AmateurRadio.com

The FoxTrak APRS tracker board is finished, and works, but I took the long way round getting there. Building the board was by far the easiest part of the project. Setting up and testing it was a trial of patience, ingenuity and lateral thinking.

After building the tracker it has to be programmed with your call and a few other options by connecting it to a computer and running some configuration software. The documentation was not specific and I was not sure if I could just connect it to a serial port. The tracker is just a 16F84A PIC which works at TTL logic levels, but a PC serial port produces RS-232 at +/- 12V. What’s more, the FoxTrak website mentions a null modem adapter with MAX232 chip which is a TTL to RS-232 level converter, suggesting this might be required. However I had a USB to TTL serial adapter module that I bought some time ago for another project so I decided I should be able to use that. I did, and the configuration software was unable to detect the tracker.

After thinking about it for a few hours I decided to take a chance and use a normal serial connection. I used a Prolific USB to RS-232 serial adapter. That worked, and I was able to program my settings into the tracker.

The next step was to calibrate the tones produced by the tracker. 1200baud packet uses mark and space tones of 1200 and 2200Hz. Due to some hardware limitation of the 16F84A PIC, the tones are actually spaced about 1050Hz apart and the calibration software uses a default setting that puts them as near equally spaced over a centre frequency of 1700Hz as possible so the error in the generated tone frequency is shared equally between mark and space. To generate constant tones so you can measure them using a frequency counter you must connect to the tracker using a terminal program and send Esc T 0 or Esc T 1. I tried this using Windows HyperTerminal and nothing happened.

I now wasted quite a lot of time as I didn’t know what was supposed to happen. I didn’t know whether the PTT LED would illuminate when the test tone was produced so I didn’t know whether the absence of a tone was because the PIC hadn’t received the command to send it or some other reason. Eventually I decided that perhaps HyperTerminal wasn’t talking to the tracker so I tried another terminal program called RealTerm. This time Esc T 0 immediately produced a nice waveform on my oscilloscope which also counted the frequency for me and told me the tones were within 1Hz of the documented frequency for the default calibration value. Good, or so I thought.

Now I wanted to feed the audio output into a radio and see if my Kenwood TM-D710 would decode the packets it produced. I had wired a push-to-make switch in the “Transmit Now” position but what I didn’t know was whether the tracker would transmit a packet when it had no GPS data. I don’t have a GPS I can use with it at the moment, but even if I had, I would have trouble getting a fix inside the shack due to the high electrical interference levels.

The tracker wouldn’t transmit anything without a valid GPS fix, but it occurred to me that it must be possible to write a program that pretends to be a GPS and outputs NMEA packets to a serial port in order to test GPS applications. I didn’t want to write such a program, but other people had the same idea and Google found me several GPS emulators. Unfortunately the so called “free downloads” required a fee of $30 to $40 to use them. Blow that, I’d rather spend that money on a real GPS receiver.

An enquiry on the APRS Yahoo! group and another few hours wait and I was pointed in the direction of two free GPS simulators: gpsfeed+ and NMEA Generator. With these I was able to send fake GPS positions to the tracker board. The GPS light came on, as did the PTT light whenever a position was sent. At last!

Around this point I wanted to change a couple of the settings I had programmed in to the tracker. I re-ran the configuration software and found that when I tried to write the new settings back to the PIC it failed with a mismatch error. Reading back the settings they were now corrupt. I could not seem to clear the problem and wondered if I had blown something up.

I tried another USB to serial converter, one with an FTDI chipset which is normally more reliable in transceiver control applications. That could not even detect the tracker board. Oh dear! As a last hope I tried the Prolific adapter again and, having in the process switched both the computer and the tracker off and on again it worked this time. It seems that if you are going to configure the tracker it’s best to do it first before trying anything else. I was glad to have found a solution and that it was still working but I had wasted quite a lot of time getting to that point.

The next problem was getting the packets transmitted by the radio. I tried the Motorola GP300 first of all but for some reason it went into transmit as soon as I inserted the 2.5mm jack into the socket. So I tried the Kenwoods. Both the TH-F7E and its grandparent the TH-205E use the same type of connections. But on those I could not get PTT to work at all. I could really have done with some diagrams of how to wire up the tracker to these radios. I was, however, able to transmit some audio by manually pressing the radio PTT and then pressing the Transmit Now button on the tracker to send a packet. From this I was able to determine that no matter what audio level I used the TM-D710 would not decode the packets from the tracker.

I tried what must have been an infinite number of different level settings without success. Yet the tracker packets sounded exactly the same as ones I was receiving off-air which were being decoded. I remembered that I had the VX-8GR which also has a packet TNC so I decided to see if that could receive them. The Yaesu decoded the tracker packets over a wide range of audio level settings, even when the transmission was undermodulated. So what didn’t the Kenwood like about them?

I decided to set up AGW Packet Engine to decode packets via my FT-817 which was conveniently connected up to a sound card. That decoded nothing either. Clearly something was wrong with the AFSK output from the FoxTrak board. Even though my VX-8GR could decode it, it was going to be of no use to me if its packets would not be decoded by my gateway.

Finally, on the basis that there was nothing left to try, I decided to try different calibration settings to vary the tone frequencies. After another fight with the serial adapters I programmed in a calibration value of 36 which should result in a mark tone of 1200Hz and a space of 2250Hz and was rewarded by beeps from the TM-D710 indicating that packets were being decoded. They were also appearing in the monitor log of the AGW Packet Engine. The VX-8GR was still decoding them, too. Success at last!

I am relieved that it works after all this effort. Now all that remains to be done is to acquire a serial GPS, figure out the radio PTT connections and box the FoxTrak up with a suitable battery pack to make it into a usable unit. That will take a while, since some of the bits and pieces (including the GPS) will be coming from China.

It is interesting that the calibration setting which resulted in the best decoding is one farthest from the default, which does not place the mark and space tones so that the difference between the actual and the correct tone frequencies is equally spaced between them. A few months ago I heard a mobile drive through the area beaconing on APRS and none of its packets were decoded. I wonder how many people build or buy these trackers – either the FoxTrak or the original TinyTrak which it is a clone of – and leave the settings to default not realizing that they are unintelligible to many radios?

Welcome to Handiham World!

Photo: John Hoenshell, N0BFJ, enjoys being a VE and handles the paperwork at radio camp sessions and also volunteers during VE sessions at Dayton HAMVENTION. He believes that team members with disabilities can participate in a successful session.

Can a VE session be more than just a process of overseeing test takers in a room and handling their FCC paperwork?

This morning I had a different, but VE-related, question from one of our blind members. She was asking how she might participate in a VE session if she became a volunteer examiner. She mused that being a VE sounded interesting and that she would like to participate, but she wondered if it would be practical since she couldn’t see a room full of test takers. Since this topic comes up from time to time, I thought I’d take another look at what a VE session is about. While I am by no means an “expert” VE by experience, I can relate to testing in general – I was trained as a teacher, after all – and I have observed people with disabilities for decades. I have been present at many VE sessions over the years, especially at Handiham radio camps, but have only relatively recently become a VE myself.

I got to thinking about the very best VE sessions I had observed. What made them stand out from the others? It was more than the success of the candidates, though that always helps. It was more than the team arriving prepared and being able to process the paperwork efficiently, too. It was more than promoting the session and arranging a good location, though those things were important.

But what was it?

Well, let’s discuss the typical VE session a bit.

Our blind Handiham member is right in assuming that a blind VE cannot observe a room full of test takers as a sighted person might do during a VE session. That does not mean that a blind VE cannot participate. At our radio camp VE sessions, I suggest that blind VE team members sit at the tables where the exam is being read by volunteer readers to blind test takers. This assures that the exam is being proctored so that all rules are followed. A sighted VE simply looking at a room of test takers cannot know what is being said at each table in this kind of an adapted test session. Blind VE team members understand how tests are given to blind candidates and are potentially better at this kind of observation than anyone else.

The paperwork table is probably one place a blind VE would not be as useful. In every VE session, the team leader should try to match skills & capabilities with the tasks at hand. If there are no blind test takers to proctor, a blind VE might instead be part of the meet & greet team, setting candidates at their ease and answering the usual questions about what to expect during the testing, any rules of conduct (no smoking, quiet please, bring test to table at the side of the room when finished, etc.) As testing progresses and candidates start to turn their exams in for grading, a blind VE can then be stationed outside the testing room to answer questions that candidates might have. Typical information requested ranges from when they can use their new privileges if they pass an element upgrade to the location of the rest rooms.

Another job that every VE team has is communicating test results to the waiting candidates. There is no reason a blind VE cannot help with this job – and a savvy VE team leader will know who is best-suited for the hardest job – the delivery of the bad news. If a blind VE can handle telling a candidate that they didn’t pass but can do so in such a way as to help that person accept the news in a positive way, the entire VE team will be grateful! You don’t have to see to help candidates, successful or not, learn more about your ham radio club. Post-testing is a great time to talk with candidates and invite them to club and ARRL membership, and yes, even Handiham membership if they have a disability.

For the excited new Technicians and Generals, you might start a conversation about which radios are best, pointing out the availability of the club’s repeater system or the best ways to check out the the HF bands during the improving sunspot cycle.

In the end, a successful VE session is one that provides an opportunity for the candidates not only to pass their exams, but to leave the test site with the information and enthusiasm that will carry over to participation in the club and regional activities as well as getting on the air! When you look at a VE session as more than just three team members overseeing a room of test takers, you can easily find places for blind VE team members to be a part of this most rewarding of volunteer activities.

I hope to hear you on the air soon.

A dip in the pool

No one told you there was going to be a quiz, right? I thought it would be fun to pick a question out of the question pool and see how many of us can remember the right answer. Ready? Here we go:

E6A02

What type of semiconductor material contains more free electrons than pure germanium

or silicon crystals?

A. N-type

B. P-type

C. Bipolar

D. Insulated gate

Did you pick answer A, N-Type? That’s the right choice, and easy to remember if you think of “N” standing for “negative” and an excess of electrons in a material would give it an overall negative charge.

Yesterday, through my friends in the Harwell Amateur Radio Society, I was very saddened to learn of the death of Robin Greenwood, G3LBA.

When Julie and I moved to Longworth around 8 years ago, we decided to attend one of the barn dances to get to know people. Julie went to pick up the tickets from a house in the village and came back saying, ‘there’s a chap who’s got a lot of stuff like yours’! At the barn dance, I met this chap, who turned out to be Robin, G3LBA (Gee Three Light Brown Ale as he put it). That was our first enjoyable meeting.

Over the years we met at many village events and always had fun! Robin was an avuncular character, always interesting to talk to. He had an interesting professional background and had worked for the European Space Agency. Stories about the International Space Station were often heard in the Village Hall!

On the air, I think we had about two contacts in 8 years! Being around 500 yards apart we were quite loud with each other, on both HF and VHF. I suspect we were active at different times. Robin had done a lot of work with the local repeater groups and several local repeaters have bits of Robin’s work in their configuration.

I last saw Robin about three weeks ago at the village fete. He’d been suffering from thyroid cancer and was very clearly not well. He had hopes of seeing his next grandchild born early next year, but very sadly that was not to be.

Robin joked that I would soon have the airwaves in the village to myself. Frankly, I like a bit of company. Farewell friend.

See the Harwell tribute to Robin here

My home made USB digital modes interface “SignaLink clone” has been completed. It has been in use for several days and is currently in use with my K2 for 30m APRS.

USBlink interface with cables for FT-817

I have written up the project on the G4ILO’s Shack website. See home-brew USB digital modes interface.

Amateur Radio magazine for October 2010

Highlights from this month’s edition of Amateur Radio, published by the Wireless Institute of Australia include:

Commentary from WIA President Michael Owen VK3KI on the crucial role of the ITU, the global agency that sets the framework – regulations and frequency allocations – for hams wherever they live.

“Simply, it will not happen, whether it is good or bad, unless it happens first at the ITU.”

That simple proposition drives the whole four year planning process that culminates in a four week meeting in Geneva – WRC-12. Michael details the complex rounds of regional meetings and negotiations that lead up to that meeting.

“…this now never-ending series of meetings… Represents the focus of the protection and advancement of the interests of amateurs that face national societies like the WIA.”

The WIA's 'Tune-in to the World' logo

There’s also detail of the inaugural national day of amateur radio promotion aka the WIA National Field Day scheduled for Saturday 23 October. Professional marketing strategy has arrived to help lift public awareness of ham radio and recruitment to new levels. The article describes a range of merchandise related to the event as well as pointers to files to be used to print professionally designed signage for the day.

WIA clothing for the first National Field Day

There’s a report of the breaking of the national record for 47 GHz – 58 km. A wok lid held up one end of the successful attempt!

Paul McMahon VK3DIP presents the second part of his ‘Generic PC interface for the amateur experimenter’ with the focus on how to use the unit. This project was described in an earlier post.

There are reports and photos from the recent ILLW and an update on the growing amateur activity in Australia on 137 kHz and 500 kHz and info about this month’s JOTA, Jamboree of the Air 15-17 October.

The Biggest Bird in the Pond

On my morning walk yesterday, I had quite a treat. Sure wish I had taken the camera along. On the shore of the flood control pond that flows out into the golf course, were 4 fine Florida water birds. It is not common to see them bunched together like this. A Great Blue Heron, a Little Blue Heron, a Great Egret and a Comorant were lined up in a space of about 8-10 feet. There was a good bit of shoving and jockeying for position and they were working down the bank fishing in the same small spot.

Cormorant is like a living submarine or scuba diver

Made me think of the pileups a DX station creates…      The comorant had a distinct advantage as the only real swimmer and diver of the bunch. It ranged up and down the bank picking off small fingerlings and bullying the other birds by swimming right up to their skinny legs and surfacing. Reminded me of some of the pileup busters I’ve observed from time to time.

At the same time, the little guy, the Little Blue Heron, and the regal looking, very white and tall Great Heron      were left to glean around the edges and pick off the fish that were panic striken and confused by the other birds fishing in the midst. This reminded me of all the contests where I have to dodge the big birds and pick off what I can around the edges.

Funny thing is there are tens of thousands of fish all along the bank, not just where these birds were bunched up. What is it about us that piles us up and forces such fierce competition? Hmmm?

Yep, I am a devoted CPG (Contest Point Giver), who had a nice morning walk and got to see a great outdoors show for free. That is why I love operating QRP portable. Being outside and enjoying the free shows only adds to the enjoyment of the hobby and the friendships made on the air.

72,

Kelly K4UPG PB #173

Tall White Bird is really quite skittish

This little Blue Heron really gets around fast

There was a time when developments in the realm of amateur radio were relevant in relation to the rest of the world. In those days, a young man might become interested in the technology of radio and his first steps in that venture may have been as a radio amateur. Through building and experimentation this neophyte might eventually make a living as a radio and TV repairman, or find work as an electronics technician. He might even follow a path to becoming an electronics engineer developing new methods and hardware for commercial or military communication.

There was a thread of commonality between his hobby and his vocation. Radio amateurs were on the leading edge of discovery and experimentation and these developments were closely mirrored in the non-amateur world. In fact, what this fellow was doing on the workbench in his ham shack was often a step or two ahead of what he did for his employer.

But at some point in the flow of space and time, amateur radio reached a critical crossroad. It could proceed one direction into the future or choose the other direction – a long, and circuitous route back to the past.

For good or for bad, we chose to jettison the future and return to the past.

Consider carefully the position of amateur radio just prior to this crossroad. We had pioneered FM radio at VHF and UHF and had blanketed the countryside with repeaters such that an operator with a handheld radio could make contact with others far outside his line of site. We had already worked out the protocols and network topology necessary for passing data through the ether at rates comparable to landline methods of the age. And we had our own fleet of satellites that pioneered new methods in space communication as well as low-cost spacecraft construction and launch.

Future developments in the non-amateur world of radio from that point included cellular technology and the transmission of higher speed data over the air. Commercial applications for broadcast radio and television have changed radically and now include the imposition of digital methods. Military applications for secure battlefield communication use satellite and terrestrial means like mesh networking for voice and data transmission. Our homes, restaurants and coffee shops are bathed in RF transmitted data that keep our mobile devices connected to the Internet.

None of these “new” technologies would have been even the least bit foreign to the radio amateur had we taken the path to the future. Youngsters would have been encouraged to become involved in our hobby as it could very well lead to a rewarding career in one of many growing and lucrative technical fields – just like in the earlier days.

The most important point I want to make is this: technology didn’t pass amateur radio by because we weren’t intelligent enough to have adapted to the rapid changes it produced, we could have lead that revolution, ham radio enthusiasts were the proto-geeks on this planet.

No, technology didn’t abandon us, rather, we voluntarily chose a path that led back to the past and in so doing, watched the future march ahead without us.

My guess is that we chose this path because the future involved changes that seriously challenged the old dogmas. The old guy who could pound brass would be dimininshed in the new world while the young kid with the computer connected to his radio would be raised up and this was deemed unacceptable.

Of course there remain some facets of our hobby where higher tech methods are required. For instance, it would be difficult to argue that bouncing a radio signal off the moon and then receiving the echo from it isn’t one of the more challenging things that hams do. But consider how many amateurs are active in that pursuit and you must conclude that it’s a small fraction of even one percent of all licensees. Why? Probably because of the degree of technical difficulty required for success. It’s much easier, trivial in fact, to toss a wire over a tree limb and make a 40 meter CW contact; so more choose to do that instead.

Low-power enthusiasts, (QRP) have spent decades trying to make the point that HF communication is possible with practically nothing at all. That you or I could whip up a two-transistor transceiver in a single evening and make radio contacts with it is widely seen as the magic of radio among those in this camp, however, it really only serves to make the point that they have embraced the simplest, lowest elements of RF technology and have no intention of moving beyond it.

In selecting the path to the past, we also decided that the entertainment value of amateur radio was more important than the rapidly expanding field of communication technology.

Consider the many ways that we have made two-way radio a game. We chase DX until all of the countries of the world have been worked and then we invent new ones. Weekends are dedicated to non-stop operation with the goal being to earn the most points. We make radio contact with others and then trade post cards to prove that we actually did it. Certificates (wallpaper) of all kinds are offered for contact with specific stations or during specific events, etc.

The lingua franca of amateur radio is the Morse code and those who are proficient in CW are more valued than those who are not. Like Latin, it’s a dead language that is non-essential yet it serves as a powerful totem for an entire belief system internal to amateur radio and nothing else under the sun.

In selecting the path to the past, the hobby has determined that nostalgia is more important than innovation and therefore we must now depend upon nostalgia to drive future growth; this is a critical point.

The United States has a population with a soon coming glut (baby boomers) of new retirees. Folks like me who enjoy looking at the past as much or more than looking ahead. This is a ready-built market for nostalgic growth and we should anticipate that those who enjoy reading about the radio distress call from the Titanic, restoring old radios or building new equipment with vacuum tubes, etc. will swell our numbers for a season. It’s completely unsustainable over the longer-term, but it is here and now and it will contribute to some additional growth for the hobby.

Though ham radio is a delightful and enjoyable hobby, we are forced to own up to the consequences of the decision that was made not so long ago. Ham radio has become like an old trading post on a lonely stretch of Route 66 somewhere in the desert. You stop to admire the wooden Indian, the old time gas pumps and the soda machines. You snap a few pictures, buy a few trinkets for your niece and nephew and spend a moment warmly remembering what the Old West was like long ago.

And then you get into your car and return to the real world.

None of this will diminish the enjoyment that enthusiasts can derive from this unique hobby. There are people in the world who enjoy building old steam engines, restoring antique cars, and making butter by hand. Technology doesn’t always improve the quality of life and it has many unintended consequences. But reality demands that we acknowledge our proper place in the grand scheme of things, and when it comes to amateur radio, we are no longer of the same ilk as those who innovate and invent. It’s been decades since we last put a dent in the universe and it probably best we live out our days quietly playing with our radios.