Author Archives: Thomas

The role of radio intelligence before the Pearl Harbor attack

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Photograph taken from a Japanese plane during the torpedo attack on ships moored on both sides of Ford Island shortly after the beginning of the Pearl Harbor attack. (Source: WikiMedia Commons, Public Domain)

Many thanks to SWLing Post contributor, Michael Guerin, who writes:

Interesting article from the US Naval Institute on the role of radio intelligence before and during the December 7 attack.

“The key to the success of the Japanese attack on Pearl Harbor-specifically, what enabled the Pearl Harbor Striking Force to reach its launch point undetected (and totally unsuspected) by the Americans-was Tokyo’s radio denial-and-deception actions. Significantly, these activities simply were not just a “bag of tricks” meant to bemuse U.S. naval radio intelligence. Rather, they constituted a function of the change in Japanese strategy and were meant to convince the Americans that there had been no change from defensive to offensive intentions.”

See “How the Japanese Did It”

http://m.usni.org/magazines/navalhistory/2009-12/how-japanese-did-it

Fascinating read! Thank you for sharing this bit of WWII history, Michael.

RRI’s annual “Personality of the Year” poll

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Many thanks to SWLing Post contributor, David Iurescia (LW4DAF), who shares this appeal from Radio Romania International:

Personality of the Year 2016 on RRI

We would like to ask you which person you think left their imprint on the world in a positive way in 2016. We are preparing to designate, based on your options, “The Personality of the Year 2016 on RRI”. Will this person be a politician, an opinion leader, a businessman, an athlete, an artist, a scientist, or even a regular person with a special story? It’s up to you! We would also want to ask you why you picked that particular person.

You can send your answers, as usual, by commenting on our website, at rri.ro, by e-mail at engl@rri.ro, on our Facebook, Google+, Twitter and LinkedIn profiles, by fax at 00.40.21.319.05.62, or by post, at 60-64, General Berthelot street, sector 1, Bucharest, area code 010165 (PO Box 111), Romania.

The “Personality of the year 2015 on RRI” was German Chancellor Angela Merkel.
The “Personality of the year 2016 on RRI” will be announced on January 1st 2017.

1940 Pearl Harbor QSL card

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pearl-harbor-qsl

Many thanks to SWLing Post contributor, Bill Patalon, who shares the following QSL card via Twitter:

Thank you, Bill!

Holiday Deals: Eton Traveller III at HRO

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hro-holiday

We’ve been posting holiday deals since before Thanksgiving. HRO seems to be extending some of their special pricing through December 12, 2016.

The Eton Traveller III

The Eton Traveller III

I did notice that, among other discounts, HRO has the Eton Traveller III for $49.95. Not a bad price for a great little portable!

Check out their full sale by clicking here.

Jazz from the Left returns to WRMI tonight!

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Zenith-Dial-2

Many thanks to our friend, Raoul van Hall, who writes with some exciting news:

Hi Thomas,

Wanted to let you know that Jazz from the Left returns to WRMI stating tonight for two weekly broadcasts.

0000-0100 UTC Wednesday on 7730 kHz.
2000-2100 UTC Tuesday on 11580 kHz.

Brilliant Raoul! Nothing like Jazz over the shortwaves.  I’ll certainly tune it. And, hey–your show starts in about two hours at time of posting!

Chris tracks down sources of radio noise

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spectrum-waterfall-sdr

Many thanks to SWLing Post contributor, Chris Smolinski, who shares this guest post from his blog, RadioHobbyist.org:

Yet Another !&*%$! Noise Source

by Chris Smolinski

The past few days, I have noticed higher than usual noise levels, generally on the lower frequencies, and particularly on the longwave band, including the 285-325 kHz DGPS band, where I run nightly SDR recordings, to later process the data and decode and detect DX DGPS stations using my Amalgamated DGPS app.

Thinking back to what new electronics devices have been added to the house, two came to mind, a new cable modem, and a new ethernet switch. The switch is up here in the shack, so it seemed to be a likely candidate. The switch is a D-Link DES-1008E 8-Port 10/100 Unmanaged Desktop Switch. It uses a mini USB port for power, using either the included AC adapter, or power from a USB port. When I installed it, I decided to not use the AC adapter, but rather a USB port on my UPS, figuring it was better to not add yet another potentially noisy switching power supply to the mix.

The test was easy, I just unplugged the power to the switch. Sure enough, the noise vanished. Great, the switch is a RFI generator. Or is it? As another test, I plugged it into a port on a USB hub. No noise. Hmm… so it seems that the noise is indeed from the USB port on the UPS. I did not notice any increase in the noise floor when I got the UPS a few months ago, but It’s something I should look into again, just to be sure. The UPS is a CyberPower CP1350PFCLCD.

Here’s a waterfall from the SDR, showing the DGPS band, 280-330 kHz. You can see where I changed the power to the switch from the UPS USB port to the USB hub, the bottom part of the waterfall is when the switch was still powered by the UPS (click to enlarge it):

pmuv3bc

I still have a noise source just above 305 kHz to hunt down.

Update

I decided to see what I could do to improve things, and reduce the noise floor.

Here is the baseline, after no longer powering the switch from the UPS:
qormmpg

First, I relocated the AFE822 away from the computer and rats nest of assorted cables behind it, powered from an HTC USB charger:
kljq7ef

The squiggly noise around 305 kHz vanished!

I then switched to an Apple USB charger / power supply, as their products tend to be a bit better made:
goyrdt4

Another improvement, the overall noise floor is a bit less now.

But can we do better? I then switched to an older USB hub for power to the AFE822, that I thought might be better filtered:
k0e8eaw

I then changed to a linear supply plugged directly into the AFE822. I don’t notice any obvious improvement? Maybe it even looks like a little more noise? Difficult to tell. You can see a DGPS station popped up on 304 kHz while I was switching things around, between the last two tests, it was likely Mequon, WI.

ocsavij

Thank you for sharing this, Chris! I find a wideband spectrum/waterfall to be such a useful tool for tracking down sources of noise. Not only can you “see” the noise, but you can measure its bandwidth and identify what portions of the dial it affects.

Follow Chris at RadioHobbyist.org.

Pacific Beat: ABC decision to halt shortwave broadcasts criticised

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Radio-Australia-Banner(Source: ABC News)

ABC decision to halt shortwave broadcasts criticised

A decision by the ABC to halt shortwave broadcasts early next year has been criticised by a former manager of Radio Australia.

The shortwave transmissions to Asia and the Pacific will cease from January 31st next year, as alternatives such as FM and internet become more prevalent.

Former head of Radio Australia and subsequently a consultant on international broadcasting in the Pacific, Jean Gabriel Manguy, tells Bruce Hill the decision is short sighted.

Audio Player

Click here to listen and read on Pacific Beat’s website.