Category Archives: Mediumwave

More field time with the new Icom IC-705 general coverage QRP transceiver

I’ve been using the Icom IC-705 pretty heavily since I took delivery of it a couple weeks ago.

The more time I spend with this radio, the more I like it.

Serious functionality and features

I originally stated that I’d probably sell the IC-705 after my review/evaluation period because it simply doesn’t have the design characteristics I like in a field QRP radio.

I tend to prefer simple field radios with a basic high-contrast LCD or analog display, and a protective cover over the display. I’m not personally the biggest fan of pressure sensitive touch screens in field applications.

Earlier this week, I stopped by Lake Norman State Park for a quick Parks On The Air (POTA) activation.

I wrote a field report on QRPer.com noting the fact that the IC-705 is a superb SSB transceiver. It truly is. I included a video showing the IC-705 as I worked a few stations on the 40 meter band, and another video demonstrating SSB memory keying (politely overlook the fact I had the rig set to LSB on 20 meters in that video–!).

Listening in

When I finish a park activation, I often spend a little time on the broadcast bands tuning around and enjoying the low-RFI setting.

At Lake Norman, I decided to make a short video highlighting the wide receiving range of the IC-705. The video only highlights a few bands–the IC-705 can actually receive from 0.030–199.999 MHz and 400.000–470.000 MHz.

The EFT-MTR end-fed antenna I had connected to the IC-705 that day was not ideal for reception above 15 MHz, but as you’ll see, it was adequate for a little radio fun. I was using the Emtech ZM-2 external antenna tuner that day because my mAT-705’s battery died. I highly recommend the ZM-2 for shortwave listeners and QRPers alike because it makes it so easy to tweak wire antennas for optimal matching and reception. In the video, however, I left the tuner in the last matched configuration. This isn’t exactly a pro video, but I hope you’ll enjoy it anyway:

The Icom IC-705: A keeper

This transceiver is so versatile, I don’t think I can let go of it. I really appreciate the IC-705’s frequency versatility and excellent performance. With this compact rig, I can do some proper SWL DXing and possibly even FM and MW DXing.

As simple as it is, the built-in digital recorder clinches the deal.

The IC-705 is a pricey piece of kit at $1300 US, but I suspect Icom will lower the price or start offering rebates once the supply/demand curves normalize. At present, retailers are struggling to keep up with customer demand and most purchases are on back-order.

Blind Audio Test results

I’ve just closed the surveys for our IC-705 blind audio tests. The response was overwhelming and the results? Well, you’ll soon find out. I hope to present all of the findings in a post within the next few days.

Boomark this link to follow all of our IC-705 posts.

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Tecsun PL-990 Hidden Feature: Toggling ferrite bar and telescopic whip antenna on MW & LW bands

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Many thanks to Anna at Anon-Co who recently shared an interesting “hidden feature” of the Tecsun PL-990 which allows the user to toggle between the internal ferrite antenna and telescoping whip antenna while on either the mediumwave or logwave bands.

Procedure:

1) Turn on the radio and then select either the MW or LW frequency band.

2) Press and hold the [ 3 ] key for about 2 seconds.

When the display shows “CH-5” (actually an “S” which stands for shortwave telescopic antenna) the radio is now set to MW/LW reception using the telescopic whip antenna.

The display will show MW (or LW) and SW on the left side of the screen.

3) Press and hold the [ 3 ] key for about 2 seconds.

When the display shows “CH-A” (“A” stands for “AM”) the radio is now set to MW/LW reception using the internal ferrite antenna once again.

The display will also show only MW (or LW) on the left side of the screen.

Pressing and holding the [ 3] key essentially toggles between these two antenna settings.

I’ve actually found that, indoors, using the whip antenna on mediumwave has been more effective at mitigating RFI with strong local stations. The ferrite bar antenna has more gain, of course, but for locals it’s not necessarily needed.

Many thanks, Anna, for sharing this tip!

Gary DeBock experiments with FSL antenna nulling to eliminate a “pest” station

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Many thanks to SWLing Post contributor and Ultralight DX enthusiast, Gary DeBock, for sharing the following guest post:

Nulling a local pest with dual FSL Loops

by Gary DeBock

After many dual FSL antenna experiments I’ve finally determined how to effectively cancel out QRM from a local pest that is off to the side (ideally 90 degrees different, but practical from 50 degrees to 90 degrees different) from a weak DX station, although I’m not quite sure of the theory behind this discovery.

This experiment was an attempt to cancel out QRM from a local pest, 950-KJR in Seattle, WA (35 miles/ 56 km to the north) and chase 950-KKSE in Parker, CO (1005 miles/ 1617 km to the southeast) during the early morning hours. The receiver was a basic (non-SSB) C.Crane Skywave, and two identical 5 inch ferrite rod FSL antennas were used. Please refer to the photo (above) to follow this description.

Step 1) Null out the pest station with the portable radio’s loopstick (away from the FSL antennas). Set the radio down in this nulled position, so that the pest station is as weak as possible, while ensuring that there is space to set up the FSL antennas to the back and side (see photo).

Step 2) Take the “Reception FSL” and use it to peak the pest station’s frequency, setting it up parallel to the portable radio as shown, at the position providing the maximum inductive coupling gain. This will temporarily boost up the pest station, which previously was nulled.

Step 3) Take the “Nulling FSL” and pretune the frequency to that of the pest station. You can do this either by adjusting the variable cap plates to match those of the “Reception FSL,” or by temporarily peaking the pest station’s signal in a position in front of the portable radio. After setting this frequency, set the “Nulling FSL” off to the side of the portable radio as shown, with the spacing identical to the spacing between the radio and the “Reception FSL.”

Step 4) Slowly and carefully tune the “Nulling FSL” until you hear the pest station’s signal take a sharp drop. This setting will be very sharp, but once you find this position you will have nulled out the pest very effectively, and if another station is on the frequency, it may suddenly become dominant, even if it is far away (like 950-KKSE in Denver).

Some MP3’s from this morning’s experiments:

950-KJR in nulled position with the portable only

950-KKSE generally dominant over the local pest KJR when the “Nulling FSL” is peaked

Fascinating, Gary! I don’t understand the dynamics of why this works, but it’s amazing that it does so effectively. I can think of two MW frequencies in particular where I could put a system like this to the test.

Thank you for sharing!

QTC Article: Clear Channel MW Broadcast Stations in Australia

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Many thanks to SWLing Post contributor, Kris Partridge, who notes that the July/August 2020 issue of the Australian amateur radio magazine QTC (an issue we noted in a previous post is free) actually has an article about the mediumwave scene in Australia.

Click here to download a PDF of those pages only from the magazine, or better yet, grab the full issue from our previous post.

Thanks for pointing out this article, Kris. I really enjoyed reading this issue of QTC. Great to see a ham radio publication that covers more than *just* ham radio!

Bruce compares two homebrew NCPL antennas to the Airspy Youloop

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The Airspy Youloop

Many thanks to SWLing Post contributor, Bruce (VE3EAR), who writes:

I decided that more testing of the Noise-Cancelling Passive Loop (YouLoop) antenna was needed, but I wanted to start with a clean page.

I built two identical loops using some 3/8 inch heliax scraps I had on hand. Both are one metre in diameter and employ the same feed arrangement, with a balun wound on a half inch square binocular core of type 75 mix. There are four turns on the antenna side and eight on the feed line side, of #24 gauge plastic insulated wire. The feed line shield connects to the antenna shields. The only difference between the two antennas is at the top of the loop, opposite to the feed point. One has a simple one inch gap in the shield, with the centre conductor passing across the gap, while the second one uses the crossover connection of the YouLoop design.

I’ve been running some A-B comparison listening sessions, both mid-day and in the evenings after local sunset. The testing is done outside, with the antennas hanging on a low limb of a maple tree in front of the house. The feed line is about twenty feet of coax which connects to my Realistic DX-440 receiver on the front porch. Testing is done listening to the AM broadcast band and the 160, 80, and 40 metre ham bands, with the loop aligned both E-W and N-S and about one loop diameter off the ground.

Both loops work well, but I do have to give the nod to the YouLoop (by Airspy), which produces a stronger signal of two S-units higher than the conventional loop. It also has deeper and sharper nulls, which can sometimes produce total nulling of the station!

73, Bruce, VE3EAR

Thank you so much, Bruce, for sharing your findings with us! I, too, have found that the Youloop generally outperforms my homebrew NCPL antenna. I believe one of the reasons for this as Youssef at Airspy once told me is because the Youloop has a lower loss transformer than anything that can be wound by humans (0.28 dB)–this improves gain.

Click here to read our review of the Youloop and click here for step-by-step instructions on building your own Noise-Cancelling Passive Loop antenna.

Giuseppe’s cross-loop experiments

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Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who shares the following:

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

I wanted to share with you and friends of the SWLing Post community this antenna project of mine dedicated to those who do not have enough space on the roof or in the garden to install antennas.

These are two separate loops, with two different diameters, one 60 cm, the other 90 cm, each with two variables for tuning … the system is able to receive from 3 to 30 MHz.

I joined these two loops in an opposing way, better to say crossed that can communicate with each other due to the induction effect that is created between the two small coupling loops that are placed one under the other at the top.

In the videos you will be able to see how the antenna system receives. I can use one loop at a time, to detect the direction of the signal or I can use them together for a more robust signal and in an omnidirectional way.

I really like experimenting with the induction effect and you can see that even when closed at home the two loops do a great job.

From my YouTube channel:

I’m not a technician but I really want to experiment to try to listen as well as possible.

Thanks to you and CIAO to all the listeners of the SWLing Post community.

Giuseppe Morlè iz0gzw.

Very cool, Giuseppe! I must say I’ve never tried dual loop experiments like this where one can experiment with the induction interplay. I imagine this could give you some interesting nulling capabilities if you have an unwanted station interfering with a target low-band signal. Thank you again for sharing!

Radio Waves: Narco-Antennas, Pirate Radio Beginnings, Arqiva Restructure and Redundancies, and the Ghostly Buzzer

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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 Skip Arey, David Goren, Paul Evans, Kanwar Sandhu and Dave Porter for the following tips:

Special Report: Drug cartel ‘narco-antennas’ make life dangerous for Mexico’s cell tower repairmen (Reuters)

MEXICO CITY (Reuters) – The young technician shut off the electricity at a cellular tower in rural Mexico to begin some routine maintenance.

Within 10 minutes, he had company: three armed men dressed in fatigues emblazoned with the logo of a major drug cartel.

The traffickers had a particular interest in that tower, owned by Boston-based American Tower Corp (AMT.N), which rents space to carriers on its thousands of cellular sites in Mexico. The cartel had installed its own antennas on the structure to support their two-way radios, but the contractor had unwittingly blacked out the shadowy network.

The visitors let him off with a warning.

“I was so nervous… Seeing them armed in front of you, you don’t know how to react,” the worker told Reuters, recalling the 2018 encounter. “Little by little, you learn how to coexist with them, how to address them, how to make them see that you don’t represent a threat.”

The contractor had disrupted a small link in a vast criminal network that spans much of Mexico. In addition to high-end encrypted cell phones and popular messaging apps, traffickers still rely heavily on two-way radios like the ones police and firefighters use to coordinate their teams on the ground, six law enforcement experts on both sides of the border told Reuters.[…]

How Pirate Radio Rocked the 1960s Airwaves and Still Exists Today (HowStuffWorks)

If you’ve been binge-watching movies lately, you may have come across “Pirate Radio.” Director Richard Curtis’ 2009 comedy-drama stars the late Philip Seymour Hoffman as The Count, a disc jockey for an unlicensed rock radio station that broadcast from a rusty, decrepit ship off the British coast in the mid-1960s, defying government authorities to spin the rock records that weren’t allowed on the BBC at the time. The plot is based loosely on the saga of an actual former pirate station, Radio Caroline, that was founded by an offbeat Irish entrepreneur named Ronan O’Rahilly, the inspiration for the character portrayed by Bill Nighy.

“Pirate Radio” is a period piece, set in a time when the Rolling Stones’ “Let’s Spend the Night Together” and the Who’s “My Generation” were still scandalous and controversial rather than nostalgic anthems for today’s aging baby boomers. So you couldn’t be blamed for assuming that it depicts a long-vanished phenomenon, like Nehru jackets with iridescent scarves and psychedelic-patterned paper mini dresses.

To the contrary, though, more than a half-century later, pirate radio is still a thing. In fact, it’s possibly more widespread than it was in the 1960s, even in an age when streaming internet services such as Spotify and Pandora put the equivalent of a jukebox in the pocket of everyone with a smartphone. And as a bonus, Radio Caroline still exists — though, ironically, it’s gone legal.[…]

Arqiva confirms restructure and redundancies (IBC.org)

[Note: Arqiva is the UK domestic broadcast transmission provider.]

Arqiva is working on a restructure of its business that could result in a third of its staff being made redundant.

According to a report in the Telegraph, the media infrastructure business is preparing to cut around 500 staff, which is approximately a third of its workforce.

An Arqiva spokesperson confirmed to IBC365 that some job losses will occur.

They said: “The sale of our telecoms business makes Arqiva a smaller organisation, changes our revenue profile and reduces our available profit pool.

”We are therefore conducting a review of the costs and systems we need to run our business over the next three years.

”Regrettably, we will need to reduce the size of our workforce, but it’s much too early to speculate about numbers.”

The Telegraph report cites the shift to streaming and a drop in income for broadcasters as reasons for the potential cuts.[…]

The ghostly radio station that no one claims to run (BBC Future)

In the middle of a Russian swampland, not far from the city of St Petersburg, is a rectangular iron gate. Beyond its rusted bars is a collection of radio towers, abandoned buildings and power lines bordered by a dry-stone wall. This sinister location is the focus of a mystery which stretches back to the height of the Cold War.

It is thought to be the headquarters of a radio station, “MDZhB”, that no-one has ever claimed to run. Twenty-four hours a day, seven days a week, for the last three-and-a-half decades, it’s been broadcasting a dull, monotonous tone. Every few seconds it’s joined by a second sound, like some ghostly ship sounding its foghorn. Then the drone continues.

Once or twice a week, a man or woman will read out some words in Russian, such as “dinghy” or “farming specialist”. And that’s it. Anyone, anywhere in the world can listen in, simply by tuning a radio to the frequency 4625 kHz.

It’s so enigmatic, it’s as if it was designed with conspiracy theorists in mind. Today the station has an online following numbering in the tens of thousands, who know it affectionately as “the Buzzer”. It joins two similar mystery stations, “the Pip” and the “Squeaky Wheel”. As their fans readily admit themselves, they have absolutely no idea what they are listening to.[…]