Author Archives: Thomas

DSP technology is amazing, but maybe I’m just a legacy receiver kind of guy?

The PL-380 was one of the first portable DSP radios I purchased. It was mind-blowing at time of introduction and I still have it in my radio arsenal.

Without a doubt, DSP (Digital Signal Processing) technology has forever changed the portable receiver market in so many positive ways:

  • It’s made portable radios more affordable for consumers
  • It’s increased the profit margin for manufacturers
  • It’s made features like SSB mode and variable filter width affordable
  • When properly implemented, DSP technology can provide DX-grade performance even in Ultralight receivers
  • All-in-all, DSP technology has made portable receivers more accessible and has undeniably  reinvigorated the shortwave radio market over the past decade

All very good things!

But I must admit, I do miss legacy receiver design–for example, dual-conversion frequency synthesized radios like the Sony ICF-SW7600GR:

Or the Panasonic RF-B65:

For me? It’s all in the noise and static.

I think we’re probably all wired a little differently when it comes to how we listen.

I know radio enthusiasts that can pull station IDs out of the noise with their AM or SSB filters set to very narrow widths. I have trouble doing this and tend to actually widen filters when doing weak signal work (assuming there are no adjacent stations). It’s as if the filter in my brain needs more information–more bandwidth–to increase intelligibility. I only engage narrow filters to block adjacent signals or (for narrow bandwidth modes like CW) to decrease the influence and effects of atmospheric/natural noises (QRN).

I find that many DSP portables add a “mushy” audio quality to the static found in the noise floor of the receiver. I hear DSP artifacts and that “watery” quality especially if using headphones. No doubt, it’s the DSP simply doing its thing: minimizing background noise and seeking to clarify voice and audio information. But this actually tinkers (or interferes) with my brain’s ability to pull out intelligible information to some degree.

I find I prefer the audio quality of static in analog receivers.

Of course, a bit of this might also be tied to a receiver’s dynamic range and AGC; qualities I also tend to prefer in my benchmark legacy portables.

Does this make any sense?

In truth, this is difficult to explain and, dear reader, I may very well have lost you here. If not, I’m curious what you think.

Do you prefer the audio characteristics of DSP receivers, or legacy receiver architecture? Are there aspects you like of both? Please comment!

Mike Harwood explores active magnetic loop antennas with SDRplay

Many thanks to Jon Hudson with SDRplay who shares the following announcement:


Introducing a new series of videos comparing the performance of wideband active loop amplifier/antennas for HF frequencies and below. In this introductory video, Mike Harwood shows how an RSPduo enables a real-time comparison of two antennas – in this demo, he uses a Wellbrook 1530AN and one of his own compact loop creations. You can see that he has lined up several other active loop antennas/amplifiers to try in future videos, including the Bonito Megaloop FX, the LZ1AQ amp and the Cross Country Wireless amp.

SDPlay will endorse antennas which work well and formally recommend them on its website antenna suggestions page: https://www.sdrplay.com/antennasuggestions/

This is one of many videos from SDRplay – makers of the RSP family of SDR radios. See the full list of SDRplay videos and applications documents on: https://www.sdrplay.com/apps-catalogue/

The RSP family of SDRs from SDRplay cover 1kHz to 2 GHz with no gaps and give up to 10MHz spectrum visibility.

SDRplay is a UK company. The RSP SDR receivers are made in the UK and can be purchased for worldwide delivery directly from http://www.sdrplay.com/ (click on purchase and select your country to view shipping costs) or you can buy from any of our worldwide resellers listed here: http://www.sdrplay.com/distributors/ Many of the resellers offer local free shipping and/or local language technical support.

The SDRplay YouTube Channel is: https://www.youtube.com/c/SDRplayRSP

The new ATS-25 Si4732 receiver with color touch screen

Many thanks to SWLing Post contributor, Robert Richmond, who writes:

An ATS-25 receiver has appeared on eBay and similar sites. It appears to be a touchscreen and user interface update to the previous ATS-20 model. I suppose it remains to be seen if there are any improvements to the underlying electronic design and construction quality.

Click here to view on eBay (partner link)

At $130+ I am not sure if I am inclined to find out, but perhaps someone out there might be interested. Given the design shortcuts and potential build quality concerns of the current ATS-20, I would suggest considering the ATS-25 a possible “kit radio” as well until if or when proven otherwise.

Best Regards,

Robert Richmond

Thank you for the tip, Robert!

I would certainly welcome a guest review of the new ATS-25. If you’ve purchased this radio and would enjoy reviewing it here on the SWLing Post, please contact me!

KMTS Summer Test Transmission

Many thanks to SWLing Post contributor, Fastburstradio23, who shares the following:

Beaming to you from the transmitter’s location, forget summer vacation, it’s time for summer school. Get your pencils sharpened and thinking caps on for the KMTS Summer Test (transmission)! Numbers, poetry, the science of strange tones, music and mountaineering are all part of the curriculum.

And if you are one of those cats who was too hip for school the first time around, we understand. We’ve been there! When you use one of our proprietary quantum radios passing is as easy and pleasant as a breeze blown in from a deserted tropical island. All the answers tp all the questions are right in some reality or timeline!

And after you’ve peaked out with us at the crown of KMTS, you can join us for a Mai Tai at the Tiki bar on top of the mountain as we go over the summer test results.

6070 kHz at 1700 UTC on Tuesday 27th July and 3rd August 2021.

Radio Cameos in Japanese Cinema

Many thanks to SWLing Post contributor, Jon, who writes:

Good day,

I regularly visit the SWLing Post and very much appreciate the breadth of content you provide on the shortwave hobby. In between the receiver reviews and stories on broadcaster activities, I much enjoy the pieces showing the radio gear that folks notice in television/films. Over the course of the COVID19 pandemic, I have been watching a lot of films from Japan, and in the process have spotted quite a few interesting receivers here and there. Below are some photos and details on some of these unsung stars of Japanese cinema. I think that JRC enthusiast Dan Robinson will agree with me that it’s the ensemble cast of JRCs in Virus that steal the show! 🙂

1. Masahiro Shinoda’s 1961 Epitaph to My Love opened with a very nice shot of a Sony TR-812 multi-band portable in a scene where a news broadcast is being heard in a bar setting.

https://www.radiomuseum.org/r/sony_tr_812_tr812.html

2. A Sony AFM-152J is shown in a contemporary home setting in Hiroshi Teshigahara’s 1966 film The Face of Another.

https://www.radiomuseum.org/r/sony_fmam_automatic_tuning_radio_esaki_diode_afm_152j.html

3. Kihachi Okamoto’s 1978 sci-fi film Blue Christmas featured a brief shot of a Sony ICF-7600 – the first of a legendary line of Sony portables that would carry “7600” in their designation.

https://www.radiomuseum.org/r/sony_icf_7600.html

4. There were several radio appearances in Kinji Fukasaku’s 1980 Virus – a film that took disaster movies to a new level by depicting both a global pandemic and a nuclear holocaust.

A range of JRC gear was captured in a scene that was set in a Japanese Antarctic base. Identifiable rigs include the NRD-10 and the NRD-71.

https://www.radiomuseum.org/r/jrc_nrd_10nrd1.html
https://www.rigpix.com/jrc/jrc_nrd71.htm

In another scene from the Antarctic base, a Trio (Kenwood) TS-820S is shown powered up.

https://www.radiomuseum.org/r/trio_kenwo_ts_820s_ts820s.html

5. Lastly, we have an unidentified tube receiver from Masahiro Shinoda’s Childhood Days – an interesting 1990 film about a school aged boy in World War II era Japan who, because of the bombing threat, is sent from his Tokyo home to live in a rural village.


Thank you for sharing this, Jon! It’s wonderful to include radio sightings from Japanese cinema in our ever-growing collection of radios in movies!

Alan Roe’s A21 season guide to music on shortwave (version 4 update)

Many thanks to SWLing Post contributor, Alan Roe, who shares his latest A21 season guide to music on shortwave.

Click here to download Music on Shortwave A-21 v4 (PDF)

Alan notes that this might be the final update of the A-21 broadcast season.

This dedicated page will always have the latest version of Alan’s guide available for download.

Radio Waves: The Enduring Appeal of Shortwave Radio, Ampegon Ships 100kW Transmitter, 4,270 km FM DX, Emisión Sefarad, and the Eswatini Transmitter

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 David Goren, Tracy Wood, and David Iurescia for the following tips:


Deep in the dial: Lawrence English on the enduring appeal of shortwave radio (The Wire)

To mark The Wire’s Radio Activity special issue, the Room40 label head examines the uncanny sonic properties of high frequency transmission

100 years ago this December, voices spoken on one side of the Atlantic shot through the atmosphere and materialised on the other side of the ocean. It was a moment of jubilation for those involved and proof of concept that formalised the possibilities of an emergent zone of signalling and communications called radio. It also helped to bring into focus the unrealised potential of this technology as a mechanism for access to, and transference of, signals of all sorts from around the globe.

These first transatlantic voices were carried on wavelengths of around 200 metres. At that time, which was before the creation of the International Telecommunication Union who coordinate the use of various frequency bandwidths on the radio spectrum, the length of the waves sat at the cusp of two bandwidths: the lowest end of medium wave and the highest end of shortwave. Not only had this amateur broadcast achieved new distances over which communication might pass, but it also demonstrated the process of skywave propagation. This method, whereby radio signals are bounced off the ionosphere (the electrically charged upper layer of Earth’s atmosphere), extends the range of transmission of a radio signal considerably.

What made skywave propagation especially interesting was that, as a technique, it was being actively explored by both amateur radio enthusiasts (the so-called ham radio movement) and commercial interests alike. In fact, throughout the 1920s experimental approaches to radio (broadcast and otherwise) were an area of intense interest and research. This attention was aided by booms in broadcast hardware and a growing understanding about how the technology could be deployed to radically reconfigure the ways in which transmission of voice, music and other signals might be achieved over greater and greater distances.[]

Ampegon Ships First of Four 100kW Shortwave Transmitters (Ampegon)

Ampegon has shipped the first of a series of four new 100kW shortwave transmitters from its factory in Kleindöttingen, Aargau, Switzerland. The transmitter RF and PSM sections were carefully moved out of the factory and onto a lorry for transfer to our shipping partner. There it will be securely packed in shipping crates and prepared for onward transport.

Ampegon’s TSW-2100 100kW shortwave transmitter is an economical and reliable transmitter system intended for regional to international broadcasting. Its relatively high output power provides good signal strength hundreds of kilometers away from the transmitter when attached to a good antenna, while it is still of sufficiently low power to allow operation from standard low voltage three-phase electrical connections.

Almost all shortwave transmitters currently in production feature digital DRM capabilities, since they are specified with DRM modulators and content servers. This permits the delivery of stereo FM-quality sound and a digital data channel over the same 9/10kHz broadcast band as an analogue transmission. Additionally, when used in DRM mode, power consumption is reduced by approximately 40%-50%, saving broadcasters hundreds of thousands of dollars each year in electricity costs!

With this transmitter safely on its way to its new home, attention turns to completing the next two systems currently under testing. All transmitters undergo rigorous factory acceptance testing to ensure installation and commissioning can be completed with minimum possible disruption.

For further information about Ampegon’s high power shortwave transmitter range, please see our product pages at: www.ampegon.com/products/sw-tube-transmitters/

To learn more about DRM transmissions, please visit the DRM consortium here: www.drm.org[]

FM radio station on 90.7 MHz near Quebec is heard across the Atlantic in Ireland – 21st June 2021 (EI7GL)

21st June 2021: This was a remarkable day for VHF propagation with a very rare trans-Atlantic opening on the 88-108 MHz FM band.

As outlined in a previous post, Paul Logan in the north of Ireland managed to hear a radio station from Greenland on 88.5 MHz from roughly 13:00 to 14:00 UTC on the 21st of June.

Near the end of this opening, Paul also managed to hear a radio station near Quebec in Canada, a distance of approximately 4,270 kms !

The radio station in question was the 100 kilowatt transmitter of CBRX-FM-3 ICI MUSIQUE which is located at Riviére-du-Loup just to the east of Quebec City in Canada.

A short audio clip from Paul is embedded below…

 

[Click here to continue reading this post on EI7GL’s blog…]

For 35 years, mother-daughter duo has run a radio show on Ladino and Sephardic Jewish culture from Madrid (South Florida Sun Sentinel)

Matilde Gini de Barnatán and her daughter Viviana Rajel Barnatán didn’t set out to make Jewish history in Spain.

In the 1960s and ’70s, Matilde, now 85, established herself in Argentina as a prominent researcher, teacher and scholar of the history of Sephardic culture and the Spanish Inquisition in Ibero-America. Her extensive expertise and recognition in Argentine intellectual circles helped her become a close friend of the renowned writer Jorge Luis Borges.

Viviana Rajel, now 55, studied acting in Buenos Aires.

But in April 1986, as Israel was establishing its diplomatic relations with Spain, so did the Spanish government with its Jewish ancestry. Through its state-owned public radio service, the country set out to develop a cultural project in the form of a radio show to reintroduce Ladino — or Judeo-Spanish, an endangered Romance language spoken by past generations of the Sephardic Jewish Diaspora — as a vital piece of Spanish heritage.

It was “a gesture of friendship between Spain, Israel and the Sephardic communities around the world,” according to Viviana Rajel.

Due to the lack of native Ladino speakers in Spain at the time, there was virtually no one available to take on the endeavor. Through academic networks of Sephardic scholars that linked Spain with Argentina, Matilde was found and asked to relocate and be the project’s primary role — which its developers pitched as a way to redress the historical wrong of the Spanish Inquisition, the 15th-century expulsion of Jews from the country.

Viviana Rajel followed her mother because she wanted the show to portray the matriarchal essence behind the oral tradition of Ladino, which traditionally passes from generation to generation through the women of the family.

Hence was born “Emisión Sefarad” (or “Sepharad Broadcast”), a weekly radio show available online and on shortwaves in Judeo-Spanish that broadcasts every Sunday on the Spanish National Radio’s overseas service. April marked 35 years of the program, which has aired uninterrupted since its launch.

Click here to continue reading, noting that this article is behind a paywall.

The incredible reach of the Eswatini transmitter (Evangelical Focus)

TWR Africa has been spreading hope throughout the African continent since 1974 engaging millions in more than 50 countries.

Radio, the internet, mobile devices, TWR360, and other media sources open doors to allow the gospel to spread to countries where Christianity is legally forbidden, to animistic tribes in the Nuba Mountains who are cut off from the rest of civilization, and to displaced people fleeing war in northern Mozambique. We have been equipped with powerful media tools to take the Good News into places where we physically cannot go. Through the power of the Spirit, we can use radio and other mass media to accomplish the task Jesus gave us to make disciples of all nations.

TWR broadcasts from various transmitter sites in Africa including TWR Eswatini and the Middle East on shortwave, and TWR West Africa on medium wave (AM). In addition, TWR broadcasts programs via several TWR partner FM radio networks and a satellite channel that offer direct-to-home services to various parts of the continent.[]

 


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