Thursday, December 9, 2010

Make Yourself Heard!

I just noticed the New QuickStats Poll Now Available on the ARRL Web Site.

It's a far cry from a comprehensive survey, but it's a start.

Vote in all or even just one of the QST QuickStat polls below. We'll publish the results in an upcoming issue of QST (look for the QuickStats page in the Table of Contents).

This months questions include CW and ARES!

Results from this QuickStats poll will be published in the March 2011 issue of QST on the QuickStats page, located in the rear advertising section of the magazine. Along with monthly poll results, QST QuickStats offers colorful charts and graphs that highlight interesting Amateur Radio statistics.

Another way to help fine-tune the League is by letting them know your favorite articles in each issue of QST magazine.

This survey has been around a while longer. I discovered it about a year ago.

I'm encouraging all ARRL members to vote more often for the articles you like. We won't change the whole world, but at least we can make a point to speak up.

I also noticed this, which I think is a good idea:
The ARRL is sponsoring its first-ever video contest! We are looking for ARRL members to shoot and submit videos that showcase how fun and electrifying our hobby is!

So, maybe they do listen. I remember grumbling about the ARRL Homebrew Challenge not promoting anything new.

Here is another idea for the league. Perhaps if you feel the same way, you can make youself heard on this too.

Back in January 2008, the Senior Discount (65+) was eliminated for ARRL Membership. Citing risen costs.

Fact is seniors now make up a huge proportion of the membership, so discounting them is a huge drain.

I wonder if the League has considered extending a discount to hams under age 25, or those enrolled in a relevant schooling. Sure couldn't hurt the hobby could it?

I speak from experience, as I was lucky back in 1997 to be a recipient of a Foundation for Amateur Radio scholarship that I applied to my college electronics schooling. And I am still active in the hobby, including helping helping elmers, now in walkers, get to the store. lol!

Wednesday, December 8, 2010

Microwave Projects =/ ARRL

It was very sad to read the passing of John Champa, K8OCL. He was former Chairman of the ARRL HSMM (High Speed Multimedia) Working Group. He was also the High Speed Multi-Media Radio Contributing Editor for CQ VHF Magazine.

Unlike most hams he had a high level of energy and ambition for his work on HSMM and in other areas of the hobby not well explored.

I am beginning to sound like Wayne Green with my ARRL critical comments.

But hey, they led me on, to think there was some sort of Microwave Bandplan changes in the midst. Truth is, I am not sure of the status if this, and can't get any real answers from the league.

Regardless if these jokers want to live in the past or not, here is an interesting thing to consider:

Amateur Allocations - Little known fact

Did you know in the US amateurs have access to approximately:
3.75 MHz of HF (160m-10m) spectrum
67 MHz of VHF/UHF (6m-33cm) spectrum
24.095 GHz of microwave (23cm-300GHz) spectrum

Of the above, over 99% of hams use a tiny fraction (0.3%) of the total ham frequency allocations while the remainder of our available ham allocation is essentially ignored. By the way, ARRL said that as of 4/2010, there were about 688,500 personal ham radio licenses in the USA. If only one percent of these were microwave users, that would be 6885 hams. We often hear that the majority of licensed hams are inactive. How many microwave experimenters do you know?


The realization occurred I was just a Technician over 10 years ago was that wow, there is a lot to explore and learn in the Microwave arena.

Since then I have learned a lot and found it absolutely critical to have that under your belt.

I remember reading the HSMM partnership with the North Texas Microwave Society when John, K8OCL moved to Texas. And have to concur that is a great idea.

Since the ARRL has been so quiet, I have decided I need to do the same. But I will be supplementing my blog space with more technical microwave experimentation articles in hopes of helping spur others on.

Since the mid-90's when I got into the hobby I have been connected to a then- high-school technology club. Ever since the same basic group of now 30's aged guys get together to shoot-the-shit, complain about the ARRL :-) and most importantly see what we can build.

What you will notice from my future blogs is that there have been few HF related projects, and many microwave. As it should be.

It's a shame the ARRL doesn't understand simple math. There is far more to lose in our microwave spectrum than HF. Because there is tons more of it, and hardly any hams use it, and the commercial squatters actually see it as useful spectrum.

Hmm, if only we could do more than throw money to protect spectrum. Perhaps the following microwave projects could be QST material to help foster so actual use? Naa.. that is right we don't want to make anyone smarter. I am a believer that if ham radio is to evolve, then QST needs to. The concept that QST needs to continued to be watered down just doesn't stick with me.

The Proposed NTIA "Fast Track" Spectrum Reallocation shows that our 2.3 and 3 GHz allocations may be endanger. So to start off here is a 4 watt power amplifier for 2 GHz.

Wednesday, December 1, 2010

D-Star for iPhone/Android

This was the subject of a short thread on the dstar_digital yahoo group started by David, KC2WNW.

I chimed in and mentioned that there are several SIP/VOIP apps out there. For desktop computers as well as Ipods and Smart Phones.

As long as the client can support a non numeric SIP addressing scheme, I really think this is a do-able idea.

I've mentioned the idea before as well has John, K7VE who first shared the concept with me.

A validated user account on a D-star to SIP bridging site would have to be established. You'd program that into your SIP phone client app. From there you could connect to a remote D-Star system using the SIP address convention
sip://, etc.

The age old duplex / half-duplex PTT phone patch problem rears it's ugly head here.

The Asterisk radio guys have their own custom application that has a software PTT. Or you can set DTMF digits to control the PTT. Much like how the CAT controller phone remote function works. When you press 1, the this enables transmit (and a soft steady tone is fed back to the phone user while they are in transmit as a reminder), and 2 to go back to listen mode.

While not as elegant as a custom App with a software PTT button, this approach ensures compatibility with any standard SIP phone with this age old phone patch dilemma.

I use MIXphone/MIXVoip on an Ipod touch to connect to my own Asterisk phone and analog radio system. But it doesn't look like it supports non numeric SIP dialing. However, I am sure there is one that does.

Thursday, November 11, 2010

Our Community Leaders

I just received the December QST Magazine. There wasn't anything that really to terribly interesting and usefull for me in this issue again (sigh)... However the "It Seems to Us" editorial did catch my eye.... (here is a snippet)

Our Community Leaders

"Why do people become radio amateurs? If you ask new licensees, frequently you will hear that they are interested in radio technology or that they want to be prepared for emergencies and to provide public service communications. But there's more to it than that."

In general, people join groups with whom they have something in common and whose company they enjoy. Sometimes a desire to learn - to tap into a body of knowledge and expertise - is the motivator. At other times, sharing a common goal is enough to bring people together who might otherwise have no occasion to interact.

Amateur Radio is a global community. We can lay claim to being the first technology-based social network. The common goal that sparked the creation and early growth of the ARRL was the desire to develop a network of relay stations to overcome the limited range of the crude radio equipment of the day, so that amateurs could exchange messages with others well beyond the reach of their own stations.

Read the whole thing in the December QST, Page 9.

It's kind of interesting and fitting as I re-post this on a different social network. Oddly enough, where sharing expertise and knowledge doesn't require you to at the radio at the time of relay... A different demonstration of global communication nearly 100 years later.

It's also important to realize that the primary leadership role of a club is likely changing.

In the 90's maintaining a local repeater (or two) was the key to the local ham radio social network.

As more hams have since gained access to the internet and cellular phones, and now social networking sites online the repeaters are less active and less important.

It's time to step back and reevaluate the clubs role and priorities in 2010 and beyond.

And finally I have to repost this from Wayne Green's 11/01/10 blog:

A Ham Note

A note from Ben Alabastro W1VM chuckled over the September 2010 issue of QST having an article on a solar-powered repeater…and the Ham Radio December 1978 issue having an article on solar-powered repeater design. Glad to see you guys in Newington are still right on the ball.

Far's I can remember, our champions at the ARRL have never pioneered any new ham technology. To this day they're still pushing CW, a hundred-plus-year-old technology....

As pointed out, good leadership is hard to find at a national level. In summary: Local clubs really need to put more emphasis on leadership.

Wednesday, November 10, 2010

Tower Bonding & Repeaters

I recently helped a friend put up a Rhon 25 tower. We got into the discussion of what he might put on the tower. And proper grounding, etc.

This lucky guy got a hold of someone who had an attachment for a Hilti hammer drill to drive the 8 foot ground rods. (Notice the plural, as in two).

Years ago I wasn't able to find anyone with this so I did mine hard way.

Then I brought up the idea of relocating repeaters and such.

From the Hardware Noise section on
Without the proper grounding and bonding you may constantly be looking for noise sources. Pay particular attention to any point where two conductors are in poor contact with each other.

Tower bonding is something I didn't find a whole lot on when I did a google search.

Every 10 feet you have a semi-conductor. Snow and water do get into those joints on your Rhon tower, and over time there is light rust in those joints. This is a recipe for degraded repeater performance.

I showed this on an un-bonded tower that we once had our tech club repeater on.

We'd notice that on windy days, the weaker guys on HT's and such would have excessive creaking and popping on their signals.

So I keyed the repeaters local mic and went out and shook the tower as a demo.

Degraded noise floor.

After installing Copper Clad/ Zinc Grounding Clamps above and below each joint of the tower (as shown) this went away.

It's important to note that we also ran some RTV silicone around those clamps to prevent yet another water / rust joint. And finally spay paint them, as copper clamps rust easily.

There is a whole lot more I could write on keeping a quiet noise floor in duplex environments. But most of it has been covered elsewhere.

Most people don't understand how important this all is. I think this is because their experience is only in simplex operations. When you have something transmitting at the same time it is receiving the whole tower becomes like a charged capacitor.
This situation happens when transmitter power is put into the antenna and the surrounding area is lit up with the RF energy - yours or someone elses. What happens is the RF then creates tiny arcs and sparks in the broken joint and the receiver is desensitized by the wide band RF created by the sparking.

And RF Grounding is different than surge or safety grounding.

In RF, the length of the ground runs has much more to do with the fraction of a wavelength at the frequency involved than the DC resistance of the wire.

Good RF grounding can add several S units to the receive signal and dramatically reduce noise on the signal. Think surface area, and creating as big as RF counterpoise outside at your ground system.

Monday, November 1, 2010

Kenwood TKR-850 as a D-Star Repeater

In my opinion this type of thing needs more attention. After all do-it-yourself has long been a hefty part of this hobby. And there is no better way to learn than a hands-on project like this.

Reason number two would be economics, but I think that is obvious.

The third is spectral savings. D-Star is narrowband, but buying a new system just robs another frequency pair from the pool. It seems people rarely take repeaters off the air, even if nobody really uses them. And these days it seems there are more repeaters in a geographic area, than there is activity.

So it seems best in my mind to convert something already out there. This would make a great club project.

This is great example of continued innovation of D-STAR technologies by incorporating non-Icom products into D-STAR environment.

Date: Thu, 07 Oct 2010 05:32:17 -0000
Subject: K8BIG Port B Using Kenwood TKR-850 Interfaced to ID-RP2C

The K8BIG Port B D-Star Repeater in Cincinnati, Ohio is successfully running using a Kenwood TKR-850 Interfaced to the Icom ID-RP2C in place of the Icom Band module (ID-RP4000V). The usable range of the repeater has been effectively doubled from around 25 miles radius to 50-55 Miles radius.

The K8BIG system is on the WCPO-TV Tower overlooking downtown Cincinnati, OH with the antenna at 700' AGL. There are 3 50,000 Watt FM Radio transmitters, 1 250,000 Watt VHF DTV Transmitter, and 2 3,000 Watt LPTV stations on the same tower along with various commercial VHF/UHF/220 transmitters so the RF environment is pretty harsh - add in the neighboring (2 Blocks) tower with a similar complement of transmitters and it is downright brutal for any radio equipment.

The Icom band module was being swamped by the high RF levels at and surrounding the site, causing very poor effective receive sensitivity even after the TX-RX BpBr Cans and an additional band-pass cavity. I had partially remedied this with one side of a reject-only mobile duplexer, but that introduced around 6 dB of insertion loss. Even with the 6 dB insertion loss the effective sensitivity was improved. The Kenwood repeater has a much tighter front end and much better selectivity with adjustable front-end helicals so the additional receive filter is not necessary and the 6 dB insertion loss was removed.

After the interface was built we were able to plug and play into the Icom ID-RP2C controller and gateway. With the exception of the increased range there is no operational difference in the repeater - everything works identically to the Icom band module. Commands work, data works, D-Rats works, etc.

I will be building more of the interfaces shortly which can be used to interface any 9600 baud-capable analog repeater directly to the ID-RP2C. Anyone interested please let me know.


Dan Woodie

You may want to look at;
Michael, VK5ZEA's Homebrew DV Node Adapter to ID-RP2C interface.

John, K7VE's Kenwood TKR-820 Node adapter retrofitting.

And/or my Motorola GM300 retrofitting and commentary.

As a technical side note, one thing to consider when converting analog repeaters is the receiver IF bandwidth. To date there has been little discussion on narrowing receivers bandwidth to match the narrower D-Star signal. Just be aware that converting a 1950's era repeater to D-Star that might have a 60 Khz I.F. would be vulnerable to adjacent channel interference. A good overview of the theory can be found in a reprinted article from Ham Radio Magazine 1985, by WD5IBS.

Wednesday, October 6, 2010

Interesting Article Bounty

Okay I'm not happy with the magazines I have been receiving. It has been over a year since I have read anything on HSMM. And I have yet to see the word Asterisk in QST, QEX, or any CQ magazines.

And when I read the recent ARRL Homebrew Challenge I said to myself, why encourage something that has already been done?

While I have high hopes for a couple new ARRL staff, and the future if ham radio. I am presenting a challenge.

During an interview, the Beaver Valley ARA revealed that ARRL President, Kay Craigie, N3KN got licensed in 1983 because she was jealous of all the fun her husband was having with ham radio. She was a computer hobbyist at the time and became a ham just when computers were starting to be integrated with amateur radio.

She was also the vice president when the HSMM working-group was formed back in 2001.

So it would seem natural to assume her stance on the future of digital communications is strong.

Brennan Price, N4QX is the new Technical Relations Manager filling the vacancy created by the retirement of Paul Rinaldo, W4RI.

It was Paul, W4RI's recommendation (back in 2001), to the Board that the HSMM Working Group be founded.

I don't know much about Brennan, N4QX, other that his stated goal is to "defend Amateur Radio spectrum." So it would seem that encouraging microwave/HSMM use would be logical.

I fell strongly about the ARRL Technology Task Force. I hope he can fill the shoes as well as Paul did.

My challenge is to get more hams to submit articles to QST, QEX, and CQ magazines.

My homebrew challenge would be to document a bi-directional amplifier in QEX magazine. Since there are more non-overlapping channels on the 5 GHz and 900 MHz band I would encourage it to be for either of those bands, or 3 GHz.

Contact me if you are up to that challenge, as I am offering a small bounty. I also have other gifts for anyone else who steps forward to write anything else interesting. If you write, and don't tell me, I'll likely be getting a hold of you to thank you.

Monday, October 4, 2010

60 Ghz and the Future

In one of my earlier blogs, I pointed out that about 40 years ago 2 meters and 70 cm were basically uncharted areas. Now they are populated. Undoubtedly the future of ham radio is in our huge - virtually unused microwave allocations. They have the necessary bandspace to support wideband modes.

Jim, KC4BQK was first to repost this good video about 60 Ghz and the future of LANs. Blogger Craig Mathias from the Fairpoint Group dose a good job explaining 60 Ghz and the difference between WiGig and WiMedia. This could be something in the future that could include Ham Radio.

Check out his blog

Sunday, October 3, 2010

Linux Speech Recognition

I've been looking for Automated Speech Recognition for Linux for a while. I keep seeing Dragon Naturally Speaking on the selves locally.

I have read some discussions where people have gotten Dragon to work under Wine. But I really need something that works standard in and out style, so I can script things to work with it.

I have all kinds of ideas for two-way radio integration and Asterisk projects. If only something existed.

I have played with CMU Sphinx in the past, but it's not as developed as I'd like.

If anyone has experience in the area of Speech Recognition with Linux, I'd like to hear from you. Ideally I am looking for something that is under $200, and works as well as Dragon. It need not be open source, just Linux compatible.

Specifically if anyone has experience with Voxeo's Prophecy, or LumenVox, I am eager to hear more.

I doubt this online petition for a version of Dragon Naturally Speaking for Linux, will convince Nuance Communications, but I suppose it's worth a try.

Saturday, October 2, 2010

P25 Development

It's been a while since I reported on anything P25 related.

Much has been happening with the op25-dev group.

The code is still on the private sedition repo until they are ready to make an initial release and the current re-engineering of the code has been held up by a need to complete a thesis.

Apparently the plan is to re-home the repository on CGRAN or Google Code before the year end and make a public release at the same time.

If you are not familiar with the work going on, simply put; it's a Huge interoperability stride for narrowband digital radio.

An interesting suspected fork of this work is a package called the Digital Speech Decoder.

This already decodes C4FM off a sound card with a discriminator connection, and it error corrects.

If it was possible to take this a pipe it back out a sound card (without passing it to mbelib) to a transmitter in theory you could build a P25 repeater using a computer and a couple sound cards with the appropriate discriminator and varactor connections.

Jonathan Naylor, G4KLX has done this sort of thing with D-Star. And I found it most impressive.

From there the raw IMBE bit stream and headers could be IP encapsulated, sent
over the internet for the purpose of P25 repeater linking.

I don't know how many P25 groups are out there, but I'd encourage them to get the
word out to anyone with the potential programming talent.

And possibly place a bounty to help encourage this type of development.

Monday, September 27, 2010

Miscellaneous HSMM

For those not aware, a normal 802.11 channel is about 20 MHz wide.

The Atheros Chipset used in some of the professional grade 802.11/Wifi products (like Ubiquiti) can support half (10 MHz) and quarter rate (5 MHz) channel widths.

Obviously the maximum data rate (normally 54 Mbps for a conventional 20 MHz wide channel) drops, but even at quarter rate is still very usable with a maximum data rate of 13.5 Mbps.

The open Atheros driver talks directly to the hardware abstraction layer (HAL), and is also capable of frequencies outside of the Part 15 band.

[For a while no open source HAL's existed that can let you do 5/10 MHz mode. You had to use MikroTik, StarOS, IkarusOS, DD-WRT and a few others for these modes. As of June 2010, it appears that 5/10 Mhz support seems to be implemented in ath5k now.]

You can see the feasible channel selection overlay here:
The channels in light blue fall into overlapping amateur band space. And are acceptable for HSMM operation.

As you can see you can squeeze seven 5 MHz wide channels below the first Part 15 channel on 2.4 GHz, two of which are completely outside of the Part 15 overlap. (Thus, should have quieter noise floors)

On the 5 GHz band, there are thirteen channels that are completely outside of the Part 15 overlap.

And even more interesting is that that within the Atheros chip it is possible for licensed developers to enable a local oscillator generation for a direct conversion radio transceiver. This is Not an open function, but irregardless, this is how 802.11 products on 900 MHz (Ubiquiti XR9), and 3 GHz (XR3) (as well as other places) are possible and on the market.

Open source drivers unlocked the possibility of additional frequency support. It allows programmers to be able to write a driver. In summary; Atheros has allowed a third party to create a layer between the low-level functions of its chips and high-level drivers via the madwifi/ath5k development.

So what about unlocking additional channels in other chipsets/hardware?

Broadcom is the the chipset of most common Linksys WRT54G routers.

Broadcom has for a long time declined to provide non-licensed access to it's chips. A project that has been working to reverse engineer access using legal means had released its first working drivers for Broadcom 4300 series chips a few years ago.

If you are into the nitty-gritty, a recently released (2010) Broadcom wireless driver seems to have structures which imply the PHY in the chips can be directly controlled to program HSMM channels.

Also see:

For a slightly less technical overview of the various aspects of Modifying Consumer Off the Shelf Wireless LAN devices for specialized Amateur use, have a look here:

I was recently asked my opinion about the use of Amateur Radio Networks like HamMesh, HamWan and BCWarn.

The question is pretty generic.  It all seems to stem from the ARRL HSMM working group from a number of years ago.  Despite that group falling apart, independently amateurs all over the place have embraced the technology.  It's great in my opinion.  As interest in voice  repeaters continues to wane, multi-media networks do make perfect sense.  These more modern types of networks have the potential to draw new blood into the hobby.  New hams who have software skills that can help the community with software defined radio and so forth.

Outside ham radio, as consumers were now live in a world where to keep thing interesting and new we have a flexible application space.  Be that apps on our phones, software on our PCs, and even firmware updates to our more hardware like devices.

That that has been notable absent in ham radio.  I.e. What it is when you buy it, is what it will be 5 years from now unless you want to totally replace it for the tune of several hundred dollars.

Ham radio used to be a good starting place for many who later entered broadcast and electronics careers.  Today those positions are few and far between due to disposable electronics and consolidation of engineers with mega broadcast groups.  What is the most notable/abundant "tech" career today is IT (information technology) work.

In my humble and simple opinion: These types of networks are long over due, and I am glad they are continuing to grow.  It helps ham radio stay relevant.

Steve, KB9MWR

Thursday, September 9, 2010

HSMM network in California

Jason Spence, KF6RGF writes that there is movement in the San Francisco, California area to build a HSMM network. He needs volunteers with access to towers to help build it out. More information can be found here:


The amateur radio service has a good chunk of the Internet address space (, and it's not being used for its intended purpose: a worldwide packet radio network. Meanwhile, the rest of the Internet is crowding into the remaining address space and will no longer have any left in the near future.

The address space isn't being used because of a chicken-and-egg problem: the necessary digital repeaters aren't available for users, and there are no users to justify building the repeater network.

The cost of the equipment has finally come down to the point where even a modestly funded amateur radio club can afford to set up a small regional network by themselves. Through advocacy and standards development, Noisebridge is building a packet radio network modelled on the original vision of the Hinternet.

Members of Jason's group will be touring the SFBA ham clubs and giving presentations at their monthly meetings to gather the necessary volunteers.

Tuesday, September 7, 2010

Miscellaneous D-Star Developments

I've been backing off on the D-Star blogging. But here are a couple interesting developments that you'll likely never read about on any of WB9QZB's yahoo groups.

The first comes from DARPA (The Digital Amateur Radio Projects Association)

World Wide Routing for DSTAR

Hello to the group,

The gateway is now turned on and now we can play around with routing. But here is the catch.

The routing is a new world wide routing system call ircDDB (built by the Germans). It will route to both D-Star system that joins the world wide routing scheme.

The two D-Star systems that can handle routing are the US ROOT, which is made up of only ICOM and one Home brew system; and the Multi-Trust Servers that the Europeans built with the help of a few here in the US. There system is made up mostly of Home Brew and some ICOM systems. Of course the DARPA gateway (KJ4NYH) is built under home brew network (Multi-Trust Server). So with the new routing scheme we can now route to US root or anywhere else that has the same system.

More US gateways are joining this new routing method because it’s faster than the US ROOT routing.

You can view the dash board at Look for Gateway KJ4NYH on the dash board with a green light that means it ready for routing.

So what can or where can we route to? Well you can route repeaters/area gateways and also call signs that are placed in the UR Field, i.e. W4AES is the gateway for Orlando, FLA so my UR field will look like this—> /W4AES C.

Give it a try and see what will work. Just check out the dash board and look for US calls.


Will – W4WWM

Digital Amateur Radio Project Association – DARPA
Expanding the digital experience.

And here is a good video overview from Michael, VK5ZEA demonstrating it.

The second, is a note from Ramesh, VA3UV on his Free Star* Project.

I started working on a project called 'FREE STAR*" about a year or so ago. FREE STAR* was an attempt to build a vendor neutral digital communication network and allow bridging between various VoIP protocols that are in use amongst radio amateurs today (app_rpt, IRLP, D-STAR, etc.).

I'll keep this brief - further info can be found on my website:

We have built a few systems on top of our Allstar / ACID boxes, they seem to work well.


Ramesh, VA3UV

Allstar Node 2200 > Bridged to XRF005A.

Friday, September 3, 2010

For nearly a dozen years, Al Waller, K3TKJ ran

He started it to provide webspace to help further the abilities and interest of the Amateur Radio Community.

There is a tremendous wealth of information hosted on the pages of

About a year ago, Al retired from offering these services, and turned over these systems to Scott Neader, KA9FOX.

I encourage you to take a look at what is all hosted on and consider sending an email to K3TKJ, thanking him for all his years of work. And consider a sending a donation to KA9FOX to help ensure that the tremendous amount of resources is available to the amateur community for many more years to come.

Wednesday, September 1, 2010

DIY Emergency Cell Tower

Chris Paget, KJ6GCG has over a decade of experience as an information security consultant and technical trainer for a wide range of financial, online, and software companies. Chris' work is increasingly hardware-focused, recently covering technologies such as GSM and RFID at venues such as Defcon and Shmoocon.

At the recent Defcon 18 conference he displayed a spoofed GSM cellphone tower using a Universal Software Radio Peripheral (USRP) transmitting 25 milliwatts, to present a GSM air interface to a standard GSM handset and uses the Asterisk software PBX to connect calls. The combination of the ubiquitous GSM air interface with VoIP backhaul could form the basis of a new type of cellular network that could be deployed and operated at substantially lower cost than existing technologies in the developing world.

FCC rules aside, this is some powerful stuff. Imagine being able to restore cellular coverage in a disaster area using the foundation he has laid.

You can read more here:

Here is a video that shows a test call being placed from a softphone talking to an Asterisk PBX in conjunction with GNU radio and a USRP to create a Part 15 signal level call to a cellphone.

Regarding using HSMM style techniques for running an amateur cell site:

Here is a similar project which modifies android phone to use asterisk running on something called a mesh potato. This would be great for developing areas. Just drop some of the MP's with a battery and a solar cell and poof... a phone system.

Another favorite is using asterisk with amateur radio and repeaters

Tuesday, August 10, 2010

ARRL says help protect the $pectrum!

The radio spectrum is a finite and increasingly valuable resource. Mobile broadband providers are willing to pay almost any price for access that they can sell back to the public. Yet, who can put a price on a community, devastated and cut off by natural disaster, being able to communicate reliably when normal channels have failed? What is the dollar value of a young person being inspired, by his or her hands-on experience as a radio amateur, to pursue a career in science or engineering? On a more personal level, what is the enrichment that Amateur Radio has brought to our own lives worth to each of us? 

Think of how much we owe to those who came before us, who made certain that Amateur Radio would survive and flourish after they were gone. We can never repay them – except by doing the same for future generations.Every day, ARRL volunteers and staff work tirelessly to protect our spectrum access.....

In 2010 ARRL launched a newsletter, Spectrum Defense Matters, to keep members information on issues related to the protection of Amateur Radio frequencies.

But again it's really only a sales pitch to round up some extra donations. More importantly (to me anyhow) is how can we get more stuff on the air. How do we get hams out of the wood work, and get them to try new things?

Back in 2005 the HSMM working group prepared two recommendations for Board consideration:

-A new all-digital license scheme to attract Internet-savvy technical individuals to ham radio, and
-A frequency bandwidth plan that will allow for adequate digital development of Amateur Radio into the 21st Century.

Improving and Expanding Amateur Radio in the 21st Century

50 years ago, amateur radio service gave its licensees access to wireless voice communication services that were otherwise unobtainable and trained people for careers in industry. It should be doing the same for today's wireless communication but isn't. This is a proposal for a 21st century novice license oriented towards HSMM. It would change amateur radio somewhat, but would ensure its existence by attracting younger users and make it more relevant to today's technology. First, let me explain why new novice licenses are needed.

The current Amateur radio licensing system assumes that everyone wants HF access and they proceed along an upgrade path to get it. License classes are hierarchical. However, there are several groups of users within the ARRL that have different interests. Some are interested in having the best HF station and contesting or chasing DX. Others are interested in weak signal communication using portable stations on the microwave bands. One large group is interested in personal communication and emergency communications with VHF and UHF repeaters. Another group is interested in digital communication using computers. The "one size fits all" arrangement does not serve any group well and creates unnecessary contention among groups.

If license classes were organized by area of interest and new hams just picked the licenses that fit their needs, each license could better fit the interests of each ham. Rather than acting as an unnecessary impediment that is shrinking the ranks of the hobby, licenses could encourage new growth. Licensing that fits user needs could be more restrictive for HF spectrum where the number of users that can be supported is small and become less restrictive as the frequencies go up and large numbers of users can be accommodated.

Many amateur HF users prefer the traditional form of FCC regulation with highly structured bands and a Morse code requirement for their portion of the spectrum. The existing license structure largely fits their needs. However, hams interested in buying HTs and using voice repeaters face a lot of examination requirements that are unnecessary for their purpose. They should have a simpler license where they learn how to set up a limited station and agree to certain operating procedures and frequency ranges. This would encourage new membership and build the pool of emergency communicators.

Hams who want to set up repeaters or do high-power weak-signal communication on the VHF and UHF bands require more knowledge as they will be setting up larger, more complex stations. The current license examination system with an exam that stresses design requirements and RF safety fits these needs. However, a new license class for HT users would benefit the radio clubs setting up and maintaining repeaters by providing more members.

Those interested in computers and digital communication are under-represented in amateur radio ranks. They are technophiles as we are, but the current system does not serve them well. This is disturbing, as digital communication is the future. In particular, amateur radio should encourage the participation of those interested in software as all electronic communication now depends upon it. There should be a license class where they agree to certain frequency ranges and non-interference provisions. This type of license would expand the use of new technology, make the learning experience of amateur radio more relevant to ham's personal lives, increase the use of our microwave bands and allow the development of and experimentation with new high-speed multi-media applications. It also assists us in supporting public safety, health and welfare agencies during times of emergency as the majority of the information that must be communicated becomes digital.

This new license wouldn't be called a "novice" license (as that might discourage its use) but a "digital communication" license and would......

After consolidating to three license classes, I think a digital license class like what was presented is a great idea. I'm all for something radical in this hobby.

Ten years ago a survey conducted by the ARRL Technology Task Force, of League members and other amateurs revealed that the number one interest in new technologies was in high-speed digital networks.

Today, you hear nothing from the Technology Task Force. But still plenty about how the ARRL needs money, and how hard they are working to protect spectrum. (Note: TTF is in hiatus due to W4RI's retirement)

The economy is in the toilet, instead of money can we see some other ideas on how to protect the spectrum by encouraging new uses?

Just a thought...

Thursday, August 5, 2010


Most hams are probably not well experienced at operation at 900 MHz and above. Microwave propagation is a different animal for these folks.

Reading and understanding it and the expected path loss is one thing, and then real world experience is a whole another thing. You can then compound your confusion on expected performance by realizing that wide band spreading modes are yet another layer to the mix.

I built a simple analog 900 MHz repeater so that I could get a better idea of how signal propagation on the band. I was rather impressed. On the same token I was also impressed using the slower Aerocomm FHSS units on 900 MHz. But trying to draw comparisons between narrow to wide is a bad plan.

The XR-9 is a logical step for the average ham, with a modest tower. The versatility in data rates and ability to change the channel width from the default of 20 MHz spreading to a half-rate of 10 MHz and even a quarter rate of 5 MHz is ideal.

Overall in all the experimentation of wide band spread spectrum at 900 MHz and 2.4 GHz, from the Proxim Symphony, origional 900 MHz WaveLan, Ubiquiti Bullet to the XR-9, I feel the average ham will be mildly disappointed. (Also see David Rowe, VK5DGR's blog on Wifi is hard.)

All this stuff works great if you can get a central node/AP up high on a commercial tower. Not so great if you live in an established neighborhood with medium to mature size trees.

I have experienced the difference between 1 watt and adding a 10 watt BDA's on both bands. For the average ham, living in the city with a modest tower, this does improve things significantly, and provides something usable.

In light of the recent spread spectrum rule change, I would highly appreciate if TAPR would consider getting behind a BDA project.

I would appreciate if the ARRL would clarify how spread spectrum fits into the existing band plans on 902 and above.

To help things along here is a recent article I stumbled into detailing construction and theory on a switchless bidirectional amplifier for 2.4 GHz using circulators.

The theory can be applied to BDA development for less crowded bands like 3 GHz, 5 GHz or even 900 MHz.

Most commercial bidirectional amplifiers use radio frequency (RF) switches which switch between two signal paths. Their switching time can cause data loss at a high transfer rate. For instance, with a data rate of 54 Mbit/s the time duration for 1 bit is 17.66 ns. Switching times of commercial available bidirectional amplifiers can be as high as 2 ms, causing a loss of more than 100 bits. There, bidirectional amplifiers realized as monolithic microwave integrated circuits (MMIC) bias a transistor circuit in such a way that it amplifies either in the one or the other direction......

In the following, a switchless bidirectional amplifier is discussed. It is compared against a bidirectional amplifier concept using RF switches as commonly used in commercial wireless communication systems....

Back in June 2007, L-com acquired HyperLink Technologies of Boca Raton, Florida.

Below are some internal pictures of their 900 MHz 802.11 amplifier. Both their HA910I-APC and newer HA905I-DM are essentially the same.

The same variable attenuator input, M68772 RF power amplifier, and MD003 PIN diode switch. The newer model has much better heat dissipation, and runs at 12 volts in stead of 13.5 volts. So even the newer advertised 5 watt model is capable of more.

I don't like the idea of using Amplifiers on 2.4 GHz as the channels overlap and there is the potential to disrupt to many other users.  However there is a cheap amplifier 5-8 watt for that band, the EDUP EP-AB003 2.4GHz Amplifier for about $50-60.

Steve, KB9MWR

Tuesday, August 3, 2010

HSMM Mesh Network in Texas

In Collin County Texas a groups of hams have been making good use of HSMM technologies to update their Amateur Radio Communications Health-care Emergency Services (ARCHES). This was traditionally setup of two meter/ 70cm voice and packet radios at 9 Austin, Texas area hospitals.

The setup provides key patient data to the City of Austin Emergency Operations Center, during significant incidents, even if normal communications are unavailable. It's highly successful. During every activation, patient data and other traffic passed more quickly and accurately than all other techniques tested during the activations.

The ARCHES program has been so successful, we have been asked to expand the system to ~ 40 additional area hospitals and clinics in central Texas.

Due to the existing significant number of packet collisions using traditional packet radio with just 9 nodes, they are migrating to HSMM.

With 40 or more packet stations in the area, passing packet data could slow to a crawl due to packet collisions.

The stations could only transfer data at 1200 baud, at best. Attempts at using 9600 baud showed that common radios do not pass 9600 baud data well. They distort the data so badly, that many resends are needed to get data through.The effective data rate seldom exceeds 1200 baud.

The HSMM proof of concept was demonstrated least year by AD5OO, NG5V, and KD5MFW who achieved a 10 mile point to point link across downtown Austin, Texas using only 35mw.

The Austin HSMM SIG has incorporated Optimum Link State Routing (OLSR) into custom firmware to provide automatic linking of radios that will be placed on Water Towers throughout Collin County Texas.

For more info see:

Sunday, August 1, 2010

HSMM VOIP Network in Spain

There is an interesting HSMM/ Asterisk VOIP network in Spain:

Alex EA5HJX, Andres EA5HIQ, Pepe EA5SW, Paco EB5HTC, Javier EB5BXA, Boletin EA5SW, Paco EB5EA, Sergio EA5HFB, Ernesto EB5JDY and several other hams are researching new technologies and telecommunication systems.

Can you explain are in street language, What is Intended and this project will bring to ham radio and its benefits?

So we can all understand, a HSMM network is just one of many highway lanes that can move large amounts of data at high speed. What would be technologically wireless broadband network of high capacity in her ability to integrate all technologies: RF, VoIP, multimedia, data ....

What are the Objectives of the Project HSMMN?

To promote knowledge and new technologies to the general public: The HSMM project has not only a technical aspect but also a social aspect, with aims to bring new technologies and their application in the real world to the public with expertise or not. Disseminating knowledge and new technologies to the general public: The project has HSMMN Not Only But Also to Technical aspect of social aspect, with aims to bring new technologies and their application in the real world to the public with expertise or without them.

We intend that anyone interested can collaborate, learn and practice the knowledge acquired. Anyone interested can collaborate, learn and practice the acquired knowledge. To this end, talks and workshops are planned in various radio clubs and associations interested in the project. To this end, talks and workshops are planned in various radio clubs and Associations interested in the project.
Creation of a research group developing new technologies to the world of amateur radio: This project not only aims to develop the network, which is the chief end of it, but to bring together people interested in researching and learning about new technologies to help amateur radio operators and emergency services communications.

Unifcar technologies: using computer systems and hardware elements to create an IP data highway you can travel by all types of information: audio, video, telemetry, APRS, etc ...

Collecting, processing and sending information through a variety of different technologies such as for sending APRS weather information (winds, rainfall, air pressure, barometric pressure, etc)

Ability to provide automated voice announcements from a centralized control room radio repeaters as required. Capacity to Provide automatic voice announcements from a centralized control room radio repeaters as required.

Creating an information service of communications systems available by region, by using a geographic number to gain access from the fixed, mobile and IP (VoIP).

Integration of other communication networks: IRLP, DSTAR, WIRES-II, E-QSO, etc.

Interconnection of repeaters using wireless technologies: Wireless, WiMAX. Each repeater could put a computer capable of processing all the telephony and transform it into Voip (voice over IP) that is transported through the network to reach another repeater HSMMN and is decoded by joining together all repeaters creating a mesh. Each repeater Could put a computer capable of processing all the telephony and transform it into VoIP (Voice over IP). That Is Transported through the HSMM network Reaches Another repeater network and is decoded by joining together all repeaters creating a mesh.

The whole process will be use Free Software.

Entities in the world of emergencies communications in Spain have shown interest in this project as an additional operational tool to consider for future medium to long term. Access from the PSTN will be in collaboration with This is an area open, free and neutral telecommunications network built through a peer to peer agreement where everyone can join the network

It looks like a nice mix of HSMM, Asterisk SIP and app_rpt technologies.

Alex Casanova EA5HJX, writes that he is working to develop a box that is a router (IP), and Asterisk (VoIP) and gateway with radio (analog and digital radio). Maybe this box can help in disaster like Haiti. Around the HSMMN´s Project we are investigate to integrate Asterisk VoIP with analog or digital radios.

Monday, July 5, 2010

Keeping relevant & moving forward - case in point

The following is a partial excerpt from a presentation by Glenn Currie, KD5MFW at Ham-Com 2010 held June 11-12 in Texas. (You can read the full presentation and others at:

Those deploying communications technology in developing countries are deploying systems in areas where there is little or no infrastructure... much the same as after a natural disaster.

They are using wireless mesh systems for much of their infrastructure. When you have no infrastructure due to disaster, natural or otherwise, Wireless mesh networks are being deployed.

An organization called Inveneo works to bring communications infrastructure to under developed countries.

They use Wi-Fi (802.11) wireless broadband equipment for much of their work. They set up Wi-Fi communications links and add their own resources including small web servers and end user net top computers so people can send email and check websites for emergency information.

Inveneo deploys to Haiti after the recent earthquake. The got in fast with gear and two man teams.

Inveneo installed a Wide Area Network using Wi-Fi type equipment. Inveneo quickly deployed an emergency network that served many agencies

Amateur radio passed some traffic in the aftermath of the recent Haiti earthquake. I have read the reports on the Internet and in the printed amateur radio magazines. Hats off to all the hams that pitched in and helped strangers in a bad situation.

But what systems past what percentage of the emergency traffic during the emergency? What really worked and carried the bulk of the emergency traffic?

It is known that the network deployed by Inveneo passed Thousands of Messages for multiple agencies, and their networks continue to pass traffic.

Amateur radio needs to have a broadband offering in their tool box.

All emergency communications organizations are making wide use of broadband RF communications techniques – except amateur radio.

I am confident, that if amateur radio manages to remain relevant, in the area of Emergency communications, future amateur radio license exams will include questions On how to configure wireless routers. This technology is that pervasive in the world. Hams can step up to the plate get into broadband, or they can leave it to groups like Inveneo and to provide emergency communications, in the ham bands.

I recently tried to point out that WinLink is showing its age and is far from ideal.

I was trying to suggest that we focus our efforts on the future, and made reference to a geostationary satellite as one avenue.

I received a bothersome/bullheaded comment from Stan Piekarczyk, Outagamie Co ARES EC "Should we wait another 10 years for this to get launched?"

To answer the question, NO!

The first step is admitting that something isn't cutting it, or is less than desirable. Step two is making it happen by stop being an amateur radio user, and becoming an innovator.

Ham radio technologies can Only advance if We make the happen. Glenn, KD5MFW points out some wake up calls for hams in his presentation. It's time to think ahead.

KC4BQK also blogged on this:

Thursday, July 1, 2010

Two new books

There is a brand new Microwave book from the Radio Society of Great Britain.

It is all up-to-date stuff, not a re-hashing of old QST articles like many of the ARRL microwave books. It covers interesting test equipment, and the latest software. Most importantly, the projects are modern too, using easy-to-find transistors.

The second recommended book is from the American Radio Relay League on PIC microcontrollers.

This book was written to be understood in a chronological fashion. The book seems to fill in stuff all the other PIC books seem to miss.

Thursday, June 3, 2010

Digitally Linking Analog Repeaters

Those from Wisconsin might be familiar with the Wisconsin Interstate Network. It's a wide area coverage UHF linked repeater system, composed of nearly 20 systems throughout the state. It is all RF linked, so from an emergency commutations standpoint it's very handy resource.

Now imagine if you can if it was all linked digitally, but still using RF, not the internet.

It would not be very expensive to convert the analog audio to digital at each site and run inexpensive outdoor ethernet cable up the tower instead of a hardline line for linking. Since each analog repeater site is at significant heights, achieving line-of-site linking on 3 GHz or 900 MHz should be possible.

If you did this, you would have a high-speed statewide digital RF backbone independent from the internet, that not only connects all the analog sites, but has plenty of bandwidth left over.

ARES / user LAN access could be on 440 or 900 MHz. I'm talking about sending 20 MB of pictures from your ARES incident across the state in seconds. Or hooking an IP phone up and having a fairly secure conversation if the situation warrants it.

All this is possible, all fairly inexpensively. You just have to think different.

Wecomm is a smaller linked repeater network project going on in the state, that I have blogged about before.

They are building data networks into their site deployments.

What I am showing above is a very inexpensive way to stream audio digitally. Wecomm (so far) has been using expensive JPS Ratheon ARA-1 radio interface devices to accomplish this.

USB server adapters are fairly new. They allow you to use USB devices as network devices... cheaply.

When you are dealing with many sites, far away, the idea of having a computer at each site is less than ideal. Fairly inexpensively you could build a computer with no moving parts using flash drives to increase reliability..... But can you do this for under $50?

If a plug and play solution is what you seek, check out the CAT CL-100 Internet/802.11/HSMM Linking Controller.

Tuesday, June 1, 2010

Ham Radio in KA9Q's eyes

It took me a while to find this snippet of comments from Phil Karn, KA9Q in WT Docket No. 97-12 from about 10 years ago:

....amateur frequencies are still occasionally involved in emergency communications despite being almost completely eclipsed in recent years by cellular phones, portable satellite links and the like. But the amateur service has always been primarily an experimental, technically-oriented service. It is not a critical operational safety-of-life service like public safety or aviation, nor is it a common carrier utility like cellular telephones....

For those of you who aren't familiar with the Phil Karn, KA9Q:

He is an engineer that worked for Bell Labs in the 70-80's. He was on the ARRL future systems committee/Technology Task Force for nearly a decade. He had had his fingers involved with many Amateur Satellite Service projects.

Has helped develop the Internet as he as been a strong contributor to its architecture. (His name is on at least 6 RFCs, as a member of the Internet Engineering Task Force)

He is well know for his work with digital communications specifically with DSP and forward error correction (FEC) and spread spectrum.

Since 1991 Phil was been with Qualcomm, a wireless telecommunications research and development company, as well as the largest cellular chipset supplier in the world.

Simply put: Your cellphone works on CDMA technology that Phil Karn helped develop. Phil is the best example I can think of where ham radio served as an "experimental, technically-oriented service" that served(s) as a breeding ground for technological development that later the rest of the world greatly benefited from.

Thursday, May 13, 2010

An Univeral Radio Interface

All of the various digital modes out there require some sort of interface to your soundcard. Most of these interfaces use the serial port (RS-232) for keying, or some of the newer "Rig-blaster" interfaces can do provide that over a USB connection in the absence of traditional com ports on the newer computers.

There is still one thing lacking. Their own dedicated sound card. There is nothing more embarrassing than forgetting to disable your computers system sounds. And on the same token having to mess with the mixer settings each time is also annoying.

Thanks to the hard work of Steven Henke, W9SH and Jim Dixon, WB6NIL, they have ground work for a Univeral Radio Interface.

You can build your own using inexpensive USB sound FOB's/sticks. Or you can buy a pre-manufactured interface from DMK Engineering.

The basis of it all is the C-Media electronics CM-108, CM-108AH, or CM-119 USB interface chips.

PTT and optional Carrier Detect are accomplished using unused general purpose I/O lines of the USB sound devices chipset. Just plug this into a USB port of your computer, no other connections to the PC are necessary!

If you build your own, the sound fob will require some modifications to bring out PTT, block DC on the audio outputs, and attenuate the receive audio to match the microphone levels.

Unfortunately the number of programs that support this type of interface are presently limited. The good news is any one coding a program like ham radio deluxe or the like can easily adopt support for this interface. The channel driver is open and authored by Jim Dixon, WB6NIL and Steve Henke, W9SH.

If you an author of such a program you can find the definition in file chan_usbradio.c. I encourage you to add support for this inexpensive to build interface.

Sunday, May 9, 2010

WinLink Failure

At the April 8th meeting of the Green Bay Mike & Key Club, Dennis, KC9OIS had an ARES report on a demonstration of a mobile Winlink station and it's emergency email capability.

The station was setup by Outagamie County ARES at the Paper Valley Hotel in conjunction with the WI ARES/RACES at the WI Governor’s Conference in March on Emergency Management....

While the demonstration was successful, John, NA9J and my (Dennis, KC9OIS's) messages never reached their destination successfully.

Paul, N5XMV writes:
I don't see the purpose of continuing to find new ways to use Ham Radio, whether for experimental, emergency, or commercial use, if the average Ham is not able to understand the full concept, build it, and implement it... What happens when it fails, reach over, and get a new piece out of a stockpile of new stuff??

Paul, N5XMV, makes a good point. Emergency communications weakest link is in the operator behind the equipment.

At the same time, exercises and demonstrations like this let you experience the mistakes and correct them before the time comes that you actually need to rely on it. My question is what is being done to prevent a repeat performance?

I don't know much about how the Winlink network works. But it seems to me that if "emergency" messages can be lost, this is Not a well thought out design.

Are outdated networking protocols are the basis of Winlink? It sound like a kludge of much how the old KA-nodes worked, and the hierarchical BBS message forwarding using a system of mail rewrites and mail exchangers.


RFC's for SMTP mail delivery ensure that the sender should get a return message in the event that a message is undeliverable to to a broken path route or server being down. If Winlink cannot at the very least support this, perhaps it's time to re-think the network topology.

Think "real-time network" .... it can be done. In the 90's we here in Wisconsin could test the deliverability of a message with the ping command.

traceroute is another good network debugging tool.

Here is an old reference on Emergency Operations and Packet Radio

Here is some interesting history on Winlink.

July, 2003: In cooperation with its partnership with Homeland Security & at their recommendation, the ARRL Board sought to provide a Nationwide digital system to enhance the communications capability of the Amateur Radio Emergency Service (ARES) There are situations, the Board said, when ARES "must have the capability to pass digital traffic across the Nation quickly and accurately.

ARRL Resources Volunteer Committee determined that the new network should: provide rapid transfer of emergency traffic between sections; use available and future digital modes, interface with commercial communications systems such as conventional telephone, cellular telephone, and the Internet, etc., have speed, performance and accuracy.

The digital network will provide a value-added service for ARES and will continue to be viewed very positively by our served agencies," the committee said in its report. "This allows ARES to be viewed as modern and necessary instead of antiquated and invasive."

A quote from the former FCC Director of Engineering and Technology:

In the past, hams have adopted more spectrally efficient technologies - for example, by migrating from double-sideband amplitude modulation to single-sideband modulation and, more recently, by shifting to more efficient modulation for digital modes. I would urge you to continue shifting towards more spectrally efficient communications techniques - especially digital techniques. Such a shift has a number of benefits:

First of all, it demonstrates to policymakers and regulators that you are good stewards of the public's airwaves even without direct economic incentives.

Second, by using what you have efficiently, it strengthens your case when you need to ask for additional spectrum.

Third, by allowing more users to access the available allocations simultaneously, it improves the amateur experience and ultimately increases the attractiveness of the service to new and old users alike.

Fourth, it provides the opportunity or "headroom" for increases in data rates to more closely match those available on wire line networks and, in the future, on commercial wireless networks as well.

Fifth, as the rest of the telecommunications world makes the transition to digital techniques - and there are very few exceptions to that trend - the amateur service will look antiquated if it is not making progress in that direction as well. So looking to the future of the amateur radio service in the new century, I would urge you to continue your traditional role in public service by being prepared for and providing communications in times of emergencies, conducting experiments, providing training in radio communications, and encouraging international comity. But I would also urge you to focus particular attention -- for the reasons I just mentioned -- on experimentation with digital techniques."

So far the basis of Winlink on a county/state level seems to rely on 30 year old packet radio technology.

For example it will take over and hour to send a 540 KB .xls file of names... or in just a half an hour you might be able to send a 270 KB attachment at 1200 baud.

So even if the demonstration messages would have made it, Winlink still appears as a failure to me in that regard.

Friday, May 7, 2010

NWR SAME software decoder?

Server weather season is upon us.

I have often thought it would be nice if there was an open source (soundcard/ FOB based) SAME decoder solution.

One could dedicate a cheap USB sound FOB to a receiver parked on their NOAA weather radio frequency that would sit and decode any SAME data bursts.

I am thinking for interfacing to repeaters to provide custom weather alert signaling.

It does appear that software to decode SAME data exists, just not open source.

A SAME software decoder would benefit projects like thelinkbox, and asterisk app_rpt as well as other projects.

{Update 6/11}
Greg Hewgill, has updated the source to his NWR tools, now at:

"Drew" Kirkman, W4KMC writes:
NOAA’s Specific Area Message Encoding (or SAME) protocol is used to further streamline the Emergency Alert System. Information about an emergency message (such as locations affected, type of message, where it’s coming from, and how long it will be considered effective) is transmitted in the form of digital bursts at the beginning and end of said message. These bursts are AFSK-modulated data with a throughput of 520.83 bits per second. Mark tone (binary 1) is 2083.3 Hz and space tone (binary 0) is 1562.5 Hz, with each tone lasting about 1920 microseconds. Bytes are transmitted in reverse order (LSB -> MSB), that is, 00010111 would be transmitted as 11101000. There are other technical specifications regarding its use in the real world, but it’s irrelevant here. Essentially, if you handed the right text to it, I have a SAME encoder. It outputs true SAME-encoded data."

See his NOAA SAME web based audio encoder/decoder at:

I also stumbled into:

"Using an Arduino Uno and a few other external components, I've been able to reliably decode the SAME messages."

{Update 2012}
Someone updated multimon, and it now has EAS / SAME decoding support!

And this PHP-based SAME AFSK encoder:

Tuesday, May 4, 2010

Why experiment? Why not roll over and die?

Quoting N2XTS (from a recent QRZ thread on new technologies) on why ham radio's days are numbered:

It isn't the hospitals, the Part 90 encroachment, the ARRL,

It's the closed minded, living in the past old farts who refuse to accept that we are supposed to be on the forefront of communications technology. The same people who forget about our service existing to provide a trained technically minded pool of radio operators ready to be called upon to serve their communities in times of need also neglect the part about advancing the art of radio communication as spelled out in our basis and purpose in Part 97 it appears.

So we should just stick to using 50 year old analog FM, HF and not experiment with anything that might actually have any intrinsic technical value? What is the big deal here? Let me guess you all are opposed to IMBE, AMBE, OFDM, VOIP, and anything else that might actually require YOU to become technically competent and proficient with MODERN RADIO COMMUNICATIONS TECHNOLOGY and not your brass keys, vacuum tubes, and Gonsets?

If all we do is jaw jack on 50 year old technology occupying 40 billion dollars worth of spectrum exchanging post cards... what is the point to us even existing anymore?

Some good food for thought, that goes along with how I feel. Bill, just managed to put the words to it first.

Tuesday, April 6, 2010

DIY Compatible D-Star Repeater - Green Bay

I have an experimental 440 MHz analog repeater that has been converted to D-Star. The GM300 radios have been interfaced using a Mark Phillips, G7LTT GMSK node adapter clone. The node adapter is in a duplex configuration, so in reality it has nearly all the functionality of an Icom D-Star repeater.

A D-STAR repeater is an expensive proposition. And many people are not happy with the Icom D-Star repeater performance. It's a number of things, most notable the poor receiver sensitivity. ~.45uV... In many cases the "repeater" is nothing more than two 28XX series radios in a rack mount box ... Pictures in the d-star digital yahoo group confirm this. Receiver desense is also on the list due to the use of plain-jane RG-58 inside the units. In addition, the receiver is prone to overloading by out of band high power FM broadcast signals.

Apparently the Icom G2 software is also not impressive, as discussed on the D-Star Gateway mailing list back in November 2009.

To build this adapter the cost about $100 (+ your analog radios) as compared to the cost of a Icom RPC-2 Controller plus a RF band module at about $2900.

For the longest time I was running Mark, KB9HKM's DVAR Hotspot Windows based software to compliment the board. For remote repeater site use I haven't been real keen on the idea as Windows computers seem to need reboots at inconvenient times.

So I have had a watchful eye on two Linux developments.

The first is by David, G4ULF, but he is still in the midst of releasing the program.

The other (probably less prominent) is by Scott, KI4LKF. His "rptr" program is available now.

All-in-all, I'm happy to report, version 2.93 has been running stable for me. Under Linux at least I have been able to script some ideas by trapping the debug messages with Perl.

For now, the frequency is 441.4625 +5 (SNP) The 40 watt GM300 radios are running cleanly at 20 watts.. The repeater is located in the village of Allouez near Heritage Hill State Park. The antenna is a Comet GP-6 Omni (9 dB), at about 35 feet. It is fed with LMR-400 coaxial cable. It appears to have about a 15 mile coverage radius.

Maxtrac/GM300 radios have a jumper inside (JU551) that sets whether the external connector will have flat or discriminator audio. You want discriminator. You may also need to add some 10 uF DC blocking caps on the RXA and TXA lines.

For more Information on the GMSK/ DSTAR Node Adapter/ Hotspot, please visit the websites below:

Specifics on node adapter setup

If you are seeing what else you can do on a Linux platform with D-Star, I'd love to hear more about it.

{Edit Oct, 2010}
You may also want to take a look at John, K7VE's recent blog where he converts a Kenwood repeater for D-Star.

{Edit Nov, 2010}
And a Cincinnati OH, club using a Kenwood TKR-850

Monday, April 5, 2010

Wisconsin Amateur Packet Radio (WAPR)

I was starting to miss the Wisconsin Packeteer columns that Andy Nemec, KB9ALN wrote for several years.

So I revived the old website.

It's interesting to look back and see how excited hams were about this new mode, and how quickly it grew.

Then there is the downside. There was plenty of drum beating to look to the future, especially in the last 10 years.

Well known Buck Rogers, K4ABT even wrote an article 10 years ago promoting spread spectrum for higher speed networks. (link)

Andy's conclusion was right on:

We have steadily lost the digital speed race to the wired network. This means there is little to retain experienced operators, not much to entice newcomers.

All of this points to the need for drastic action to be taken by the ham community, specifically the Amateur Packet Radio community. As I mentioned before, the ability to carry digital audio could gain the interest of the general ham radio public in addition to we who spend a lot of time with packet radio.

So where are we now?

Just last month the spread spectrum rules were proposed to be relaxed once again.

But will that change anything?

Probably not.

The funny part is with all the increased band threats you'd think interference resilient spread spectrum modes would be heavily promoted.

Just think all those amateur operations affected by Pave Paws, might not have been if using spread spectrum.

I'd like to see spread spectrum come to the 70 centimeter ham band. I think there is plenty of room there (unused ATV chunks), and point to point uses similar to D-Star's high-speed Digital-Data (DD) mode could prove useful.

The problem is how does spread spectrum fit into the existing ham band plans? Will your coordinator even acknowledge a request? If these are not made clear, you will likely never see a commercial solution made specifically for hams.

Sunday, March 7, 2010

Reasons to like / dislike D-Star

Here is a thought from a local club member that contacted me about D-Star:

The thought occurs to me that D-Star is one future standard and why not purchase a D-Star radio ahead of the roll-out? One issue is that it adds expense and why buy something today that you can’t use when the standard may evolve to something better in the future. Therefore, a waste of money now?

He actually has a good thought process. The thing I see is that since D-Star is based on the JARL standard, some parts of it cannot change. By that I mean, GMSK modulation and data rates for example. Evolve, yes it already is, and that is why I like it.

What he means is be replaced (not evolved) by something else radically different, perhaps TDMA based or what have you.

My feeling is that this is not a big consideration/fear simply because ham radio is in such a decline. You will likely never see another replacement simply because it's not on ham manufactures priority list as they market is simply not there.

Resons I like D-Star:
I've been in the hobby for nearly 15 years. I'm starting to become a been there, done that kind of guy. This is something different... a step in the right direction, to the future.

From a repeater stand-point the slow speed data & voice are not only spectrally efficient, but efficient on the club pocket book. Else you have to deploy separate APRS and voice repeater feedlines and antennas.

The framework is open so some development and evolution is possible. This paves the way for additional functionality that can be added later.

And it can be done remotely (SSH) since this is a digital system. No more spending $$ on new controllers and scheduling trips to the site to interface them.

D-Star helps attract a new breed to the hobby. The computer savvy. Which is good, since we should be one the path to software defined radio (SDR).

Some of my dislikes:

-Closed codec.
-User radios are not firmware upgradable
-DTMF encoding implemented wrong ?
-The term "D-Star" trademarked by Icom
-One vendor

The attached images shows some starter ideas of how to add additional functionality.

One of the problems since ham radio is so stagnant is that no one really monitors. It becomes so infrequent that people are on at the same time. Those once 24/7 radio active hams are now amusing themselves with Ipods and smart phones.

So one of the script ideas report the callsigns of who is in the air to twitter. This way people know when to put down the Ipod and pick up the HT. Other scripts report current temperatures as text messages periodically.