Posts Tagged ‘SDR’

Elecraft KX3 NaP3 Configuration Highlights

In mid November I sold my Kenwood TS-590 to finance the purchase of an Elecraft KX3 and become a full time QRP operator.  One of the advantages of the KX3 is SDR I/Q output, which can be used to drive a panadapter.  After some fidling around, I have a configuration that works with the popular NaP3 software and thought I would share the highlights in hope of saving you some effort.  This is by no means an exhaustive setup and configuration guide for NaP3, but it should be enough to get you started.  Remember you can click on the images to enlarge them.

For this example I have used the integrated sound card in my PC and have not yet put a ground loop isolator inline which are both opportunities for improvement.

 

NaP3 Audio In Advanced Tab

NaP3 Audio In Advanced Tab

We begin by manipulating the input sound card port configuration as shown above.  This will vary somewhat from sound card to sound card, but we want to be sure that we are capturing two channels and that the sampling rate is set at the maximum your card supports, which may take some experimentation and is not necessarily the highest sampling rate shown in the drop down.

 

NaP3 Setup Tab

NaP3 Setup Tab

Here on the setup tab of the NaP3 configuration, we need to select the sound card input we are using and where we would like NaP3 to output decoded audio.  Once again we have the option to manipulate the sampling rate, which as you can see is 48k for my sound card.  In addition, we need to select “Elecraft K3” for the Rig Type and specify our CAT parameters.  I began this adventure trying to use the “Elecraft KX3” Rig Type, but I found it to not work very well.

 

NaP3 IF Tab

NaP3 IF Tab

Here is the “fun” part, at least it was for me until I started banging my head on the desk.  Be sure to set your “Global Offset” to 0 and select “Swap I/Q Channels”.  The “IF Frequency Offsets” is where you will have to spend some time playing.  The method I used was to tune to WWV in CW mode on the KX3 and determine the differential between the frequency displayed on the KX3 and the panadapter display.  I then set the offset to compensate.  To configure the offset for USB and LSB modes, I reduced the offset by the amount equal to my CW sidetone.  This should get you pretty close, but may still require a little tweaking.  Feel free to try my numbers, but I am unsure if they are valid from KX3 to KX3.

If you determine some other method to set the offsets, please let me know as this is the most time consuming portion of the configuration.

 

NaP3 Spanadapter View

NaP3 Spanadapter View

When it is all over, this is similar to what you will end up with, a nice broad view of the spectrum centered on your rigs current frequency!

Show Notes #088

Introduction:

  • A sticky, stormy night in Texas, just right for podcasting and Russ’ attempt to take over the MintCast.

Announcements:

Topics:

  • Pimpin’ the network: If you have a podcast and want to reach LHS listeners, please visit Black Sparrow Media and contact us to become a member! The Waveguides Podcast did and so can you.
  • Who is your hero in amateur radio, living or dead? Let us know! Richard is gathering information for his super-secret project.
  • Storm watchin and workin on radios. While a storm raged in Texas, Richard received an email about an IC-735 that would not power on reliably. Richard’s trouble-shooting philosophy: start with the things that are cheap to replace.
  • Richard is hoping to pursue a high-speed multimedia (HSMM) and mesh radio project using DD-WRT or OpenWrt for use in emergency communications. Used routers, such as the Linksys WRT54GL, are ideal and can be found for little money.

Feedback:

  • Leif, KC8RWR, wrote to clarify a comment to episode 86, explaining that he’d like to try using an NE602 frequency converter to an RTLSDR radio to receive ham bands.
  • Brian, G3XGY, heard Russ on the Mintcast and is looking forward to listening to episodes of LHS! Welcome, Brian.
  • Leif, KC8RWR, offers a suggestion for Grant, who was having difficulty with the LHS live Linux CD handed out at Dayton. He thinks it may have been due to Linux not recognizing Grant’s video card. Thanks, Leif.
  • Harrison, VE2HKW, a sometime participant in MintCast, expresses his appreciation for episode 85, our interview with David Rowe and discussion of Codec2. Thanks, Harrison. Speaking of Codec2, Russ reports that David Rowe has won the 2012 ARRL Technical Innovation Award for his work on Codec2. Congratulations, David!
  • Harrison, VE2HKW, wrote to ask for help with his Icom IC-735 (as mentioned above).
  • Claudio of the LinuxBasement podcast thanks us for the mention in episode 87.

Contact Info:

Music:

  • “The Television Song” by Bryan Dunn, from the album Vicious Waltz, courtesy of Jamendo.
  • “Total Breakdown” by Brad Sucks, from the album Out of It, courtesy of Jamendo.

RTL-SDR Adventures

RTL SDR with SDR#

DVB-T Dongle

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

Show Notes #086

Introduction:

  • Tonight’s episode is proof that LHS is at least as popular as the All-Star Game.

Topic:

  • Interview with Bob Finch, W9YA, principal maintainer of yfktest.
  • Bob got involved with the yfktest project because he was looking for a logging program like the old DOS program, WR9R.
  • His ideal logger did not use graphics, did not require a mouse, and was very easy to learn. yfktest was close, but had a few problems, so Bob began submitting fixes and improvements.
  • Over the past year, Bob began submitting code changes and eventually became the principle maintainer of the program, and has made over 150 patches in that time.
  • Russ described his problem with the program for Field Day logging. Bob explains that the issue was due to the error checking, and had Russ not tried to enter the signal report into the Class field, it would have worked fine. Russ suggests having a line of text above the fields that provides hints as to what each field should contain. Bob added that to his To-Do list.
  • yfktest is written in Perl, so no compilation is necessary to install.
  • Bob is working on a version that is completely contained on a USB stick that would be operating system agnostic.
  • Rudimentary networking features are in the code now, but disabled. So, it’s possible that networking might be a future enhancement.
  • Get your copy of the latest version of yfktest by following the instructions in the README.NOW link at bfinch.net.
  • Bob then describes another of his interests, rocketry, and is involved in the open source/open hardware rocketry project Altus Metrum.

Feedback:

  • Rich, KD0BJT, of the Low SWR podcast writes to tell us of a Field Day logging program called fdlog. It’s written in Python and has networking capabilities for multiple stations. Rich also mentions the Java-based logging program JL. Thanks, Rich. fdlog is a graphical Field Day logging program written in Tcl/Tk, but hasn’t been updated in about a year.
  • Leif, KC8RWR, sends us a link to a series of Youtube video tutorials for GNU Radio, the open source software project for RTL Software Defined Radios. He wonders if he could use an NE602 at the front end of the radio for HF, and use a Raspberry Pi to run GNU Radio. Our hosts discuss this and the Signetics NE602, a balanced mixer and oscillator on a chip.
  • Dave, M0DCM, has been catching up on LHS episodes while convalescing. He describes his system for listening, and some experiences with the Ettus SDR, Funcube Dongle, and digital modes with his new Yaesu FT-817ND.
  • David, KE0AZ, tells us that the power output of the Ettus transmitter daughterboards is anywhere from 50 to 200 mW.

Contact Info:

Music:

  • “Ancient (The Deepest Sky I’ve Ever Seen)” by Olga Scotland from the album Castles Under the Water, courtesy of Jamendo.

 

The $20 Software Defined Radio

Introduction:

Despite my interest in boat-anchors I do find myself peeking ‘over the wall’ from time to time and taking a look at new and emerging technologies. After several demonstrations from friends I had become convinced of the incredible potential of software defined radios and even found thinking about owning one … one day.

Perhaps the best known SDR in amateur radio circles are the FLEX rigs from FlexRadio. I had the chance to see a FLEX-3000 in use during Winter Field Day 2011 and had to admit that, barring the lack of knobs & dials, it was a very impressive rig!
One thing stopped me from running out and buying one straight away was the cost and perhaps the notion that once the new had worn off I would regret the significant outlay required to own the blue box. So, I shelved the idea of owning an SDR and found other things to occupy my time.
This changed when a post on www.reddit.com/r/amateurradio/ mentioned an unmodified digital TV receiving USB device that had been used as a software defined receiver in the 60MHz – 1.7GHz range. The best part was the cost, around $20 for most examples of this kind of device. Finally software & commodity hardware had come together to deliver useful receiver that everyone can afford.
The nuts and bolts:

There are specific parts required to put together your own $20 SDR but I will document what I used to get mine running and hopefully you can follow along.
Hardware: The device that I used was a Ezcap EZTV668 DVB-T Digital TV USB 2.0 Dongle purchased from DealExtreme. The part was shipped from Asia and I gather from reading else ware that DealExtreme is a middleman and not the actual supplier. Be prepared to wait a while if ordering from this supplier, my Ezcap took about 3 weeks to arrive but I have heard that a month or more is not uncommon.
The upside is that shipping is free and your purchase involves 0% tax, this really IS a $20 SDR.
This particular DVB-T dongle uses the RTL2832U chip which is required for use as an SDR, other dongles with this chip may work but if it does not have the RTL chip it will NOT work currently.

Software (Linux) : After poor results with the software running on MS Windows I moved across to Linux and got it working well there. I can’t point you to a single howto for this because I used several different guides and tried a few things before it started working. The most helpful, and probably all you really need, are the build-gnuradio script which gets hardware support and gnu-radio running and the “Getting Started With RTL-SDR” page by Tom Nardi which covers installing Gqrx. All the software used is in development and requires familiarity with the command line to install and use at the moment.

Software (Windows) : I had another shot at getting the MS Windows software running and stumbled across the excellent website http://rtlsdr.org. Rtlsdr.org mentions using a new version of SDR# software which worked very well! 
I would recommend following the instructions under the Windows Software section, this had me up and running in a matter of minutes. Follow the instructions EXACTLY, I made life hard on myself by not paying attention to details and I think was responsible for my earlier issues.
Going further – Antenna : The stock antenna that is supplied with the Ezcap EZTV668 is sufficient for testing but you’ll want to add something a bit more substantial for regular use. You may even want to remove the existing (hard to find) antenna connector from the board and install a standard connector and a less flimsy metal casing. This will help with RF shielding and temperature stability. 
If you are going to use a larger antenna, especially an outside antenna, you’ll want to check to make sure a protection diode has been fitted to the input. The Ezcap EZTV668 is a very inexpensive device and others have found units in which the protection diode was not fitted to save costs.
Going further – 160M – 6M ? : I’ve just seen an interesting blog post titled FunCube Upconverter where the author, George Smart, has built a converter allowing the reception of 160M – 6M using the FunCube dongle. The FunCube is functionally the same as the RTL dongles available for $20. For any home brewers out there this could be a great project as George has included all the details including schematics and board artwork required to build the converter.


Update : Thanks to a link from Neil W2NDG to an EBay sale I’ve been able to track down a pre-assembled HF up-converter on this page : New HF Converter Kit for the SDR Fun Cube Dongle The price seems to be 45 euros, or about $55 US.

I’ve had a lot of fun using the $20 SDR to listen to AM aircraft traffic, local repeaters, emergency services and amazingly good quality broadcast FM stereo programming. Its easy to see, with an SDR, just how wide a radio broadcaster is transmitting and move your filter bandwidth to match.

Hopefully this is just the beginning of inexpensive SDR hardware that the radio community can re-purpose and re-engineer. 

Show Notes #084

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
    • The LHS Mailing List
    • The LHS Mobile app. Follow our updates via the mobile applications available for iPod, iPhone, iPad and Android devices.
    • 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:

Music:

  • None.

LHS Episode #084: GNU Radio

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!


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