Showing posts with label ham. Show all posts
Showing posts with label ham. Show all posts

Monday, May 27, 2013

TK-890 Amateur Radio Mod

Over the past weekend a friend of mine asked if I would help him convert his Kenwood TK-890 mobile to work on the ham bands.  I wasn't sure how successful we'd be, since most every online search came up with at best little information or at worst flat out statements saying "Nope, can't be done."  As it turns out, it can be done.  Kudos to Tim K for his notes posted to Radio Reference which gave enough hints to make this happen. 

In general this is how it went.  My friend wanted his radio to work on the Bay-Net repeater system, which operates 443.225 with a +5 MHz TX split.  TX was fine, but RX was giving a steady "beep-beep-beep..." which indicates PLL unlock.

In the PLL section, under the copper foil, are three adjustment pots: A = TC302, B = TC303, and C = TC301.  (Don't ask why they're out of order.)  According to the Service Manual, Pot A sets the PLL for the low end of the receiver range, Pot B sets the high end of the receiver range, and Pot C sets the TX PLL.  The goal is to monitor test point CV with a voltmeter and adjust for minimum voltage during RX and TX.  This requires re-programming the radio's test frequencies to match the band of interest, so you'll need the KPG software and cable. 

Once we had the PLL voltages minimized for RX and TX, I found that the radio's TX frequency was way off, so a frequency alignment was needed.  This again required the KPG software - for some reason we couldn't get the radio into Panel Test/Tune via the control head.  It was easy enough with the KPG, once we realized you need to press "Enter" to lock the modified value. 

Other things like adjusting the BPF and checking deviations should be done.  In the end, the conversion was very easy and the radio is working well on the UHF amateur band.

Friday, January 7, 2011

You're doing it wrong

The ARRL kicked off 2011 with a news item that hopefully is not a harbinger of more retro-tech lameness to come during the new year.  (Hint: It is.)  "Ring in the New Year with Morse Code Ringtones" started off well enough; make your cellphone ring with CQ CQ CQ or some such.  I did this almost two years ago and it's great fun; I even made ringtones with my wife's name, the callsigns of hams in the Bay-Net group, etc.  I got lots of good comments on my ringtones from folks at the 2010 Dayton Hamvention; a few even requested that I email them copies of my MP3 files for their phones.

The ARRL article fails on two fronts; first off it talks about creating Morse Code ringtones like it's a completely new thing (clearly it's not), and secondly it goes into detail about the horribly convoluted process Tom AD1B used to create his tones.  Tom actually used his Ten-Tec rig and a keyer paddle to generate the Morse Code, recorded the audio (article is unspecific on how he did this; my money is on "8-Track Tape Deck"), massaged the audio files in Audacity, and then generated MP3 files.  Talk about using a bazooka to kill a mosquito.

Clever.  And completely unnecessary.  I generated my MP3 files by going to LWCO.net, a website created by Fabian Kurz, DJ1YFK.  Fabian's website (the URL is an acronym for "Learn CW Online") offers a number of useful tools, many of which are based on Fabian's excellent open source "ebook2cw" library.  One of the tools on LCWO is "Convert text to CW".  You type in text.  It generates an MP3 file for download.  You put the file on your phone.  Done.  I can generate a library of unique ringtones for twenty people in the time it takes Tom to record and process one.

And even my method is now somewhat obsolete with the advent of apps for smartphones that convert text to Morse Code on the fly.  MorseRing for Android is available in the Android Market for 99 cents.  It converts Caller ID strings to Morse Code.  The beauty of MorseRing is that I now know who's calling me even if my phone is 25 feet away.  I'm sure there is similar apps for the iPhone, possibly one for Palm, likely not for Blackberry.

Tuesday, October 19, 2010

Pacificon 2010 Wrap Up

This past weekend the Mount Diablo Amateur Radio Club hosted ARRL Pacificon at the San Ramon Marriott.  I was glad to see the event back this year, after last year's debacle which forced the organizers to move the event to Reno in conjunction with EMCOMM West.

This year's event was well-attended.  There were some great presentations, I got a chance to see some folks I don't often see, and I was given the chance to speak twice; including delivering the final keynote on Sunday.

I promised several people that I would post my presentations, so here they are:


Sunday, November 22, 2009

SO2R -- The hard way


This past weekend I had the privilege to be a guest operator for the Radio Club of America on their special event station W2RCA, celebrating the 100th anniversary of the RCA. The station was co-located with the anniversary event in Washington DC, and I wasn't able to attend in person, so the operation was handled using remote PC access and VOIP software, similar to the setup which I described back in late 2007.

A problem with remote setups is that they require a fast Internet connection to work well; the primary challenge being the speed (or lack thereof) at which you can switch from receive to transmit and back again. Because the W2RCA special event station was scheduled to happen during the ARRL's November SSB Sweepstakes, it was decided that we would work the contest as W2RCA. Being in a contest situation meant that rapid TX/RX switching would be a must.

As it turned out the network connection between my home and the RCA event location wasn't quite fast enough for the furious pace of the contest. I was having a hard time getting the remote radio keyed quickly enough to bust the pileups. In some cases I would bust the pileup only to have the target station get frustrated because I wasn't coming back to him fast enough. Not good, not good...

Out of curiosity I turned on my home station and tuned to the same frequency as the W2RCA remote. I found that despite being separated by 2,500 miles I could hear the target station well on both radios! Not wanting to give up on the contest for lack of fast TX/RX switching I decided to try an odd twist on SO2R (Single Operator-Two Radios) setup. I activated transmit on the W2RCA remote station, muted my microphone, and plugged my headphones into my home station. Because SSB is carrier-less mode the remote radio would not transmit any power with the microphone muted.

The next time the target station called QRZ I unmuted my microphone and called him, and heard him come back to me on my home station! I was able to work several stations this way, although there were still a few challenges. First was the effort of keeping the frequency of ftwo radios in sync. Second was some of the stations I could hear clearly on my home station were outside the range of the W2RCA remote station. But in general it worked and was an interesting way to get around the slow TX/RX switching issue.

Thursday, September 10, 2009

..-. .. .-. ... - -.-. --- -. - .- -.-. - <= (First Contact)


This week marked a big milestone for me; I successfully completed my first radio contact using CW aka Morse Code. It was a tough contact; conditions were bad but the guy I worked was polite and patient with me so we managed to pull it off.

I had always believed that I simply did not have an "ear" for code; it sounded like noise to me and I was never able to get past a basic understanding of the mechanics. After the amateur radio code requirement was lifted I was thankful and quickly upgraded to the highest level license. Still, in the back of my mind I felt I should make a real effort to learn code; if for no other reason than to overcome a personal limitation. (If you think I have a strong aversion to being told what to do; I have an even stronger aversion to being told what I can't do -- even if I'm the one doing the telling.) So my 2009 resolution was to learn enough code to complete a radio contact. It took me nine months, but I made it. I don't know that I will ever be a "real" CW operator, but right now I'm having fun and feeling good about my accomplishment.

I would like to thank the following people who helped make this happen for me:
  • Gerald Wheeler (W6TJP) - Author of the Code Quick learning method. A great basic foundations course.
  • Fabian Kurz (DJ1YFK) - Developer of the LCWO.net website. An awesome online Koch-method trainer. Did I mention it's free?
  • Leon "Skip" Stem (WB4DAD) - CW operator, FISTS member, and the first entry in my CW contact logbook. Thanks for being patient with me.

Wednesday, August 26, 2009

You, um, expecting trouble? BIG Batteries...


Through a contact at an SF Bay Area web hosting company I recently obtained for free a set of used -- but still very strong -- UPS batteries; the Deka/Unigy 31HR5000. This hosting company offers their customers a 100% uptime guarantee which means that they can't wait for their UPS batteries to fail; they are used for a number of months and then they're replaced. Since the hosting company has to pay someone to come haul them away they're happy to see them repurposed.

These batteries aren't the typical deep-cycle marine variety you see on Field Day. They weigh 95 lbs each. Fresh from the factory they're rated at 135 amp-hours, which is about 1,800 watt-hours. My main HF rig (Kenwood TS-2000) consumes about 200 watts worst-case (when keyed on 2 meter FM, set for 100 watts) which means that using one of the Deka batteries I could leave my rig keyed-down on 146.520 FM @ 100 watts and it would remain on the air for about 9 hours.

I now have 3 of these monsters running in parallel on my home station. That's over a full day of continuous talk time. Left in receive-only mode my station will run off-grid for about 8 days.

Total cost? About $40 for some 4-gauge jumpers and misc hardware.

Bring on the zombie attack. I'm ready.

Monday, February 16, 2009

Economy takes a dive; amateur radio vendors fail to notice


You'd have to be living in a cave to not know what's going on with the economy, or at least what Washington D.C. is trying to terrify us into thinking is going on. Setting aside this Recession vs Depression debate for the moment; it's clear that the economy is struggling at some level. We're seeing home values drop sharply, credit is hard to obtain, auto dealers in some parts of the country offering 2-for-1 deals, etc. One need only visit your local Best Buy, Fry's, etc to find smoking hot deals on consumer electronic equipment. A buyer's market you say? Apparently not for amateur radio.

Recently I decided to buckle down and learn CW aka Morse Code. I've been using various tools, including a great online trainer called LCWO (Learn CW Online). I've also been using W6TJP's Code Quick; good for getting the sound-alikes for each character but my advice would be to save your money on the optional software and focus on sites like LCWO.

Needing a paddle/key in order to practice sending CW I decided to stop by Ham Radio Outlet (aka "the candy store" and buy the Bencher BY-1 for what their printed catalog said was $99. I pulled up in front of the store and the parking lot (normally full of vehicles festooned with antennae) was so empty I had a momentary thought that maybe it was a holiday and I'd just forgotten. I walked into the candy store (normally full of amateurs festooned with antennae) and was greeted by one lonely salesman. Recession? Depression? Clearly business is slow.

Inquiring about the Bencher paddle I found it was in stock...and that it cost $109. Ex-squeeze me? Catalog says $99. Yes, but the price went up. Since when? Since the catalog was last printed, apparently. I see... So other retailers are slashing prices, people are spending less, your store is completely empty for the first time I can recall...and you're raising prices.

To his credit my friend gave me the catalog price. Normally I'd also get a discount for being a member of the Cactus Intertie group, but not this time. It started me thinking that I've not really seen prices fall on amateur radio equipment the same way that mass-market consumer electronics have fallen. For example; I've been saying that I'll buy an IC-7000 once the sale price drops below $1,000. And yet the price remains above $1,300 and from some retailers seems (like my Bencher paddle) that the price have actually increased.

Is amateur radio immune to economic downturns? Sure seems like the manufacturers and retailers think they are.

Friday, September 19, 2008

Where's David?


Been a while since I posted. Most of the summer was spent doing various projects; some for pay and some for fun. One of my new interests is APRS - Automated Packet Reporting System. It started when a ham friend of mine decided to hike the John Muir Trail and wanted me to keep in touch with him and his girlfriend as they hiked. He carried a Kenwood TH-D7A(G) APRS handheld; so I decided that I would set up APRS to track him.

In the process of doing this I learned a lot about APRS and the mechanics of routing packets through RF. I set up an "I-Gate" which is a system that passes received RF packets into the APRS servers via the Internet. Turns out this was quite useful to some local hams that carried Kenwood TH-D7A(G) APRS handhelds which could not normally reach the mountain-top APRS repeaters aka "digipeaters". So now my station's running 24/7; not great for keeping the electric bill small but I guess that's why I have a 3 KW solar PV array on my roof, yeah?

In exploring APRS I learned that when it comes to digipeaters "more" is not necessarily equated to "better". RF packet is about passing packets to the target (or targets) with little (or ideally no) redundancy. For the most part we enjoy a great VHF environment here in the Bay Area; the Silicon Valley is ringed by mountain ranges which provide line-of-sight at nearly any time to at least one of the wide-area digipeaters. Any additional digipeaters are redundant and therefore create extra packet traffic. (The exception to this is of course low-level/low-power "fill-in digipeaters" designed to serve small pocket valleys, urban canyons, etc.) With a dense population and a lot of hams using APRS it's a constant battle to keep the 144.390 MHz APRS channel from becoming too crowded. I-Gates don't contribute to the crowding problem; that is if they're set up as receive-only I-Gates.

I'm having a good time with APRS; besides just being able to track locations I've also been exploring how it can be used for text communication; I had a nice QSO with YB2TJV in Indonesia recently. It's also proving useful to study VHF propogation in the area. I have no idea why my callsign was used by OH7LZB as an example in his blog post on the new I-Gate coverage function on aprs.fi; but I was flattered anyway!

I'll be hosting a forum on APRS at Pacificon 2008 which runs from October 17th - 19th in San Bruno, CA. My forum is scheduled for 8:00am Sunday the 19th; if you're in town please do come by and say hi!

Tuesday, May 6, 2008

Wireless at Maker Faire 2008


Last weekend my wife went on a short trip with some friends, leaving me home to try my hand at single fatherhood. Still, I managed to get away from my "Mr. Mom Weekend" for a few hours on Friday and Saturday nights (paid a babysitter on Friday, and cajoled my mother-in-law into service on Saturday). On Friday I attended the PAARA amateur radio club meeting in Menlo Park, and on Saturday I drove up to the Maker Faire in San Mateo. The role of wireless technology at the Maker Faire was very evident, but not in the way you might expect. For the uninitiated; the Maker Faire is a combination of Burning Man + science fair + flea market. People come to show off their contraptions and creations; robots, alternative fuel vehicles, lots of stuff which uses embedded controllers, and (especially after the sun went down on Saturday) enough fire and explosions to satisfy even the most ardent pyromaniac. The highlights for me were:
The contrasts at the Maker Faire are numerous and glaring. The parking lot is filled with hybrid cars, and the usual "Impeach Bush"/"Obama 2008" bumper-sticker polemic you expect to find in the SF Bay Area. So you'd think the Maker Faire would be focused heavily on eco-friendly and minimal carbon footprint exhibits. And yes, there were a huge number of exhibits showing off renewable energy and transportation technology; solar, wind, algae-fuel, bio-diesel, electric motorcycles, pluggable hybrids, etc. But after sunset there were also many combustion exhibits and shows using propane, kerosene, lamp oil, etc. The smell of incompletely burned hydrocarbon was everywhere, as tongues of smoke curled up against the deepening sunset in the chilly evening air. How to reconcile this? I don't know that I can. Is the Maker Faire a neutral zone in the global warming debate, a sort of United Nations of carbon consumption? Or is this yet another example of hippie hypocrisy? Best if we leave that one to the philosophers.

If you're still reading, you might be wondering how this all relates to wireless. It does, and thanks for sticking with me as I get around to that. Wireless technology of all types was very evident and widely used at the Maker Faire, but the operating word here is "used". There were no exhibits (that I saw) which showed off anything related to innovation in the wireless space. There were a ton of people using Wi-Fi, Bluetooth, proprietary ISM data-link radios, radio-controlled servos, etc. Wireless was everywhere, but in all cases it was "user wireless"; projects created with off-the-shelf modules and in some cases chipsets. Wireless is a tool to complete projects, not the project in and of itself. I find that this echoes a growing trend I've observed at the WCA and in the wireless industry as a whole: Put plainly, wireless technology is becoming a commodity.

Some of the hams from PAARA set up an amateur radio special-event station to make 20m and 2m/70cm contacts from the Maker Faire. I never found this exhibit, but a few people on the N6NFI repeater say the station had to contend with some bad RFI; which I can imagine given that a giant Tesla generator was operating nearby. I'm quite sure that most of the Maker Faire was essentially a gigantic FCC Part 15 violation.

It's unfortunate that the hams did not have a bigger role at Maker, because amateur radio has its roots in innovation and home-brewed technology; ham radio is a great-great-granduncle of the Maker movement and should rightfully hold a place of honor and respect in the Maker community. I think that the problem is that a lot of amateur radio has become consumerized and is now ironically an example of the "culture of learned helplessness"; ironic because the technology consumerism which is the fastest growing segment of amateur radio (i.e. people who chose to buy versus make) is at odds with the hacking/creation/innovation core elements of the Maker movement.

The amateur radio community still certainly has a lot to say about innovation and technology; the huge number of hamfests, tech days, field days, DXpeditions, etc is evidence of this. The problem seems to be that amateur radio events have become somewhat insular; we're doing events for ourselves, and not reaching out as much as we should to non-hams. By way of example; this month's AM-TECH Day is on May 10th. Past proof shows that it will be popular, or at least popular with hams. Wouldn't it have been better to push AM-TECH up a week and hold it at the Maker Faire? How many Makers could we have licensed if we'd held AM-TECH and a VE test session a week earlier at the Maker Faire?

I also think that we need to seriously rethink our approach to new technologies. Hams are spending way too much energy on "maintaining the tradition" in modes of operation such as CW and voice, and not exploring how amateur radio might benefit from integration with other technology. I think radio amateurs still have a lot to offer the wider technical community, but we need to reach out and open our doors. This means far less worrying about nurturing traditions and whining about the evils of no-code HF, and a lot more mold-breaking. The concept of the Maker Faire and amateur radio is to hack, to repurpose, to change forms and function. We can learn a lot from the Maker community, and they from us. How do we make this happen?

Monday, February 11, 2008

Expensive Desktop Mic Get Pwned By $12 VOIP Headset


A while back I purchased an entire amateur radio set from a ham who was getting out of the hobby. A rare occurrence, mind you. I really only wanted the radio (a Yaesu FT-1000D) but the guy sold me everything except the feedlines and antennas for less than I'd expected to pay for the radio. Everything worked as expected. In the plethora of boxes I lugged home were a lot of accessories; among them a West Mountain Radio RigBlaster Pro.

The RigBlaster sat in storage for almost a year, until recently when I watched K7AGE on YouTube talking about his homebrew Bluetooth headset interface. One of the accessories which came with the FT-1000D was a Yaesu MD-100A8X desk mic. I've frankly been less than pleased with performance of that mic; it's very sensitive to any change in sound level due to distance from my mouth which means that keeping the FT-1000D's ALC from kicking requires that I constantly ride the PA drive control--and that's tough to do when I'm focused on maintaining a constant mouth-to-mic distance. So I started thinking about getting a headset. Of course, you can spend a ton of money on a "good" headset; e.g. Heil Sound is the name in radio mics and headgear and their stuff starts over $100 and goes up from there. Being the cheapskate I am I decided to experiment with a $12 General Electric VOIP headset I got from Target to do Skype while I was traveling through Asia in 2006.

Interface to Yaesu was a snap using the RigBlaster. As with most amateur radio accessory companies, West Mountain Radio's website and manuals are poorly written but I was able to decipher them enough to set the jumpers properly for the Yaesu. Most computer headsets are have electret voice elements which require a 5 VDC bias on the ring terminal; the RigBlaster can provide bias on the MIC2 jack which also happens to be the perfect size for a PC headset plug. I didn't bother to route any of the receive audio paths; for now I just have the receive side plugged into the headphone jack. I have the MD-100 plugged into the RigBlaster--just in case--but its primary function now is to act as a PTT switch.

The results were impressive. I checked in to the 75M late night net and got an unsolicited report of "great sounding audio" from W6EZV. A flattering report, considering that the 75M late night guys are used to hearing perfectly processed and equalized audio from people like W6OBB aka Art Bell. I'm now able to operate with both hands free, and the headphone has an added benefit of making sure the receive audio is not bothering my family after they've gone to bed. My audio settings are a lot more consistent and don't require constant fussing with the PA drive and speech processor levels. Best of all I'm no longer inclined to go out and spent hundreds of dollars to get a high-end Heil headset. I'm now curious to find out if my successful experiment is unique to this particular VOIP headset or if I can get the same results with other brands.

Wednesday, December 19, 2007

TS-2000 Remote Control w/ Audio


One of the fun but also useful capabilities to have in your shack is the ability to run your rig remotely. I decided to do this for my Kenwood TS-2000 since it's basically a radio wrapped around a computer and has a zillion interface options. Kenwood makes ARCP-2000, a remote display program which frankly isn't worth the $250 they ask for it. Ham Radio Deluxe (aka HRD) is a great program; it's feature-rich, highly configurable, and best of all free. You can run it over a screen-scraper like VNC, Remote Desktop, or even X-Windows. A better solution is to use the HRD remote access system; this essentially allows you to tunnel serial data to your rig and control it via a remote instance of HRD.

Two challenges exist here; publishing the HRD server over the Internet without open router firewall ports, and creating a high-quality and stable audio path.

Dealing with the server question first; I absolutely do not recommend opening holes in your firewall. There are a lot of solutions available which eliminate that need. I use Hamachi which has an additional benefit in that the clients are coordinated via a central server so a static DNS is not required. I simply point my remote HRD instance at the private IP assigned to my home system by Hamachi and I'm connected.

Getting quality audio across the Internet used to be a challenge, but after using Skype this year for business I think it's ready for prime time. I created a separate Skype client ID intended only for receiving inbound calls from me when I'm remote. I set Skype to auto-answer, and point the audio paths to my rig's sound interface.

Detailed diagram of my setup is available here.

Wednesday, July 4, 2007

How not to build a transceiver


Primarily due to its flexibility, one of the most popular mobile rigs for amateur radio is the Kenwood TM-742A and associated models such as the 942, 741, etc. The TM-742A is a tri-band rig which can accept up to three band modules out of an available five; 10m, 6m, 2m, 1.25m, and 70cm. Interesting trivia; the MSRP in 1994 was $660. Today, clean TM-742A rigs can and do go for over $750 and rising as replacement parts and band modules become harder to find.

Every rig has its quirks, and a quirk of the TM-742A is that the 2m module is prone to failure. The 2m power amplifier is a Toshiba S-AV17 which is a set of power transistors and associated components soldered onto a beryllium ceramic substrate. Symptom of the failure is that the rig will transmit enough power to be heard on other close-by (within a few tens of feet) rigs but makes no power at the antenna. Most people just pony up the $65 and replace the S-AV17. Others have discovered that the failure lies in a microscopic crack in the ceramic that breaks one of the microstrip filter traces. The fix for this is to remove the S-AV17, pry off the plastic cover, and run a rapid thermal recovery soldering iron (like a Metcal or Hakko) over the crack area. A standard resistive heater iron will not work; because the ceramic module is designed to absorb lots of heat so the trace won't get hot enough to flow. It takes 15 minutes to disassemble the rig and 15 seconds to solder it. Thanks to Kevin W3KKC for his webpage discussing the problem and walking through the repair process; complete with photos.

(Disclaimer: beryllium is nasty stuff. You don't want to inhale it. If you're not comfortable doing this; don't have the right equipment; etc blah insert dire warnings here then pay the $65 and don't try to repair the amplifier!)

Interestingly enough, and relevant to the title of this post, is to examine why the module fails. The reason for the failure is excess heat. The stock configuration for the band modules is to have the 2m in the middle, which means that the 2m power amplifier is buried about as deep in the rig as it can be. At 50W the 2m module is also capable of the highest power output, so therefore it gets hotter than the other modules. The ceramic cracks and you get a dead S-AV17. I would accept this explanation readily enough except that every 2m module I've disassembled has had the same problem; the S-AV17 is mounted dry. Not one has used any form of thermal grease to promote conductivity into the heatsink and transceiver structural frame. This would be like a high-speed CPU being installed onto a motherboard without thermal grease; the CPU is essentially guaranteed to fail from thermal overload. This is (or more accurately was) a blatantly stupid move on Kenwood's part that has cost radio amateurs thousands (if not tens of thousands) of dollars in unnecessary repairs, replacements parts, shipping costs and downtime. Can you demand a recall of a 14 year old product?

Monday, May 28, 2007

Amateur Radio: 5,200 miles on 50 watts and a $2 antenna


Lately I have been getting prepared for the annual ARRL Field Day, which is an annual operating exercise and public showcase event for the amateur radio world. Amateurs all over North America will set up in campgrounds, parking lots, and fields and attempt to make as many contacts as possible using various "modes"; everything from Morse Code and "phone" (what normal people would call voice, talking into a microphone) to exotic digital setups which use computers connected to radios. My club (the Northern California Cactus Radio Association) will operate as K6SRA from a campground in Henry Coe State Park, near Morgan Hill CA.

I'll be running the digital station this year, and plan to use (in addition to the usual PSK31 and RTTY setup) a very new mode called JT65A-HF. JT65A isn't new to amateur radio as it's been used for a while for "moon bounce"; and yes, I mean literally for bouncing signals off the moon. Earlier in 2006, a few people decided to transmit JT65A signals over the HF bands; primarily 20 meters (14.076 MHz) and 40 meters (7.076 MHz). In only a few months this new mode has exploded in popularity, primarily due to the very high sensitivity afforded by a Reed-Solomon forward error-correction algorithm implemented this mode. It's mathematically provable that JT65A signals can be detected with 100% certainty even if the received signal is -22 dB under the noise floor.

In preparing for working JT65A-HF on Field Day I've been learning to use an application called WSJT which is used mostly by the moon bounce and meteor-scatter folks but now also HF enthusiasts. I've made some amazing contacts this way; just tonight I logged a contact with a guy in Australia using only 50 watts of power and a homemade antenna I built with $2 worth of parts I had lying around my garage. This is the equivalent of someone being able to see a 50 watt light bulb from space at a distance four times that of the International Space Station, or of someone talking from San Jose CA to San Diego CA on a CB radio. I expect we'll be seeing a lot more of JT65A in the HF bands, especially as radio amateurs suffer through the poor radio propogation conditions created by the current solar minima.

Update (15 June 2007) : I just beat my Australia record with a solid contact to ZS6WN in South Africa. 10,526 miles, same power, same antenna!

Update (24 Sept 2007) : WA3LTB has created a video demo of WSJT and posted it to YouTube.