I’m Giuseppe Morlè from Formia, central Italy on the Tyrrhenian Sea.
I want to share with you my latest ferrite antenna for listening; it is composed of 3 ferrites of 20 cm each in a tube for electrical systems with 2 separate windings, one for medium waves and one for short waves, 40 turns for medium waves, 4 turns for short waves. I use a 750 pf variable to tune the 2 windings and a switch is used to eliminate a winding. Since there is only one variable, if you listen to the medium waves I interrupt the winding of the shorts.
On shortwaves it is preferable to place the system on an iron railing which, due to inductive effect, behaves like a really long wire antenna.
For the mediumwaves it is enough to bring the receiver close to the ferrites and also in this case, the induction will have its effect with an excellent increase in signal and modulation.
Many thanks to SWLing Post contributor, Gareth Buxton, who writes:
I see that Anon-co have the Tecsun PL-990 Ferrite rod aerial for sale. It even says in the product description “You can use it for your DIY projects.” I thought it might be of interest to your MW/AM radio constructors, especially if they can build a radio that receives more stations than the Tecsun using the same part!
Many thanks to SWLing Post contributor, Pavel Kraus, for the following guest post:
Building a Drain Pipe FSL Antenna
by Pavel Kraus
Hi, I greet all DX fans and the entire SWLing Post community! I enjoy reading reading this blog and the diversity of contributions from our authors and contributors; many thanks from me for so much useful information.
The following are the construction notes of my FSL antenna, which I designed thanks to the suggestions of GaryDeBock, and other FSL designers.
The antenna is a classic design featuring 60 ferrite rods 200x 10 mm, which are placed on a plastic sewage pipe.
Pict 3: Pipe with ferrite rods and windings
Pict 4: Pipe with ferrite rods and windings
In addition, sewer pipe sections are used for the entire antenna cover. I assume that this material can be obtained in other countries as well. Continue reading →
Many thanks to SWLing Post contributor, Giuseppe Morlè, who writes:
This is Giuseppe Morlè again. First of all, Happy New Year to you and to the whole SWLing Post community! I’ve been continuing the tests on my “T Ferrite” antenna for medium wave and the 160 meters ham meter band.
I tried the antenna inside my shack listening to Rai Radio 1 from Milan Siziano, about 800 km from me, on 900 kHz in the early morning after sunrise. The antenna, despite being inside, proved to be perfect for the cancellation of the electrical noise that I had around me.
Disconnecting the antenna from the receiver–a Sangean ATS-909–the noise occupied everything without being able to listen to anything. Putting the antenna back, the noise disappeared completely making the modulation re-emerge, with a weak signal, it was already day, but with good understandability.
For the two windings, I used a small section of cable used for telephone systems that is rigid enough to model perfectly on the ferrites–43 turns for the primary and 3 turns for the coupling link to the receiver. The variable capacitor is 850 pf.
I should mention that the magnificent W1VLF channel was my original source of inspiration for this antenna.
That is amazing, Giuseppe! We often think of magnetic loops as the only choice for coping with urban noise and RFI, but ferrite bars–especially configured like yours–are a brilliant tool for indoor low-band listening. Thank you for sharing! We love your experiments.
I’m Giuseppe Morlè (IZ0GZW) from Formia, on the Tyrrhenian Sea, in Italy .
I built this simple rotating directive ferrite antenna for medium waves and the 160 meters ham band.
Inside the tube there are 2 ferrites with 43 cable windings and 3 for the coupling link that goes to the receiver.
In this video the test as soon as I assembled everything …
In broad daylight, it was 12.00 local time, you could hear well over 2000 km.
The antenna is very directive and perfectly manages to separate several stations on a single frequency.
The pipes are in plastic for plumbing use (PVC), I bought only that one, 5 Euros, the rest is all recycled.
I wanted to share this simple and very functional project of mine with the SWLing Post community.
Thanks and I wish everyone a better year.
Greetings from Italy.
Thank you, Giuseppe! What a simple, effective antenna project. I like how you’ve invested so little and recycled parts from other projects. I also love your view there looking south over the Tyrrhenian Sea! What a great place for radio.
Many thanks to SWLing Post contributor, The Professor, who shares the following review of the RFA200 external ferrite antenna:
The Tecsun R-9012 and RFA200 MW antenna (Photo credit: The Professor)
A Quick Review of the RFA200
I’ve considered saying something here about RFA200, as I bought one of these not long after its existence was announced on this blog a few months ago, but I’ve been hesitating because I didn’t have much good to say about it. A couple of times I’ve placed it up snug up against the the top of the two Tecsun sets I have handy (the PL-310ET and the PL-880) and found that despite a lot of knob turning it had little or no effect on improving signal on medium wave stations. I was not impressed.
But I guess I’ve kind of changed my mind on that. And oh yeah, I bought another radio. It’s funny how you can talk yourself into things when you’re talking someone else into something. But after I had mentioned to a reader here the other day that the very inexpensive Tecsun R-9012 was a worthy analog DX portable, I decided to drop twenty and pick one up for myself. After all, it was about the same price as a fancy Brooklyn hamburger. It arrived a couple days ago.
So, I have been playing with it a bit over the last few days. It’s as good as the other ones I’ve had which are the same basic radio (I’d mentioned that the bandswitch slider broke in a couple of mine). It’s single conversion. The bandwidth is a little wide, but it’s a very sensitive and simple analog set.
Yesterday I was going through the AM band and remembered that ferrite from Greece, and I pulled it out recalling that in my experience some radios are more susceptible to reception improvements using passive loops than others. Maybe this ferrite bar might be similar. And sure enough, the antenna made a notable difference this time. By placing it up against the R-9012 and tuning the thing I could certainly increase signal a bit. And I could even see it in the slight brightening or steadiness of the tuning light.
So, not a total waste money after all. I would emphasize that the difference in reception doesn’t seem to be as dramatic or sustaining as you might hear with a tunable loop antenna next to your radio. But it’s not junk either. Then again, for fifty dollars shipped it is a little pricey. Twice as much as a Tecsun tunable loop antenna, and two and half times more expensive than the R-9012 itself.
I found the best way to use this antenna is to tune the radio separately first and when you find a weaker signal you want to improve physically go ahead and rotate the radio until the signal is strongest and THEN put the antenna along the top of the radio and adjust the tuning knob on the antenna. Focus in on strengthening the signal you actually hear, going back and forth until it gets strongest. If you seem to be pulling up other stations it’s because the antenna adjustment will bring in adjacent stronger stations if you move it too far either way.
I’m surely not able to pin down the science involved in exactly how these things work, but perhaps somebody can chime in on this. I’m wondering if analog radio tuning in particular is better suited to the use of these tunable passive antennas, as opposed to PLL and DSP radios?
If you buy one of these be prepared to wait. At least mine took weeks to get here from Greece. And don’t expect miracles. But it seems rather well constructed, and will probably work with some radios. The seller has a 100% rating on eBay and has all sorts of interesting antennas for sale. I’m glad to see people succeeding in that business.
Many thanks, Prof, for sharing your fine review of the RFA200! Thanks for also mentioning the Tecsun R9012–I purchased one a couple years ago with the intention of reviewing it, then gave it to teenager who expressed interest in shortwave. I don’t think I actually put it on the air myself. I do enjoy simple old school analog radio–especially when making band scans.