Tag Archives: Patrizio Cardelli

Patrizio seeks information about mystery signals he’s discovering across the HF bands

Many thanks to SWLing Post contributor, Patrizio Cardelli, who has discovered some interesting signals on the HF bands and is seeking information about them.

A little background: Patrizio asked me about these signals a few weeks ago and based on a quick glance at the spectrum and waterfall images I assumed it was DRM (Digital Radio Mondiale). I was wrong, of course. Had I looked at the actual frequency and bandwidth, I would have immediately realized is was not DRM. My email load has been so heavy as of late, and my time to reply at such a premium, I rushed through the reply–my apologies, Patrizio!

Patrizio followed up with this message:

Hello Thomas,

I hope this message finds you well. I wanted to share my recent radio exploration based on your advice. I followed your suggestion and investigated a sample signal within the 60-meter band, specifically settling on the one at 4.962 kHz.

I attempted to decode it using the Dream software but encountered no success. It seems this isn’t a Digital Radio Mondiale (DRM) transmission. To rule out local QRM (interference), I tested various Kiwi SDR receivers across Europe, both to the south and north of my QTH. Interestingly, I managed to pick up this signal everywhere, with a stronger intensity noted in the northern locations.

I’m eager to publish this article to find out if other Shortwave Listeners (SWL) have been able to decode this transmission. Additionally, I’d like to mention that similar signals, either continuous or intermittent, are present on various HF frequencies.

I look forward to any insights or experiences others in the community might have regarding this intriguing signal.

Audio sample:

While I recognize these signals now, and I’m sure most of you who cruise the bands have seen/heard these as well, Patrizio is a relatively new SWL, turns out, and I thought it might be fun exploring just what these signals are. 

Readers: If you know what these signals are, please comment. Indeed, I’m sure there are a number of SWLing Post readers who have hands-on time with generating these signals as well in a past life or current career. Let’s explore!

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Patrizio uses Speechtexter to translate foreign broadcast content


Many thanks to SWLing Post contributor, Patrizio (IN3032SWL), who writes:

If you are a fan of foreign radio broadcasts (BCL), you may have experienced the difficulty of transcribing the details of the programs, especially if they are in an unknown language. In addition, many radio stations have their own web pages where listeners can input their listening data, but these pages often do not allow the upload of any kind of file, even partial recordings of the broadcasts.

For these kinds of problems, Speechtexter can be a great help. It is a speech-to-text program that can automatically transcribe audio in real time, allowing BCL fans to have an accurate and detailed transcription of what they are listening to.

Speechtexter can recognize a wide range of languages, including Italian, English, French, Spanish, and many others. The program is completely free and does not require any registration. Moreover, it is very precise and offers high-quality transcriptions. It is also available online, which means that you can access it from any internet-connected device.

Using Speechtexter to transcribe foreign radio broadcasts is very easy: simply go to the official website and click on the “Start talking” button. The program will start transcribing everything that is said during the broadcast, and the text will appear automatically on the screen.

Video demonstration

In conclusion, if you are a fan of foreign radio broadcasts and want to transcribe the programs you listen to accurately and quickly, Speechtexter could be the solution for you. Try it now and see how it can simplify your life as a BCL listener! Here’s the link to the website: https://www.speechtexter.com.

73 Patrizio
IN3032SWL

Very clever, Patrizio–what a great trick! Thank you for sharing.

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Patrizio’s simple homebrew NCPL antenna

Many thanks to SWLing Post contributor, Patrizio Cardelli, who writes:

I’m Patrizio (SWL I – 5184 /AN) from Riva del Garda, Italy.

A few days ago, I built a Noise-Cancelling Passive Loop (NCPL) antenna. I built the 1:1 balun with a couple of ferrite 175 – 285.

I got a good result on medium wave on my ICOM IC R 71 E with the antenna inside my house installed behind the desk just to avoid any problems with my wife.

On shortwave, the signal was low in comparison with the Bonito mini whip but in my QTH I have a lot of QRM and with this antenna I solved my problem.

Yesterday I tried the balun with my random wire (15,2 meter long) also with good results.

About my NCPL antenna: I made mine with RG-58 coaxial cable just to have easy portability in SOTA (please see photo) and also the feed line is made by the same coaxial cable. OK, you are right…it’s ugly:

Electrical connections are not soldered, still I don’t see any mechanical issues and this antenna since it is made for SWL / BCL purposes (meaning, RX only, no TX).

Concerning the binocular ferrite core, I didn’t have one, so I used two ferrite core type 175 – 285 (28,5 mm length, external diameter 17,5 mm and internal diameter 9,5 mm) normally used to reduce HF interference:

For the winding I used PVC insulated cable cat no: 7/0,2 type 2 (def61 – 12) conductor 7/0,2mm TSCu X 0,3mm R/T type single (4 turns primary and 4 turns secondary). It’s the same cable with which I built my random wire antenna (also portable for SOTA but now installed on my balcony until the COVID – 19 emergency is over).

The attached videos show the situation in comparison with my BONITO MINI WHIP active antenna (also installed inside my house). Recently I changed my QTH and unfortunately here I have a lot of interference both on MW and SW. The better results that you can hear are achieved with my NCPL antenna.

I have made this test with my ICOM IC R 71 E + BHI noise cancellation speaker…..you can assess yourself, the better results that you can hear are achieved with the NCPL antenna and in the case of Tecsun PL-660 without any noise cancelling filter (BHI speaker off).

Thanks for sharing this, Patrizio! As you say, the NCPL loop seems to do a fine job helping to eliminate local RFI/QRM. The Bonito Mini Whip is a fine antenna, but not optimal for environments with a lot of radio noise–that’s where the NCPL antenna really shines.

You also make a good point that if you’re simply experimenting and only using an antenna for receiving, you can be more relaxed about the build because you’re not sending RF through it. In the end, however, properly soldered and protected connections will last much longer and provide better, more reliable performance.

Thank you, again, for sharing your build, Patriio! Those reception results speak for themselves!

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