Category Archives: Shortwave Radio

Tivdio V-115: Simple modification to abate internally-generated noise

Many thanks to SWLing Post contributor, Marc Thomas, who shares a link to this site which describes modifications to eliminate the Tivdio V-115’s internal noise.

In a nutshell, the author made two small mods:

Decouple the power/battery with an electrolytic capacitor of around 10uF soldered to the battery connector inside the radio (see photo above)
The author also grounded the speaker, but didn’t test to see if this alone had any positive impact

I could not find contact details for the author of this mod, so I hope they don’t mind the fact I shared it here on the SWLing Post.

Note that the Tivdio V-115 is also known as the Audiomax SRW-710S and Kaimeda SRW-710S (and likely rebadged as a number of other models).

Click here to read reviews of this radio.

Retailers:

Bedside radio: Jeff ousts the Sangean WR-2 in favor of the Grundig G4000A

1 Reply

(Source: The Herculodge)

Our friend, Jeff McMahon, over at the Herculodge blog has just replaced his bedside radio–he writes:

Inexplicably, the Sangean WR-2 wasn’t getting 89.3 KPCC without static, distortion, and bleed-in from another station, over the last few weeks, even with the wire FM antenna attached to the back of it. Who knows why FM reception is subject to variation. It could be the weather.

In any event, I put the Sangean WR-2 in my daughter’s room (she gets her pop station MyFM 104.3 very easily, with the pigtail antenna on the back) and put the 13-year-old Grundig G4000A by my bedside. With the telescopic FM antenna alone, KPCC has a weak signal, evidenced by the Grundig’s reception meter, but when I put the wire SW antenna to the side SW antenna port, the reception is strong and clear.

Over the years, I’ve had many portables, including the Degen 1103, and some old Tecsun models from about 10 years ago. They all suffered from weak tin speakers. Not so with the Grundig G4000A. The speaker sound is very pleasing.[…]

Continue reading at the Herculodge.

The NSA’s Software Defined Radio application “RedHawk” is now open source

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

Not kidding, a friend told me that NSA released a bunch of software to open source, the main list being here:

https://code.nsa.gov/

While looking at the list of projects on that page, halfway down the page, I found a project called “RedHawk” which is described as:

“A software-defined radio (SDR) framework designed to support the development, deployment, and management of real-time software radio applications.”

Now, being curious I opened the github link:

https://github.com/redhawksdr

[It] contains quite a number of subprojects, modules and other stuff, then I checked the main “RedHawk” project:

https://github.com/RedhawkSDR/redhawk

Here’s the documentation:

https://redhawksdr.github.io/Documentation/index.html

It seems really interesting; apparently it allows to define a wealth of processing stages (e.g. filters, converters…) and connect them to process signals coming from an SDR; I think it may be a very interesting and useful tool to fiddle/experiment with SDR receivers, if I’m not wrong it may allow to push an SDR to the limits, improving its performance, and may also be useful to write SDR software!

Fascinating! Thank you for the tip, Andrew!

Post Readers: It appears this project has been in the public domain for a little while. Please comment if you’ve tried implementing RedHawk in your SDR system!

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Australia: International broadcasting, soft power and the wisdom of the crowd

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Many thanks to SWLing Post contributor, Nigel Holmes, who writes:

Here are a couple of interesting url following the joint Australian DFAT & DCA Review of Broadcasting Services in the Asia Pacific. [One] gives a good overview and the [other] is a concise assessment of HF and Radio Australia in the role of broadcasting to remote areas. Have a look. Former RA Head Jean-Gabriel Manguy made a submission, I did not this time. The submissions are in the public domain.

Click here to read Trevor Bird’s submission (PDF).

Click here to read Jean-Gabriel Manguy’s submission (PDF).

(Source: Lowy Institute – The Interpreter by Geoff Heriot)

International broadcasting: the ABC vs the wisdom of the crowd

The findings of two related government reviews – on international broadcasting, and soft power – should offer an incoming Australian government the potential of a substantial policy reset following the general election in May. Specifically, they may help clarify the purpose and place of state-funded international broadcasting/digital media in Australia’s foreign relations, following a decades-long cycle of investment and dis-investment.

Shortly before Christmas, the Department of Communications published most of the 433 submissions (92 private individuals, 31 organisations or groups, and 310 signatories to a pro-forma submission) made to the first of those reviews, Australian Broadcasting Services in the Asia Pacific, excluding those whose authors wished them to remain confidential. Finalisation of the broadcasting report precedes the related Soft Power Review, being undertaken by the Department of Foreign Affairs and Trade, which has proposed a completion date of around March.

So it is timely to take note of the wisdom of the crowd, as expressed through the more discursive submissions to the broadcasting review, and to compare them with the institutional perspective of the ABC as the responsible agency for international broadcasting.[…]

Click here to read the full article.

Finding a repair service for boat anchors and other vintage valve/tube radio gear

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Vintage tube radios will likely survive an EMP, but how do you power them without mains electricity?

Here’s a common question I receive from SWLing Post readers:

“Where can I have my vintage valve/tube radio repaired? Can you recommend a good repair service?”

The answer isn’t always a simple one, especially for those living in rural or remote parts of the world.

Go local

The short answer is: try to find a local repair service.

Unlike modern solid state radios, “boat anchors” (metal chassis vintage radios) are heavy and very pricey to ship.

Some repair services and retailers won’t even consider shipping vintage metal chassis radios because of the likelihood of damage or a tube or other component loosening during transit resulting in a DOA (Dead On Arrival) situation. They insist on in-store or local pickup/delivery.

Last year at the Dayton Hamvention I was speaking with an acquaintance who restores and repairs vintage tube radios–he specializes in WWII and Cold War era boat anchors (Collins, Signal Corps, Hallicrafters, National HRO, etc.). Although he makes a tidy profit from doing repairs, it’s most certainly a labor of love and not the most profitable use of his time. He told me that he recently stopped accepting any repairs other than those delivered and picked up locally.

He told me he took great care in packing equipment after repairs had been made–he’d secure all components so that they couldn’t budge during shipment and would either double box or use industrial strength cartons. Being so diligent, his return shipments almost always arrived unscathed, but customers would complain about the shipping costs. He could, of course, skimp on packaging, but then risk his repair work being undermined by rough handling. He was never willing to compromise on shipping and I certainly don’t blame him.

So again, due to the complexities of shipping heavy gear, I always recommend trying to find someone local to do your “boat anchor” repair work first.

Where can you find a local repair shop? If you belong to or know of a local ham radio club, stop by a meeting and ask around. If there’s a vintage radio repair technician in town, someone in the club can likely connect you.

Shipping boat anchors

With that said, there are some excellent repair technicians out there who will take work via parcel shipments, but be prepared to pay upwards of $50-150 each way each way (depending, of course on the radio size and weight).

Lighter tube radios are easier and cheaper to ship, but should still be packed carefully. Bakelite radios, for example, are lightweight but incredibly fragile.

In short: if you ship your vintage radio, pack meticulously and confirm that your repair person will do the same.

And where do you find repair services? I point readers to radio repair service reviews on eHam.net. You might also search the QRZ.com forums or even post a question.

Let’s be clear: some radios are worth the shipping costs!

I am fortunate in that I do have a local friend and mentor Charlie (W4MEC) who repairs tube gear. Better yet, Charlie is willing to teach me how to do repairs and alignments myself. This, I would argue, is the best of both worlds!

A Note of Caution: When it comes to repairing tube/valve gear, I believe you should always learn the ropes with an experienced technician. Unlike battery-powered solid state devices, tube gear is mostly high voltage. If you don’t know what you’re doing inside the chassis of a tube radio, you could be severely shocked or even electrocuted. No radio is worth that price.

Who do you recommend?

If you have any advice about repairing boat anchors and other vintage electronics, please comment! Also, if you can recommend a repair service, please share details.

DE1DGK reviews the affordable Tecsun R-9012

Tecsun R-912 retailers:

Amazon.com / Amazon.co.uk / Amazon.fr / Amazon.de (affiliate links)
eBay
Anon-Co

Guest Post: A visit to Tokyo’s Akihabara district

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Many thanks to SWLing Post contributor and word traveler, Chris Johnson, who shares the following:

This past year while traveling for business in Japan I decided to explore a district within the city limits of Tokyo known as Akihabara or better known to locals as the “Electronics District”.

After jumping off the train I found my senses bombarded by a cacophony of sounds and enough neon from the street to the sky to put your senses into overload. The streets were crowded and the stores were filled with every modern electronic device known to man.

Click here to watch video.

My imagination ran wild, I started wondering what this place would have been like in the 1970’s when some of the most cutting edge electronics were CB radios or shortwave receivers, the different brands, models etc… Perhaps some of that still existed here so I started wandering the streets and found more of the same you would find in a big box store but multiplied by 10, overwhelming.

Just when I was ready to give up the search I turned the corner down a side street and discovered a red awning with “Tokyo Radio Department Store” emblazoned on it, I felt like I discovered a lost treasure amongst the modernity.

I walked through the main entrance and was immediately drawn down a maze of narrow corridors that were staffed with small stores and stalls that sold electronic parts both popular and obscure, it was incredible. That was just the first floor with 3 more above to discover, I thought to myself if I ever wanted to build a transmitter this is the one place in the world where you could shop and find all the parts you need.

As I ventured up the narrow stairs to the floors above once again I felt like I found a treasure of gold, before me were shelves and displays crammed full of radios, some I haven’t seen in many years and some from the recent past .

This was like a Hamfest and eBay together under one roof. Truly incredible as you will see in the pictures below. I couldn’t get close to some of the ones wrapped in plastic but maybe a sharp eyed enthusiast can Identify them. I highly recommend anyone traveling to this part of Asia to check out this hidden gem you will not be disappointed.

Thank you so much for sharing this photo tour, Chris! I mean…WOW! There are so many radio gems here. I see some classic solid-state receivers, ham radio transceivers and even valve gear I’ve never seen before. Amazing!

Thank you for taking the time to share your tour of the Akihabara district of Tokyo!

Post readers: Please comment if you’ve ever visited the Akihabara district or any other “Radio Row” districts in the world. please consider sharing your photos!