube channel. If you haven’t check out this channel before, and you are really eager to learn more about electronics, this is a wonderful YouTube site.

So, in the latest episode, Mr Carlson takes us on a tour of a very large Gates BC-250-GY broadcast transmitter from the 40’s era. Lots of big tubes, transformers and capacitors! This is an old mediumwave transmitter that he has restored. Although the technology has changed markedly since the 1940s, the basic principals of transmission are still present. And, interestingly, he points out that this particular unit was in regular service right up until as recently as 2003!

It’s an interesting show and even if you can’t grab onto all the technical information presented, I think you will enjoy looking at technology from a past era.

73 and good DX to you all,

Rob Wagner VK3BVW

Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.