Category Archives: Ham Radio

Ham Radio Friedrichshafen 2020 has been cancelled

Many thanks to SWLing Post contributor, Harald Kuhl, who shares the following announcement from Ham Radio Friedrichshafen:

Radio silence due to coronavirus COVID-19: Ham Radio not taking place as planned
15.04.2020

Friedrichshafen – Due to current developments in regard to the spread of coronavirus COVID-19, Messe Friedrichshafen has been forced to make a very difficult decision: the international amateur radio exhibition Ham Radio will not be taking place in the planned period of June 26 to 28, 2020, but instead from June 25 to 27, 2021. The Federal Government and the Minister-Presidents of the Länder decided yesterday, April 15 that no major events shall take place until August 31, 2020.

“Due to current developments relating to the coronavirus, we have the unfortunate duty of announcing that we cannot hold the 45th edition of Ham Radio as planned,” explains Klaus Wellmann, Managing Director of Messe Friedrichshafen. In recent weeks, it was already necessary to make the same decision in regard to other events (Aqua-Fisch, IBO, AERO, Tuning World Bodensee, and Motorworld Classics Bodensee). Project Manager Petra Rathgeber also expressed her sadness about this turn of events: “We very much regret that this event cannot take place as planned. However, the health of all exhibitors and visitors is of utmost importance to us. Unfortunately, our trade fair calendar and the dates of other industry events leave no room for postponing this fair to another date this year.” Christian Entsfellner, Chair of the German Amateur Radio Club (DARC), adds: “Our members, domestic and foreign guests, and we ourselves have been hit hard by this decision, which now became necessary to make on short notice. Until we get together again in Friedrichshafen, we as amateur radio operators are looking forward to keeping in contact with one another using amateur radio.” However, radio amateurs do not have to do without everything the Ham Radio fair normally has to offer: On the Ham Radio website, exhibitors will be presenting product innovations in the form of a virtual trade fair. DARC will also be offering presentations there.

The exhibitors, visitors, and partners involved are currently being informed about this opportunity.

Thank you for sharing this, Harald! Not a surprising development, but sad nonetheless. I assume Covid-19 might also lead to the closure of Ham Fair 2020 in Tokyo.

Hack a broken VGA cable to make a binocular ferrite cores for your NCPL antenna

13 Replies

Many thanks to Oscar (EA3IBC) who shares this simple hack.

I’ve gotten quite a few emails from Post readers telling me that the only thing holding them back from building a NCPL antenna is the BN-73-302 binocular ferrite core needed for the 1:1 Balun. While so much of the world is sheltering at home due to Covid-19, it’s less convenient to purchase one just for this purpose.

But almost everyone has an old VGA or USB cable with ferrite cores they can cannibalize for this very purpose. Oscar shared this super-simple hack on Twitter:

1. Cut the cable and remove the ferrite cores

2. Tape the two cores together

3. And wind four turns on both sides

Admittedly, this 1:1 balun might not have the same properties as the BN-73-302 from our tutorial, but it seems to be working for Oscar. Check out this screenshot he shared from SDR# while hooked up to his NCPL antenna:

Thanks again!

Readers, you can follow Oscar on Twitter by clicking here.

Interview on the ICQ Podcast

Beating the Quarantine Blues: Readers build homebrew NCPL antennas

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My homebrew version of the NCPL antenna.

Recently, I published a step-by-step guide on building a Noise-Cancelling Passive Loop (NCPL) antenna. Evidently, this antenna project really resonated with readers! [See what I did there? If so, my apologies!]

I think this passive loop antenna project has been so appealing because (1.) most of us around the world are sheltering at home due to the Covid-19 pandemic and (2.) this project is simple and you likely have all of the components in your tool shed or junk box at this very moment.

A number you have written to tell me about your antenna builds and some of you have agreed to allow me to share your projects with the SWLing Post community.

Below, you’ll find three fine homebrew examples of the NCPL antenna–all of which were made with what these fine radio enthusiasts had on-hand:

Jerome van der Linden

Jerome’s NCPL antenna

Jerome writes:

Hello Thomas,

Well, I took up the challenge and built a NCPL antenna pretty close to your instructions.

Unfortunately, the coax I had available used (had aluminium shielding, and too late into the project I discovered solder would not take to it. My solution was to cannibalize a coax cable joiner (see photos attached), where – normally – the centre conductors are joined / held by a plastic centre piece and screw fittings.

The braid / shield for the two bits of coax is clamped / squeezed by an outer metal piece. My cannibalising effort involved removing the plastic centre bit which joins the two centre cores, and keeping just the outer metal component which I used (after completely cutting through the coax) to clamp the two metal braid sections, while the two centre copper bits were far enough apart for me to solder the leads for the ferrite balun.

Of course, I could not do the same at the top of the loop where the internal and external conductors need to swap over. I soldered some quite thick copper wire (perhaps 2mm in diameter) to each center core, pushed the center core into the opposing coax and coiled the 2mm thick copper tightly around each end of the coax.

Once it was all taped up it looks no worse than yours, and it does indeed WORK! [see photo above]

Here in Oz, I could not source the identical ferrite, but I think it’s pretty close. Best performance for me is on 11MHz, where the Radio New Zealand signal on 11725 is markedly better using the loop than the internal whip on my Tecsun PL-880. Other bands not quite so significant, but the Noise level is definitely lower.

As you say, Jerome, once all packaged up, it looks great! Sure, the mixture of materials you had on hand wasn’t ideal (aluminium shielding, etc.) but you found a way to make it work from the resources you had in your home. And I love the fact it’s lowed your RFI level! Thanks for sharing!

Giuseppe Morlè (IZ0GZW)

Dear Thomas,

I’m Giuseppe Morlè (IZ0GZW), from Formia, central Italy, on the Tyrrhenian Sea.

I wanted to build your noise canceling loop seen on SWLing Post …
seems to work well especially from 40 meters. upward…
the diameter is 50 cm.
I will do other tests soon.
You can see the initial test on my YouTube channel via this link:

Thanks for the nice idea and a greetings from Italy.
73. Giuseppe IZ0GZW

Thank you, Giuseppe! What an amazing view you have there from your balcony! I’m quite impressed your PL-660 can take advantage of this design so well. We look forward to your other tests! Grazie mille!

John Mills

Hi Thomas,

My idea was to use a fitness hoop 75cm diameter bought off eBay. I removed the flashy striping to reveal a plastic like hoop that was joined in one spot with a plastic insert.

I have wrapped the whole hoop in tin-clad copper foil tape that has a conductive adhesive backing, but to be sure I have soldered all the overlapping seams. I drilled two holes opposite each other for the upper foil connections and the lower exit to the Balun.

Hopefully the three pictures will be helpful, I did the 4 turn design on Airspys website and it works really well connected to my RSPdx.

73

John

Thank you, John. What a fantastic way to build the NCPL antenna without using a coax for the loop. Indeed, since your plastic hoop has a small insert in the middle, you’ve an ideal spot to make the shield to center conductor cross-over. Very clever! I also like how you mounted the 1:1 Balun (or Unun) on a small board. Thanks for sharing this.

Got Loops?

Post readers: If you have your own unique NCPL antenna design, please consider sharing it with us! Contact me with details and photos. I’ll plan to publish at least one more post with examples here in the near future.

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Radio Waves: Dave Moves, IC-705 delay, High Speed Telegraphy Meet, and WWI Biplane Wireless

3 Replies

Radio Waves: Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers. To that end: 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 Dave Zantow (N9EWO), Paul Evans (W4/VP9KF), and Mike Hangen (K8RAT) for the following tips:

Dave’s Radio Receiver Page Moves Again (N9EWO)

With all of the strange happenings and excessive “Pop-Up” issues on Angelfire (even more so of late), we have finally decided to move off of that web host and made the move to QSL.NET.

So “Dave’s Radio Receiver Page” new URL is :

https://www.qsl.net/n9ewo/

Please, for anyone who have web pages that have my web page linked (with the now old URL), I would appreciate the correction. Hopefully this will be the last time I will need to move the page.[…]

Please Note : Are still a few pages that still need to be transferred, but I expect to have that completed over the weekend. This has been quite a bit of work recoding all (again).

Icom IC-705 availability delayed due to Coronavirus

Paul Evans notes that Martin Lynch and Sons (ML&S) has just updated the product page for the IC-705 with the following note: “RRP £1199.95 incl 20% VAT. Estimated delivery now July 2020 due to major component shortage.”

Icom America retailers (Universal Radio, Ham Radio Outlet, Gigaparts, etc.) have not published an estimate for availability.

QRQPoint – The meeting place for high speed telegraphy enthusiasts in Europe (Southgate ARC)

Dear OM and all CW lovers,
I will you proudly inform, that our website http://www.qrqpoint.com is now online.

The idea of this meeting place for CW enthusiasts was born by me and the webmaster, Fabian, DJ1YFK, brought it very nice to the web. Thank you Fabian!

Everybody is very kindly invited to be there QRV.

The frequency is 3567 khz. To make a sked or just to say Hello we have a little Shoutbox on the site.

I hope to see you there!

Kindest regards,

Olaf, DL1OP

In World War I, British Biplanes Had Wireless Phones in the Cockpit (IEEE Spectrum)

Pilots on reconnaissance missions could immediately call in their findings

As soon as the first humans went up in hot air balloons in the late 1700s, military strategists saw the tantalizing possibilities of aerial reconnaissance. Imagine being able to spot enemy movements and artillery from on high—even better if you could instantly communicate those findings to colleagues on the ground. But the technology of the day didn’t offer an elegant way to do that.

By the early 20th century, all of the necessary elements were in place to finally make aerial reconnaissance a reality: the telegraph, the telephone, and the airplane. The challenge was bringing them together. Wireless enthusiasts faced reluctant government bureaucrats, who were parsimonious in funding an unproven technology.

[…]One early attempt involved wireless telegraphy—sending telegraph signals by radio. Its main drawback was size. The battery pack and transmitter weighed up to 45 kilograms and took up an entire seat on a plane, sometimes overflowing into the pilot’s area. The wire antenna trailed behind the plane and had to be reeled in before landing. There was no room for a dedicated radio operator, and so the pilot would have to do everything: observe the enemy, consult the map, and tap out coordinates in Morse code, all while flying the plane under enemy fire.

Despite the complicated setup, some pioneers managed to make it work.[…]

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DUST “Voskhod”: A Sci-Fi short that features ham radio

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Many thanks to SWLing Post contributor, Scott Gamble, who shares the following science fiction short film called “Voskhod” by DUST.

The synopsis:

After repairing his HAM radio using parts found in the forest, a recluse radio operator receives a distress call from a stranded Soviet cosmonaut in orbit.

I thoroughly enjoyed this short film. We radio enthusiasts will certainly notice some inaccuracies on the radio side of things–feel free to comment on those–but I suggest you exercise a willing suspension of disbelief and truly enjoy this piece!

Click here to view on YouTube.

Can you identify the National radio model? Please comment!

Radio Waves: Crossband Test Postponed, VI3RA Event Videos, WWII Radio, and Look Inside a Panasonic RF-4900

Radio Waves: Stories Making Waves in the World of Radio

Many thanks to SWLing Post contributors Harald Kuhl, Michael Bird, and Carel Kuijer for the following tips:

Annual Armed Forces Day Crossband Test Postponed (ARRL News)

Due to the ongoing COVID-19 response and mitigation actions, the 2020 Armed Forces Day (AFD) Crossband Test scheduled for Saturday, May 9, has been postponed. Because it’s uncertain just when stay-at-home orders will be lifted across the US, AFD planners chose to postpone this year’s event, because the government stations that typically support this event may not be available. Armed Forces Day Crossband Test planners are considering scheduling a November event in honor of Veteran’s Day, depending on COVID-19 mitigation actions. During the AFD Crossband Test, military stations in various locations transmit on selected military frequencies and announce the specific ham frequencies they are monitoring to work radio amateurs. — Thanks to US Army MARS Program Chief Paul English, WD8DBY

Radio Australia Event – Antenna Overview (Mount Evelyn DX Report)

Thanks to Lee VK3GK for this short video of the antennas used for the recent Radio Australia event using the call sign VI3RA. Take what will possibly be a final look at the feeders, switching boxes and antennas before they are pulled down and junked!

Also here is the final transmission of the event weekend with, of course, the famous Radio Australia music box interval signal.

Click here to view both videos at the Mt Evelyn DX Report.

World War II and Radio (All Things Radio)

I have added an article I wrote some years back on the code breaking efforts of the Allies during WWII. While certainly not exhaustive, I found many of the connections between countries and equipment rather fascinating, and new things continue to pop up regarding Bletchley Park’s role in training officers and decoding texts. While most famously known for breaking the Enigma code, also significant was the breaking of the Lorenz Cipher.

Click Here to download the article in PDF format.

73, Robert K4PKM