Category Archives: How To

SDRplay: Updated ADS-B for Raspberry Pi 2 and Pi3

Image Source: FAA.gov

Many thanks to Jon Hudson with SDRplay who shares the following announcement:

We now have an updated beta version of ADS-B for both the Raspberry Pi 2 and 3. This is based upon the 16bit Mutability version of dump1090 developed by Oliver Jowett and unlocks the full 12 bit performance of the RSP1. People should see a significant performance improvement over the dump1090_sdrplus version, which was based upon 8 bit code. The latest beta version can be downloaded in binary form from http://www.sdrplay.com/rpi_adsb.html .

Should anyone have questions or feedback, please contact [email protected]

Section 1 is how to load a brand new image onto an SD card

Section 2 should be straightforward – 2 commands – one to get the software and another one to run it.

Though I don’t live in a metro area with a lot of air traffic, I am often in the flight path of a couple major airports. I’ve been looking for a simple way to try ADS-B (and ACARS). As soon as I locate a dedicated monitor and keyboard for my Raspberry Pi 3–and a little dedicated time–I will give the ADS-B app a go. Thanks again, Jon!

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Have you ever installed a covert shortwave radio antenna?

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The Hammarlund RBG CHC-46140 (Photo by Rich Post, KB8TAD)

Yesterday, in a comment thread, SWLing Post reader Dan described a covert antenna he once installed in a student apartment:

I’m waxing nostalgic now, but I had a great set-up for a couple of years back in the ’70s. The receiver was a black WW2 Navy surplus Hammarlund RBG CHC-46140. (I still have it).

I was a student living in an apartment on top of a two story, wood-framed apartment building. The attic access for that building was from the ceiling of the wardrobe closet.

During a Christmas break I was probably the only occupant of the building. I snuck into the attic and installed a set of five switchable dipoles. I had a good 60′ of space to work with and the antennas were broadside to the southwest. This was quite a memorable listening post.

When I moved out, I cut the coax to the dipoles and used toothpaste and borrowed pieces of “cottage cheese” to fill the five holes in the ceiling. Those antennas are probably still there.

Indeed, I bet they are still there, Dan!

In reply to Dan’s comment, Walt Salmaniw, noted:

Dan, reminds me when I was stationed in Germany in the early 80’s.

We lived in old French officer’s quarters. Basically, 4 story buildings with the upper floor/attic uninhabited.

The Kenwood R-2000 (Photo: Universal Radio)

I put up some nice 60 m dipoles in that space, with a goal of hearing a lot of tropical band DX, which I did using my Kenwood R2000 receiver.

Those were the glory days of dxing!

Thanks, Dan and Walter, for sharing those stories. The thread reminds me of a post we published sometime back where one young listener installed a wire antenna in his home while his parents were away. (I can’t seem to locate that post at the moment for a link!).

Though not nearly as elaborate as Dan and Walter’s antennas, I did install a small covert antenna once myself.

In the early 90s, I lived in Grenoble, France, in a four bedroom house in which three bedrooms were occupied by university students. The landlord was a rather fussy elderly woman who lived on the ground floor. I never dared ask her if I could string a random wire outside my top floor bedroom window. Though she was mostly fair and even sweet at times, I knew what the response would be if I asked for permission: a firm “Non.”

One night, I opened the bedroom window and carefully connected a short wire antenna to a nail on the side of the house, above and slightly to the side of the window. I had to stand on the window and hang out of the house to do it.

The Realistic DX-440

The antenna dangled there the whole year I lived in that room and served me quite well. I’d simply open the window and clip it to my Realistic DX-440. I did remove the antenna before before I moved back to the States, but it was virtually undetectable against the exterior wall of the house.

Other covert antenna installations?

Please comment if you’ve ever installed a hidden antenna as well. (I love this stuff!) Besides…who knows…your antenna might benefit someone in need of a hidden antenna today!

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Guest Post: Tracking High Seas Pirates on Shortwave Radio

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Suspected pirates surrender to crew members of the CGC Boutwell. (U.S. Coast Guard photo)

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN) for the following guest post:

Tracking High Seas Pirates on Shortwave Radio

by Mario Filippi (N2HUN)

(All photos taken by author–click to enlarge)

Ahoy! After spinning a radio dial for over a half-century, shortwave listening still provides a source of adventure and interesting intercepts. While major broadcasters continue to move to the Internet and dwindle in number, there nonetheless remains plenty of utility intrigue to be had; you just need to know where to look, and be comfortable with other modes of communication such as RTTY (Radioteletype).

RTTY remains on HF (3 – 30 MHz), albeit mostly encrypted, but there are some stalwarts of this mode that transmit important and interesting information for ships at sea. The information can take the form of weather broadcasts, hazards to navigation, information on ships lost at sea, and pirate activity. Yes, pirate activity but not radio pirates; real honest-to-goodness modern day pirates looking to loot, plunder and prey upon commercial ships making an honest living or other leisure watercraft just out having fun.

Who knows what dangers lurk behind that dial? Trusty AOR AR-3000 receiver and SignaLink™.

Has your interest been piqued? When avast mateys as I spin ya’ a yarn on how to find out where these sea-faring scoundrels lurk from the Caribbean all the way to the South China sea!

Pirate activity is not something of the past; it exists today and is a threat conducted by ragtag armed ragamuffin groups. To keep abreast of the action you’ll need the following gear: a shortwave radio with single sideband (SSB), a decent antenna, a means of decoding RTTY, and WLO, a station from Mobile, AL that transmits information to ships at sea.

You’ll do well to add WLO’s frequency to your receiver’s memory list as it’s a pretty active station that faithfully serves the sea-faring community and is one of the gems on HF.

First, tune your receiver using USB (Upper Side Band) to around 8.472 MHz and listen for that warbling sound. You will also need a way to pipe the audio from your shortwave receiver to a computer (I use a SignaLink™ USB) and a decoding program for RTTY, such as MMTTY.

To decode you’ll need to set the baud rate (45.45) and shift (170 Hz) on MTTY (or software program of choice) and tune your radio slightly up and down frequency until the software starts decoding.

You may have to press the “Reverse” or “Rev” selector at times. MMTTY is my favorite for RTTY decoding, and a picture of it is below.

WLO, Mobile AL, with RYRY idling loop, MMTTY decoder, 45.45 bauds, 170Hz shift, “Rev.”

MMTTY is available as a free download from Makato Mori, JE3HHT. I’ve used his program for over a decade and it performs well.

You can also use MultiPSK or FLdigi to decode RTTY so it’s the user’s choice as to which is a better fit.

Anyway, what are these pirates up to? Well the next few screenshots (click to enlarge) show some interesting activity as per WLO’s RTTY transmissions:

Pirates use element of surprise with guns and knives as armaments.

Somali pirates reportedly armed with automatic weapons and rocket-propelled grenades. Yikes!

Give ‘em hell boys! An alert bulk carrier crew aborted hijacking with teamwork and water cannon.

Ships are encouraged to report pirate activity via FAX or phone.

Well mateys that’s enough high seas adventure for now, so first shove off to the galley for some grub (or grog) and then head to the radio room, turn on that rig and get ready for action on HF, you’ll find plenty to choose from, it’s out there for you.

I would like to thank the operators of WLO for providing such a valuable service to mariners and for providing us radio aficionados with interesting reception! And thanks readers!

P.S. Note that WLO alternates from RTTY to Sitor B so just make sure you are listening to the RTTY broadcast. If the transmission is in Sitor B then you can use a NAVTEX (e.g. YAND) decoder instead.

Thank you so much, Mario, for sharing yet another fascinating aspect of our radio world! FYI: I’m planning on purchasing a SignaLink USB at the Dayton Hamvention this year.

Readers, you can read all of Mario’s posts by clicking or bookmarking this link.

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Nothing to hear on shortwave? Jacques disagrees…

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Many thanks to SWLing Post reader, Jacques Catherine, who left the following comment on our post from 2012: Is there anything to listen to on shortwave?

“I live in Mauritius Island in the Indian Ocean and I’ve been listening to Shortwave since I was a kid (I’m 58 today) on my dad’s good old Phillips wooden valve radio.

I’m sorry, but shortwave is certainly not dead. After having read all the comments above, I come to the conclusion that reception definitely depends on your location.

The Tecsun PL-660.

I have two Tecsun receivers ( Tecsun S 2000 and PL 660) hooked to a Windom antenna and an ATU. I receive dozens of stations from all over the world here as well as a lot of stuff on ssb, including – in the morning – New York MWARA (8825.0 usb), Gander (8831.0 usb) or, in the evening, Brisbane (5634.0 usb).

Broadcast stations from Japan, Taiwan, India, Iran, Australia, Singapore, China, Africa and even the US, come in here loud and clear with very little static, depending on the season and time of the day. I think I’m privileged to be located where I am !

And I bought some years back a pair of cheap small wooden amplified speakers in Hong Kong that reproduce exactly the sound of my dad’s old valve radio!”

Thank you for your comment, Jacques. You’re right: it’s all about your location…and you certainly live in a prime spot!

I’m most fortunate that I live where I do–quite far away from sources of noise that plague our urban readers/listeners (and that have plagued me in the past). My location is not ideal (from a radio/receiving standpoint) because my ground conductivity is very poor and I’m in North America where very few broadcasts are targeted these days. I do, however, have the space for a rather large horizontal delta loop antenna that serves me well across the HF bands. I might have invested $50 in the antenna wire and components five years ago.

When propagation is good, some broadcast bands are actually packed tightly with signals. Indeed, Thursday last week, I could’ve easily logged two dozen stations on the 31 meter band alone. Here’s a screen capture from the spectrum display of my SDR:

If you live in an urban area and feel that you’re missing out on the action, consider taking your receiver outdoors and away from interference. Take your receiver on hikes, camping trips or to the beach. You might be surprised by the number of stations you’ll log!

Recently, our friend London Shortwave has been posting an amazing array of broadcast recordings he’s made in a park in the middle of London, England. He’s the guru of mitigating urban interference.

When I have time to curate the recordings, I hope to do a 2016 update of “Is there anything to listen to on shortwave?“–it’s been on my to-do list for a while now.

Jacques, thanks again for your comment and reminding us to keep listening!

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Guest Post: Using the HackRF One for DGPS Beacon Reception

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Many thanks to SWLing Post contributor, Mario Filippi (N2HUN) for the following guest post:

Receiving with a HackRF One, SDR#, and MultiPSK

by Mario Filippi (N2HUN)

The HackRF One is a Software Defined Radio manufactured by Great Scott Gadgets (www.greatscottgadgets.com) and has been on the market for a few years. Having used an SDR-Dongle for several years I felt it was time to “step up” to this wideband (1 MHz – 6 GHz) receiver to investigate a broader breadth of the radio spectrum, so one was purchased from Sparkfun (www.sparkfun.com).

Recently I performed a rudimentary evaluation of its ability to receive DGPS (Differential Global Positioning System) beacons found in the Longwave band between 285 – 325 KHz; this frequency range is well below the HackRF One’s stated lower receive limit of 1 MHz.

DGPS beacons, when tuned using SSB, emit a distinctive warbling sound, and at this QTH, depending on band conditions and time of year, can be heard as far away as the Midwest. Winter brings the cold weather but also excellent conditions for receiving these beacons, some of which were former marine radiobeacons retrofitted to provide greater DGPS accuracy.

The HackRF One, when used with SDR#, MultiPSK, audio piping software, and a good (43 foot vertical) receiving antenna was able to receive DGPS beacons, and two screen captures are below:

DGPS beacon from Sandy Hook, NJ. SDR# using HackRF One in foreground, MultiPSK software in background with decoded information. Click to enlarge.

DGPS beacon from Moriches, NY. Click to enlarge.

I was very pleased that the HackRF One was able to receive DGPS stations, though tuning them in seemed a bit trickier than with a standard RTL-SDR dongle. Since this time of year is not optimal for monitoring DGPS beacons, as well as the Longwave band in general, it’s reassuring to know that come winter I’ll be able to do some DGPS beacon DX’ing with the HackRF One. However, anyone with a shortwave radio and a good antenna can avail themselves of DGPS beacon hunting, just tune down between 285 – 325 KHz and listen for the distinctive warble.

To decode, look into an excellent program like MultiPSK (http://f6cte.free.fr/index_anglais.htm). 73’s!

Thank you, Mario, for another great post!

When Mario told me he had purchased the $299 HackRF One, I was hoping he would do some guest posts about this SDR–DGPS beacons was use I had never thought of. Looking forward to more of your guest posts, Mario!

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Aluminum foil: Larry’s simple AN200 antenna modification

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Many thanks to SWLing Post reader, Larry Caracciolo, who comments:

I bought the AN-200 in the spring of 2015 off of eBay. I was favorably impressed with the product. Comparing it to my old 9′ diameter tuned/shielded loop from 1992, there are some similarities and differences.

The Hallicrafters SX-96 (Image: Universal Radio)

I live in an apartment complex so plenty of radiated electromagnetic noise is present. I use a modified [Hallicrafters] SX-96 (AVC ckt was modified for improved modulation acceptance). The AN-200 does null out local static sources, somewhat, but not well enough to dig out weak stations. The tuning range for the loop is just at the bottom of the AM band (about 535 khz) to just over 1700 kcs.

On a whim, I wrapped aluminum foil around the loop and grounded it to the SX-96 chassis – in wistful hope of achieving some shielding from the RF has. As soon as I connected the aluminum foil ground clip to the rx chassis, all RF noise ceased and signals appeared from the mud. However, the tuning range is attenuated above 1200 kcs.

My favorite frequency on the AM band is 590 kcs. During the night, as many as seven different stations rose from the noise and provided station IDs at just the right moment. My best catch here in Everett, WA is KCSJ, a 1KW station in Colorado Springs.

From time to time, stations on the low portion of the AM band are accompanied with echoes – what I took for two stations and a small time delay between the same broadcast was actually multi-path to the degree that nearly 1/2 second separated the arriving signals. Short-delayed echoes, anyone? I’ve not observed this on frequencies above 1000 kcs.

Other sources of RF noise can come from the laptop, the cable modem, and even CFBs in other rooms. For truly noise-free listening environment, I place the laptop in sleep mode and unplug the cable modem. I’m quite happy with the AN-200 loop. Affordable, easy to use, easy to tune.

Thanks so much for sharing your experience with the AN200 loop antenna, Larry!

As anyone who grew up in the era of TV rabbit ears knows, aluminum foil can simply work magic in a pinch! There is no easier material to work with either!

As I pointed out in previous posts, the AN200 loop antenna is quite affordable. I just did a quick price search:

The Tecsun equivalent of this antenna (the AN100) is available from various sellers on eBay from about $15 – $30 US.
The Kaito AN200 (Kaito’s branded version) is available on Amazon for $30 shipped.
With the purchase of the Eton-Grundig Traveler III, Eton-Grundig Field, or Eton-Grundig Satellit, Universal Radio will include a free AN200 with your purchase.

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Guest Post: Building a magnetic loop antenna & broadband amplifier for your SDR

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Many thanks to SWLing Post contributor, Dave Gahimer (K9ZCE) for the following guest post:

Small Magnetic Loop Antenna with Broadband Amplifier for SDR Reception

by Dave Gahimer (K9ZCE)

Those with limited space, or antenna restrictions, might find a small 1 meter loop antenna a solution.

My son lives in an apartment. One Loop leaning against a wall gives him acceptable reception with the SDRPlay RSP on the ground floor–2nd or 3rd level flats should have very good reception.

Ten meters off the ground outside should give reception equal to any SWL antenna. We all with SDRs fight the image problem. Normal resonate ham band antennas show too strong reception of unwanted bands/stations. Did I mention noise? Loops are well known for –6 db noise reduction.

Then there is the possibility of SDR chip damage from your 1.5 KW station! In researching Loops we came across LZ1AQ. A Brilliant design /engineer (http://www.lz1aq.signacor.com/). Deep reading sometimes, but a great understanding of what makes a good receiving loop antenna.

Those who chase DX know that sometimes fading is caused by the signals’ polarization changing in the Ionosphere. Having both vertical and horizontal loops, and the ability to combine both signals diminishes this fading problem. Being able to filter the powerful, commercial FM transmitters diminishes image problems. Clipping strong signals at the antenna from very near powerful antennas/transmitters could save the SDR receiver from damage.

The LZ1AQ broad band Amp solves all these problems. http://active-antenna.eu/amplifier-kit/.

My son Ted and I built three, one meter loops from soft ½ inch copper plumbing tubing. One for his apartment, two for my crossed loops antenna. We weather proofed the Copper from corrosion by coating with outdoor clear spar varnish. We shaped the circle by drawing the tubing around a round glass top patio table.

The soft copper loop in held by white PCV plastic plumbing pipe. 1” or 1.25 inch schedule 40. Be careful to check that the PVC is schedule 40, thick wall. The thin wall pipe is not strong in the wind and will crack when you try to drill it.

Drill up to a 3/8 hole for the ½” copper tube to go through, then file out to fit. Here are some photos (click to enlarge):

Check out these links (all courtesy of LZ1AQ) to acquaint yourself with the loop construction and amplifier installation:

http://active-antenna.eu/tech-docs/2_ActiveAA_Mount_20.pdf

http://active-antenna.eu/tech-docs/1_ActiveAA_DandS_20.pdf

http://active-antenna.eu/tech-docs/3_ActiveAA_Antena_11.pdf

Many SDR receiver owners have seen improved noise and Image reduction by placing the plastic cased SDR unit on a small shielded/ grounded case.

The Amp needs 12VDC from in the shack. The Amp has two relays that you can switch, from in the shack, to select Vertical or Horizontal loops, or a dipole. The loop amp connects back to the shack via a shielded Cat 5 cable, Make sure you get shielded CAT 5 to reduce noise pickup. Make sure you provide an adequate good Ground below the antenna, less noise pickup and lightening protection.

Have fun!
Dave, K9ZCE
Retired from EE Dept @ Rose-Hulman Institute of Technology
Terre Haute, Indiana

Thank you so much, Dave!

Readers: yesterday I saw Dave’s loop antenna photos on the SDRplay RSP Facebook page. I was fascinated by his horizontally/vertically oriented loops and asked if he would write up a short guest post. He kindly obliged in a matter of hours!

If you have an antenna project you’d like to share, please contact me. So many SWLs and ham radio operators live in areas with restrictions and pervasive RFI–projects like Dave’s can revive one’s radio life!

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