Category Archives: AM

Edward reviews this unmarked thrift store radio find

Many thanks to SWLing Post contributor, Edward Ganshirt, who writes:

I spotted this “keychain” radio [pictured above] at a Savers thrift shop. Savers is a chain of thrift stores in the Northeast that is an outlet for Goodwill and possibly others. What caught my eye is (in addition to price) an 11 band radio: AM, FM and 4.75 to 21.85 Mhz in 9 short-wave bands. It has no brand markings (or FCC id) and of course made in China. I purchased it for less than a latte at Starbucks and brought it home.

It uses 2 AA penlight batteries and has a 14″ telescoping antenna. Turning it on demonstrates its low performance.

It has ample sensitivity on FM but difficult to tune clearly. AM band is better. Shortwave is a different story.

At night I get several shortwave stations, difficult to tune in. Connecting an external antenna demonstrated its weakness. I picked up the entire AM band and every other station below 30 MHz no matter what setting the tuning knob was set to, with varying signal strength , depending what short-wave band setting selected. I live less than 4 miles from a powerhouse radio station on 680 KHz that bleeds through the IF filter. Deconstructing the radio reveals its design shortcomings

It contains 2 chips: A CSC2822 stereo audio 8 pin dip and a 16 pin CSC2003P “jungle” chip. Comparing app notes to the receiver reveals short cuts in the design. Just absolute minimalist component count–only one 455KHz IF filter.

Fortunately, it has a ferrite loopstick antenna. (That explains why it works on AM. There is less IF bleed-through on AM).

Using a signal generator, on shortwave reveals non existent image rejection, beat notes on harmonics of the local oscillator (yes it is a superheterodyne).

This is a radio to take to the beach. If the tide grabs it and washes it into the ocean or a sea gull snatches it, you would not be disappointed.

In my opinion it was a bit steeply priced. You don’t win them all but I will still go to Savers in the future for other buys as they present themselves.

Thank you for your report, Edward. I think what is highlighted here are the shortcomings of inexpensive–truly “cheap”–radios. They have only the most basic components, regardless if they resemble a quality radio aesthetically. Edward listed the hallmarks of a cheap analog receivers: overloading, stiff inaccurate tuning controls, mediocre sensitivity/selectivity, poor audio, and poor shielding.

Thanks for pulling this one apart and taking a look inside, Edward.

Taking it to the beach, Ed? Let us know if it floats or–better yet–if a seagull decides to grab it–! Who knows, they may tune through the FM and find one of their favorite 1980s songs:

(Sorry, couldn’t help the reference–it is Friday after all.)

Advice on cancelling locally generated noise

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An SWLing Post reader recently contacted me with the following question:

“What devices work well to cancel out local RFI? I’ve been told that both the Timewave ANC-4 and a number of BHI products are all worth considering.”

Unfortunately (or fortunately, for me) I’ve no experience with outboard DSP or noise cancelling devices because I live in such an RFI-free area.

I know this reader already has a Wellbrook Loop, but he’s looking for a way to even increase noise mitigation further at his home listening post.

Post Readers: Can you help guide him? Please comment with your experience. Is a product like the Timewave or BHI the next logical step? If not, what is?

The Bonito Boni whip: proving to be excellent portable antenna for DXing

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Hi there, if you’re a subscriber to the Oxford Shortwave Log YouTube channel, you will be aware that I have been using a Wellbrook ALA1530 H field antenna, for 15 months or so, with (at times) excellent results. A while back I was on the lookout for a second antenna, however at more than £250, I couldn’t justify purchasing a second Wellbrook. Ultimately I splashed out on the Bonito Boni whip E-field wideband active antenna (20 kHz to 300 MHz) and with a very compact form-factor suitable for DXpeditions/portable operation in general, the Boni whip definitely ticked all the boxes. Furthermore, with reasonable second and third order intercept points of +55 and +32.5 dBm respectively, the Boni whip, on paper at least, looked like a pretty good buy at around £100.

Initial testing at home confirmed, perhaps not surprisingly that the Boni whip could not match the SNR provided by the Wellbrook ALA1530 in a noisy, urban environment. However, less predictably, the Boni whip has proven to be a truly excellent antenna away from the ubiquitous blanket of ‘electrosmog’ at my QTH. Furthermore, it really is so compact, I simply leave it in the car in a small flight case, with a portable and connectors etc. for ad-hoc listening sessions. Since returning from my most recent trip to Brazil, I have had a chance to review my most recent catches with the Boni whip, some of which are realy pleasing and most definitely underline the excellent performance of this diminutive antenna. In particular, signals from Radio RB2 on 11935 kHz and Radio Aparecida on 11855 kHz, both low power Brazilian stations, are testament to how sensitive the Boni whip is in an electrically quiet environment. Check out also the quality of longwave signals from Poland and the Czech Republic – simply amazing for such a physically short antenna. Finally, there’s a personal first from Lusaka, Zambia, Voice of Hope Africa on 13680 kHz. All the more rewarding that this was actually copied in my work office!

I hope you found this article interesting. There are embedded reception videos below and text links for all, which will take you directly to the relevant video on the Oxford Shortwave Log YouTube channel. Thank you for reading/watching/listening and I wish you all excellent DX!

Click here to watch on YouTube

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

Standing Inside a Broadcast Transmitter While it’s ON!

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I stumbled across a video from the fabulous Mr Carlson’s Lab YouTube channel. If you haven’t check out this channel before, and you are really eager to learn more about electronics, this is a wonderful YouTube site.

So, in the latest episode, Mr Carlson takes us on a tour of a very large Gates BC-250-GY broadcast transmitter from the 40’s era. Lots of big tubes, transformers and capacitors! This is an old mediumwave transmitter that he has restored. Although the technology has changed markedly since the 1940s, the basic principals of transmission are still present. And, interestingly, he points out that this particular unit was in regular service right up until as recently as 2003!

It’s an interesting show and even if you can’t grab onto all the technical information presented, I think you will enjoy looking at technology from a past era.

73 and good DX to you all,

Rob Wagner VK3BVW

Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.

AIR launching Phase II of DRM conversion

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All India Radio (AIR) Headquarters in Dehli, India. Photo courtesy of Wikipedia.

(Source: Radio Mag via Dennis Dura)

AIR Launching DRM Conversion, Phase II

NEW DELHI — All India Radio was recently congratulated by India’s Union Minister for Information and Broadcasting Shri Venkaiah Naidu for having completed phase I of the national DRM digital radio roll-out in India. Thirty-seven DRM transmitters have been installed by AIR throughout the country, and all are now operational, according to DRM news.

Of the 37 new transmitters, 35 are medium wave and 2 are shortwave transmitters. Both SW transmitters are for international service and are broadcasting in pure DRM. […]

AIR is now in the process of launching phase-II of the DRM project by offering full features and services from these DRM transmitters and further improving service quality. When Phase-II is complete, the full-featured DRM services will be available to the audience and a public information campaign will be initiated to inform the Indian citizens of the completely new and future- oriented DRM radio platform and its many benefits. […]

Phase-III, as presented by AIR, will eventually culminate in the complete transition of radio services to the digital DRM platform, further improving the number and quality of radio services and extra features for the listeners, while also saving tremendous amounts of transmission power every year, according to the same article.

Click here to read the full article via Radio Mag Online.

While it sounds like the broadcasting side of DRM is progressing with AIR domestically, I haven’t read anything recently about affordable DRM receivers being developed for the market in India (other than possibly the Titus II and Gospell GR-216 which, I suppose, could be imported).

Based on messages I’ve received from readers/listeners in India, any new DRM receiver must be very affordable ($40 US or so) if wide adoption is to be expected.

I believe this is an opportunity for a manufacturer like Tecsun to step in and make an affordable DRM portable for the market in India–something with a simple display and controls. Otherwise, this might be another “cart before the horse” situation for DRM. That would be sad.

Titus II at NAB

The least expensive portable DRM receiver on the horizon could be the PantonX Titus II (not yet in production). PantronX has claimed the Titus II will cost “less than $100.”

And speaking of the Titus II, SWLing Post reader, Ed, notes:

pantronX is reportedly going to announce its Titus II Android SDR boombox at NAB April 22-27, which is another indication this radio is for real.

http://www.thebdr.net/hotlinks/mfgr.html

We’ll post updates about the Titus II as they become available. Follow the tag: PantronX Titus II

All India Radio investing heavily in DRM tranmitters

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All India Radio (AIR) Headquarters in Dehli, India. Photo: Wikimedia Commons

Many thanks to SWLing Post reader, Pradip, who shares the following story from Radio and Music Biz online:

AIR has acquired 37 DRM transmitters, in talks to get cheaper radio sets

NEW DELHI: All India Radio (AIR) has introduced digital radio technology in the AIR Network by installing new state of the art Digital Radio Mondiale (DRM) Technology transmitters by replacing old outlived 37 Medium Wave/ Short Wave transmitters.

Minister of State for Information and Broadcasting Rajyavardhan Rathore told Parliament however that the provisions contained in Policy Guidelines on expansion of FM Radio broadcasting services through private agencies (Phase-III) do not provide for private FM broadcasters to adopt digital radio technology.

He said Digital Radio allows significant improvements in service reliability, audio quality, more radio services and higher efficiency.

The new AIR transmitters include 35 new state of art technology Medium Wave (MW)/ DRM transmitters as a replacement of old technology valve based MW transmitters. Additionally, two new state of the art technology Short Wave (SW) DRM transmitters have been approved for installation as a replacement of old SW transmitters.[…]

Continue reading at RadioAndMusic.com.

Daytime DX: Gary compares Terk Advantage with homebrew FSL Loop

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

Daytime DX Shootout– a new-design 4.7 inch FSL antenna ($62 construction cost) goes up against the Terk Advantage AM commercial loop ($58 on eBay) in the daytime DX reception of 650-CISL (10 kW at 160 miles, in Vancouver, B.C.).

The first 20 seconds are on the Terk Advantage, and the final 24 seconds are on the new 4.7 inch FSL (using 27 of the commonly available 62mm Russian surplus ferrite bars).

Signal strength is roughly equal, but the FSL’s lower noise advantage gives it the edge.

Click here to download MP3.

Thank you for sharing this comparison, Gary. You’re right: the FSL provides lower noise and a more stable signal to boot. Still, I’m impressed the Terk was able to compete! In terms of commercially-produced loops, the Terk Advantage is certainly a good one.