Category Archives: Recordings

Which is the best? Sony ICF-2001D/2010 or ICF-SW77? The halfway score

Hi there, here is a summary of the first half of tests comparing the Sony ICF-2001D against it’s replacement the ICF-SW77. Both receivers are widely acknowledged as being amongst the best shortwave portables ever made, but how close are they in performance? Is there a clear winner after the first 8 reception tests? I hope you enjoy the summary video. Links to the first half of reception tests follow again, below, whilst the second half will follow in a separate post. Thanks and good DX to all.


 

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

Shortwave Radio Recordings: Radio Thailand English language service

Paul-Walker-Galena-Alaska

Many thanks to SWLing Post contributor, Paul Walker, who shares this recording from his home in Galena, Alaska. Paul notes:

Radio Thailand (13745 kHz) English service to North America at 0000UTC on November 8th, 2016:

Click here to view on YouTube.

Not the strongest I ever hear them, but a good solid clean nearly noise and nearly fade free signal.

That’s an impressive signal, Paul, especially considering the fact that propagation conditions have been somewhat shaky as of late. Thanks for sharing!

Which is the best? Sony ICF-2001D/2010 or ICF-SW77?

sony-test

Hi there, subscribers to my YouTube channel Oxford Shortwave Log  will be aware that I currently operate both of these wonderful vintage portables. I purchased the ICF-2001D only 18 months ago from eBay, based largely on its reputation as one of the best performing portables ever made. Previously I had been using my excellent ICF-SW55 as the mainstay receiver for my numerous DXpeditions, coupled with irregular appearances from my Sangean ATS-803A and the excellent value-for-money Tecsun PL-360. The ICF-2001D proved to be a revelation in terms of sensitivity, selectivity and contrary to popular belief, with careful planning (to avoid crowded bands), is able to cope pretty well with very large antennas. As regards audio bandwidth filtering, SSB and synchronous detection, in my experience, the ICF-2001D is as good as it gets in a portable – or a vintage portable at least. I have lost count of the number of personal-firsts I’ve achieved using this wonderful receiver and as someone who likes to push the envelope a little, I soon started to wonder whether it’s replacement, the ICF-SW77 might prove to be an even better performer. Subsequent online research  confirmed there was no absolute consensus on this issue, with followers of these two great receivers firmly placed in both camps.

Sometime later, a good friend of mine, fellow radio hobbyist and subscriber to Oxford Shortwave Log very kindly offered to send me his cherished ICF-SW77 on long-term loan. Like me, he was intrigued to know how it compared to it’s venerable predecessor and thus the deal was done! Upon it’s arrival in July, I started planning a back-to-back series of comparison tests at the very quiet wood in Oxfordshire I used for my DX’peditions, using the same antenna for both recievers – the excellent Wellbrook ALA1530 active loop. In total, I made fourteen reception videos comparing the ICF-2001D and ICF-SW77 and posted them to Oxford Shortwave Log. Both receivers performed very well, delivering excellent reception on the Tropical Band and elsewhere on the shortwave spectrum from Bolivia, Brazil, Guatemala, amongst others. At the halfway stage, I generated a video to summarise the results to-date and this will follow in my next post to swling.com.  In the meantime, I hope you enjoy the first half of the reception videos; which follow below:



Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

Portable shortwave spectrum capture for the urban city dweller

A guide by London Shortwave

Portable Spectrum Capture Set-up

Capturing the shortwave spectrum out in the field.

Radio interference is a major problem in big cities when it comes to indoor shortwave reception. One effective solution I have found is to head for the local park and engage in scanning the bands there. However, since my time for making such outdoor trips is limited, I would always feel like I am missing out on a lot of radio action by monitoring a single frequency, which is all you can do with a standard shortwave radio. There are so many signals out there — which one should I go for? This inspired me to put together a lightweight, portable set-up that would let me capture large chunks of the shortwave radio spectrum out in the field, which I could later explore in detail. After two years of experimenting with various Software Defined Radio (SDR) technologies I am pleased to report that I finally have a solution that works well for this purpose.

A good SDR can give the user access to large portions of the radio spectrum via a graphical user interface. The user can then either process a specified part of it in realtime or record the chosen spectrum window in its entirety onto disk and analyse it later with the supplied software. Here is a short video showing the playback of one of such spectrum captures I made in a London park in September 2016. Note the final part where I zoom out to show the entire recorded frequency range (covering two broadcast bands with one ham band in the middle!):


When I got home from the park, I was able to replay that part of the spectrum capture many times over while scanning the frequency space, which is how I was able to identify a weak signal from a very distant ham radio operator that I might have otherwise missed.

Below is the list of the components I have used to put together my “portable spectrum capture lab”.

Components

Component List

Hardware

1. Toshiba Encore 8″ Tablet (Windows 8), 2014 Model ($169)

I bought this tablet in July 2014, based on the following criteria: the device had to have a reasonably powerful Intel processor, running the Windows 8 operating system. I believe that there are currently models on the market that are at least as powerful and are substantially cheaper (<$100).

2. On The Go USB Adapter ($15)

3. AirSpy R2 SDR ($169)

Owing to its unique hardware design, the AirSpy SDR can monitor large parts of the radio spectrum (up to 10 MHz in bandwidth) while offering a high dynamic range and robustness to overloading, with almost no mixing/imaging products.

4. SpyVerter HF UpConverter ($49)

This additional device enables AirSpy to cover the shortwave bands (in fact, the entire frequency range between 0 khz and 30 MHz) and must be connected in-line between the AirSpy’s front end and the antenna feed line, as follows:

AirSpy / SpyVerter

Connection cables

Below is a small collection of cable accessories to connect the antenna to AirSpy/SpyVerter:

5. 10cm SMA Male to SMA Male Straight RF Coaxial Jumper Pigtail ($2)

6. BNC Male Plug to SMA Female Jack Adapter ($2)

7. BNC Female Coupler ($5)

8. 3m long BNC cable ($15)

Matched dipole antenna

Antenna Schematic

I use a three-terminal matched balun connected two 6 metre copper wires via its antenna terminals as a dipole antenna, and connect it to the SDR via the feed line terminal with the 3m BNC cable listed above. The balun (Wellbrook UMB130) is engineered in a way that prevents the radio noise current from the tablet (usually a significant source of interference) flowing into the receiving part of the antenna.

Dipole Antenna

9. Wellbrook UMB 130 balun ($60)

10. 2 x 6m Copper Wire ($16)

Miscellaneous

11. Fight Case ($35)

This foam-filled flight case comfortably houses all of the components. The parts 1 to 7 can remain assembled together, reducing the deployment time in the field.

12. Samsung 64G Ultra-High-Speed MicroSD Card ($19)

Samsung MicroSD Card

I use this fast MicroSD card as the destination for my outdoor SDR recordings. The high transfer speed is critical – using slower MicroSD cards will result in large portions of the spectrum being dropped from the recordings. 64 Gigabytes can accommodate roughly one hour of spectrum data at 3 MHz bandwidth.

13. FAVI Bluetooth keyboard with trackpad ($37)

FAVI Bluetooth Keyboard

Windows tablets suffer from one major drawback: the touchscreen interface is usually inadequate for software that was designed for traditional computers with mice. A portable Bluetooth keyboard with a built-in trackpad solves this problem.

14. Bluetooth Wireless Audio Transmitter & Receiver ($17)

Bluetooth Transmitter / Receiver

This small gadget turned out to be a very important part of the entire project. The Toshiba tablet has a rather unusual interference quirk that initially caused me hours of frustration. It turns out that significant amounts of radio noise are injected into the SDR when the tablet’s external speakers are active. One way to fix this is to plug a pair of headphones into the tablet’s line out jack, but this forces the listener to be glued to the device. The alternative is to pair the tablet with a Bluetooth audio receiving unit, such as the one listed above. It is worth noting that my other Windows tablet — a Dell Venue 8 — also suffers from this strange artefact.

Total cost: $610

Internal layout of the flight case

Flight Case Internal Layout

You’ll see that I have stacked the SpyVerter enclosure on top of the AirSpy one. As the latter can get very hot, it is essential to leave a sufficiently large gap in the foam for ventilation. It’s also worth leaving a small gap next to the tablet’s power button to prevent Windows from accidentally going into standby mode.

Software configuration

The best software to use with the AirSpy/SpyVerter combination is SDR#. It offers an impressive collection of features that many software packages and conventional radios don’t have, such as advanced noise reduction and synchronous detection with passband tuning. The following adjustments are required to make recording the spectrum a seamless experience:

Install the Baseband Recorder and File Player plugins

Baseband Recorder: this plugin enables efficient recording of very large spectrum (or “baseband”) files. Download and decompress the plugin zip file. Copy the .dll files into the directory with the SDRSharp.exe executable. Open the MagicLine.txt file and copy the first line of text into Plugins.xml file, just before the “</sharpPlugins>” line.

File Player: this plugin enables the playback of recordings made with the Baseband Recorder plugin. Download and decompress the plugin zip file. Copy the .dll files into the directory with the SDRSharp.exe executable. Open the MagicLine.txt file and copy the first line of text into FrontEnds.xml file, just before the “</frontendPlugins>” line.

Configure Baseband Recorder

Open SDRSharp.exe and check that the program reports no errors when it loads.

Baseband Recorder Plugin

Baseband Recorder configuration

In the plugin pane on the left, expand the Baseband Recorder tab and click “Configure”. Change the File Format to WAV RF64 and make sure that the File length limit check box is not ticked. Click “Folder select” and choose the MicroSD card as the destination directory for the recordings.

Adjust AirSpy settings

Disclaimer: in this section I describe how I capture the maximum spectrum bandwidth that my tablet’s CPU can handle. It involves operating SDR# in “debug mode” and exposes some internal functionality of AirSpy, which, if used incorrectly, can damage the radio. If you choose to copy my approach, please understand that you are doing so at your own risk and follow my instructions carefully to avoid voiding your AirSpy warranty.

Open SDRSharp.exe.Config file in Notepad. Look for “<add key=”airspy.debug” value=”0″ />” line and change it to value=”1″.

Once the AirSpy and SpyVerter have been connected to the tablet, open SDR# and select AIRSPY in the Source tab. You will see the following configuration dialog.

AirSpy Settings

AirSpy configuration

In the “Sample rate” field, type in “6 MSPS”. For the “Decimation” option, choose “2”. This setting will result in spectrum captures of 3 MHz bandwidth (although only 2.4 MHz of it will be shown on the waterfall display). To capture smaller chunks of the spectrum, increase the decimation value. Make sure the SpyVerter check box is ticked. Do not touch any of the fields or buttons under the “Address Value” line.

Make a short test recording

Press the play button in the top left corner and set the desired frequency.

In the Source tab, select the “Linearity” option. Keep increasing the Gain value by one position at a time until you notice that the radio signals suddenly become “saturated” (the waterfall display becomes full of artefacts and the signal you are listening to gets swamped with noise). Take the Gain value back down by two positions. This will ensure high sensitivity while preventing AirSpy from overloading.

In the Baseband Recorder tab, press “Record”. While recording, do not change the radio frequency and do not move/drag the waterfall portion of the display. Stop the recording after a few minutes.

File Player Plugin

SDR# FilePlayer plugin

In the Source tab, change the input to “File Player” in the drop down menu. Click the Settings cogwheel button and select the spectrum recording file from the MicroSD card. A vertical band visualising the timeline of the spectrum capture will appear immediately to the right of the plugin pane. Click on the play button and select a radio signal to demodulate in the spectrum display. Listen to the audio carefully to make sure there are no dropouts or clicks: if so, your tablet and MicroSD card are capable of handing and storing the specified spectrum bandwidth.

Keep an eye on the gain

While making longer spectrum recordings, select a weak radio signal and keep monitoring its audio for signs of overloading. If the overloading does occur, reduce the Gain value further by one or two positions.

Some example spectrum captures

Shortwave For Lunch

Shortwave for lunch. Playing back parts of the shortwave spectrum captured earlier in the park, inside a local cafe.

Below are some example videos in which I play back and explore the spectrum recordings I made during the trips to my local park.



Tropical and the 49m bands recorded outdoors on 03/07/16 at 0432 UTC. A good time of the day for listening to Latin America on shortwave.

 

 

Listening to Radio New Zealand International.

Radio Aparecida from Brazil, usually a challenging catch in Europe.

Comments, suggestions?

Closed Flight Case

Drop me a line in the comments section or hit me up at @LondonShortwave. This article originally appeared on the London Shortwave blog.

Oxford Shortwave Log: dxing in the tropical rainforest of Pará, Brazil – part 1

img_0213

Hi there, I was fortunate enough recently for my work to take me to a very remote area of tropical rainforest in Pará, Northern Brazil and of course, I travelled with a shortwave radio. In fact I take a portable with me everywhere – even to work – just in case. During this trip I was using a Tecsun PL-680, for very specific reasons:


  • It can handle a longwire very well without overloading (I actually only used a 5 metre wire)
  • An excellent synchronous detection circuit and audio bandwidth filtering options
  • Excellent sensitivity, as demonstrating by the many DX reception videos on YouTube
  • If it got lost or damaged it would be a pain of course, but not difficult to replace

pl-680

img_9928 img_0221Although effectively travelling on business, I was hoping to find the time for a DXing session because I felt it would be really interesting to find out what could be heard on shortwave (and medium wave for that matter) out in the jungle, in the middle of nowhere! The environment was challenging – around 37/38 degrees C during the day and still 33 degrees C at 2 am, all day and night, every day and night! Furthermore, as you might imagine for a tropical location, the place was crawling with bugs lol, including mosquitos and thus a number of vaccinations were necessary, prior to the trip. Several days after arriving, I eventually managed to find the time for a DXing session in the jungle (with another the following week in Barcarena, on the coast).

So, what can you hear in the jungle? Part 1 of my group of reception videos follow below – I hope you enjoy them.


Tropical rainforest DX in Pará, Brazil: Radio Romania International 7335 kHz

 

Tropical rainforest SW in Pará, Brazil: Radio Nacional Brazilia 6180 kHz

 

Tropical rainforest DX in Pará, Brazil: WHRI 7385 kHz, Cypress Creek, Georgia, USA

 

Tropical rainforest DX in Pará, Brazil: Radio Mediterranee 9575 kHz, Nador, Morocco

 

Tropical rainforest DX in Pará, Brazil: EWTN (WEWN) 11520 kHz Vandiver, Alabama, USA

 

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.