Japan’s Longest Day: August 15, 1945

1 Reply

Many thanks to SWLing Post contributor, Fred Waterer, who writes:

At Noon on August 15, 1945, Emporer Hirohito spoke to his nation by radio for the first time, ever. The intrigue surrounding the recording of his speech and the effort to get it on the air would be worthy of a Hollywood film. When word started getting out that the broadcast would be made, fanatics who wanted to keep fighting staged an attempted coup. An NHK (Japan Radio Corporation) engineer had a gun to his head as an officer attempted to hijack the station at 5am. His coolness under pressure saved his life. He also temporarily severed the line to the transmitter, just in case the officer changed his mind about killing him.

Meanwhile at the palace, the NHK recording engineers had recorded two versions of the speech. The recordings (and the engineers) were hidden overnight, as was the Emporer, in the labyrinth of the palace. Coup leaders searching for the disks to destroy them failed. Eventually troops loyal to the Emporer took control of the situation, with many of the coup plotters killing themselves. At noon, the recordings were in the NHK studios and were broadcast as scheduled.

The actual broadcast:

In 1967 a film about these events was made in Japan, called Japan’s Longest Day and starring the great Toshiro Mifune.

The recording scene:

Looks like quite a film!

Thank you for sharing this, Fred.

Can you help Bob identify this mystery signal?

8 Replies

Many thanks to SWLing Post contributor, Bob (K7ZB), who shares the following note and recording: 

Hi Thomas,

I recently started using an SDRplay RSP1A with their new software release SDRconnect.

Quite a nice piece of work and my first foray into SDR after 60 years of analog radio (K7ZB).

Today I was listening to WWV on 10MHz and it was being interfered with a strange type of digital signal that pretty much covered the band.

I finally tracked it down to 9.979MHz, recorded it and sent it to a friend who did a bit of audio analysis on it by expanding out the signal to look at individual bursts.

I certainly don’t recognize the modulation although it sounded like a form of CW in burst mode.

I am just curious if you have any insight on this signal or where I might go to find out more about it.

Thanks,

Bob
K7ZB
Gilbert, AZ

Post readers: Can you identify this signal? If so, please comment and thank you in advance!

“Don’t throw out that radio in the basement after all”

5 Replies

“Don’t throw out that radio in the basement after all”. Well that got my attention.

With the wildfires in the North West Territories causing the evacuation of the Territorial Capital I received a daily email from the Canadian version of The Conversation with that subject line.

The article outlines the difficulty of getting information to thousands of Yellowknifers who have scattered to communities and cities in BC and Alberta, from Edmonton to Calgary and to remote campgrounds by the sides of major highways. Some are thousands of kilometers from home. At the same time Meta is in a dispute with the Federal Government and has blocked the posting of news articles of any kind on Facebook.

This has complicated things and left AM and FM radio as the key and sometimes only method of informing this diverse population. CBC Yellowknife has even relocated to Calgary.

It makes for interesting reading here:

Paul’s short recording of Marconi Radio International

3 Replies

Many thanks to SWLing Post contributor, Paul Jamet, who writes:

Hi Thomas,

I tried in vain to pick up Radio Marconi International … And I’m not the only one! I’ve used several SDR kiwis installed in Italy, and only one has enabled me to listen to this station, which has only a very weak transmitter.

Here’s the audio file below [RMI signing on at 18hOO UTC] and a snapshot of the screen of my PC (see above):

 

Kind regards.

Paul JAMET
Radio Club du Perche

Thank you for sharing this recording, Paul!

KiwiSDR 2 on the horizon…

4 Replies

A number of SWLing Post readers have shared a link to this post by KiwiSDR creator John Seamons on the KiwiSDR forum. In it, he (somewhat reluctantly) describes a new version 2 of the KiwiSDR that is in the works.

Image source: KiwiSDR Forum

John writes:

I don’t like to announce something before it’s ready. But my hand is being forced.

So please consider this a pre-announcement. There are no guarantees.

The PCB and bill-of-materials (BOM) are finished and ready for prototype construction.

The problem is I don’t know WHO is going to build this or HOW. So I don’t know WHEN it might be available. And most importantly I don’t know what it might COST.

If YOU have specific ideas about these questions please email me. I’m especially interested in full-service manufacturing and distribution outside of China.

KiwiSDR 2 Goals:

Minimal changes. Fastest time-to-market with lowest possible risk. BUT since the PCB is going to be re-spun fix some of the known limitations that don’t add too much risk:

    • New RF front-end:
      •   Balanced input via balun transformer
      •   Digital attenuator (per the advisory group: pSemi PE4312, 0 – 31.5 dB, 0.5 dB steps)
      •   Gas discharge tube (GDT) across input in addition to TVS diodes
      •   Static drain resistors (100K) from input connections to ground
    • External ADC clock brought out on third SMA connector
      •   Self test loopback mode using a short cable between this SMA and antenna input
    • New GPS chip to replace current one which is now EOL
    • Reverse polarity protection (via P-FET) on 5V DC input
      •   TVS diode across 5V input

I have an email advisory group. Many, many other changes and additions were considered and deferred. They have been put onto a list for the future.

Additional info as things progress.

Thank you.

Readers: If you have suggestions for John regarding a manufacturing and distribution facility outside of China, please connect with him on the KiwiSDR forum.

In my opinion, the KiwiSDR has been the most accessible and effective web-based SDR platform out there. I’m looking forward to version 2 and hope it becomes a reality in the near future.

Luke discovers a treasure trove of CIDX newsletters! (And I believe everyone should join the CIDX!)

12 Replies

Many thanks to SWLing Post contributor, Luke Perry, who writes:

Hi Thomas, thought that you and your readers would enjoy my recent “find.” I came across an old copy of the “Messenger”, which was a magazine put out monthly by the Canadian International DX Club.

While looking for the current garbage bill I was shuffling through my file of bills and receipts, and lo and behold I came across one copy……how it ever got in there I have no idea. Anyway it sparked a lot of nostalgia and remember how excited I used to be when a new copy arrived in the mail.

I knew that I had more, but had no idea where as I tend to not throw things away, especially anything associated with electronics or cars. After a day or so of brainstorming I had an idea of where they might be, and lo and behold there they were.

They mostly date from the mid-90’s right before the internet basically killed off “zines” like this. Oh well.. progress marches on.

Anyway, I hope that people can enjoy the pictures and maybe have some insight or memories of the club and/or the guy who ran it. I believe that his name was Sheldon.

Take care,
Luke Perry

Wow–what a treasure trove you unearthed there, Luke! I could spend hours looking through those copies!

Join the CIDX!

I have good news for you: The Canadian International DX Club (CIDX) is very much alive and well! Check out the cover of the the August ’23 issue of the Messenger above.

Here’s an article I posted about the CIDX in the past and how much I enjoy the Messenger. And yes, Sheldon Harvey is still at the helm along with some other amazing, devoted volunteers. I’m a member and I’d encourage everyone else to become one, too. It’s one of the best deals in the world of radio.

The Messenger is now in digital format only, but I actually prefer it this way since I’ve so little room to store printed material these days.

For more information about joining the CIDX–only $10 per year or $25 for three years–click here!

Thanks again, Luke, for sharing this!

The New RTL-SDR Dongle Version 4

6 Replies

Many thanks to SWLing Post contributor, Dennis Dura, who notes that the latest version of the RTL-SDR dongle is now in production. Here are details from the RTL-SDR blog:

RTL-SDR BLOG V4 DONGLE INITIAL RELEASE!

We’re happy to announce the first release of our new RTL-SDR Blog V4 dongle which is based on the R828D tuner chip. The pricing is US$39.95 for the V4 dongle with antenna set, and US$29.95 for the dongle only, including free shipping to most countries.

Currently we are only shipping this model from our warehouse in China and the initial production batch is small and so we are limited in stock. However, now that we have confirmed that production of the first small batch of V4 has gone very well, we will be ramping up production, and stocking Amazon USA within 1-2 months as well.

The units are available for purchase on our store page.

The V4 comes with several improvements and changes that are listed below.

    • Improved HF Reception. Now uses a built in upconverter instead of using a direct sampling circuit. This means no more Nyquist folding of signals around 14.4 MHz, improved sensitivity, and adjustable gain on HF.
    • Improved filtering. The V4 makes use of the R828D tuner chip, which has three inputs. We triplex the SMA input into three bands, HF, VHF and UHF. This provides some isolation between the three bands, meaning out of band interference from strong broadcast stations is less likely to cause desensitization or imaging.
    • Improved Filtering x2. In addition to the triplexing, we are also making use of the open drain pin on the R828D, which allows us to add simple notch filters for common interference bands such as broadcast AM, broadcast FM and the DAB bands. These only attenuate by a few dB, but may still help.
    • Improved phase noise on strong signals. Due to an improved power supply design, phase noise from power supply noise has been significantly reduced.
    • Less heat. Due to the improved power supply design the V4 uses slightly less current and generates slightly less heat compared to the V3.
    • Cheaper price! The price of the R860 chip which is used in the V3 and most other RTL-SDR brands increased significantly at the beginning of 2023 which is part of the reason as to why RTL-SDR dongles have been increasing in price recently. For the V4 we are making use of an existing stockpile of R828D chips which are now priced cheaper than new productions of the R860. In a time when high inflation keeps pushing prices up this is incredibly welcome.

There are some other minor changes including a new bias tee LED and a small cutout hole in the enclosure so it’s easy to tell when the bias tee is on.

Of course the same innovations that we brought in with the V3 are still implemented such as the sleek conductive black metal enclosure which works as a shield and doubles as a heatsink, a thermal pad to sink heat away from the PCB, 1PPM TCXO, SMA connector, USB noise choking and improved ESD protection.

The V4 however does come with some disadvantages compared to the V3 that need to be noted [Click here to continue reading…]

Note that the RTL-SDR dongle can be purchased (when it’s stocked) from Amazon via our affiliate link which supports the SWLing Post at no cost to you. Thank you!