Tag Archives: RFI

“Burundi to suspend BBC and VOA radio broadcasts”

(Source: The Independent via Mike Hansgen)

Nairobi, Kenya | AFP | Burundi’s press regulator on Friday said it was suspending broadcasts by the BBC and Voice of America (VOA) by local radio stations ahead of a constitutional referendum on May 17.

The head of Burundi’s National Communications Council told journalists in the capital Bujumbura that a six-month ban would come into force on Monday.

Karenga Ramadhani accused the BBC and VOA of “breaches of the law governing the press and ethics”.

The BBC, he said, “damaged the reputation” of President Pierre Nkurunziza during a discussion programme and had “ignored” previous warnings.

Burundi’s government earlier this week urged the regulator to “take action” against the BBC which it accused of spreading “incendiary statements… hatred and subversion”.

VOA is accused of spreading “very tendentious” information and hiring a journalist “sought by Burundian justice”.

French broadcaster RFI also received a warning for disseminating “tendentious and misleading” information.[…]

Click here to read the full article at The Independent.

DARC’s initiative to track the state of radio interference

Many thanks to SWLing Post contributor, Alexender (DL4NO), who shares the following comment in response to our recent post about LED bulb QRM:

The DARC does even more: It is planning a long-term project with some 50 automatic monitoring stations with standardized, calibrated antennas and according to standardized methods to document the changes.

Every monitoring station will scan the bands for free frequencies and measure the background noise there. Every 15 min it will send its findings to a central database where the data will be collected and evaluated.

This way the DARC wants to document the ever increasing interferences in a way that is valid according to the relevant standards. Most monitoring stations are planned to be placed at fixed locations all over Germany. But a few are planned to be placed for a limited time in especially interesting locations.

Presently relevant findings are collected. If you live in Germany see https://www.darc.de/der-club/referate/emv/emv-abhilfemassnahmen/. Also see the DARC magazine cqDL 12-2017, p. 15.

To emphasize it again: Informal reports to your radio club are good. But if you wish to communicate with the legislative bodies you must do your measurements according to the standardized rules using calibrated equipment. Otherwise the authorities will not accept your findings.

See:
https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.372-13-201609-I!!PDF-E.pdf
https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.560-4-199710-I!!PDF-E.pdf

Most impressive, Alexander! I love the fact that DARC is using objective observations to support their initiative. The concept is a fascinating one that I should hope other national radio clubs could copy. I will certainly send this to the ARRL.

Thanks again, Alexander!

DARC asks that you send RF polluting LED bulbs to Elektor Magazine

Photo By Trung Pham Quoc

(Source: Southgate ARC via Mike Hansgen)

LED Bulb RF Pollution – Elektor Magazine investigates

DARC, the German national amateur radio society, are requesting amateurs to send LED bulbs which pollute the RF spectrum to the magazine Elektor for investigation

A Google English translation reads:

Elektor-Verlag GmbH calls all readers and especially all radio amateurs to send non-compliant LED bulbs including power supplies. Elektor wants to investigate this EMC-technical and then forward it to the competent market surveillance of the BNetzA.

The reason for the action: As a result of a press release of the DARC in September 2017 on the significantly increasing interference of radio communications, other radio services and the DAB reception by non-EMC compliant LED bulbs Elektor had investigated such lamps (as well as LED strips). The result showed a progressive electromagnetic pollution.

The Federal Network Agency as competent authority for market surveillance in accordance with the EMVG has welcomed the call for the submission of suspicious copies. In addition, the Federal Agency would like to be informed if disturbing lamps attract attention. She then wants to investigate this situation and take the products out of the market, if they are still offered.

Please send suspicious copies

Elektor-Verlag GmbH
Kackertstr. 10
52072 Aachen

Please enclose a note with the words “EMC LED lamp” so that everything runs correctly in the inbox. You can also announce your submission via e-mail to redaktion@elektor.de with the subject “EMC-LED-Lamp”. Elektor Verlag GmbH then checks the lamp, publishes an update if necessary and informs the Federal Network Agency.

Here the link to the Elektor article from 23.04.2018
https://www.elektormagazine.de/news/bundesnetzagentur-zu-schicken-sie-uns-verdachtige-led-lampen

Source DARC http://darc.de/

2017 RF pollution from LED bulbs in Elektor Magazine
http://www.southgatearc.org/news/2017/september/rf-pollution-from-led-bulbs-in-elektor-magazine.htm

RSGB presentation on RF Interference

Digital-Frequency-DialMany thanks to SWLing Post contributor, Gary (W4EEY), who writes:

I want to recommend an excellent presentation on RF Interference from
the Radio Society of Great Britain (RSGB) Convention in 2015. The
presenter is Ian White, GM3SEK, who has a Blog website here:

https://gm3sek.com/

You can find the presentation video on YouTube here:

Click here to view on YouTube.

The presentation runs for about one hour and contains some valuable
information to help you fight noise and interference in your shack.

Thanks for the tip, Gary!

Indoor shortwave antenna options to pair with a new SDR

Many thanks to SWLing Post contributor, Chris Freitas, who writes:

“I am thinking of the new RSP1A SDR. Would you know of a good indoor antenna that would work well with it?”

Your antenna question is simple, but the answer is complex!

First off, I think the RSP1A is a great choice as it’ll give you proper exposure to the world of SDR (1 kHz to 2 GHz!)  at a modest price.

Unlike a portable radio of course, your SDR must be connected to a PC, laptop, tablet or some sort of mini computer like Raspberry Pi. This limits your ability to easily try different antenna locations within your home compared to, say, a battery-powered portable radio. It might take some dedicated experimentation and patience.

Indoor antennas are so vulnerable to the radio noise within your home.

If you live in an off-grid cabin with no radio interference nearby, even a simple $1 random wire antenna hooked up to RSP1A’s SMA connector would yield results. I occasionally spend my summers in an off-grid cabin and it’s simply amazing what you can do with a modest setup when there are no man-made radio noises around.

Listening to the final broadcast of Radio Netherlands in an off-grid cabin on Prince Edward Island in 2012.

But how many radio enthusiasts live in an off-grid cabin? Answer: very, very few! Most of us only get to experience off-grid life during natural disasters when the electrical grid has been damaged in our neighborhoods.

The reality of indoor antennas

You’ve told me previously that you live in an apartment in an urban setting, hence you probably cope with a lot of RFI.

When an antenna is indoors, it is forced to function within this RFI-dense environment. Your telescoping whip or wire antenna doesn’t discern between radio noise and your target broadcast signal. Thus, noise can overwhelm your receiver, essentially deafening it to all but the strongest shortwave broadcasters.

And simple, inexpensive portable amplified shortwave antennas? I’ve expressed my opinions about them before. They amplify the RFI as effectively as they do broadcasters.

This is why if you had a means to put a small random wire antenna outside–even if it was simply draped outside a window–it would likely perform better than an indoor antenna. I’m guessing this isn’t an option for you, Chris.

Think loops

A broadband loop antenna (image courtesy of wellbrook.uk.com)

Magnetic loop antennas are a popular topic here on the SWLing Post for a reason: they’re one of the best frontline tools for fighting urban noise. (Here’s a great tutorial/presentation [PDF] describing how mag loop antennas work.)

The compact Bonito Mega Loop FX

While you can build an amplified mag loop antenna (like our buddy, TomL) it’s not a simple project.  Passive single turn loop antennas, on the other hand, are quite easy to build but are narrow in bandwidth (here’s a very cheap, simple passive loop project). You would likely design a single passive loop to serve you on a specific brodcast band and would have to retune it as you make frequency changes. You could build a passive loop antenna for less than ten dollars if you can find a good variable capacitor. Here’s another tutorial.

Commercially produced amplified wideband magnetic loop antennas are not cheap, but they are effective. If you’re a serious SWL, a good mag loop antenna is worth the investment.

Here are a few of my favorites starting with the most portable:

PK Loops

The PK Loop

The most affordable and portable mag loop antenna I own is the PK Loop.  I have the more compact PK Loop C-LOOP-HDSW6-18 (6 – 8 MHz), but Guy Atkins also touts the slightly larger Ham Loop which he finds tunes beyond the advertised 3.5 – 14.5 MHz range.

PK Loops are not as broad in bandwidth as the other antennas I mention below. You will have to retune the loop with any band changes and sometimes even within a specific meter band.

Click here to check out PK Loop offerings on eBay.

W6LVP Loops

The W6LVP Loop Antenna

To my knowledge, the W6LVP is one of the most affordable larger diameter amplified wideband mag loop antennas. We’ve published positive reviews of this antenna in the past.

W6LVP sells two versions of the antenna–since you’re not operating a transmitter, this $250 model would be all you need. indeed, if I were in your shoes, this would likely be the loop I purchase–very cost effective.

Wellbrook Loops

Wellbrook antennas are the staple magnetic loop antenna for many DXers.

Wellbrook loops are manufactured in the UK and have been on the market for a very long time. Their re-engineered Active Inoor Loop Antenna LA5030 would serve you well. At £240.00 (roughly $330 US) plus shipping, it’s one of the most affordable in the Wellbrook line, but over a $250 budget.

Wellbrook makes a number of loops, but since you have no plans to mount this outside, I believe their indoor model would suffice.

Other loop options

There’s no shortage of magnetic loop antennas on the market, but most are pricer than the models I mention above and I know you have a tight budget. Here’s are some models we’ve mentioned on the SWLing Post in the past:

I have the RF Pro-1B and am very impressed, but it’s overkiil for your application (and twice the price of the W6LVP loop).

Fighting urban noise

Even if you build or purchase a magnetic loop antenna, you still need to eliminate as much RFI as you can on your own.

A couple years ago, our friend London Shortwave wrote a brilliant guest post about fighting urban noise. Read through his piece and try to implement as much of his advice as you can.

I hope this helps, Chris! This post is by no means comprehensive, so I hope others will chime in and comment with their experiences. Good luck fighting urban noise and I hope you enjoy your journey into the world of the SDR!