Tag Archives: WebSDR

Radio Waves: Eugène Aisberg, Filter Design, ABC Workers Face Cuts, and Data via Web SDRs

Radio Waves:  Stories Making Waves in the World of Broadcasting 

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Paul, Marty, and Michael Bird for the following tips:

Eugène Aisberg, Radio Writer (OneTubeRadio.com)

After a wartime absence, the January 1946 issue of Radio Craft carried an article by writer Eugène Aisberg.  While that name might not be familiar to American readers, Aisberg was a prolific author in the early days of radio, and wrote some of the best treatises on radio for the popular audience.  He was fluent in French, Esperanto, German, Russian, and English.

Aisberg was born in Odessa, Ukraine, in 1905, and lived most of his life in France. He was the director of the French magazine Toute la Radio and a prolific author of a number of books. His most popular book, which is still in print, is La Radio? Mais c’est très simple (Radio? But It’s So Simple!)  The book, currently in its 29th edition, an extremely solid background covering all aspects of electronics, and is written in a popular, easy-to-read style. While the book was ultimately translated into several languages, it was apparently never published in English.[]

Filter Design Software (Nuts and Volts)

If you’ve ever lived close to an AM broadcast station, you probably experienced the phenomenon known as fundamental overload. It occurs when a receiving device is functioning entirely properly but unable to reject a strong signal. The receiver might be a wireless telephone, a scanner, or even a TV or radio receiver. The AM signal is completely legal but just too strong, disrupting the function of the receiver or overriding the desired programming.

[…]Hams often experience fundamental overload on the 160 meter band (1.8–2.0 MHz) which is adjacent to the AM broadcast (BC) band (550 kHz–1.7 MHz). Antennas for those frequencies pick up a lot of AM band RF, overloading the input circuits and creating distortion or false signals inside the receiver. The usual solution is to install a high-pass broadcast-reject filter at the receiver input, attenuating the unwanted AM signals below 1.6 MHz while passing the desired 160 meter signals with little attenuation.

So far, so good, but a filter that doesn’t attenuate signals very much above 1.8 MHz while attenuating them significantly in the adjacent broadcast band is not a simple thing to design. There are tables and equations, but they are tedious to work with. Practically, you’ll need to build the filter with standard-value components as well, and that will affect filter performance too. Sounds like a job for some filter design software, doesn’t it?

There are several filter design software packages ranging from simple calculators to sophisticated CAD programs. Luckily for hams and other experimenters, there are plenty of free or low-cost programs to try.[]

ABC workers face anxious wait over job, program cuts (The Age)

David Anderson did not mince words at a Senate Estimates hearing last October. “There will be job losses,” ABC’s managing director warned. “It’s not something I can quantify at this point in time. There’s still more work to be done.”

Towards the end of March, Anderson will reveal a five-year plan for the national broadcaster. To the frustration of staff, it’s unlikely to specify which parts of the organisation will bear the brunt of these cuts or how many workers they might lose.

Several senior sources spoke about the situation at ABC on the condition of anonymity, given sensitive funding negotiations are yet to be finalised.

“All these media reports claiming the redundancy numbers will be finalised in March are just wrong,” says one ABC executive. “What we need is some clarity [about long-term resourcing] from the government.”[]

Receiving Data With Web Based Shortwave Radios (Nuts and Volts)

Your computer and the Internet give you free access to over 100 web based shortwave receivers that you can use as if they were your own. Unfortunately, employing these radios to decode data transmissions can be very difficult or impossible — unless you know the secret. So, read on and we’ll guide you through the details of how to do it.

Web based shortwave radios are an amazing new implementation of software defined radios (SDR). These SDRs are free to use and widely available on the Internet. Even more remarkable is that they are located in countries all around the world.[]


Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

Spread the radio love

RSGB 2018 Convention Lecture: DC to Microwaves on your smartphone

(Source: Southgate ARC)

The presentation by Noel Matthews G8GTZ on the Farnham WebSDR given to the 2018 RSGB Convention is now available on YouTube:

Click here to view on YouTube.

This presentation gives an overview of the Farnham WebSDR, available at http://farnham-sdr.com/ which currently covers the LF bands through to 10GHz.

The presentation describes the system architecture and antennas currently used on each band and how the team has used RTL dongle receivers, available for under £10, to give good RF performance on all bands from DC to 10GHz. There is a demonstration of the SDR in use on both PC and smartphone.

Spread the radio love

CATSync: A new tool to control WebSDRs with your tabletop radio

(Source: Southgate ARC)

Introducing CATSync – The new CAT tool for WebSDRs

Oscar, DJ0MY, has developed a new software tool for radio amateurs and SWLs.

CATSync allows the user to control public WebSDR receivers with a real rig connected via CAT. It supports the classical Web-SDR servers as well as the newer Kiwi SDR servers publically available on the internet.

This gives you access to dozens of web based receivers with the comfort of tuning your rig at home. This software helps you to bring you back into the fun of ham radio when you are suffering from local temporary or permanent high noise levels in an urban QTH location.

The software has the following features:

  • Synchronizes any public WebSDR server with your real RIG…
  • Supports a wide number of RIG’s (it uses the popular OmniRig engine)
  • Supports WebSDR and KiwiSDR browser based SDR receivers
  • Tune the VFO of your radio and see the web SDR follow in real time !
  • Switch modes (SSB, CW, etc.) on your radio and see the web SDR switch mode in real time.
  • Listen to the same frequency as your rig via web SDR
  • Ideally suited e.g. for people suffering from local QRM
  • Can track RX or TX VFO (e.g. to find that split of a DX station) if radio CAT supports both simultaneously
  • Can be interfaced with popular logging software using OminRig or via VSPE port splitter

For more information visit the author’s website: https://catsyncsdr.wordpress.com/

See a YouTube video of CATSync under: https://www.youtube.com/watch?v=UbSHfkjhx0c

Click here to read the full article on the Southgate ARC.

Spread the radio love

U Twente antenna damaged

Many thanks to SWLing Post contributor, Dan Robinson, who shares the following item from BCL News and Richard Langley:

Antenna of Twente SDR receiver damaged // Bclnews
http://www.bclnews.it/2017/10/06/antenna-of-twente-sdr-receiver-damaged/

The antenna was damaged yesterday during a storm. As posted on the WebSDR website:

“The antenna currently is not working properly. After a preliminary repair of rain/storm damage on October 5, it seems reception has faded away again during the night. We’ll try to fix this soon, weather and spare-time manpower permitting.”

(Richard Langley via dxld yg)

Spread the radio love

KiwiSDR network updates include native HF FAX

Many thanks to SWLing Post contributor, Mark Fahey, who writes:

Lots happening with KiwiSDR – there are now over 130 live 0-30MHz fully controllable SDRs scatted around the world some in really interesting locations. Using Kiwi’s around the world is like being able to go on a exotic DXpedition any time.

Here (attached graphic) is a map of the current locations, you can see the live status of online receivers here:

http://rx.linkfanel.net

and as a list of receivers here:

http://kiwisdr.com/public/

KiwiSDRs now include HF Fax reception natively, just select Fax in the Extension menu, select the part of the world you are interested in and the Kiwi will tune the weather fax frequency and receive the weather fax all natively (no extra software needed) – too easy!

Lots more great things happening.

Here is the latest news…

http://www.kiwisdr.com/#id-31-may-17

Cheers,
Mark

Thank you for the update, Mark! I had no idea the KiwiSDR app had an HF Fax extension. After reading your message, I loaded a KiwiSDR session in Europe and used the Fax feature. It couldn’t have been easier. The screen grab (above) came from my first attempt.

The KiwiSDR network is truly amazing. I use it all the time–especially if there’s an important broadcast happening and I can’t easily receive it at home or while traveling. As an example, during the recent French elections, I listened to results roll in on France Inter mediumwave from a KiwiSDR in Italy. It felt like being there.

My one feature request would be that the KiwiSDR app include some form of native broadcast recording like the WebSDR at U Twente.

Many thanks for the update, Mark!

Click here to read about Mark’s KiwiSDR installation.

Would you like to host your own KiwiSDR?

The whole system only costs $299 US. The KiwiSDR site has a list of distributors around the world.

Amazon has units in stock at $299 US shipped.

I would have purchased a KiwiSDR ages ago–during their Kickstarter campaign–if I only had the Internet bandwidth at home to support it. My Internet speeds are likely lower than anyone else here in the SWLing Post community. One of the compromises living in a relatively remote spot with no RFI. 🙂

Spread the radio love

Mark’s multi-user SDR is now online

mark-fahey-beagle-kiwi-sdr

SWLing Post contributor, Mark Fahey, has just announced that his new Beaglebone-powered KiwiSDR receiver is online.  Mark notes:

Please try out my multi-user 0-30MHz SDR[.] The test system is operating from my monitoring station at Freemans Reach in south east Australia (near Sydney).

fahey-qth

Freemans Reach, Australia

[…]The test system is fully self contained and self operating. The antenna (ALA1530S+) we are using is a magnetic loop with an impedance tracking amplifier designed and manufactured by Wellbrook Communications, Llanwrth Wells in Wales. The receiver and CPU is the result of the Kickstarter funded project “KiwiSDR” which was conceived and designed by John Seamons ex Pixar and Lucas Films.

[…]You can use Chrome, Microsoft Edge, Safari, Firefox – but Internet Explorer is not supported at this stage. Tune in on this URL…

http://mediaexplorer.ddns.net:8073/

mark-fahey-shack

Mark’s radio shack.

[Four] simultaneous users are supported with totally independent tuning and control

Mark's Wellbrook antenna

Mark’s Wellbrook ALA1530S+ antenna

Many thanks for sharing your KiwiSDR, Mark! Though demand has been quite high, I have managed to claim one of the four user seats on Mark’s SDR and “listen like a local.”

Mark: you’ve done a great job making a proper listening post for your remote listeners. The KiwiSDR/Wellbrook ALA1530S+ combo is performing admirably!

Click here to use Mark’s KiwiSDR.

Spread the radio love

Check out the new web-based KiwiSDR in New Zealand

Kiwi-SDR-1

Many thanks to SWLing Post contributor, Andrea Borgnino, who shares a link to a new web SDR in New Zealand: The KiwiSDR installation.

Andrea posted the following on Twitter:

I agree with Andrea: this WebSDR has an amazing display and user interface. It even includes both a spectrum and full-color waterfall.

I’ve enjoyed tuning around the mediumwave band in New Zealand this morning. My Internet connection is terribly slow (and unreliable) but I was still able to view the full display while streaming audio with only a few hiccups.  With a moderately robust Internet connection, I believe you’ll be pleased with the KiwiSDR.

Click here to visit the KiwiSDR online.

Many thanks, Andrea, for the tip!

Spread the radio love