Archive for category D-STAR
Last weekend, I had the privilege of attending the Pacificon amateur radio convention in Santa Clara, something I have been trying to do for several years now. It is a great event, with good technical programs and a super venue.
The most interesting presentation I saw was the one on digital voice (DV) technology by Bruce Perens K6BP. The presentation was mostly about the digital voice known as FreeDV, an open source approach to DV that uses the Codec 2 voice codec for digitally processing/compressing speech.
I won’t cover all of the technical details here but you can follow the links above to go deeper on the topic. The initial FreeDV efforts are focused on the HF bands, using the sound card plus computer approach to implementing DV. This is a good approach since it is a relatively easy way to adopt this technology. (Compare this to VHF/UHF where you need to solve the repeater infrastructure problem to make progress.) FreeDV operates with a bandwidth of 1.25 kHz, narrower that the standard 3 kHz or so SSB signal. FreeDV also has the benefit of degrading gracefully as the signal-to-noise ratio is decreased, with less of a digital dropoff that we see with D-STAR and other DV technologies.
Like many hams, Bruce pointed out the concerns and limitations of the proprietary AMBE chip used in D-STAR, DMR and now the new Yaesu DV system. I totally get this point and support the idea of a an open source codec. On the other hand, this work is coming more than a decade later than the creation of D-STAR. I like to refer to this phenomenon as “our ideas are better than their products.”
Bruce introduced Chris Testa KB2BMH to talk about the “HT of the Future”. This is a handheld transceiver implemented using Software Defined Radio (SDR) and inspirations from the world of smartphones. As Bruce said, “Why isn’t your HT as smart as your smart phone?” This is similar to the Android HT idea that I blogged about a while back. See Chris’s blog and this HamRadioNow video for more information.
Another presentation that I attended was about D-STAR with several speakers, including Robin AA4RC. The innovation continues to happen in the D-STAR world with a strong theme of using Raspberry Pi computers to create D-STAR hotspots and repeaters. Robin described the “DV Pi” being developed…a DVAP-like daughter board that plugs into a Raspberry Pi. Jim Moen K6JM talked about the many ways you can implement a D-STAR Hotspot. For more info on that see his D-STAR Hotspot page.
There’s much innovation happening in the area of Digital Voice. It got me thinking about it again so I dug out my ICOM D-STAR HT and put my DVAP back on the air.
73, Bob K0NR
I’ve been watching all of the innovative work going on in the smartphone and tablet arena and wondering how we could get more of that going in ham radio. To be sure, there are always radio amateurs developing creative technology. Some examples are adaptations of D-STAR, IRLP, improvements on APRS and sound card modulation modes. However, amateur radio is missing a standardized platform for handheld communications. Such a radio platform could open up lots of software innovation in this space.
What I have in mind is a dualband (2M/70cm) handheld transceiver that is built on top of the Android operating system. (Sorry Apple Fan Boys, iOS is a non-starter based on Apple’s walled garden philosophy.) This radio would have some of the hardware features we now take for granted in smartphones: GPS, WiFi, USB, maybe even a camera. I’d also include APRS hardware built-in, similar to the Yaesu VX-8GR or the Kenwood TH-D72A. I’ve hacked together a concept photo shown on the left of this post (click to enlarge). We would probably want to maintain some of the most important direct hardware controls such as PTT, volume and channel select. The rest of the user interface would be done via a touchscreen display, where the power of the Android OS comes into play.
While this hardware configuration is exciting, the real power comes from having a software developers kit (SDK) with a stable Application Programming Interface (API). This would unleash the creativity of all those software-oriented hams out there and a plethora of apps would emerge. There are plenty of ham radio apps available on the Apple and Android platforms…it’s just they are missing the radio as part of the package. An obvious area for innovation would initially be in APRS or maybe D-STAR. We could actually have the equivalent of SMS text messaging on ham radio, backed up via the WiFi connection. (Yeah, this kind of exists already but it is really cumbersome to use due to the
braindead menu-driven user interfaces of current radios.) Just think how easy programming the radio would be with a touchscreen approach.
This is the type of product development that requires significant investment, but the technology is readily available. I suppose a garage shop operation could get this done but one of the big radio manufacturers could easily pull this off. Maybe one of those upstarts from China might want to take this on. Whoever does it, just send me $5 per unit and I’ll be happy :-).
That’s my best idea for this morning. What do you think?
73, Bob K0NR
ICOM has shown the new IC-7100 at the JARL show in Tokyo. The interwebz is buzzing with information, including a preliminary data sheet.
My scan of the preliminary datasheet indicates that this radio is in the class of the IC-7000 or even the IC-706. It covers all modes on HF plus 6 Meters, 2 Meters and 70 cm. (It also has the 70 MHz band which is a nice add for the European countries that have that band.) The radio includes DV (D-STAR) modulation capability and has a new touchscreen user interface. The slanted control panel is meant to make the touchscreen more accessible.
A new HF plus VHF/UHF radio always gets my attention (see my plea for an FT-950 with 2 Meters). I am starting to think that the real benefit of this rig is the addition of D-STAR capability, which would a good but not essential feature to have.
What do you think?
73, Bob K0NR
At this point in time Vertex Standard believes the C4FM (4-level FSK) FDMA or TDMA are the most suitable selections for Amateur radio applications. In early 2012, we will release a C4FM (4-level FSK) FDMA Handy-Talky and a Mobile transceiver into the Amateur radio market. After our initial introduction, we plan to introduce a C4FM (4-level FSK) TDMA (2 slots) or TDMA Handy and Mobile transceiver into the Amateur market.
This just in from the Things That Make You Go Hmmm Department: the amateur radio portion of Yaesu splits from Mother Motorola while the land mobile portion stays. This is right on top of an announcement that Yaesu will pursue a digital amateur radio offering based on land mobile technology (i.e., definitely not D-STAR).
The K0KDS blog has a post about the split, so go there for the full story. The ARRL has this news item about the organizational change. Here’s the paper that Yaesu published about their move into digital technology for amateur radio.
73, Bob K0NR
As the year 2010 comes to an end, I feel compelled to write something really insightful and meaningful as we log another trip around the sun. Perhaps some brilliant insights for the coming year? Or predictions of future technology breakthroughs?
Instead, I am writing this.
This is a mishmash of my thoughts about amateur radio at the start of 2011:
- Tech License Class: One of the most fun and rewarding ham radio things I did this year was help teach a couple of Technician License Classes. There is nothing like engaging with newbies to the hobby to give you a new perspective on how cool amateur radio really is! I have a great set of teammates that made this class fun and successful: Stu W0STU, Paul AA0K and Joyce K0JJW.
- Next Challenge: The challenge we see right now is helping these newly licensed Techs get engaged with amateur radio, so they don’t drop out. My belief is that the Technician License is a beginners permit that only enables a person to get started in the hobby. We are cooking up some fun activities to keep them going.
- Public Service: We have a good thing going with the local fire district and the RACES group in our county in terms of real engagement on emergency communications. This is fun, rewarding and a good thing for our local community.
- Dayton Hamvention: I am going to skip Dayton (again) this year. Instead, I’ll attend the International Wireless Communications Expo (IWCE), a trade show centered on land mobile and mobile wireless communications. For me, it has an interesting mix of emergency communications, land mobile, data/voice convergence and test & measurement topics. Oh, did I mention that it is in Las Vegas? I suspect that it will be a better venue than Hara Arena
- ICOM IC-9100: I have been patiently waiting for this rig to move from vaporware status to reality. Maybe it will happen this year?
- Keep On Writing: I find that writing is good therapy, so I will keep that on the list for 2011. Mostly it will be this blog and the FM column for CQ VHF magazine.
- Operating: It seems I don’t actually get on the air as often as I’d like, certainly not for the casual ragchewing QSO. Operating events seem to be a good way for me to get some air time: VHF Contests, Colorado 14er event, Colorado QSO Party, maybe an HF contest or two.
- D-STAR: I haven’t been spending much time with D-STAR lately and I want to increase the focus on it. D-STAR falls into that dorking around with new technology category where experimenting with it and learning about it is the main activity. The technology continues to grow in adoption…arguably slow in real terms as the analog modes have such a huge installed base.
- APRS: Oddly enough, I have been messing around with APRS again, mostly thinking of it as a tracking tool for hiking and other outdoor activities. Maybe we need to look at bridging APRS with D-STAR location data?
Amateur radio is clearly my #1 hobby interest, and by a wide margin. But it is primarily a hobby (yes, with a public service hook to it…at least for me). It is important to keep it in perspective and not let it turn into another job. I already have one of those.
What are you going to be doing in 2011?
73, Bob K0NR
Some upcoming events: ARRL June VHF QSO Party and the Colorado FM Sprint, on the weekend of June 12th. The FM Sprint runs concurrently with the ARRL contest but only on Sunday afternoon. This is a good chance to get on the air with very basic equipment and have some fun.
The ARRL Field Day is coming up on June 26th and 27th. This is arguably the biggest on-the-air amateur radio event in North America.
I was playing around with setting up an SMS text messaging system for callsign lookup. The idea is that you send a text message (containing an amateur call sign) with your mobile phone and get the FCC or QRZ info back. In the meantime, I found that this problem has been solved by Callsign By Text. Very nice, check it out.
Female radio amateurs should check out Chick Factor International. It looks like a fun group.
I picked up a DV Access Point (DVAP) for D-STAR. This is a neat little device that provides flea-powered D-STAR access on 2 Meters by plugging it into a PC with internet connection. The South Yorkshire Repeater Group has a good description of the product. So far, this thing works really well.
By the way, the South Yorkshire group has a really good web site…interesting and timely information. Although they are in the UK, I find it relevant to US ham radio activity, too.
The Technician Class License question pool will be updated as of July 1, 2010. Our next Tech Class in Monument will be in October, so we’ll be updating the classroom material before teaching that class. It is clear that more technical content is being added to the question pool, which I think is a good thing. See KB6NU’s posting on the topic.
From The Complete Waste of Time Department, the FCC once again dismissed a petition from K9STH to change the amateur radio station identification requirements. Look, the FCC doesn’t see a problem here (and neither do I) so save yourself the trouble.
The FCC is seeking comments on the proposed new rules concerning emergency communications. I took the time to file a short comment, basically saying that the FCC is on the right track but they should remove the reference to “government-sponsored drills”. Any legitimate emergency communications drill should be included, regardless of who sponsors it. The ARRL made similar but more detailed comments.
- 73, Bob K0NR
Ham radio VHF enthusiasts have been patiently waiting for the ICOM IC-9100. This HF/VHF/UHF/Satellites covers most or all of the popular amateur bands. Recently, ICOM has posted the specs and brochure on its web site.
The rig has dual receivers that allow monitoring two bands at once and it is set up for full-duplex on satellites. The built-in antenna tuner covers HF and 50 MHz. Operating on 1.2 GHz requires an optional module.
There is an optional DV (D-STAR) option that works on 10M, 6M, 2M, 70 cm and 1.2 GHz. This is the first combo HF+VHF+UHF rig that has DV available.
The 100 Watt output power all the way up to 50 MHz and 144 MHz is a real plus and 75 Watts on 430 MHz is not bad either. The 1.2 GHz option would be nice, too. This would be a great radio for portable VHF contesting. Oh, and I guess it works HF, too.
So everyone was expecting a big ICOM announcement at the Dayton Hamvention. Based on the reports I heard via the D-STAR system in Dayton, one unit was shown “under glass” so attendees could look but not touch. Also, a number of people have reported that the ICOM booth staff are saying that the 9100 will be available later this year (fall timeframe?) at a price of ~$US 4000.
Ouch. Most observers see that as a bit too expensive. I’ll withhold judgment until it is really in stock at a dealer with a real price.
- 73, Bob K0NR
We’ve been looking at optimizing the performance of the D-STAR repeater here in Monument (W0TLM, 446.8875 MHz), so I’ve been searching the web for information on what other groups have uncovered. Not surprisingly, there has been some creative reverse-engineering and re-engineering of the ICOM D-STAR repeaters.
Here’s a summary of some Good Stuff that I found:
1. NU5D paper on DSTAR Repeater Modifications & Interference Testing
2. A good overview of the ICOM D-STAR repeater block diagram and a few modifications to the ICOM repeaters on the dstar.ca web site
3. The N5EBW LED Board – a drop in board to add transmit/receive LEDs to the ICOM D-STAR repeaters
4. The Utah VHF Society D-STAR page — some of the best technical information and practical evaluation of D-STAR technology
If you come across other D-STAR resources, please let me know.
73, Bob K0NR
I have been traveling quite a bit lately for work, so here’s a catch up on a number of things spewing forth from the interwebnet.
I’ve recently re-discovered High Frequency Electronics Magazine, edited by Gary Breed, K9AY. This is a top quality trade pub that targets RF design engineers. In Gary’s September editorial, he highlighted the environment that the college class of 2013 grew up in….such as “text has always been hyper.”
I came across this summary of Top Ham Radio Blogs. They clearly have excellent judgment, since my blog is listed.
Google’s Eric Schmidt talks about the future of the web…some interesting thoughts. I hope his prediction of 100MB broadband comes true…but I am not expecting it to come down my road any time soon.
KB9MWR posted an interesting article about the radio range of D-STAR.
Last weekend was the CQ Worldwide DX Contest (SSB version), so I did get on the air for a few hours. Mostly, I got clobbered on 20 Meters with my 100-Watts-to-a-dipole station being overrun by the Big Gun Stations. I did manage to work some DX on both 15M and 20M.
The FCC actions concerning EmComm and Part 97.113 have exposed different views on the role of amateur radio in emergency communications. See the comments on my blog posting, this article by Steve K9ZW and N5FDL’s blog. There seems to be some pent up frustration with ham radio EmComm folks coming from some corners of the ham community.
I encourage everyone to go back and read Part 97.1, the Basis and Purpose of the Amateur Radio Service. It lists five different items as the purpose of amateur radio, all of which are relevant and important. I’d also suggest that everyone lighten up just a bit (and be sure to stay on your meds).
73, Bob K0NR
The interest in D-STAR continues to grow in Colorado. I have responded to a request to talk about D-STAR at the Mountain Amateur Radio Club (MARC) meeting on Wednesday night. It will be a basic introduction to the mode/technology along with a demo of D-RATS. I don’t think I am an expert on the topic so I asked Elliot KB0RFC to assist. Between the two of us, we have enough experience with D-STAR to handle the topic well.
The MARC club is a fun group, so stop by if you get a chance!
Bob Witte (KØNR) and Elliot Linke (KBØRFC) will be presenting a program and demonstrating the basics of D-Star, the new amateur radio digital mode that can be used for both voice and data, at our MARC Meeting at 7 pm this Wednesday, Sept. 16th, at the Woodland Park Library. I hope you will make plans to attend!
See you then!!!
73 Wes KØHBZ
I am trying out a new twitter ap called DestroyTwitter. There are many to choose from, so as I reloaded my PC I decided to give this one a try. So far it seems to be good, which means compact, not too fancy and easy-to-use.
John C. Dvorak wrote that Twitter is the New CB Radio. I think he is right. My enthusiasm for twitter drops about 1 dB per week.
The VHF/UHF crowd is excited about the new ICOM IC-9100 that was shown recently at a Japanese ham radio show. This is basically an HF + 6 Meters + 2 Meters + 70 cm transceiver set up for satellite and (optional) D-STAR. Kind of does everything.
I am very much in favor of a Cash for Clunkers program for amateur radio gear and computer gear more than 5 years old. It seems like the gubment is handing out money to everyone else (without much logic applied), so why can’t we get a piece of that?
Interesting piece from the ARRL about power line companies and their responsibilities concerning radiated interference. Despite all of the concern about Broadband Over Powerline messing up the ham bands, there are far more incidents of good old power line noise causing trouble for ham radio operators. I have been involved in several of these cases and it is generally a real mess….especially if the utility is incompetent.
AMSAT has rejiggered its Suitsat program to fly without the spacesuit. I always wondered why they needed a spacesuit to make this work anyway. It turns out they don’t. The new suitless name is ARISSat-1.
There has been plenty of bickering on the AMSAT-bb email list as various people have complained about this project or that project AMSAT is pursuing. For some reason Suitsat-2 has become a target for complaints. My philosophy? Anything that involves amateur radio in space that works is OK by me.
I continue to play around with D-STAR now that the repeater is up and running in Monument. I was sitting there last night fiddling with the radio when VK2LOB from Sydney, Australia comes on the frequency looking to demonstrate D-STAR. We had a nice, short chat — what a pleasant surprise!
73, Bob K0NR
One of our local radio groups has put a 70 cm D-STAR repeater on the air here in Monument. Here’s the announcement from Elliot KB0RFC:
The W0TLM B repeater and gateway are on the air in their new PERMANENT home in monument near hwy 105 and I 25, coverage reports are needed. All gateway functions are operating please feel free to link to the repeater, or just call around.
The repeater is a joint effort between the Tri-Lakes Monument Fire radio association, the Tri-Lakes Monument Fire Department Communications Auxilary, And the Tri-Lakes Monument Fire Protection District. The purpose of this repeater is to support emergency communications in northern El-Paso County. we will do what we can to create an environment conducive to training and support for actual emergency events.
We run a net on 447.725- 100.0hz tone every Monday night except the last Monday of the month where we have our monthly meeting at Tri-Lakes Fire station 1. All are welcome We hope to be participating in the CO-D-STAR net soon. W0TLM++B and W0TLM++G are on 446.8875- please check it out!
Please email any questions to firstname.lastname@example.org
I got a chance to try D-STAR out from a remote perspective when I was out in the San Francisco Bay area. I got on the W6YYY repeater in Oakland on 440.03750MHz and chatted with Elliot KB0RFC back in Monument. This is way cool!
OK, you may be thinking “I can do that with EchoLink or IRLP”, which is true (and that is also way cool). The benefits of D-STAR are still emerging, but one big difference is that each transmitted packet has callsign routing. One feature that I see as useful is the callsign squelch mode. I can keep my radio squelched expect for people specifically calling me. Other advantages of the “all digital” network are starting to surface, so stay tuned on that.
There are several D-STAR repeaters popping up in Colorado. The group leading the way is the Colorado D-STAR Association in the Denver area. The Cheyenne Mountain Repeater Group has a system on the air in Colorado Springs, currently in a test phase (limited coverage) on 446.9125 MHz (KC0CVU B). A group in Boulder is also working on a system but I am not sure of the status of that effort.
New technology, new learning, new fun.
73, Bob K0NR
The D-STAR buzz continues to build in Colorado with a few repeaters on the air and more to come. For an overview of D-STAR, take a look at the article I wrote for CQ VHF magazine. I decided to dig into the digital modulation format that is used in D-STAR so I could understand it better. (Moving Forward!) At first, I figured that this newfangled digital modulation had nothing to do with FM but later realized that this is not completely true. (No, FM and D-STAR do not interoperate.)
It turns out that D-STAR uses Gaussian Minimum Shift Keying (GMSK), the same modulation format that GSM mobile phones use. What is that, you say? Let’s start with Frequency Shift Keying (FSK)…when the digital signal is a logical one, a particular frequency is generated. When the digital signal changes to a logical zero, a different frequency is generated. On the receive end, we just keep an eye on the frequency and decode the digital signal accordingly. In concept, we could generate this FSK signal by hosing the digital signal into an FM modulator. Minimum Shift Keying is a special case of FSK where the frequency shift (and the phase changes) are carefully controlled (modulation index of 0.5) to keep the phase discontinuities low and the bandwidth minimal. Add a Gaussian filter on the front end of this and you have GMSK. (The gaussian filter smooths out the digital transitions and gives an even narrower bandwidth.) I found this GMSK tutorial to be very helpful.
On the air, a GMSK signal has a constant amplitude, just like FM. It will switch back and forth between two frequencies as the digital signal goes high and low. The digital signal can be recovered using an FM detector but the output of the detector is the digital format.
Of course, GMSK is only part of the D-STAR modulation system. The other key component is the vocoder, which is the AMBE-2020™ Vocoder from Digital Voice Systems, Inc (DVSI). This chip performs the magic of smooshing the digitized voice signal into a reasonable number of bits per second so that when they are turned into GMSK they fit within the rather narrow bandwidth (6 kHz nominal). Since this vocoder chip is proprietary, it has caused some hams to grumble about the lack of an “open” vocoder algorithm. I think they have a point but it does get overblown. I have heard statements that this proprietary algorithm adds $100s to $1000s of dollars to the price of a D-STAR radio. My sources tell me the chip sells for about $20, a very reasonable price for this functionality.
I’m in the process of turning this investigation into my FM column for the Winter issue of CQ VHF, so there will be more detail there. I hope this short note gets your brain thinking.
73, Bob K0NR
Here is another milestone in my D-STAR experience….my first repeater contact using the technology. (I had previously been using D-STAR on simplex.) There are no D-STAR machines within range of my house, but there is one west of Denver (the Colorado D-STAR Association, W0CDS).
I was headed to the Denver airport for a business trip to the west coast and I realized I would be within the W0CDS repeater coverage. I had previously programmed my IC-91AD with the right info to access the W0CDS UHF repeater on 446.9625 MHz. (If you think getting the right CTCSS tone plugged in is difficult, wait until you deal with the callsign routing for D-STAR.) I tossed the HT in the car and gave a call when I got close enough to Denver. Barry KA0BBQ came back to my call and we chatted for a few minutes.
As widely reported, the D-STAR audio is fine but you have to get used to how it cuts out under weak signal conditions. You don’t have the gradual fade of increasing FM noise…it just starts cutting out, similar to a digital mobile phone. I just had the HT rubber duck antenna inside the vehicle, so the signals were a bit on the weak side.
Watch www.dstarusers.org to see D-STAR activity.
73, Bob K0NR
At Dayton, I picked up an ICOM IC-91AD handheld radio, with D-STAR capability. The thing is, there are no D-STAR repeaters within range of my house. Fortunately, Elliott KB0RFC also picked up a D-STAR handheld and we arranged a sked on 2M simplex. The de facto calling frequency for D-STAR is shaping up to be 145.67 MHz, so that is what we used.
I have to admit that the audio quality was better than I expected. When the radio is not dropping bits, the audio is quite clean and clear. When the Signal-to-Noise Ratio degrades, you do start to hear that digital twang as the vocoder does its best to recover the audio in the face of digital errors. Overall, I was favorably impressed.
Tonight, we did some additional testing with DV mode and were surprised at the range of the handheld on 2M. The 70 cm band seemed even better, apparently due to the improved efficiency of the handheld antennas on that band.
There is lots more stuff to play around with, so stay tuned.
Digital voice on the ham bands? Must be the 21st Century!
For more info on D-STAR, see my article from CQ VHF.
73, Bob K0NR
The Colorado Council of Amateur Radio Clubs (CCARC) and Ham Radio Outlet (HRO) teamed up to encourage the adoption of D-STAR technology in Colorado. To date, there are no D-STAR machines on the air in the state so HRO offered to provide equipment to a suitable ham radio group to help get things started. The CCARC, the repeater coordinating body for the state, agreed to assist in the selection process. According to the letter from the CCARC and HRO, the equipment grant was awarded to the Colorado D-STAR Association, a newly-formed group of radio amateurs in Colorado. The donated gear is a “full stack” of ICOM D-STAR repeaters: 2M, 70 cm and 1.2 GHz.
This is a very creative way to get the ball rolling on a new technology for ham radio. Yes, HRO has a vested interest in having a D-STAR machine on the air in the Denver area….they will sell more D-STAR radios. But it is good to see that they coughed up some equipment to help get this going.
The Radio Amateur Information Network (RAIN) Report has an interview with Jay Maynard, K5ZC, from the National Frequency Coordinators Council concerning the use of digital repeaters. Jay discusses the issues around the alledged FCC statement that “D-STAR systems are not repeaters” and gives a good overview of the challenges of adopting digital repeater technology.
The interview exists in two parts:
If you are interested in the future of amateur radio repeaters, this is worth a listen.
73, Bob K0NR
Just in time for the Dayton Hamvention, ICOM has announced the IC-91AD 2M/70cm handheld transceiver with D-STAR capability. I’ve written some about the new digital voice standard, D-STAR. Universal Radio has this new rig priced at $525, a definite premium over equivalent FM radios. This is the first dualband handheld that supports D-STAR.
73, Bob K0NR
I’ve posted a few things about the D-STAR digital radio standard for ham radio. If you want to find out more about it, check out these links:
The QST Product Review section from June 2005:
(ARRL membership required…….what, you are not a member????)
Also, the ICOM web site:
The forums on ICOM’s web site
The Texas Interconnect Team (K5TIT), a group that is active on D-Star