Author Archives: Thomas

Jazz from the Left returns to WRMI tonight!

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

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

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.

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

Radio Australia to end shortwave broadcast service on January 31, 2017

radio-dial

Like many SWLing Post readers, I’m a huge fan of Radio Australia’s service on 9,580 kHz. For ages, listening to their news headlines over shortwave has been a part of my morning routine. I’ve been listening to Radio Australia since I was 8 years old.

I’m going to miss this friend on the shortwaves.

(Source: Australian Broadcast Corporation Press Release)

ABC Exits Shortwave Radio Transmission

The ABC will end its shortwave transmission service in the Northern Territory and to international audiences from 31 January 2017.

The move is in line with the national broadcaster’s commitment to dispense with outdated technology and to expand its digital content offerings including DAB+ digital radio, online and mobile services, together with FM services for international audiences.

The majority of ABC audiences in the Northern Territory currently access ABC services via AM and FM and all ABC radio and digital radio services are available on the VAST satellite service.

ABC International’s shortwave services currently broadcast to PNG and the Pacific. Savings realised through decommissioning this service will be reinvested in a more robust FM transmitter network and an expanded content offering for the region that will include English and in-language audio content.

Michael Mason, ABC’s Director of Radio said, “While shortwave technology has served audiences well for many decades, it is now nearly a century old and serves a very limited audience. The ABC is seeking efficiencies and will instead service this audience through modern technology”.

The ABC, working alongside SBS, is planning to extend its digital radio services in Darwin and Hobart, and to make permanent its current digital radio trial in Canberra. Extending DAB+ into the nation’s eight capital cities will ensure ABC digital radio services can reach an additional 700,000 people, increasing the overall reach of ABC digital radio to 60% of the Australian population.

ABC Radio is also investigating transmission improvements to address reception gaps in the existing five DAB+ markets. It aims to ensure a resilient DAB+ service in every capital city, with enhanced bitrates and infill where necessary.

“Extending our DAB+ offer will allow audiences in every capital city in Australia equal access to our digital radio offering, as well as representing an ongoing broadcast cost saving owing to lower transmission costs,” added Michael Mason.

ABC International’s Chief Executive Officer Lynley Marshall said the reinvestment from closing international shortwave services would maximise the ABC’s broadcast capabilities in the region.

“In considering how best to serve our Pacific regional audiences into the future we will move away from the legacy of shortwave radio distribution,” Ms Marshall said. “An ever-growing number of people in the region now have access to mobile phones with FM receivers and the ABC will redirect funds towards an extended content offering and a robust FM distribution network to better serve audiences into the future.”

Once international shortwave ceases transmission, international listeners can continue to access ABC International services via:

Audiences can access further information via the reception advice line 1300 139 994 or via ABC Local Radio (Darwin & Alice Springs).

For more information
Louise Alley
P: +61 2 8333 2621
alley.louise@abc.net.au
(ABC Radio queries)

Nick Leys
p: +61 3 9626 1417
leys.nick@abc.net.au
(ABC International queries)

FAQs
Domestic and International

WRTH 2017: Available to pre-order

2017-wrth-coverMany thanks to SWLing Post contributors Andrea Borgnino and Tom Ally who’ve notified me that WRTH 2017 is available for pre-order!

Here’s a description from the WRTH website:

The Features section for this 71st edition includes articles on Remote Receivers, a Pacific Radio Adventure, The Mighty KBC radio station, CKZN St John’s, the International Radio Disaster Relief Project, and a reminiscence by Vagn Fentz. There are equipment reviews of the Icom IC-7300, Reuter Elektronik RDR55D, SDRPlay RSP, Wellbrook ALA1530LNP, and Bonito AAS300, as well as other articles, information and maps.

The remaining pages are, as usual, full of information on:

  • National and International broadcasts and broadcasters
  • Clandestine and other target broadcasters
  • MW and SW frequency listings
  • National TV by country
  • Extensive Reference section

Click here to pre-order your copy!