AmateurRadio.com

When I get asked ‘what is ham radio?’ I generally get a bit tongue tied and waffle on a bit. There is nothing harder as a ham than actually defining the hobby. This is really down to how diverse the hobby is. Fundamentally at the core is a like of RF. Other than that it sort of sprays out a heap of sub genre’s that have a variety of different followers. Amateur TV, DX chasing, GHz…. the list goes on and on. Perhaps one day a map will be available that shows the full spectrum and a few of the relationships, but for now here is another one. I’m going to call it ham radio services as a working title, it is defined as the ham who uses his knowledge and equipment to provide a service based on RF. APRS igates are an example of this.

So what else is there? The Raspberry Pi has certainly opened up the opportunity to provide low cost services. I have one the is an APRS igate, one that runs my SatNOGS ground station and that was it until last week when I put an unused older Pi2 to good use as an ADSB receiver using a system called PiAware. Essentially a way of melding together an RPi, rtl-sdr dongle and an ADSB antenna. All so that it can listen out for the aircraft beacons and report positional information to the Flightaware website.

The ‘project’ took no more than a couple of hours, mainly because my Micro-SD card died and I had to scrabble around for another one. It is very simple to do and will put your Raspberry Pi to good use. Steps are summarised as

1. Sign up with the Flight Aware website and read through the docs on the PiAware page
2. Download the image
3. Burn the image to a (non corrupt) micro SD card. Plonk it in the pi
4. Plug in an Rtl-sdr (or you could splash out on a Flight Aware Prostick)
5. Power on
6. Find IP address of RPi on network (look in the router settings)
7. Go to site (mine is 192.168.1.100). You should have a screen that looks a bit like this

1. Claim you receiver (Instructions are on the screen). There will be a link in the place where it says ‘View your site statistics online’
2. Sit back and watch the packets come in. When you’re ready go to the FlightAware website and see how well you are doing.

Looking west is best as always from my QTH. Where’s the fun in that? I hear you say?

Its good to experiment, after all there is DX to be had, just not in the conventional sense. Lets take a comparison between WSPR and ADSB. A bit off beat but here goes, WSPR will tell you the distance and signal to noise of your station as heard by another, DX, station. You do the transmitting and someone else does the receiving. With the PiAware setup someone else does the transmitting and you do the receiving. Is this not the same thing? A different band ok but actually the same thing.

Beats attempting to get in contact with some short lived station in a rarely activated location by shouting into a microphone for hours on end. Say I. Wouldn’t it be boring if we all liked the same thing.

One final note. There are lots of RTL-SDR dongles to choose from. The cheap £3 ones from eBay work, they are reliable enough and coupled with the (normally) supplied antenna give me a range around 150-200 nautical miles. the Pro Stick mentioned earlier will extend that range by using a broadband low noise amp (LNA). If you live in an urban environment you can use the Pro Stick Plus that comes with a band pass filter or add in your own. you may also need to adjust gain settings and have a play. I am only using a wire antenna, I will find a reasonable supplier for a colinear or similar and report back.

Onwards and upwards

If, like me you have an rtl dongle, there is another ‘thing’ you can do with them that I bet you never knew. Ok you did but I’ll bet all of you didn’t know. Its called OpenWebRX

You can also arm yourself with one of those old netbooks you’ve got loafing about in the corner and put it to use into the bargain.

To tell the truth I’d not heard about it until Daniel, 2E0DNX mentioned something in passing as I was driving him back from the club night last Monday. I can’t remember what started it but we got onto the subject of putting receivers on the web a la WebSDR and the well known Hack Green SDR. This time, as we are both cheapskates, it was around the use of the cheapo dongles.

So, after downloading a copy of Lubuntu (A lightweight ubuntu distro) I installed it onto an old netbook. I thought I followed the instructions on the website and but I hadn’t and after a false start with some rubbish spelling had a receiver running on the local host. I did get some pretty speedy support from the developer though who helped to narrow down my incompetence.

Getting it on line is a little more complicated and needs a bit of fettling. In order to get it listed on the site it needs a web presence. To get that you can pay for it and host it or you can be a cheapskate and use a service like N0-IP.  Guess which route I went? They provide a web address that you can use and some really handy instructions for linux installations, if, like me, its not a natural environment to work in but you can largely follow instructions.

After all instructions followed correctly (there are no spelling mistakes in your config file ) then the last thing to do is make sure your router lets the traffic through (port forwarding). This can be a pain if you’re on BT like me and can lead to no end of frustration that was eventually fixed with a new, non BT router. I’ve got my head round this and will now look to set up a more permanent installation, perhaps with a RPi2 if its got the right mojo.

All in all you’ve got to hand it to people who set out these environments as they are becoming a great way of distributing amateur radio to a wider audience. Thanks Andras, HA7ILM and well done!

OK, this is very low power but it shows you what can be done. A QRPP transmitter or signal generator anywhere between 500MHz and 1.5GHz.

Please note the image below is not on my blog (it is linked as shown) and will be immediately removed if this is a problem.

http://rtlsdrblog.rtlsdrblog.netdna-cdn.com/wp-content/uploads/2015/06/transmit_hack_rtlsdr-500×375.jpg

See http://www.rtl-sdr.com/using-the-rtl-sdr-as-a-transmitter/

See also http://www.steila.com/SDR/RFgenmod/index.html .

Hello, esteemed listeners. Welcome to the latest installment of Linux in the Ham Shack. Tonight, Richard and Russ take the first third of the podcast to get a few topics off their minds that they’ve been thinking about over the past several weeks, whether or not those topics have anything to do with amateur radio or Linux. Wedged in the middle, discussion of wireless networking comes up, using HSMM and inexpensive Linksys hardware to provide Part 15 and Part 97 based communications for local, regional and EMCOMM use. Then our cagey hosts finish up with a mad dash through feedback, giving useful advice to those listeners with enough mettle to write in. Thanks as always to our loyal followers. We appreciate each and every one of you, each and every fortnight.

73 de The LHS Guys

RTL SDR with SDR#

DVB-T Dongle from eBay seller digitalhome88

I received my DVB-T dongle from eBay finally about a week ago.  Here’s a link to the vendor I purchased from.  After getting the drivers loaded in Windows 7 on my aging Dell D630, I was able to get the SDR running.  Using the instructions here at rtlsdr.com, I finally got things up and running.  There was one mistake that made me lose several minutes.  I missed the instruction:  If your dongle doesn’t automatically show up, select Options then List all Devices.  Read carefully!  I’ve found that in my case, SDR# is the better choice of software.  For some reason HDSDR causes the dongle to lock up after changing bands.  I’m sure I’ll find out why because I see many others having good luck with it.  The old Dell was able to keep up, but seemed a bit choppy.  I dropped the sampling rate down a bit, and everything was fine.

My first tests were a little disappointing, yet this was with the cheesy antenna the dongle arrived with, and then with MacGuyver-ing an antenna adapter together.  The DVB-T dongles have a PAL-female connector on them, and nothing in my tin-o-connectors seemed to work.  Radio Shack carries an adapter that is PAL-male on one side and F-female on the other.  I went out and picked one up, as well as an extra F-to-BNC adapter.  Then I was able to go from the dongle to my simple outdoor antenna.

With a solid connection to my outdoor wire antenna (just a wire thrown into a nearby tree, and a counterpoise out on the roof slope), I was able to get all of the local repeaters, as well as repeaters in Manhattan, and much farther.  4 different NOAA stations came in, and aircraft traffic from the whole tri-state area.  I even grabbed a couple of 2 meter USB contacts, and quickly switched over to the TR-9000 to speak with one of them.  Performance with this setup was much, much better than I had expected.

My Elmer had stopped by Sunday to deliver a rig he repaired for me on his way out to Eastern Long Island, and I gave him a quick demo.  After playing with it for about 20 minutes he said “Send me the info.  I need to get one of these!”  Here is a quick video I took of some local repeaters, including a Ham ordering coffee from a McDonald’s drive-thru.  Sorry for the shaky video.

Click here for video: RTL SDR with SDR#

–Neil W2NDG

Introduction:

• No music this time; just one hour jam-packed with LHS goodness!

Announcements:

• Remember to sign up for the following LHS services:
  • The LHS SubReddit
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  • Be an LHS Ambassador! Please join our Ambassador program. The event calendar has expanded quite a bit and we need your help. These events are now world-wide, so we could use some help outside the US as well as all over the country from California to Maine.
• YFKtest: Yes, there really does seem to be a problem. It’s been confirmed by John, EI7IG, that the program does not log contacts for the ARRL Field Day contest. Other contests work fine. Russ plans on emailing the developer, DJ1YFK, with these observations.
• From the “Yes, It’s an Antenna” File: Multi-band HF dipole made from horse fencing.
• Pulling a Lunduke: Holding Source Code Hostage. Our hosts discuss this blog post by Tom Nardi about Bryan Lunduke’s recent move to open source his software. Bryan is one of the hosts of The Linux Action Show.

Topics:

• Software Defined Radio (SDR)
  • A common topic Russ encountered at Dayton was about the available Linux options for software defined radios.
  • GNU Radio Project
    • Version 3.6.0 released in early May, 2012.
    • Version 3.2.2 is in the Debian Sid repository.
    • The latest version can be retrieved with git. (Install git with the command “apt-get install git”.) To download the software, issue the command “git clone git://gnuradio.org/gnuradio”.
    • Build instructions are available for most of the major Linux distributions.
  • SDR Hardware
    • Ettus USRP series works with the GNU Radio Project software. There are various models ranging in price from $700 to $2000, depending on the frequency range and options. Various modules allow receive and/or transmit on bands from 30kHz to 5.9GHz. Unfortunately, power output appears to be just 50-200mW, depending on the bands provided by the transmitter daughter board chosen.
    • Funcube Dongle costs £128 (~$200) and is a receiver only. The Funcube Dongle is a “radio receiver designed to allow anyone to try their hand at reception of satellites like FUNcube”. It covers 51.5MHz – 1.7GHz, less the region from 1.1GHz to 1.2GHz.
    • Perseus SDR costs $1000 and is also receive-only. It receives 10kHz to 40MHz.
    • SoftRock SDR is a kit available in various models from $20 to $90. Most are receive-only, but the Ensemble is a 1W HF transceiver. Some models are unavailable at the moment. The SoftRock RXTX Ensemble Transceiver Kit will allow you to build a 1W transceiver for one of the following bands or band groups: 160m, 80m/40m, 30m/20m/17m, or 15m/12m/10m.
    • RTL-SDR Devices range in price from $20 to $200 and are receive-only. More on the RTL-SDR project in an upcoming episode.

Feedback:

• Stewart, VA3PID, wrote to say that Russ was the first person, possibly ever, to correctly place his Scottish accent at Hamvention. He also remarked (in reference to a discussion in episode 71) that Chirp has come a long way; it can now program his Yaesu FT-857D!
• Jonas recently re-discovered LHS and expressed his appreciation for the show. Thanks, Jonas!
• Stefano, IZ3NVR/KD2BGM, asks for more help getting so2sdr built on his Linux machine. Russ suggests installing the compiler with “apt-get install g++ build-essential”, installing Qt and several other packages as described in Episode 83, then try building the so2sdr program again.
• Lastly, David Dominicki left a mostly unintelligible comment in response to Episode 78. Um, thanks… we think.

Contact Info:

• Contact Richard at [email protected], Russ at [email protected], or both at the same time at [email protected].
• Listen to the live stream every other Tuesday at 8:00pm Central time. Check the LHS web site for dates.
• Leave us a voice mail at 1-909-LHS-SHOW (1-909-547-7469), or record an introduction to the podcast.
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• LHS merchandise is available at the Merch link on Web site. Check out the Badgerwear or buy one of the other LHS-branded items at PrintFection.com/lhs or Cafe Press. Thanks!
• Thanks to Dave from Gamma Leonis for the theme music.

Music:

• None.

The 84th installment of your most favoritest podcast is now in the wild. As you may have noticed, we make a lot of assumptions about our listeners on this show; for example: You all love us. We have a good show in store for you today, including antennas made from electric fencing, a question about whether GPL software can be profitable, and most importantly a look at software defined radio and the GNU Radio project. Towards the end we address some feedback, solve a technical problem in Italian and try to stage an intervention for one of our more peculiar fans. ALL THIS WEEK on Linux in the Ham Shack!