Wednesday, December 9, 2009

German HSMM Hamnet 2.0

Hamnet 2.0 is a radio based network designed by German radio amateurs, which connects the already available infrastructure of the amateur radio service to each other and will provide a new powerful base for a amateur internet wireless network.

The official launch of the project and the presentation was made on the amateur radio exhibition and conference on October 31, 2009 in Hanover, accompanied by relevant lectures.

Hamnet 2.0 works on the basis of the TCP/IP protocol, so that commercially available wireless routers can be used with no or minor modifications as the hardware. In addition, a separate hardware and firmware for this application was developed. They are using the Ubiquiti WLAN module NanoStation 5 on the 6-centimeter-band (5.7 GHz).

Their situation is probably much like that over here. Sharply declining use of existing obsolete, slow, failure-prone equipment. Due to some displacement by the Internet.

The idea and hope is to support cross services (voice, images, data, video etc.) by using TCP/IP as the base. Use of affordable a technology, and setup something independent from public networks. While arousing interest in experimenting with the new technology, and developing new applications.

They started by establishing a 10 km link between DB0SHA, in Hanover, and DB0UHI in Laatzen in less than 10 minutes. This was done just by holding the units in the air, which yielded a stable 16Mbit/s connection.

They expanded faster than they initially thought. Interconnecting D-Star Relays and linking of EchoLink gateways.

Trying some more DX paths showed immediate success of Hanover to Peine (32 km) using the bare module.

They have since used this technology to replace their 23cm 19.2 k links. And have connected over 9 points, and have others planned.

Sunday, December 6, 2009

73 Magazine Index

The SolderSmoke blog noticed my 73 Magazine index project a few weeks before I completed it.

It was a rather large undertaking, but worth it in my opinion. There is a wealth of timeless information in those magazines. And for many just by taking a look at the index will bring back a wave of nostalgia.

"What a great magazine 73 was! Sure, it was a bit wacky, but it had really wonderful technical content, at just the right level for truly amateur ham radio operators. Take your own walk down memory lane:"

It is part of my effort to point out and promote what amateur radio is really about. I tend to agree with Jorge, KI4SGU's blog comment that "Ham radio needs a spokesman like Mr. Green Again." I hope the ARRL takes note.

While I have been blogging for a while, I have had recent wave of receiving email comments and feedback. I started this blog shortly before the ARRL Introduced the "Fifth Pillar" at Dayton Hamvention 2008.

ARRL President Joel Harrison, W5ZN, announced that the League will expand its identity program to include greater emphasis on technology. Harrison explained that "Ham radio operators, and particularly ARRL members, closely identify with current and emerging radio technology. Today, we are naming 'technology' as ARRL's new fifth pillar."

While I hoped this meant a greater emphasis on the ARRL Technology Task Force or Future Systems Committee, the only thing I really observed was the We Do That Radio website that was launched.

I swapped some emails with Allen Pitts, W1AGP who manages the site after it's launch as it did catch my eye.

Science, Experimentation and Technology .... We Do That!........ with Amateur Radio.

Welcome to Ham Radio in the 21st Century, Your scientific national resource!

The Amateur Radio Service frequency bands are the place on the usable radio spectrum where you as an individual can develop and experiment with wireless communications. Hams not only can make and modify their own equipment, but can create whole new ways to do things.

Learn about cutting edge Ham Radio technology and techniques.

The problem I saw and still see with that site is that it is geared for new hams. I conveyed this to Allen and shortly their after decided to start my own blog. There are plenty of fairly inactive hams bored with the same-old, same-old. I didn't feel the We Do That Radio site is geared for them, so this is my attempt to point out "something different."

Amateur Radio and Linux

One of my favorite magazines Linux Journal, also has a few articles in their January 2010 magazine.

Back in April 2007 on the Texas A&M University Amateur Radio 802.11 Mailing List I made some comments that hams of the past were perhaps one of the earliest adopters of the open source way of doing things. This was spawned from some discussion with another local ham, who happens to be one of my elmers.

Leaders in the ham radio arena who are to busy beating their own chests touting things like they are the "national association for amateur radio."

These so called leaders need to suggest/ lay some general concepts to steer the hobby to the future, or perhaps they have a lack of approach. If I read one more thing about contesting or a home-made keyer, or restoring a boat anchor I'll probably puke. Instead put that in a specialty magazine, and focus on spreading the importance of the open source concepts in the ham radio arena in your monthly distributed membership magazine. Focus on promoting the "right ideas" in that precious well distributed rag. I don't see much of this steering, just a bunch of nostalgic crap. Ham radio needs to promote exciting things and new technology to entice people to the hobby or drag people out of the wood work. Retired people will find their way into the hobby on their own, to re-live the past.. In my opinion, we don't need to have oodles of crap for these people, they will come on their own and that's fine.

Ham radio needs to promote exciting things and new technology to entice people to the hobby or drag people out of the wood work. IRLP is a good recent example. It can take that "magic of HF", and make it portable, as in HT portable. This day in age, a big old HF rig, isn't cool, nor usually an option for most renters or apartment dwellers.

Packet in the 80's & early 90's was enticing, because it was at competing speeds to the internet that was in it's public infancy at that time. The autopatch in the 90's was enticing as cellphone were not yet main steam. Both of these examples happen to fall about the time of the no-code license became available. But many seem to attribute the in-rush of hams in the 90's due to the no-code license scheme revision. That went hand in hand with the these exciting technological things, it was not solely due to the new entry class. If there is nothing "cool," I'd bet you'd have a hard time giving a license away... and that does not insure they will use it! People actually bucked down and learned code, even if they hated it... ask yourself why. It's probably because there was an aspect of the hobby they perceived
as cool/interesting at the end of the rainbow.

New and interesting things in ham radio generally means encouraging experimentation. As experimentation is what brings new modes, and discoveries to the hobby. Not everyone will partake in that experimentation, but if there is a new discovery from those who do, everyone can later "play" with it, when it catches on. Open source, open information, encourages this experimentation

Hams or the past were perhaps one of the earliest adopters of the open source way of doing things.

We acknowledged this was done out of necessity - radio stuff was expensive and out of the reach of a lot of hams. So they invented newer and mostly cheaper ways of doing things. They also came up with better ways of doing things because somebody else would see that idea in print and improve upon it. Of course the technology was rather rudimentary, and there was little way to go but up at that point in radio technology calendar.

We also felt this is not so much the case anymore.

The current demographic of hams is skewed toward old. These people seem to be in either one of two camps. First is the retired person who has "made his fortune" (or at least is reasonably well off financially) and is not worried about inventing ways to do something on the cheap. They just buy an appliance and go from there.

The second group is middle aged and sees ham radio as not only a hobby, but a way to make some bucks. These are the guys that have an economic interest in closed source. They file part numbers off of chips, they cover circuitry in epoxy, and delude themselves into thinking that they will make a nice future retirement income from that "magic" CW keyer that they designed.

They don't do ham radio for the altruistic reasons (although some may have started out that way), it is money for them.

It seems to us that any change in the hobby needs to be political/philosophical. That means a change in leadership of the ARRL as they are the most prominent force in the hobby. This has got to be a grass-roots movement and it needs to start ASAP. The hobby will be gone and replaced by a "Citizen Communication Corps" if nothing is done.

In this Linux Journal issue one of the articles is titled along with some of the same thoughts. "When All Else Fails—Amateur Radio, the Original Open-Source Project"

What most people tend not to think about is the open-source nature of Amateur Radio. While operators most often are seen working in emergency situations, many of the modern conveniences we have today—cell phones, satellites, wireless devices— were developed and tested by radio amateurs.

On page 46 "An Amateur Radio Survival Guide for Linux Users - A getting-started guide for Linux users looking to venture into the world of Amateur Radio" by Dan Smith. This is an overview of common amateur radio activities with information on how to participate using a Linux system and free software.

On Page 50 you will find information on Xastir. An Open Source Client for the Automatic Packet Reporting System (APRS). Subtitled "Plotting Mars Rover locations on a detailed map, easily done with Linux? You Bet! By Curt Mills, Steve Stroh and Lara Mills.

Starting on page 56 of this issue, an article titled "Rolling Your Own With Digital Amateur Radio" by Gary Robinson. He points out that Amateur Radio and open source are a heavenly match.

Amateur Radio operators are generally free-thinking individualists who don’t mind getting their hands dirty to get something done right. Many of us do not think twice about buying a brand-new radio for hundreds or even thousands of dollars and popping the lid on it to see if we can modify it to make it better. You do not have to look hard to find myriad articles on how to modify different pieces of Amateur Radio equipment. So, it is not surprising that we might feel the same way about the software we use.

Open-source software and Amateur Radio are a natural fit. Few operators ever would buy a piece of radio gear if it came with a license that said they could not modify it, and it’s natural to see why a lot of us navigate toward open source in general and Linux in particular.

I encourage you to pick up this copy at the newsstand if you are not a subscriber

Tuesday, December 1, 2009

Tinkering & Innovation

About this time a year ago I wrote about the same thing. I pointed out that you cannot sit back and expect the big ham manufactures to come out with new technologies. As that is what we are supposed to be doing.

John Hays, K7VE was recently interviewed by Computer World magazine. The article has a good theme on Reviving innovation in the hobby.

Reviving innovation

Decades ago, amateur radio operators were on the forefront of scores of technological innovations, including television, digital communications, solid-state design and cellular networks. The hobby's roots trace back to radio pioneers such as Guglielmo Marconi and FM-inventor Edwin Armstrong.

But in recent years, as many potential new hams were attracted to computers, the Internet and other technologies that they could explore without passing a licensing exam, some veteran hams worried that ham radio was at risk of gradually sliding into stagnation and was perhaps even on the road toward technological irrelevance. Over time, many old-timers worried, experimenters would gradually be replaced by hams more focused on the hobby's operational aspects, such as restoring antique radios and providing communications services for community parades and other charity events.

Other hams, however, believed that the hobby was actually entering a new era of innovation, one driven by the same type of people lured away from ham radio by advancing digital technologies. They reasoned that a streamlined licensing system, capped by the FCC's elimination of Morse code testing two years ago, would, over time, revitalize the hobby. This would happen by attracting technically skilled innovators who were interested in more than merely tapping a telegraph key.

Whatever the reason, a budding corps of innovators is now working to restore at least some of ham radio's past glory, focusing on projects ranging from satellite construction to power-line communications to testing long-range Wi-Fi links. "Ham radio provides the broadest and most powerful wireless communications capability available to any private citizen anywhere in the world," says Allen Pitts, a spokesman for the American Radio Relay League (ARRL), a national association of ham radio operators based in Newington, Conn.

And along the same lines the Wall Street Journal just had an article on how Tinkering is making a comeback amid the economic crisis.

Occupying a space somewhere between shop class and the computer lab, the new tinkerers are making everything from devices that Twitter how much beer is left in a keg to robots that assist doctors. The experimentation is even creating companies. With innovation a prime factor in driving economic growth, and corporate research and development spending tepid, the marriage of brains and brawn offers one hopeful glimmer.

Engineering schools across the country report students are showing an enthusiasm for hands-on work that hasn't been seen in years. Workshops for people to share tools and ideas -- called "hackerspaces" -- are popping up all over the country; there are 124 hackerspaces in the U.S., according to a member-run group that keeps track, up from a handful at the start of last year. SparkFun Electronics Inc., which sells electronic parts to tinkerers, expects sales of about $10 million this year, up from $6 million in 2008. "Make" magazine, with articles on building items such as solar hot tubs and autopilots for robots, has grown from 22,000 subscribers in 2005 to more than 100,000 now. Its annual "Maker Faire" in San Mateo, Calif., attracted 75,000 people this year.

Amateur radio operators find themselves hooked on do-it-yourself technology

Minikiewicz said through the years, his interest in the hobby has been centered on the keen sense of accomplishment one gets out of building a radio from the tubes up that allows the builder to travel -- through radio -- to distant places.

"That's that whole other element," he said. "You're accomplishing something on your own. You're not just plugging it up."

Sunday, November 15, 2009

Tonight's Family Guy

Tonight's Family Guy titled "Quagmire’s Baby" featured some ham radio references.

Peter goes to Quagmire’s garage sale and buys a Ham radio. He uses that radio to talk to a ghost of Ronald Reagan. Peter eventually ends up going back to return the radio.

More references can be found here:

Monday, October 19, 2009

ARRL Approves Study Committee to Research & Develop Plan for Narrowband


Minutes of the 2009 Second Meeting
ARRL Board of Directors

Teleconference July 17-18, 2009

29. On motion of Mr. Sarratt, seconded by Mr. Frenaye, the following resolution was ADOPTED:

WHEREAS, there is current substantial amateur radio movement, activity, and innovation in the digital narrowband area; and

WHEREAS, the FCC has mandated that by 2013 commercial radio move to narrowband channels and Amateur Radio manufacturers normally follow commercial practices; and

WHEREAS, the VHF/UHF Amateur Radio band plan currently uses 15 and 20 kHz FM channels; and

WHEREAS, with the increasing use of narrowband across the country amateurs are placing and using narrowband equipment outside the repeater subband because there is no real place to fit the narrowband pairs; and

WHEREAS, for ARRL to remain a respected leader in technology, we must be actively involved in innovative solutions to problems by bringing about a productive discussion on a technical paradigm shift; now

THEREFORE, the President shall appoint a study committee for the purpose of research and to consider developing a plan to move the US amateur community to narrowband channel spacing.

I would be in favor of this IF it meant there was some thought behind it. It would be nice to clear a few ~50 KHz wide channels on 2 meters for higher speed data applications. This of course should go hand in hand with some other modernized regulations.

Promoting narrow band just so we can accommodate more repeaters (more of the same) is a poor reason. Perhaps if there was less effort to squeeze in more repeaters, this would promote exploration of other bands.

Tuesday, October 6, 2009

FCC ferrets around for spare spectrum


FCC ferrets around for spare spectrum -Got any ideas?
By Bill Ray

The FCC is asking for suggestions in the hunt for more radio spectrum, having established that there's not going to be enough to support the next generation of broadband requirements.

The US regulator wants ideas for making better use of all the spectrum below 3.7GHz, and it wants them by 13 November 13. It's asking (pdf) for suggestions on what spectrum should be used for what and how to get hold of it.

The consultation is part of the National Broadband Plan, which has been inviting the industry to say how much radio spectrum it needs. Surprising as it may seem, the industry thinks it needs lots and lots more radio spectrum if it's going to serve customers with the sort of quantities of data it thinks they would like, as the FCC explains:

"According to Wireless Communications Association International (WCAI), a traditional handheld device, with average customer usage patterns, will consume about 30 megabytes of data in a month, a single smart phone consumes 30 times that amount, and a single connected notebook or laptop computer is consuming 450 times that amount."

So you smartphone users out there are already burning through 900MB of data a month, while laptop users are consuming more than 13GB every 30 days or so. That seems like an awful lot to use, though that includes voice traffic.

Still, the FCC is taking those numbers seriously, and it wants to know how much bandwidth you think the wireless industry is going to need. It also wants to know where that spectrum should sit, both for fixed and mobile wireless services, and suggestions to encourage existing users to hand it over for reallocation to wireless broadband.

The FCC has the same problems as the rest of the western world: Huge swathes of the radio spectrum were allocated to governmental and military operations that have no incentive to make use of it or even to keep track of which bits they are actually using.

UK regulator Ofcom's solution is to charge everyone for spectrum usage. Though calculated rates if it can't get the spectrum onto the auction block. But that's not always a good idea (billing lifeboats for radio frequencies is not good PR), so the FCC is hoping the general public can come up with something better.

The regulator is open to suggestions from 23 October until 13 November, and we look forward to hearing what the American on the street has to say on the matter.

All of 900MHz, 1.2GHz, 2.4GHz ,3.4GHzand 5.8 GHz don't even total 800 MHz of spectrum! Can you list the times the ARRL has encouraged life above 902 MHz in QST in the last 5 years?

.. oh yeah priorities... 4 MHz of HF spectrum, my bad!

Monday, September 7, 2009

Decoding D-Star / AMBE DTMF?

Having remote control over an amateur station is traditionally done with DTMF.

So far, all D-Star control functions have had to be done via the URcall field. This is totally annoying and cumbersome to me.

When it come to digital mode like D-Star the AMBE vocoder translates the DTMF to a digital signature of sorts.

Most codecs add special payload forwarding information for DTMF digits. This is because most low-rate voice codecs cannot be guaranteed to reproduce these tone signals accurately enough for automatic recognition. Codec compression and then decompression of audio will make decoding DTMF at the remote end highly unreliable.

Defining separate payload formats also permits higher redundancy while maintaining a low bit rate. (See RFC 2833)

AMBE is no exception. The AMBE chip has digital codes to signal the encoding of DTMF and to decode the same. The coding scheme can be found at starting on page 32 (Section 5.2.8)

These special digital codes can only be used if you have access to the full 48-byteframe, which is not in the case of DV data, that only forwards the 9 DV data bytes.

Due to this, it is some peoples understanding that Icom chose not to use that feature of the AMBE chip. (See: the Testing With DTMF Tones section of the Utah VHF Society page.) However, DTMF data is in fact included "in-band" along with the compressed audio data stream. (those 9 bytes of wonderful but totally opaque data..)

However, if you are trying to decode DTMF that isn't directly generated by a keypad on a D-Star radio, good luck.

The microphone audio input path to the the vocoder on a D-Star radio have not been setup correctly to decode this type of in-band processing. You may still need access to an AMBE Chip (or DV Dongle) to deal with that..

That aside, there is no reason we can't create software hooks in programs like Mark, KB9HKM's Hotspot to be able to remotely control it.

There is a ton of software applications hams could be developing if they had the ability to decode AMBE DTMF. The Icom D-Star ID-RP2C controller also lacks the AMBE chip, which makes it a no-thrills controller.

For example; the current temperature could be sent to the display of ones radio if requested via DTMF. Or time...

So is there really no way to interact with DTMF? I'm not convinced yet. It is way to clumsy to have to handle all control functions using the URCALL fields. (especially when mobile)

If you listen to the raw DV stream it sounds noticeably different when you are pressing digits.

While I haven't played with this enough, it does seem there is a digital pattern to DTMF when you analyze at the raw DV stream.

For instance;
DTMF 0 always seems to start with c3-48-3c-82-02-44-21-0b-28
DTMF 1 always seems to start with d3-08-24-f3-83-18-30-41-10
DTMF 2 always seems to start with d3-08-24-f3-83-58-30-41-10
DTMF 3 always seems to start with d3-08-24-fe-93-18-30-41-10
DTMF 4 always seems to start with 83-09-20-82-c5-14-40-c6-2c
DTMF 5 always seems to start with 83-09-20-82-c5-54-40-c6-2c
DTMF 6 always seems to start with 93-49-24-92-55-10-50-c6-28
DTMF 7 always seems to start with
DTMF 8 always seems to start with 93-c8-38-f3-04-4c-51-8e-14
DTMF 9 always seems to start with 93-c8-38-f3-14-0c-51-8e-14
DTMF * always seems to start with c3-48-3c-82-02-04-21-0b-28
DTMF # always seems to start with c3-48-3c-82-12-04-21-0b-28

There are some variations that occur, which make determining an accurate DTMF mapping difficult. Tools to record AMBE (natively) exist, so perhaps a histogram comparison routine can solve the dilemma.

If a DTMF mapping can't be accurately determined you can always add a DV dongle at the repeater site.

But ideally I'd like to see the AMBE vocoder become part of future revisions of the D-Star controller hardware. Having that in there enables hams to develop applications like I have described above.

DVSI the codec manufacture was able to be persuaded to sell the AMBE vocoder chip in small quantities to help hams. Perhaps they could be further persuaded to release or sell an affordable closed binary to enable such DTMF decoding?

First lets see what we can do as hams.

I re-introduced this subject on the dstar_digital mailing list in December 2009.

I want to try and get a better understanding of the limitations of the "DTMF Decoding" feature of the AMBE codec that is not fully-implemented in D-Star.

I've read the "Testing with DTMF tones" section on the Utah VHF Society page.

"you cannot reliably pass DTMF signaling through a D-Star link system unless that audio is generated from a D-Star radio itself! This means that if you are using a D-Star system as a gateway or as a relay of an analog channel, you should not expect DTMF control to be possible through that link."

From the limited testing I have done from an Icom Radio to an Icom radio by pressing Digits on the keypad I haven't really noticed the distortion behavior.

What I am reading is the problem is going from Analog DTMF to Digital medium within the radio? Like feeding analog DTMF from some other source into a D-Star Radio's Microphone input. (why you'd want do this, is beyond me)

Since my experimentation would involve a D-Star radio's keypad and a node adapter with DV dongle to recover the audio (and DTMF if needs be), does anyone know if DTMF is implemented correctly with the DV Dongle? Or any other perceived issues?

{Update May 2013}
The Digital Speech Decoder Software (version 1.7) was updated to support decoding of D-Star's AMBE.  The Digital Speech Decoder and xMBE codec library - can decode and recover the audio from P25 (Phase 1) IMBE, as well as Mototrbo (AMBE+2) and DMR, and NXDN.   It started off only being able to decode the D-Star Data, but not the voice portion.  This was because D-Star uses an early version of the AMBE codec that is not entirely to the proper spec of the final codec.

A TIA document (TIA-102.BABA-1) (PN-3-3633-AD1) titled "APCO Project 25 Half-Rate Vocoder Addendum" is for AMBE+2 which is similar but not identical to AMBE+ as used in D-Star.   But folks have since figured it out.

Now it is probably just a matter of time before someone codes a virtual DV Dongle to encode the D-Star voice frames.

{Edit Jan 2011}
For more information on the DTMF in-band channel with all 4 bits of DTMF information, see the ircDDB-mheard code from Michael, DL1BFF. (line 383 - his code handles the bit interleaving and FEC processing)

Kristoff, ON1ARF took Michael's code and packaged it as a proof of concept, to allow people to experiment with DTMF-controlling your D-STAR repeater.


Scott, KI4LKF implemented DTMF decoding in his multi-protocol add-on g2_link program. You can easily customize DTMF commands by editing the shell script.

Sunday, August 30, 2009

APCO 25 decoder /analyzer

Matt Robert, VK2TVK writes in the APCO25 ham radio list:

Hi List,

I would like to let you guys know about an open source P25 decoder/analyzer project that has been running for a little while now. OP25 started as the thesis for a Computer Security PHD student that is researching the security aspects of the APCO25 standard. The software is being expanded into a decoding suite that can gives various bits of information about a received signal and there is also provision for a software based repeater.

OP25 is based on the open source GNUradio package, and it is compatible with either the USRP software radio peripheral, or a conventional NFM radio connected to a sound card via a discriminator tap. One contributor is also working on adding transmit code with the intention of giving a software based P25 repeater that can be run off conventional PC hardware. Currently all the major contributors are HAM operators.

At the moment OP25 is considered pre-alpha (i.e. developmental) and we are looking for people that are interested in becoming developers/contributors to the project. The project is designed to run under GNU/Linux and it requires a bit of skill to get it going. It's definitely a HAM radio project at this stage and that's why I figured it would be appropriate for this list.

Shown here are are some sample screenshots for the curious.

Please feel free to have a look at the project homepage at and there is also a discussion list at

Kind Regards,

[Update Dec 2009]
Here is an interesting amateur video, that demonstrates the OP25 code in action with GNU radio using the USRP.

[Update April 2012]
Here is an updated video, showing OP25 code with GNU radio using a cheap USB TV tuner as a replacement to the USRP.

Saturday, August 22, 2009

Re-Crystaling WRT's

Some hams in Germany have been recrystaling Linksys WRTs to go outside of the Part 15 band: Arsene, LX1TB has modified the Linksys WRT54G(S) models to tune the frequencies below 2400 MHz for better fit with the hamradio bandplan.. Look on these German websites to get the details:

Translated version of :

And translated version of:

At the recent Ham-Com convention in Texas, Kipton, Moravec, AE5IB and Glenn Currie, KD5MFW made this chart with the data about the crystal change.

The whole screen is the amateur radio spectrum allocation in that frequency area.

The top section is the standard off the shelf WiFi. You can see that Channels 1-6 fit into the spectrum.

The second section is replacing the 20 MHz crystal on the transmitter with a 19.6608 MHz crystal (the next lowest that is readily available and costs under $1) With it we can use channels 7-11 in our band. Other countries allow the unit to have Part 15 channels 12-14.

The third section is the ARRL Band plan. he notes, because we are spread spectrum, we look like background noise to the narrow band signals.

Kipton tends to think maybe with a software change we can add those channels also and with the crystal change still be in the Amateur Radio Spectrum.

With the crystal changes, the units can not be detected by unmodified standard 802.11 devices, and impossible for them to connect.

The tests showed that by making a simple 59-cent crystal change the HSMM signals could be moved to between IEEE Channels 2-3.

Also show at the Ham-Com HSMM presentation is a spectrum analysis from Wi-SPY by MetaGeek.

The yellow shaded area shows the official 802.11 Channel 2 center. The red shaded section shows the official 803.11 Channel 11.

The CPU clock and ethemet clocks are totally different from the radio crystal, so both units "think" they are on Channel 11. Only the crystal-modified "slide band" unit is somewhere between Channels 2 and 3 as shown by the green and blue accumulated readings. Both units were tested for about 3 hours for frequency stability, etc.

You can read more about this in the latest (Summer 2009) CQ-VHF Magazine HSMM column by John, K8OCL Titled "New Amateur Digital Video (ADV) and Revolutionary HSMM-MESH at Ham-Com."

Monday, August 17, 2009

Spread Spectrum and Ham Radio

All though the 80's and 90's the big thing one kept reading about was spread spectrum and how it would revolutionize ham radio.

So lets take a trip down memory lane:

TAPR's Statement on Spread Spectrum Technology Development

TAPR was founded in 1982 as a membership supported non-profit amateur radio research and development organization with specific interests in the areas of packet and digital communications. In the tradition of TAPR, the Board of Directors at their Fall 1995 meeting voted that the organization would begin to actively pursue the research and development of amateur radio spread spectrum digital communications. At the Spring 1996 board of directors meeting, the following statement of purpose was passed:

"TAPR believes that the technical facts support our conviction that conventional and spread spectrum systems can coexist without detriment to conventional systems on all frequencies from MF to EHF. To this end, TAPR will begin to research spread spectrum systems that will develop technology for future deployment."

As stated above, the TAPR board feels strongly about TAPR's focus on spread spectrum technology and especially how it relates to the potential coexistence on frequencies that will have increased number of users occupying them. The amateur radio bands, like other spectrum will become more heavily utilized in the future. It is in the interest of amateur radio to develop systems that are interference-resistant while not interfering with other primary or secondary users on those frequencies.

TAPR understands the concerns many have with the new technology, and believes that efforts in both education and research is necessary in order to allay the fears about interference and to demonstrate the benefits of the technology.

TAPR believes that todays' communications technology is moving toward all digital transmitters and receivers. These advances in technology, combined with the swift evolution of cell based transmission and switching protocols, are opening up a new set of possibilities for unique new services utilizing intelligent networks. These will contain smart transmitters, receivers, and switches. Today's Internet is perhaps the best example of a self-regulating structure that embodies these new technological approaches to communications in the networking domain. However, to date, many of these innovations have not moved into the wireless networking arena. TAPR will work on moving these innovations into the amateur radio community.

TAPR feels that the VHF/UHF/SHF radio networks of the future will involve a mixture of links and switches of different ownership, which terminate at the end-user via relatively short-distance links. What will then be required is a built-in, distributed, self-governing set of protocols to cause the network's behavior to make more efficient use of a limited, common shared resource, the radio spectrum. Creating such a self-regulating structure for the optimal sharing of spectrum will require much effort.

One of the major problems which stands in the way of these new approaches today is the current FCC regulatory environment and the manner in which spectrum is managed and allocated under its rules.

Historically, the current regulatory approach to radio has been based upon the technology that was in use at the time that the Communications Act of 1934 was framed, basically what we would call today, 'dumb' transmitters speaking to 'dumb' receivers. The technology of that time required reserved bandwidths to be set aside for each licensed service so that spectrum would be available when needed. Given this regulatory approach, many new applications cannot be accommodated since there is no available unallocated spectrum to 'park' new services. However, given the new set of tools available to the entrepreneur with the advent of digital technology, what once were 'dumb' transmitters and receivers can now be smart devices which are capable of exercising greater judgment in the effective use and sharing of spectrum. The more flexible the tools that we incorporate in these devices, the greater the number of uses that can be accommodated in a fixed, shared spectrum.

Therefore, TAPR will focus its spread spectrum effort in the following areas:

* TAPR will work to promote rules and technologies to make the most efficient use of the spectrum through power control, forward error correction, and other means to minimize interference among spread spectrum users and existing communications systems.
* TAPR will work on issues and efforts with other national organizations to change the regulatory environment and rules in order to promote the experimentation, development, and later deployment of spread spectrum technology.
* TAPR will work to develop information on the topic to help educate members and the amateur community as a whole about spread spectrum technology, and to disseminate this information via printed publications, the World Wide Web, presentations at conferences and meetings, and other means.
* TAPR will work to foster experimentation, development, and design of spread spectrum systems, and to facilitate the exchange of information between the researchers and other interested parties.
* TAPR will work to develop a national intra-network to foster the deployment of future high-speed spread spectrum systems into regional and local communities, including the development of suitable protocols and guidelines for deployment of these systems.
* TAPR will work with commercial companies who manufacture spread spectrum devices which operate in spectrum shared by the amateur radio service (ARS), in order to make them more aware of the nature of ARS operations on those bands with the goal to work towards the deployment of devices which will minimize interference between all spectrum sharing partners.
* TAPR will work with commercial companies who manufacture spread spectrum devices in order to identify equipments that can be either used or modified for use for Part 97 operation.

Adopted by the TAPR Board on September 20th, 1996 at SeaTac, Washington Board Meeting.

Spread Spectrum Statement Committee:
Greg Jones, WD5IVD
Dewayne Hendricks, WA8DZP
Barry McLarnon, VE3JF
Steve Bible, N7HPR

In 1994 Merticom, established them selves as owner of Ricochet Networks was one of the pioneering wireless Internet service providers in the United States. They provided 128 kbps broadband services to the general public using unlicensed 1 watt 900 MHz FHSS radios mounted to light poles in several major cities by 2001, just before the filed for chapter 11 bankruptcy. At the time, many hams in these large cities complained that the Ricochet Networks made the 900 MHz band virtually unusable due to the high noise floors caused by the wide deployment.

The TAPR FHSS Radio project was displayed at the 1997 ARRL and TAPR Digital Communications Conference, October 10-12, 1997 and officially started that year.

The development of this 1 watt, 128 Kbps 900 MHz FHSS radio, suggested this is the future for amateur packet radio.

October 1999 TAPR signed an agreement with the Dandin Group to take the TAPR design from its current state into production which TAPR has access to production for sale back into the amateur radio community. This is an agreement we have been working on for several months. The bringing together of TAPR's and Dandin's capabilities will help the speed of the project tremendously.

Dewayne Hendricks (WA8DZP) , was the CEO of Dandin Group. Dewayne stated that Dandin was trying to do something like what Metricom was doing, but we were trying to do it in a different way than they were doing it, a different business model.

"The first release of the TDR-900 is designed to operate at 900 MHz with future radio modules to cover other parts of the spectrum."

From October 1999:
TAPR has signed an agreement with the Dandin Group to take the TAPR design from its current state into production which TAPR has access to production for sale back into the amateur radio community.

From Dec 2001:
The TDR-900 is being developed for both commercial and amateur radio deployment. Dandin will be handling the commercial interests in the radio, with TAPR handling the amateur radio service.

The system has been designed so that the digital and RF board are separate units. Additional bands for the radio are in development.

More information on technology availability and licensing will be available once the technology transfer between TAPR and Dandin is complete.

In the fall of 2002 TAPR announced it would discontinue it's stalled 900 MHz FHSS radio efforts. The project did not reach completion as they were faced with continuing parts obsolescence problems that resulted in continual redesign, and second, we were unable to obtain the RF design expertise needed to finalize the RF board.

The TAPR Spread Spectrum Radio

Tucson Amateur Packet Radio (TAPR) has announced that a team led by Bob Stricklin, N5BRG, Bill Reed, WD0ETZ, and Tom McDermott, N5EG, is developing the TAPR Frequency Hopping Spread Spectrum radio. At last report, the prototype radio was transmitting, although not yet hopping. The group spent about $15,000 on the project last year-on things like pc board prototypes, development software, parts, and other odds and ends that a project of this magnitude requires and anticipate spending another $15,000 to $30,000 on it in 1999. Thus far, though, TAPR has received a little less than $2,000 toward its overall goal.

TAPR will be sending out a fund raising letter in the next few months to help fund all or part of the costs of this development project. Members are being asked to donate to this worthy cause, and I'm asking the readership of CQ VHF to also consider supporting this valuable project. Please take a serious moment to consider this request and help bring this unique project closer to completion. If you have contact with a local or regional packet organization, contact them about supporting this project as well.

Donations above $25 will receive a handsome certificate acknowledging their contribution to the TAPR FHSS Project, while those donating $250 or more will receive a plaque to let everyone know of their efforts on behalf of this project. All donations are needed and welcome, no matter how large or small. Even if you simply become a member of TAPR-well worth the $20--you can be sure it's appreciated and helpful. Thank you for your consideration. Contact TAPR at 8987-309 E Tanque Verde Rd #337, Tucson AZ 85749-9399; (Phone: (940) 383-0000; Fax: (940) 566-2544. Internet: . Visa and Mastercard are accepted.

-Per N2IRZ, CQ-VHF Magazine, March 1999

The funny thing is you really don't read much about spread spectrum & ham radio anymore. It appears that the main guys who were beating the ham radio drum initially on this apparently made a buck off it in the commercial market.

Which is a dirty shame. I was a follower of the project having been involved in conventional packet radio and seeing the need for speed. Of course the idea of modifying Part 15 spread spectrum radios was never really promoted by TAPR because that was a direct conflict of what was trying to be marketed.

This TAPR / Dandin FHSS radio project wasn't fully successful for them as the project never made it to completion. The reminds me of how ham radio was a test bed, or example for how AMBE / D-Star works. This has given Icom and Kenwood a chance to perfect it and unveil it for APCO25, Phase II.

Lesson learned; commercial influences like this can sometimes screw-up a potential good thing for this hobby, and other times (like with D-Star) being the Guinea pig can help breed some new developments into the hobby and work out for the commercial entity.

Sunday, August 2, 2009

The Amateur Radio Emergency Communications Enhancement Act of 2009

This was a ARRL news piece a while back.

The ARRL is asking its membership to contact their members of the US House of Representatives with a request to become co-sponsors of this significant piece of legislation.

While this is all nice in theory... Where does one click or write to, to encourage new technologies that can help aid and advance how we communicate in emergencies? Surely if the ARRL can adopt Winlink 2000 for ARES emergency communications, they could also get behind some development of something more modern?

We had something more logical, a wide network of packet backbones in the 80's and 90's. Yet some how we end up with this bastardization called Winlink.

In the April Rain Report, CQ Editor Rich Moseson, W2VU, talked about packet's remarkable comeback and its EMCOMM applications.

About 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.

This is what led to the development of the High Speed Multi-Media working group in 2001-2005, appointed by former ARRL President, Jim Haynie, W5JBP.

The HSMM working group was an loose attempt to steer ham radio into the future by bringing awareness to the general ham populous of what is possible with HSMM.

It really could evolve into something powerful, the "next generation of ham radio." But it needs a leading force for that. The ARRL and TAPR both seem to have no interest. In my opinion, they should both be working on the community/ public relations with companies like Ubiquiti, and developers like the DD-WRT guys. Encouragement to work together and enabling hams would not only be beneficial for the hobby, but also the general populous. The HSMM working group encouraged hams, but neither larger group did anything to enable further experimentation.

I have pointed out that 802.11 and WiMax manufactures like Ubiquiti have the potential to develop built-to-order products for HSMM on VHF/UHF bands.

The Ubiquiti XR-1 is the first VHF 802.11 radio that I know of.

It's just a dirty shame someone like the ARRL or TAPR can't establish a better working relation with companies like this. Something like the XR-1 would be an inexpensive powerful Emcomm tool.

I encourage you to write to your section manager if you realize that legislation alone can't advance how we communicate.

Additionally TAPR is seeking nominations for a few good people to serve. So if you, or know of a ham with some fresh ideas, speak up!

Sunday, July 19, 2009

Homebrew D-Star Repeater?

In the past I've written about a passive D-Star capable repeater using a couple Maxtracs.

This of course is less than ideal as it's a carrier activated system, left open to intermod and such.

I have also written about Satoshi's GMSK node adapter. There was a tid-bit about this in the July 2009, QST, Eclectic Technology column by Steve Ford.

In the QST article it was talking about using Satoshi's board as D-Star Simplex Hot Spot. Mark, KB9KHM developed some windows software so one can use the node adapter as a simplex node to talk back to the gateway server of other D-Star repeaters.

Most of the bugs have been worked out, and the official non-stripped down Satoshi, GMSK node adaptor board can be used to make or convert an existing repeater for D-Star, with the capability to talk back to gateway servers for interlinking.

I suggest taking a look at David, G4ULF's blog.

His blog is a running log of development of a D-Star repeater that links to the worldwide dplus network running on homebrew components and standard UHF FM rigs.

Duplex use of the node adapter used to require two 18F2550 PIC chips running his code, instead of the one. Now KB9KHM's HotSpot software can emulate that. So you can get by with a mini-hotspot board, and just one PIC.

Satoshi's project has caught a lot of attention (and some flack), because you can construct the node adapter for about $75. An Icom D-Star system; one radio module, RPC controller and gateway runs about $3,000.

If you build or convert your existing repeater system, you can also keep backwards compatibility for repeating analog.

All you really need are direct (varactor or varacap) drive to transmit the GMSK data, and a discriminator output for receive. (As pointed out for the simplex hot spot use, most 9600 baud "data ready" radios will work.)

The retrofitted repeater system should be tuned for maximum 3 KHz deviation for best bit error ratio.

If the idea of running Mark, KB9KHM's windows based "hotspot" linking software for a permanent repeater installation doesn't thrill you, never fear, Dextra is here! (This is a very close basis of G4ULF's project)

Sunday, July 12, 2009

British Columbia Wireless Amateur Radio Network.

The BCWARN infrastructure includes and supports:

-Electronic Mail via WinLink (over 2.4ghz microwave, AX.25 packet radio and Pactor3)
-D-Star Digital voice and data
-VoiceOverIP using Asterisk private branch exchange (PBX) open source telephony switching technology
-File sharing
-Remote printing and facsimile
-Video conferencing & instant messaging

Thursday, July 2, 2009

Bandplans - 900 MHz and above

Nearest I can determine, the last time ARRL bandplans were reviewed was nearly 20 years ago for 50 MHz and above.

There is some ARRL Microwave Band Planning in it's initial stages that I welcome as it's long overdue in my opinion. So I do look forward to reading other peoples thoughts on how to tackle the problem of promoting ultra wide band data modes and somehow keeping some harmony with any existing activity on these bands.
Chairman and Liaison Appointments: Microwave Band Planning Committee: Tom Clark, K3IO, Chairman.

I noticed that Will Payne, N4YWK is a part of some sort of active ARRL Microwave Band Planning. He has a help wanted thread on the LinkedIn ARRL Ham Radio Operators group. He appears to be surveying conventional repeater use. (He is seeking help fill in two "lost decades", the 1960's and the mid-70's to mid-80's, contact Will if anyone you know who may have old repeater listings.)

The historic growth of repeater populations on the lower bands might serve as a bellwether for future growth on the microwave bands. Historic growth graphs would also be informative for the ham community at large.

Also in the The ARRL Letter, Vol 27, No 29 (July 25, 2008), there is this interesting snippet:

* ARRL Board of Directors Plans the League's Future at Second 2008 Board Meeting

Regulatory Matters:
The Board voted to establish an ad hoc study committee to review Part 97 of the rules governing the Amateur Radio Service to ascertain what rule change(s) would be beneficial to promote wideband digital modes, while at the same time minimizing potential interference to narrowband modes.

And more recently:

It Seems to Us: Coexistence - Radio spectrum management is a difficult business. The most useful part of the spectrum has been fully allocated for decades, yet new uses continue to be developed. Where can they go? It's a question that requires ever more imaginative answers.

Nov, 2011

With those observations pointed out. Basically I feel investigating and possibly revising the bandplans is long over due.

I feel that 900 MHz and above are the future of ham radio. On SHF frequencies outside the ham realm, wide band modes are exploding. Such hardware can be adapted to the amateur service. Doing so (as the former HSMM WG showed) is probably the easiest way to populate these bands. Our SHF allocations have the band space to accommodate such modes so this is a natural fit.

Therefore I feel wide band (OFDM) modes should be promoted as first class modes of operation on these bands. Presently they are see by many hams as secondary to "conventional modes" like FM and analog ATV. The present voluntary band plans for 900 and above seem to detour ham from experimenting with these "futuristic" modes, as they are unsure how they fit into to the existing plan if at all. The other detriment of antique band plans is when (potential) manufactures look at is for reference on what would be a marketable ham line or product.

Bandplans for 900 MHz and above, unlike for below 900 MHz, need to have a futuristic theme in mind, to provide a path to the future. This futuristic thinking is also because one must realize it will take years to substantial SHF utilization to occur anyway.

One of the purposes of a frequency coordinator is to recommend standard operating procedures. The frequency coordinator's main job is to make sure your repeater will not interfere with nearby repeaters already established.

They have the duty to not only produce bandplans that satisfy the needs of repeater owners within its area but also to protect the interests of coordinated systems in adjacent areas, weak signal modes, digital communications, AM and FM simplex, and satellite uplinks and downlinks. They define the bandplan for both coordinated and non-coordinated activities within its territory.

In the event your coordination body's band plan is behind the times; Aside from the FCC's frequency limits spelled out in Part 97, everything else is technically a voluntary band plan.

From what I have observed, the frequency coordinator's job (at state, regional
and nation levels) isn't an on-the-air practice so it seems they are totally off
the hook when it comes to holding up their duties.

Until things are formally updated, just observe Good amateur practice . Make your best effort to check for other band use. And if you determine the conventional band use doesn't offset your experimentation, then I tend to think what you are doing on our underutilized SHF bands IS in the best interest of the amateur radio service.

(You can see this has been on the ARRL’s to-do-list for at least a year or better. But we are talking about the ARRL here.)

Saturday, June 13, 2009

D-Star Simplex Station

Ok first off I promise not to turn into a D-Star fanatic. Nothing has urked me more lately than the D-Star hype fanatics. The most recent example is this D-Star newsletter.

D-Star isn't for everyone, nor is it the saving grace of amateur radio. Bombarding folks with growth (peer pressure) statistics from isn't cool kids.

To me; D-Star overall is Disappointment-Star. My feeling are that ham radio needs narrow band like the ARRL needs aging members. But that's no fault of D-Star's design, more so of our bandplans. D-Star was designed to work into existing ham band plans.

So why did I pick up a D-Star radio you may be wondering? Simple, it's emerging technology and experimenting with that sort of thing is right up my alley. It was hard to justify because the local big radio club around here will spend grant money on foolish redundant equipment that only gets used occasionally. But the concept of trying to define and set the pace for the areas ham radio future by deploying new infrastructure is apparently beyond them. (IMHO a CW and spark gap forever mentality.)

I've shared my thoughts before on the enormous amount of development potential there is with D-Star despite it's utterly useless low bit rate. Enhancing the no-frills controller, and a SIP to D-Star translation for IP telephony interconnection.

However that's all stuff a bit beyond what one or two guys with a HT can start messing with.

So what I have been throwing a few ideas around with and messing with some code that is doing things with the receive callsign heard data as a simplex station. Bruce, KG7WI has a nice perl routine for to get and put data from/to an IC-91AD that can be adapted for the IC-92AD as well.

The concept is, since each user transmission contains a callsign, we are able to create custom greetings based off decoded data, by using a text to speech engine such as Cepstral or Festival. "Welcome KB9MWR to the N9DKH simplex station." "You have one voice mail message from Kevin, left yesterday"... A relational database or QRZ lookup could even make it more personal with first name greetings. Last heard callsign stats could be kept and queried via touch tones and/or exported to a club webpage. D-Star low speed short messages could be posted to twitter for those hams who don't have a HT genetically attached to their hip at all times. And so much more...

To make this interactive, I was hoping the digitized DTMF would be available via CI-V. This is not the case, so they will have to be decoded externally-analog style.

Other ideas include reposting the received short text messages once can send from their radio to twitter. Or reporting recent heard - on the air status messages to twitter.

Icom could share the CI-V command codes, which could them sell D-Star, as more excitement there would be generated and people using the D-Star radios. But so far there hasn't been any openly published for this particular radio. A true bummer, as well as their choice to deny a fairly major radio issue. Those are bad business moves in my book.

Saturday, June 6, 2009

Are you narrow or wide?

Recently our local repeater coordinator began asking your emission designator on the application form. A break-down of emission designators can be found in section 2.201 of the telecommunications part of the code of federal regulations.

20K0F3E - FM Voice 20kHz bandwidth - Wide 
16K0F3E - FM Voice 16kHz bandwidth - Narrow
11K2F3E - FM Voice 11.2kHz bandwidth
8K10F1E - P25, phase 1, 12.5kHz Bandwidth
5K76G1E - P25, phase 2, 6.25kHz Bandwidth
6K00F7W - D-Star, 6kHz bandwidth

The confusion I often see lies whether a system is narrow or wide. 20 KHz bandwidth or 16 KHz. To determine this we must look at Carson's bandwidth rule.

As you can see in the analog world, your bandwidth will be determined by transmitter deviation. If you have 5 KHz deviation (now a days considered wide band I guess) you will occupy 20kHz of bandwidth. If your deviation is in the 2-3 KHz area you will occupy 16kHz bandwidth now referred to as narrow FM.

Now a days wide / narrow transmitter deviation is usually a software selectable option. The quote/unquote standard for ham radio has been 5KHz max deviation/20kHz bandwidth.

If you can't determine by software/programming configuration you'll likely need access to a deviation meter or service monitor to determine your deviation.

+/-2.5kHz maximum deviation is also a standard for 800 MHz and above and has been since the mid 90's. This is why you typically see 12.5kHz channel spacing up there. Actually I have never seen any Wide analog FM above 800 MHz except on remote broadcast studio-transmitter links. 

So if nothing else use the mid 1990's as a date of determination. If we are talking VHF/UHF commercial equipment manufactured 1997 or more recently you can probably assume it's "narrow FM"/Max 3 KHz deviation - yielding 16kHz bandwidth. Another clue is if it was in commercial service using a 12.5 kHz step/channel spacing scheme, it is likely narrow FM.

Here is the history: 
A process of "refarming" the informal name of a notice and comment rule-making proceeding (PR Docket No. 92-235) opened in 1992 to develop an overall strategy for using the spectrum in the private land mobile radio (PLMR) allocations more efficiently to meet future communications requirements. The FCC created mandates for the two-way radio equipment manufacturers. In 1997, all new two-way radio models had to be capable of operation on the "new 12.5 kHz narrowband" channels. This is often called "dual-mode" equipment since the radio can accommodate both narrow- and wide-band channels. The idea was to begin to move gently toward narrowband channel operation over time. At that time, the FCC did not create any mandates to remove older wideband radio units from service or require you to use a new narrowband channel.
The Part 90 LMR narrowbanding mandate was released 12-23-2004 by the FCC for all Part 90 business, educational, industrial, public safety, and local and state government two way radio system licensees currently operating legacy "wideband" (25 KHz) voice or data/SCADA radio systems in the 150-174 MHz (VHF) and 421-512 MHz (UHF) bands. The executive summary of the FCC order  establishes January 1, 2013 deadline for migration to 12.5 KHz technology.

(Note many ham HT's are capable of WFM / Wide FM receive, intended for reception of FM radio/ Analog TV audio. Don't confuse this with the two way standard... Broadcast Wide FM is 150 KHz of bandwith.)

True narrowbanding a receiver is what is hard.  I am talking narrowing the receiver IF bandwidth.

Just be aware that converting a 1950's era repeater to D-Star or P-25 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.

Monday, June 1, 2009

Revisting ham radios image and marketing

My first blog was about creating a more modern image for the hobby.

What I have noticed is that the oldest advertising and marketing trick in the book, using the sex appeal has significantly dropped off in the hobby. About the only really prominent in practice example are the Icom girls.

Going back looking at some older material, I have to hand it to Wayne Green, publisher of 73 magazine. He not only knew how to market his publications, but he knew how to inspire. That is something noticeably absent in ARRL publications.

Observations as of recent years show there are some operators who really are cutting-edge, advancing the state of the art and all … But on the whole there are way too many hams who are woefully inadequate in technologies that are already mainstream, and that most employable people are expected to be proficient with.

Sad but true. Instead of inspiring hams and using old marketing techniques to get their attention and sell stuff, the latest trend seems to be the Emcomm push.

But when it comes to creating a good image and turning hams off I have to say there are number of old school practices that really need to go, or at least be revisited.

Burt,  K1OIK comes off a bit cranky in some of his youtube video rants, however if you can get past his cynicism, he does have some very valid observations.

Truth revealed about ham radio; The Real World Of Ham Radio; and, Ham radio, a critical evaluation.

Yes I am suggesting that some of these old school formalities are entering the lid category. Speaking of lid, I'm fairly thick skinned but I have had to lock a channel or two out of my scanner to a local lid who refers to himself in the plural sense much to often.


31) Make people think you have a split personality by referring to yourself in the plural sense. When you're in conversation and are alone at your radio, always say "We're" or "We've" instead of "I'm" or "I've" (i.e. "we've been doing this...", "we're doing that...", "we're clear"). Everyone knows you're by yourself, but when they ask you who is with you, make up somebody important like Arnold Schwarzenegger or Bill Clinton.

Now getting back to the whole Emcomm push. You may have noticed that basically the ARRL directors come off as a bunch of ambulance chasers. This mentality is also used to help suggest "new"(cough) technologies for the hobby that such persons/ groups feel need to be implemented. An example is the ARES Winlink push. And now I see Icom has some nifty little PDF's along the same line trying to promote D-Star the same way. All this Emcomm/ARES mystique stupidity of course is prompted by money. A push for ham clubs can apply for grants to be able to implement such "new" technologies.

I feel that Ham radio does not need to become a back-up for the internet and other commercial IP communications. Nor does ham radio need to be a backup for voice communications. This is a hobby for experimentation and learning. Sadly there aren't many old school guys left that want to learn and experiment. Most people come here for "fun"? Which explains why most newly licensed hams go inactive in a short amount of time. The EmComm backup communications business is directly related to the huge frequency allocations that we are squating on. This is justified if we can provide backup communications and dedicate time to civic ARES/RACES exercises.

Just recently Google has Urged a National Inventory of Radio Spectrum. The worst part is that most hams and the ARRL won't put up an argument because they see this as no loss as there is little ham radio activity on these bands.

Sunday, May 24, 2009

APRS in a Linksys Router

From the Ham Radio at Maker Faire 2009 - APRS demo PART 3. Chris Kantarjiev, K6DBG demonstrates APRS (Automatic Position Reporting System) gear that he has collected, built and modified. This segement features a modified Linksys router (WRT54 series) and a small APRS tracking kit, "OpenTracker," produced by Argent Data Systems. (Video by NQ1R/ARRL.

Chris is running an APRS gateway on the Linksys router, taking the need for a computer out of the picture. It talks to the Linksys router over it's internal serial port. A TNC connection cable hangs out the back.

For more info see:

Monday, May 4, 2009

WeComm Digital Audio Repeater Linking

Wisconsin Emergency Communications (WeComm) is developing a statewide repeater system / voice network to provide base coverage throughout Wisconsin. Another imitative is to implement a modern high speed digital network. Both are for state, district and local ARES/RACES, skywarn, public service, and normal amateur radio communications.

The wide area analog repeaters are interlinked using SIP analog radio adapters. The Asterisk based conferencing software is virtually limitless. It provides the flexibility to connect individual repeaters into a statewide configuration, or to disconnect them to serve smaller areas or districts meeting specific needs.

This is a private VOIP network / reflector, unlike; IRLP and EchoLink. (Although the capability to link to such networks is still possible). Using IRLP, EchoLink or some other Wide Area Network linking services doesn't allow the control and flexibility that creating ones own off-network conferencing bridge. The aforementioned systems have a limited number of reflectors available and you are bound to their rules. Once the modern high speed digital network gets in gear the VOIP audio can actually be carried over these links instead of the internet.

SIP / digital audio repeater linking allows you to route / (think digipeat) . This is a great way to connect repeaters together that have quite a distance between them (or poor radio path).

SIP radio linking is also compatible with telephone circuits, and 21st century digital radio systems such as APCO-25, and D-Star. Such high speed multi-media interconnecting backbones can support radio linking of today as well as of the future.

Friday, May 1, 2009

1.25 m/ 220 MHz HSMM XR-1

This is an interesting product with lots of possibilities. It's a powerful 802.11 non line of sight radio module. Designed for Metering Applications as an built to order- 180-280 MHz Frequency Band. (There is a minimum quantity of 1000 piece per order due to the custom frequency, but it does work out to about $150 per unit.)

The XR1 would fit into the 1.25m amateur (220MHz) band frequency wise. However there is a gap in the band. As most hams are aware, we have 219-220 MHz secondary, and 222-225 MHz primary. It would be nice if the full 219 to 225 MHz was available.

Like all Atheros based radios, the XR1 specs references that channel size can be set. Even with the minimum channel size 5 MHz it wouldn't fit into 222MHz band, but there may be ways to reduce the overall spectrum requirements. Could the transmission envelope be modified to be narrower channel? That would be a good question for the guys at Ubiquiti Networks, or the Atheros MadWifi project.

Lets not forget the channel may be 5-MHz but...keep in mind Carson's Rule, the channel may be 5-MHz but...the signal bandwidth could be much higher.

If a 2.5 MHz channel option was coded the throughput would still be very usable.

This card does not have these capabilities and is not legal for sale in the US. But I don't think that would be a major obstacle for hams if it could be modified to fit into the 220 MHz ham band.

The reason I point it out is because it is the first VHF 802.11 radio I have ran across.

Saturday, April 11, 2009

Text Messaging and D-Star

I've mentioned a few times that its a bummer that the radios don't do this since 1200 baud is reserved for slow speed data.

After further research, the IC-92AD HT that I have been considering does do it. The messages have to be preset as a sort of quick text. It will store 6 messages of up to 20 characters each, which can be selected to be sent.

The ID-800 mobile works similarly. It will store 6 messages of up to 20 characters each, which can be selected to be sent each time you key the radio. When received, the message will (SLOWLY!) scroll across the display on the ID-800.

Editing these messages is a royal pain, because (of course) the radios have no keyboard.

The IC-92AD also has a kind of cool built-in voice recorder function.

The built-in voice recorder records an incoming (directed to your callsign) call for up to 30-seconds (approx.), (or 15 sec. × 2 tracks, 10 sec. × 3 tracks). For automated outgoing calls, you can pre-record up to 10 seconds of your callsign and/or CQ message in the IC-92ADs voice memory.

This functions of the callsign squelch. Out side of the DVR mode, you can set the call sign squelch function to only open the squelch only when your callsign is received.

There is also a break-in function built into this that allows a user to break into a conversation, where 2 stations are using Call Sign Squelch. The breaking station should enter the call sign of one of the stations they wish to communicate with. When you call the desired station, only the selected station will hear the call. With the break-in communication function enabled, both stations will be able to hear the call.

D-STAR also has "EMR" mode, (Emergency" mode), that was the engineer's obvious intention -- it opens all monitoring radios and even turns most models volume up to 50% if they were turned down, in order to get your call heard.

Sunday, April 5, 2009

D-Star data port?

I almost bought the IC-92AD at AES superfest. I had planned on it actually until I discovered a design flaw.

Apparently there a number of people reporting that the display goes blank after VHF transmit in DV mode. So something isn't shielded the best. Icom will fix this is you discover it and send it in. But that's just a bummer when you drop cash to buy a new radio only to have to send it in.

What did pique my interest for a while was the 12 pin connector on the handheld. There is an optional (overpriced) GPS speaker mike that interfaces to this port.

I knew it was wishful thinking that there might be access to the raw (signed 16-bit, Little-Endian, 8kHz, non-stereo audio packets.) AMBE decoded audio. Such is not the case. The 12 pin port is solely for the utterly useless slow speed data and some cloning functions.

Why anyone would bother with a 1200 baud digital data port is beyond me. We had that kind of speed with packet in the 80's. It makes sense to use that reserved 1200 baud for on-board text messaging. Or with that crazy priced GPS mic.

So it makes sense me to me that hams might want to interface to the digital audio part and callsign routing to try and create a SIP bridge.

Anyway you can't get at that DV stream which is a shame. So to experiment with interfacing a D-Star radio to Asterisk you really need to buy that overpriced DV-Dongle. Which of course lacks an over the air demodulator so you need to connect it to an analog radio.

What a bunch of bull.. D-Star isn't for me yet. I have other things to spend my money on, and there really isn't anyone around my neck of the woods with a D-Star radio. But it is interesting to read up on and play with some of the software being developed. Perhaps one day there will be such a standardized port, much like the standardized packet radio data port.

Above is a block diagram of how a D-Star radio works. As you can see analog microphone audio hits a single-channel, Analog Devices Front-End Speech Processor. This is actually what does the analog to digital and digital to analog conversion.

From there we have a RAW digital audio stream to the AMBE-2020 vocoder. This raw stream is signed 16-bit, Little-Endian, 8kHz, non-stereo audio packets. At this point this raw stream is a non-license encumbered codec, close in resemblance to ulaw (g711). The Linux SoX tool can convert most file formats, like WAV or MP3 to this RAW format.

The AMBE-2020 Vocoder Chip is configured to transmit and receive digitized speech to and from most linear, a-law, or u-law A/D-D/A codecs though its serial interface.

It kind of bugs me that there isn't a way to interface to this digital audio. I guess it's not a super big issue on a user end radio as you can always interface analog using the speaker microphone jacks.

Saturday, April 4, 2009

Wisconsin Amateur Radio Club - Digital Backbone Project

I spotted this at Amateur Electronics Superfest. Their demo was a pair of IP phones interconnected via 2.4 GHz shotgun antennas.

They are deploying a 5.6-5.825 GHz high speed digital network in Southeast Wisconsin. They are using the Ubiquiti Bullet 5HP, a 1 watt 5 GHz capable transceiver.

Due to the 6-54 megabit bandwidth, multiple simultaneous communications can take place on a single channel. Any site can act as an intelligent digital repeater into the network and thereby expand the mesh...

Due to he 12 volt operation and the small, high gain antennas, a portable station can be quickly assembled in the field and added to the digital backbone network.

Field locations provide: VoIP telephone for command posts, real time high resolution video of conditions, e-mail and file transfers, extension of the digital network, and standard voice type QSO's.

You can view the overview handout of their digital backbone project here: