Category Archives: Radios

Guest Post: Using the HackRF One for DGPS Beacon Reception

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!

The CountyComm GP5/SSB: my go-to shortwave radio for hiking

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My two hiking companions: the CountyComm GP5/SSB and Hazel the dog.

Posting the Blinq deal a few moments ago reminded me that my favorite shortwave radio to use while hiking/walking is the CountyComm GP5/SSB.

I have CountyComm’s custom GP5 case which I clip to my belt or backpack. While hiking, I find it handy to open the case from the top, pull the radio out and operate/tune it with only one hand. Indeed, the vertical form factor of the GP5/SSB is ergonomically-ideal; I can control almost all of the radio functions without having to use two hands. A huge bonus while hiking on uneven terrain!

Typically, when I start a hike, I enable an EMT scan and within a minute or so, the GP5/SSB populates temporary memory positions with all of the signals it can easily receive. When you’re in the middle of the woods–far from sources of radio interference–you’ll be amazed by what you can hear.

Of course, with the antenna fully extended, one does have to watch out for low-hanging branches, etc.

Since the telescoping antenna doesn’t swivel, it’s much easier to hold the radio in a way that the antenna points forward while you hike (bonus: it’ll catch all of the spider webs across the trail before your face does!).

So far, I’ve never used the external mediumwave ferrite bar antenna while hiking–I worry that I could drop the radio and damage either the antenna or the 1/8″ antenna jack.

I typically listen to the GP5 with headphones unless I’m walking a trail during the time of year when black bears are active (in which case the speaker helps alert bears that I’m in the neighborhood).

Of course, there are a few other radio models with an identical vertical form-factor–most notably, the:

Tecsun PL-360
Tecsun PL-365
CountyComm GP5/DSP

If you’re not familiar with the CountyComm GP5/SSB, click here to read previous posts. I also featured the CountyComm GP5/DSP (Tecsun PL-360) in an ultra portable shoot out in 2014–click here to read.

Do you have a favorite shortwave portable for hiking, biking or cycling? Please comment!

Blinq Deal: Used Sony SRF-M37W AM/FM/WX digital walkman $18.19 shipped

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I just noticed that Blinq.com has a “Used – Very Good” Sony SRF-M37W AM/FM/WX digital walkman with headphones for $18.19 shipped.

While I don’t think the SRF-M37W will win any DXing awards, it is a very practical and lightweight portable for outdoor/active use (hiking, walking, running, biking, etc). I was mighty tempted to purchase this one and mount it on my mountain bike, but I have other portables that could do the job.

Features:

Digital AM/FM/Weather stereo tuner
Direct weather and preset access buttons
20-station preset memory
Digital LCD digital with clock and battery indicators
Headphones and belt clip included

The SRF-M37W runs on one AAA battery.

Click here to view on Blinq.com.

If you miss this deal on Blinq, no worries. Amazon’s price for a new unit is only $29.91 shipped–Amazon has a number of used units around $22 shipped.

The KRC-2 shortwave regenerative receiver kit

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Tony Westbrook recently contacted me about a regenerative receiver kit he has designed and produced in the UK. It’s called the KRC-2. Here’s the product description:

1 – 30 MHz with band spread tuning.

Regeneration with a difference. The regeneration setting on the KRC-2 is unaffected by the receiver tuning or the antenna coupling. How do we achieve this? The regenerative stage is fixed at 10.7MHz and used as an IF amplifier. The main receiver board is extremely simple to construct using only one FET and an audio IC. Like all the KRC kits it comes with a comprehensive construction manual which brings this project well within the grasp of the keen constructor. It was referred to as “a very sensitive little receiver” by Rob Mannion of Practical Wireless. Its unconventional design and simplicity should amaze even the experienced constructor. Case size 7 x 4 x 3 inches. 6 x AA batteries supplied.

According to Tony, the kit comes with everything; UK orders are even supplied with batteries. Tony stated, “the only thing the customer needs is a soldering iron, solder cutters, etc.”

By request, Tony sent a few construction photos and three videos of the radio in operation:

Photos

Videos

Video 1

Video 2

Video 3

Click here to view the KRC-2 and Tony’s other kits.

Kickstarter launch: The KiwiSDR for BeagleBone

1 Reply

Many thanks to SWLing Post reader and KiwiSDR developer, John Seamons (ZL/KF6VO), who notes:

The KiwiSDR for BeagleBone Kickstarter just launched:

https://www.kickstarter.com/projects/1575992013/kiwisdr-beaglebone-software-defined-radio-sdr-with

https://www.kickstarter.com/projects/1575992013/kiwisdr-beaglebone-software-defined-radio-sdr-with

Many thanks, John!

Those of you who had such a positive response to our previous post about John’s New Zealand-based web SDR, may consider supporting this Kickstarter and even installing a a KiwiSDR at your location! Check out the Kickstarter video for more information.

Listening to the International Space Station (ARISS) with a Yaesu VX-3

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Yesterday, my buddy Eric (WD8RIF) sent the following message:

“Take your girls outside with an HT and listen to the ARISS pass in just about 10 minutes. The downlink freq is 145.800.”

Though I was in the middle of another project, I took Eric’s advice: I grabbed my Yaesu VX-3, corralled my daughters and ran outside. Eric’s message was already eight minutes old when I read it, so I only had about two minutes to get ready.

My Everyday Carry (EDC) pack, loaded with all of the essentials.

Fortunately, I always have a Yaesu VX-3R loaded with fresh batteries in my EDC pack (above).

Official NASA portrait of British astronaut Timothy Peake. Photo Date: August 28, 2013. Location: Building 8, Room 183 - Photo Studio. Photographer: Robert Markowitz

Official NASA portrait of British astronaut Timothy Peake. Photographer: Robert Markowitz

With the VX-3 tuned to 145.8 MHz, we waited as the ISS made its way above the horizon. The downlink audio of astronaut Tim Peake (KG5BVI) communicating with Walter Jackson Elementary in Decatur, Alabama, started to punch through the static after a minute or two. We listened the entire time we had line-of-sight to the ISS–about five minutes or so. We were pretty deep in a valley at that point, so I’m pleased we were able to catch even that much of a pass.

Of course, we could only hear one side of the conversation: the downlink from the International Space Station.

It was a memorable event for my girls who have seen ISS passes at night, but had never heard live audio from an astronaut before.

Here’s a short video of two of the exchanges we heard:

(Click here to view on YouTube.)

Eric pointed me to the ARISS “Upcoming Contacts” (http://www.ariss.org/upcoming-contacts.html) page where future ARISS QSOs are listed. Evidently, this particular ARISS QSO was the third Eric had monitored in two weeks.

Pretty much any receiver that can tune to 145.80 MHz FM–or a VHF scanner–can hear the ARISS downlink as long as the ISS is passing overhead during the transmission. Of course, if you have a high-gain antenna that can track the ISS as it moves across the sky, you’ll get even better results than I did with my basic rubber duck antenna.

My advice? If you want to impress a child (or your inner child–!) find a little time to listen to a future ARISS QSO!

Indeed, the next step for me is to see if I can propose an ARISS QSO for our school group!

Mark’s Icom IC-7100 go kit

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Click to enlarge

Many thanks to SWLing Post reader, Mark Hirst, who writes:

Thomas,

I have been very impressed by the shacks featured on SWLing !

I don’t really have the room to accommodate such large collections, or to dedicate a special area to just radio.

I tend to perch a radio on a spare surface in the front bedroom, and then cycle through my small collection on a weekly or bi-weekly basis, returning the previous radio to storage to await its turn in a month’s time.

Since newer houses and gardens are typically quite small in the UK, I’ve always been thinking in terms of radio on safari, so with the weather starting to improve, I present to you my ‘shack’ consisting of a recently acquired IC-7100 inside a fortuitously sized toolbox. The radio runs in the bedroom like this too, usually connected to a Wellbrook loop when not transmitting.

The picture [above is of the] head unit in stowed configuration, as the lid of the box doesn’t quite clear the unit when sitting on the base. The space on top of the radio is then filled by the SOTA Beams antenna bag and other sundries. The battery travels separately in the backpack.

My plan was to never have to connect/disconnect the ethernet style cable between the two halves, looks like the plan worked !

You can see it in action here:

This is a brilliant kit, Mark–a great way to escape urban radio interference! The Icom IC-7100 is uniquely qualified for the deep case, too, since the control head can sit on top of the body while in use. The angle of operation is also ideal. Very cool–thanks for sharing!