Posts Tagged ‘codec2’

LHS Episode #090: Purple Hays

Here we are at Episode #090, just 10 away from the century mark. Things have been rolling along fairly smoothly, and except for Russ being deathly ill for the last eight days, there’s not even a lot to complain about. In this episode, we have yet another interview. This time it’s with John Hays, K7VE, of Northwest Digital Radio. These guys are producing an entirely new purpose-built radio platform called the UDR56K. This technology promises to be a great advance in the amateur radio arena as well as in the computing arena. It’s a bit of kit that’s going to find a use in almost every radio amateur’s shack. If you want to find out why, please sit down and take a listen to this episode of LHS. We promise you will not be disappointed.

73 de The LHS Guys

Show Notes #088


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



  • 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.


  • 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:


  • “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.

LHS Episode #085: David Rowe on Codec2

Please join us for a special episode of Linux in the Ham Shack. In Episode #085, the hosts interview a vibrant and brilliant engineer from Adelaide, South Australia, named David Rowe. He is the mastermind behind the codec2 open voice codec among several other worthy and equally brilliant open source projects. He dabbles in VoIP, hardware, Open Source advocacy, engineering, voice compression, amateur radio and other endeavors far too numerous to name. David Rowe is definitely one of the more special people occupying our planet and our interview with him is nothing short of amazing. Please tune in and have your mind blown. We look forward to the overspray.

73 de The LHS Guys

LHS Show Notes #060


Topic 1: JT65

  • Richard enjoys the digital modes. Recently, he came across a signal he could not immediately identify, and found it was JT65.
  • JT65 is one of the suite of programs in the WSJT package written by Joe, K1JT, and was originally developed for weak signal Earth-Moon-Earth (EME) contacts.
  • It’s easier to install than WSPR (Weak Signal Propagation Reporter); simply download, extract, and go.
  • Because the software is designed to achieve a weak signal contact, information is sent repeatedly. If everything is working well, a simple contact will take about 7 minutes.
  • Like WSPR, stations transmit on a two-minute interval, so the computer clock must be accurate.
  • One station will “transmit on the ones” meaning he is transmitting on the odd number minutes. Each transmission is usually about 50 seconds. Then, the other station sends on the even minutes.
  • Typical contacts are callsign, signal report, and location.
  • Signals sound a bit like weather fax, usually a bit above the PSK area on 20m.
  • Richard was able to make 10 contacts in 15 minutes with 5 watts into his G5RV at 30 feet, on the 10m band, no less. He then made 5 contacts in 30 minutes on 15m, one of which was to South America.
  • WSJT and WSPR are both developed by Joe, K1JT, a physicist and amateur radio operator.
  • WSJT and WSPR can be found at
  • One of the best websites Richard found for learning to use JT65 on HF is “The Complete Bozo’s Guide to HF JT65A by Andy, K3UK”. It hasn’t been updated in a while, but is still a good resource.
  • The manual included with the program is very good, too.
  • Richard recommends using the second set of messages provided in the program, rather than the default set, as the default does not include a signal report.
  • Richard has prepared an “Intro to JT65″ video, available at the RF Podcast website.

Topic 2: Codec2

  • Bruce, VE9QRP, back in January, suggested we talk about Codec2.
  • From the Codec2 website:
    “Codec2 is an Open Source and patent-free audio codec, currently in alpha testing. It provides good voice rendition at 2550 bits per second, and we expect that its bandwidth will be reduced with continuing development. Its voice quality and latency are an improvement over Speex, when Speex is run at a similarly low bandwidth rate. The original motivation for its development was to provide a completely open codec to replace AMBE+, MELP, and other proprietary codecs for use in Amateur (“Ham”) Radio communications. However, the codec is potentially useful for commercial two-way radio, telephony, and other applications.”
  • Russ plays some audio samples, and our hosts discuss how this might be used in ham radio applications.
  • The resulting file is in a .wav container and thus can be played by any program that plays .wav files. While the result is adequate for voice, it’s not suitable for music.
  • More links:


  • We received donations from Dan W., Matt M., Andrew H., and Paul G. Thank you!
  • LHS will be at the Dayton Hamvention, in the North Hall, booth 131. We hope to see you there!
  • Jim, N2ENN, linked to us on his blog site. Thanks, Jim.
  • The Panhandle ARES group linked to LHS on their website. Thanks, guys.
  • regexorcist of The Daemon and Penguin Oggcast linked to LHS. Thank you.
  • Gary, KE2YK, has syndicated the LHS RSS feed on his site. Thanks, Gary.
  • Burt, K1OIK, thought the clip art of the foo dog (episode 55) looked like Russ.
  • B.B., sent a long email, which we’ll discuss in an upcoming episode.
  • Danny asked about the podcast that Gene has about Apple. That’s the Tech Night Owl Live program with Gene Steinberg.
  • Dave, KI6ZHD, just found the LHS podcast website. Dave has written some documentation for various Linux topics and is a recent ham. His distro of choice is CentOS. He has been documenting his adventures at his blog and thought our listeners might be interested. He asked if we talked about TrustedQSL on Linux, and we did in episodes 43 and 46.
  • Leif, KC8RWR, commented about dual-booting a computer with Windows if Linux has already been installed. He suggests using gparted to shrink the Linux partition, creating a Windows partition in the free space, and then installing Windows. Of course, it’s best to just use a spare computer or another hard drive. (We talked about all this in episode 56.)
  • Richard points out that version 1.0 of CQRLog has been released.
  • Jim, N2ENN, just installed straight Debianand offers a few hints:
    • Extra repositories: In the system/administration tab, there’s a package called software sources. Check them all and click close.
    • Flash vs gnash: don’t worry about gnash. Once the nonfree repositories are selected, open the Synaptic package manager and install flashplugin-nonfree, or from a terminal, type “apt-get install flashplugin-nonfree”.
    • Regarding codecs: all the codecs are already installed, or should be. If not, again in Synaptic, tick good, bad and ugly plugin modules, along with the base plugin.
  • Russ received this from a radio club: Steve, N1NXU, wrote that he had a Tripp-Lite power supply that needed repair and he asked them for a schematic. They declined to provide one, so he recommends Astron power supplies, as schematics are included. These are available a most of the ham radio stores.
  • John, KF6EFG, attended Indiana LinuxFest and asked Russ for a copy of his presentation from that event. Look for that information on the LHS website in the near future.


  • Some listeners have requested a calendar of upcoming LHS events. So, if you have a calendar program that uses ICS calendar feeds, go to the LHS site and on the right side, look for the ‘Follow Us’ heading. Click at the third icon that looks like a calendar. Or, to see the information in your browser, click this[email protected]/LHS-Podcast.html.
  • Again, LHS will be at the Dayton Hamvention on May 20-22. We’ll be giving away a computer, so drop by the booth and say hello. Please donate at the website to help defray the costs. Thanks.

Contact Info:


  • To be added.

LHS Episode #060: apt-get install make-pr0n-work

Hello, faithful listeners and newcomers alike. A couple of big events are coming up. The first is the Dayton Hamvention, this weekend from May 20th through the 22nd. The other is the Southeast Linux Fest, from June 10th through the 12th. Linux in the Ham Shack will have a presence at both events and we hope to see everyone there. We will be having raffles for “quite good” prizes so you don’t want to miss that either.

In this episode of our show, we catch up on almost all of our (very old) feedback and even manage to discuss a couple of items which may interest ham radio and Linux enthusiasts alike: JT65, a weak-signal digital mode, and codec2, a new audio codec designed for low bandwidth, telephone quality, error correction and to be free of patents or encumbrances of any kind. Enjoy.

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