Author Archives: Thomas

Raspberry Pi image with preloaded SDRplay RSP software

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The $35 Raspberry Pi 3

SDRplay support have just posted the following news on their community forum:

We have released a Raspberry Pi 3 image that has a number of SDR applications pre-built and tested that support the RSP. Periodically, we will update the image with software updates and new software.

The current list of software included on the image is:

SoapySDR/SoapySDRPlay, SoapyRemote, ADS-B (dump1090), CubicSDR and SDR-J DAB receiver

Please note: This is a complete OS with software image. Writing the image to a micro SD card will wipe the micro SD card of any other data that is on there, so we recommend you make sure you have backed up any data on your existing micro SD card or you use a new micro SD card.

Instructions:

1. Download image. There are two downloads provided, the 7zip version is just a smaller download but not everyone has 7zip which is why we also provide a zip download. The links are here:

http://www.sdrplay.com/software/SDRplay_RPi3_V0.1.zip (2.7 GB)

http://www.sdrplay.com/software/SDRplay … 0.1.img.7z (2.0 GB)

2. Extract the contents of the compressed file. This will extract to a .img file which will be about 7.2 GB

3. Use an image writer such as Win32DiskImager (https://sourceforge.net/projects/win32diskimager) to put the image onto the micro SD card.
WARNING: Please make sure that you use the correct drive letter for the micro SD card. The image writing software will completely remove any data that is on the destination media.

That’s it – put the micro SD card into the Raspberry Pi 3 micro SD card slot and boot the system. Allow the system to fully boot and you will see a GUI that will allow you to run each of the applications or read further information.

We also recommend that you use an active cooling system on your Raspberry Pi 3 to avoid any issues with over heating. In our tests, we have used heatsinks and a fan in a case. The CPU speed will be throttled if the temperature gets too hot, so for optimum use this is really recommended. These cases are available at reasonable prices from many Raspberry Pi stores.

If you are a developer of software that supports the RSP and you would like to be included on the image that we will release periodically, please contact us at [email protected] – currently we’re aiming to update the image every quarter, this will largely depend on software availability and what the demand is.

We are aware of other software that we are looking to get onto the next release such as Pothos and more SDR-J software. We will work with developers on any issues we’ve seen during this process so that we can get them onto future images.

Best regards,

SDRplay Support

This is great news in my book, because a fully-loaded and configured disk image makes it much easier to get started with an RSP/Pi combo.

Note that the message above is merely the announcement on SDRplay’s community forum. I would strongly encourage you to follow this thread, and the forum in general, if you’re interested in updates and announcements.

Raspberry Pi systems are very affordable and available in a number of configurations (from $35US – $80US depending on accessories) and from a number of retailers including:

2017 BBC Midwinter Broadcast test transmissions

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Rothera Research Station, Adelaide Island, Antarctica (Image Source: British Antarctic Survey)

Many thanks to SWLing Post contributors, Richard Langley and Mauno Ritola, who shared frequencies and times for the test transmissions in advance of the BBC Midwinter broadcast next week (June 21).

I didn’t get their tips in time to post prior to the transmissions yesterday, however, Mauno believes there may be another test transmission today.

This schedule was originally posted by Martin Goulding on BDXC-UK list–times are GMT:

ASCENSION

2130-2145 7360 kHz

DHABAYYA

2130-2145 – 6035 kHz

WOOFFERTON

2130-2145 7230 kHz
2130-2145 5985 kHz

Please comment if you log a test transmission today (or if you logged one yesterday)

As in years past, I plan to record the actual broadcast next week and share all of your recordings here on the SWLing Post as well.

Click here to browse the Midwinter recordings from last year.

Radio Bulgaria petition

Many thanks to SWLing Post contributor, David Iurescia (LW4DAF), who writes:

Hi Thomas: I’m sending you what I received today from Radio Bulgaria.
The petition can be read in Spanish, English or Bulgarian.

Dear Friends:

We need your support for a noble and responsible cause.

Radio Bulgaria, which belongs to National Radio of Bulgaria, is the only means of communication that presents the image of Bulgaria before the world in nine languages, as well as in Bulgarian language with programs destined to the Bulgarian communities abroad. Today Radio Bulgaria faces the risk of being in history!

We urge you to support the efforts of editors, journalists, translators and institutions against this destructive act, contrary to the interests of society and statehood of Bulgaria, signing our request to save our, and yours also Radio Bulgaria.

Here is the address of the website with the request: http://www.saveradiobulgaria.com/en

Sign, please.

Spanish Language Section of Radio Bulgaria

Many thanks, David!

Carl Laufer of RTL-SDR.com on HamRadioNow

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(Source: Southgate ARC)

Carl Laufer’s RTL-SDR on HamRadioNow

Carl Laufer isn’t a ham (yet), but he got caught up in the RTL-SDR craze in his home town, Auckland NZ, as he was completing his PHD

He began writing about them, and selling them, on his blog at www.RTL-SDR.com, and soon discovered that the little SDR receiver dongles could stand some improvement.

So he designed ways to make them work better, and contracted a Chinese manufacturer to build them with his mods. That just about doubled the price, from $10 to about $20. Yeah, big deal.

TAPR invited Carl to come to the 2017 Dayton Hamvention to talk about them at both their Friday Forum (part of HamRadioNow Episode 324) and as the main speaker at the TAPR/AMSAT Banquet.

And we got him for a conversation with HamRadioNow’s KN4AQ and PhasingLine’s Chicken With Fries in the SIB back in Tent City.

Watch HRN 328: Carl Laufer’s RTL-SDR on HamRadioNow:

Click here to watch on YouTube.

I got to meet Carl at the Hamvention this year–what a great guy and his website is certainly the best source of information about the RTL-SDR.

I should note that I also met with contributor, Mike Ladd, in person at the Hamvention. Mike now works for SDRplay.

This is one of the great things about gatherings like the Hamvention–it brings together so many people that you’d otherwise likely never meet in person!

NASA’s ionospheric experiment tonight and remembering The Woodpecker Project

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The gas mixtures from NASA’s ionospheric experiment cause parts of the night sky to glow blue and green. (Photo: NASA)

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

It might be interesting if you invited SWLing Post readers today see how NASA’s ionospheric experiment tonight (shortly after 9:00PM ET) affects RF propagation along the east coast:

http://www.smithsonianmag.com/smart-news/nasa-will-make-colorful-clouds-near-sunset-tonight-180963652/

I searched online to find any reference to this long series of NASA experiments affecting RF propagation, and found this 1980 paper:

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810005401.pdf

…which contains this paragraph:

Ionospheric Modifications

The objectives motivating various experiments based on either decreasing or increasing the ambient plasma density by means of a chemical release include: (a) obtaining measurements of the rate of refilling after creation of a plasma depletion “hole” as a means of studying ambient ionization processes, (b) studying the magnetic field aligned propagation of VLF waves by creating a propagation duct, (c) simulating the formation and movement of the natural depletion “bubbles” which occur over the magnetic equator, (d) investigations of reaction rates, recombination coefficients, airglow production, etc., and (e) creating the conditions for inducing selected plasma instabilities to produce ionospheric irregularities and spread-F conditions. The science objectives in these experiments have a direct bearing on communication problems. Other forms of ionospheric modification are directed toward studying ionospheric/magnetospheric coupling and testing plasma theories.

So it might be fun to crowdsource from the SWL community to see if we can detect any propagation anomalies Tuesday night during this brief experiment. It’s unfortunate there’s not more time to coordinate different listeners monitoring different assigned frequencies. This reminds me of participating in ANARC’s “Woodpecker Project” in 1985 with 95 other SWL’s in 18 countries to determine the interference effects on HF broadcast from the Soviet Union’s use of Over-The-Horizon (OTH) radar in the HF bands.

I wonder how many SWL’ing Post readers participated in The Woodpecker Project and still have the nice “No Woodpeckers” tee shirt they earned for submitting their findings, which were combined into a final report that condemned the Soviets for causing interference on the HF bands.

Thanks for the tip, Ed! According to the linked article, the experiment will take place this evening, “soon after nine o’clock eastern time” (or 01:00 UTC).

This would be a great time to do an SDR wideband spectrum recording since you could possibly see any propagation effects on the waterfall display and play the event over multiple times. I’ve no clue if this experiment would yield any discernable results on HF, but it would be fun trying to detect it nonetheless.

Please comment if you plan to check out the experiment and/or if you were a participant in the Woodpecker Project!

2017 Hamvention photos: Saturday Flea Market

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While looking through photos I had backed up on my laptop, I discovered a set I took at the Hamvention Flea Market on Saturday morning (May 20, 2017). I’ve gotten tremendous positive feedback from the photos I posted of Hamvention Setup, the Friday Flea Market and Inside Exhibits, so I thought I’d post these as well.

Below, you’ll find 84 additional flea market photos. Click on the thumbnail to expand each photo. I’ve tried to include price tags when possible. I’m sure some of these items are also featured in my Friday flea market photo album. Enjoy: