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!

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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

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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!

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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.

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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!

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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.

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From the Isle of Music, July 11-17:

This week, our guest is Carlos Miyares, who returns to help us present his new release Tributo a Chucho Valdés e Irakere.
The broadcasts take place:
1. For Eastern Europe but audible well beyond the target area in most of the Eastern Hemisphere (including parts of East Asia and Oceania) with 100Kw, Sunday 1500-1600 UTC on SpaceLine, 9400 KHz, from Sofia, Bulgaria (1800-1900 MSK)
2. For the Americas and parts of Europe, Tuesday 0000-0100 UTC on WBCQ, 7490 kHz from Monticello, ME, USA (Monday 8-9PM EDT in the US).
3 & 4. For Europe and sometimes beyond, Tuesday 1900-2000 UTC and Saturday 1200-1300 UTC on Channel 292, 6070 kHz from Rohrbach, Germany.
Our Facebook page is https://www.facebook.com/fromtheisleofmusic/
Our V-Kontakte page is https://vk.com/fromtheisleofmusic
Our Patreon page is https://www.patreon.com/tilford

Uncle Bill’s Melting Pot, July 11-17:
In episode 225, we enjoy music from Singapore.
The transmissions take place:
1.Sunday 2200-2300 (6:00PM -7:00PM EDT) on WBCQ The Planet 7490 kHz from the US to the Americas and parts of Europe
2. Tuesday 2000-2100 UTC on Channel 292, 6070 kHz from Rohrbach, Germany for Europe.
3. Saturday 0800-0900 UTC on Channel 292, 9670 kHz from Rohrbach, Germany for Europe with a directional booster aimed eastward.
Our Facebook page is https://www.facebook.com/UncleBillsMeltingPot/
Our V-Kontakte page is https://vk.com/fromtheisleofmusic
Our Patreon page is https://www.patreon.com/tilford

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