Thoughts on GoTenna

[Update Nov 30th 2016: The ARRL has asked Bay-Net to attempt a modification of the GoTenna for use in the amateur radio bands.  Also I should note that since I wrote this article, GoTenna has backed off on their performance claims to levels which are more in line with reality.  I'm looking forward to seeing the inside of these units and doing some real world testing.]

[Original Article posted July 20th 2014] GoTenna seems to be doing a good job of generating "buzz" for this proposed product - a cursory search of Google+ and Facebook turned up a HUGE number of posts.  Many people have forwarded this to me via email or social tagging.  The proles are calling it "Text messaging for CB radio".  facepalm

GoTenna's radio works in the MURS band - three channels at 151 MHz and two channels at 154 MHz.  Given what I know about their product, MURS rules will require them to operate on the two 154 MHz channels.  They say the product emits 2 watts, which with a 3 dB antenna would be 4 watts effective radiated power (ERP).  At that level they're going to have to undergo safety exposure testing, which is expensive - I guess this is why they're crowd-funding the project.

To be fair - GoTenna has an engineering advantage in that they're not dealing with large data streams - they send GPS coordinates, text messages (< 200 characters), and it's not real-time.  They claim 20 - 30 mile range in a "typical" urban environment - I'm struggling with the idea that something which emits 4 watts ERP can give you 20 - 30 mile urban range.

Coding gain from a forward error correction engine could help, but I can't imagine an effective coding gain of more than 10 dB.  (The device is battery-powered, and claims a 30 hours continuous on time - processors which could give them > 10 dB coding gain are going to wipe out a battery fairly fast.)  Let's be generous and say their coding gain 10 dB - this gives effectively 40 watts.  I suppose depending on your definition of "urban" this might be enough to cover 20 - 30 miles.  A more reasonable coding gain will be in the 6 dB range, which means effectively 16 watts - and I don't see 16 watts covering urban areas very well.

Here's a post on Make.com from Raphael Abrams, the GoTenna RF designer: http://goo.gl/L5rZ2e

GoTenna claims that the device can be used in-flight on commercial airliners.  This is a Bad Idea™, and I don't see the FAA signing off on this any time soon.

Lots of speculation on GoTenna right now in the radio community, but not many answers to the head-scratcher questions.

JT65 Articles from CQ Magazine

Last year (October and November 2010) I co-authored with Tomas NW7US a two-part article "Communicating Under the Noise" about JT65A on HF which was published in CQ Magazine.  Thanks to Rich Moseson for agreeing to make the articles available in digital form.  PDF copies of the articles can be obtained here: Download (PDF)

Enjoy.

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.

Way to Encourage New Ops, Dude

I'm on 80m right now listening to a Cuban station (CO8LY) on CW. The guy is doing well, about 15 wpm with a 9 wpm Farnsworth rate; just my speed. He's got a good fist and is managing the pileup well.

Three times in the past half hour I've heard guys come back to him at well over 25 wpm. He's patiently trying to confirm their calls, sending bits with a question mark at the end. It's clear that his max rx speed is around 9 wpm. And yet; these clowns won't slow down for the guy! It's like they're insisting that he match their speed. Unbelievable.

Why do CW ops do this? Slow down. It's not a race, not a competition. He who dies with the fastest key doesn't win. Give the kid a chance to learn and maybe in a few years you can work him at 30 wpm if that's what gets you off.

Power Struggle

Recently I blogged about amateur radio's culture of exclusion; a post which generated a large amount of interest, new readers, and surprisingly little if any hate mail. Based on the blog post I doubt I'll be invited to join CWops or FOC, but the SOC has welcomed me with open arms and they're a fun bunch of folks.

One of the areas I touched on was how some modes such as RTTY tend to stay away from subbands used by older modes such as CW during contests. WW2PT pointed out a post by W2LJ which indicates that RTTY contester's self-enforced deference to CW may be ending.

It's clear that there is a schism within amateur radio's digital mode world between RTTY and basically everything else. Amateur radio's so-called digimodes (PSK31, Olivia MFSK, etc) are almost always run at 50 watts or less. Some modes such as JT65 and WSPR (developed by K1JT ) are run around 20 watts. And CW (which is technically a digimode) has a large following of QRP operators who run CW using 5 watts or less.

Reason for these low power levels is that modulating/demodulating a radio signal using a digital signal processor allows the use of error-correcting techniques which results in what's termed "Coding Gain". Coding gain usually adds (depending on the code used) about 2 - 6 dB to the system gain. This means that a signal which is transmitted 50 watts into a vertical antenna (unity gain) is seen effectively as 75 - 200 watts by the receiver. Coding gains higher than 6 dB are possible. So digimode practitioners don't run "big power" because in digimodes you don't need much power to work the world.

Stack this up against RTTY where "big gun" stations running kilowatt amps into high-gain antennas are not unusual. While it's true that RTTY doesn't offer any coding gain I think that a kilowatt of power is a bit overkill. If all RTTY operators remained within the usual subbands there wouldn't be many issues. But the problem comes up during contests where the contesters spread out across the band and the other digimodes simply get wiped out; this includes QRP CW ops.

Lately there has been a resurgence of interest in WSJT modes; probably due in part to the excellent work done by W6CQZ in providing a reverse-beacon system, chat/sked system, and building upon K1JT's original software to create a new and improved application. Yet with this new interest there have been a disturbing trend of late where people have been applying an RTTY approach to WSJT modes and wiping everyone out in the process. For example; there's one guy who's just across the valley from me that's creating all sorts of havoc by (1) running big power (his QRZ vanity photo clearly shows his amps), and (2) driving his system into ALC which heavily distorts his signal. And it's not just one guy; the other night I was getting overloaded by a guy in Colorado. How much power must he have been running to overload the front-end of my receiver from 1,000 miles away?

So why is this happening? Because many operators have forgotten a cardinal rule of amateur radio; use only as much power as you need to complete the contact. I've completed three JT65a QSOs to South Africa using 50 watts of power with no sunspots on a vertical antenna that most people consider mediocre at best. Big power in digimodes is simply not necessary. Running JT65a with a linear and a gain antenna is like shooting a mosquito with a bazooka.

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.

..-. .. .-. ... - -.-. --- -. - .- -.-. - <= (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.

S 649 : Radio Spectrum Inventory Act

I posted this because I think Senate Bill 649 : Radio Spectrum Inventory Act (intro'd by Sen. John Kerry-Heinz, D-MA) is the first shot in a battle I've been predicting for some time; the application of populist politics towards spectrum management and allocation. You need only spend an hour tuning around with a decent all-band receiver to discover that the vast majority of spectrum is nothing but static. The real targets of this "spectrum socialism" are the big guns; broadcasters, the military, and even divisions of the government itself (such as NTIA) which has been "warehousing" spectrum for years while hypocritically requiring auction-winning licensees for cellular/PCS spectrum to demonstrate high levels of loading; i.e. subscribers.

Radio amateurs, I believe, are especially at risk from unintended consequences if this bill becomes law. I've previously blogged that many amateur radio frequencies are largely unused. Some amateur bands; such as 1.25m (aka 222 MHz) and 23cm (aka 1.2 GHz) are used only in certain regions of the US. (1.25m is popular in the Los Angeles area because 2m is so laden with bootleggers and jammers it's effectively become CB radio.) One reason for this is that the radio manufacturers are not selling equipment for these bands; the last 1.2 GHz equipment was the Kenwood TS-2000X which was introduced 9 years ago. Alinco is reported to be releasing a 1.2 GHz handheld, but that's not enough to drive adoption of the band. If the RSIA is an attempt to document usage of spectrum as a precursor to re-allocation based on purpose and usage, then 23 cm is one of the most likely targets for re-allocation once the limited use of that band becomes public knowledge. Our only hope is that the proximity of 23cm to radio astronomy likely precludes the allocation of that band to commercial use; but it could still be lost.

Equipment availability is one issue but at a higher-level the problem amateurs face with RSIA is simply that there are fewer radio amateurs than there were in the past; younger people prefer communicating via the Internet and if they do express an interest in amateur radio they're all-to-often turned off by the arrogance of a few hygiene-optional curmodgeons who tend to hang around at club meetings and hamfests complaining loudly and constantly about how the demise of Morse code testing will lead to the death of amateur radio; ignoring the fact that it's their own urine-soaked elitism that's probably a key element in keeping younger people from the hobby. So when faced with a trend towards populist politics and thus policies, a Congressional Budget Office estimate that the federal deficit may exceed $1.5 Trillion dollars, and huge swaths of amateur spectrum laying increasingly fallow as the number of amateurs continues to decline; the likelihood that the government will pull spectrum from amateurs and attempt to auction it off as a revenue source is increasingly likely. It's critical that we change the face of amateur radio (even if it means slaying a few sacred cows) in order to attract licensees or the day will come that some lawmaker will decide that it's politically low risk to start pulling spectrum from amateurs in order to pay off the deficit.

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.

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!

Tech Note: Radio Shack Pro-2018 Scanner

I recently purchased a cheap radio scanner to replace my venerable I recently purchased a cheap radio scanner to replace my venerable Electra Bearcat 250. I bought a Radio Shack Pro-2018 (catalog # 20-424). Reading through the Radio Shack website a few days ago I was amazed to find that they were selling the programming cable for my scanner for 97 cents!? The cable (catalog # 20-429) is being discontinued, apparently. I found a store which had one and picked it up.

Radio Shack also offers a free programming software package. It is quite frankly one of the lamest applications I've ever seen; an absolutely horrid GUI and it would only import from DBase III format (.dbf) files. A quick Google search revealed an open-source scanner loader application "ProLink" which looked promising. It doesn't specifically state support for the Pro-2018 but it does support the Pro-2017 and the Pro-79 which are (from a serial port interface perspective) the same.

The nice thing about ProLink is that it can open text and CSV files, so creating a frequency list from copied text is fairly easy. I used Excel, and copied a lot of data from RadioReference.com and K6SCC's SCCFreqs.info page. Caveat: Apparently most of these low-end scanners don't have a download function. So don't expect to use ProLink to download the painstakingly-created frequencies you may have already on your scanner.

I ran into two small but annoying glitches which I'd like to share. One glitch was that when I initially tried to open my CSV in ProLink the application would lock up and require a process-kill. I knew the application could open CSV files because it successfully opened a sample file included with the application install. Examining the good vs the bad CSV revealed that Excel did not maintain all of the commas and quotation-marks around text which apparently ProLink expects. So I had to open the CSV in a text editor and manually reformat the file. Thank you, Bill Gates.

The second glitch was in trying to get the serial interface to work. Turns out the I needed to reconfigure my USB-serial dongle for the following config: 4800-8-N-2 (4800 bps, 8 data bits, Parity=None, 2 Stop bits) and Flow control set to "None".

Once I did this the data file loaded into the scanner no problem. I'm not sure I saved any time doing it this way, but at least now I know that I have a soft copy of my frequency list and should I need to make any changes I can do this in the file and then reprogram the scanner.

The Sound of Silence

Last November we drove down to Disneyland in my wife's van, and I wired up a VHF/UHF rig and mag mount for the trip. Ever since the phone systems failed due to overloading during the relatively minor October 2007 Alum Rock quake I've been nervous about relying on cellphones in emergencies. I spent some time researching repeaters along the route, and more time programming everything into the radio.

All for naught, apparently. During the trip I was struck by the almost complete lack of traffic on every repeater I tuned in. It wasn't a problem with my equipment; there just wasn't anyone on the air. Even in the densely populated Los Angeles area, the entire twelve hour trip was mostly a never-ending chain of silence. The most traffic I heard was on linked systems such as the Cactus Intertie and the WinSystem, but that's to be expected because they have dozens of connected repeaters and all it takes is one person talking somewhere on the system to light them all up.

On my base and mobile rigs I have a lot of local repeaters programmed, ready to go. And yet at any given time; nobody's talking. Pick up the mic, announce "W6DTW monitoring".... and listen to silence. Reminds me of the This Week In Amateur Radio "Random Access Thought" segment by Bill N2FNH about a repeater that died when a spider crawled across a circuit board; shorted himself across a resistor; killed the repeater...and nobody noticed. And yet; try asking your local frequency coordination council for a frequency pair and you'll get told "there's nothing available". The howling wind of silent FM static is blowing through most of our local repeaters just as it was through the repeaters I tuned into on the trip to Southern California. So how is it that all of the frequencies are spoken for..?

Things are not much better down in the HF bands, or perhaps I should say not much better in the legal HF bands. Given that we're currently coming out of a low point in the 11-year sunspot cycle you might be tempted to allow that the amount of traffic will be low. Especially in the higher frequency bands like 10 meters, where popular wisdom says there's little propagation during the day and certainly none at night. So the 40 and 20 meters bands have some traffic (mostly contesting), 17 meters opens up around noon for a while, and we're starting to hear folks on 15 meters. But for the most part; few stations are on the air and silence above 21.5 MHz is the rule.

So then why is it that on any given weekend day, if you listen above 27.405 MHz into what's been termed the Freeband, you'll very likely hear a lot of traffic? I hear strong stations coming in from around the Western US and Mexico. Is there something odd about propagation that creates a difference between 27.915 MHz (aka the freeband "Redneck Skip Calling Frequency") and 28.400 MHz (aka the amateur "10 Meter Calling Frequency") so that one is active and the other not? Surely the Freebanders don't have some kind of secret technical prowess that allows them to punch through where amateurs cannot? The reality is likely that amateurs simply don't believe that there's good propagation without sunspots, so they don't tune in and "no propagation" becomes a self-fulfilling prophecy.

I find it amazing that while the great swaths of spectrum which amateurs can legally use sit idle; another group of people who are sometimes called "pirates" (agree or disagree with the term as you wish) are happily making use of frequencies which are right next to a band that amateurs will effectively ignore for a good 25%-40% of every sunspot cycle. Yes, Freebanders are operating illegally according to FCC regulations. No, I'm not a Freebander. However; I do have a sense of respect for them. They are (from what I can see) more enthusiastic and aggressive about pursuing the hands-on technical aspects of radio than many hams. They're out there modifying radio equipment on their own---which they have to do because there's no legal way to buy freeband radios. They're not sitting around waiting for sunspots to come back so they can get good propagation; they get on the air and take what the sun gives them on that day.

That's real radio.

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.

Pimp My Rig

During the recent severe storms we lost power at home a few times. I had my radios on battery power monitoring various emergency frequencies but at times I was struggling to read some of my equipment with non-backlit displays. A small LED flashlight worked well in a pinch, but afterwards I started to think about how I might improve the lighting at my station without using wall-socket power and/or consuming a lot of my station's reserve battery power.

The answer came to me while I was wandering around a Target store. There's a company called WinPlus that makes a line of auto accessories under the brand name "Type-S"; they offer a lot of dashboard gizmos, LED map lights, gadget holders, etc. Their stuff is actually quite well-conceived, for the most part. One of the items they sell is a "Dash Mood Light Set" which consists of two small "LEDs in a barrel" with 3M adhesive-backed swivel-mounts and a "cigarette lighter" accessory plug. Setup was very simple; all I had to do was plug in the lights (using an accessory socket) and stick the swivel-mounts on the radio faceplates. The lights draw less than 10 mA of current and provide great illumination of the displays even in total darkness. The wires are very slender so I was able to tape them down with black electrical tape and now they're essentially invisible.

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.

New Antenna!!

My wife spent the day visiting a friend, and took the girls with her, which left me about 12 blissful hours on a weekend to do whatever I wanted to do. I'd be intending to install a new HF antenna for some time, so this was the best and obvious time to do this.

I put out a call asking my amateur radio friends to come by and help. Bojan agreed, which was great. He's a bright guy, very creative when it comes to technology. If you're ever looking for someone who can turn ideas into reality, give him a call.

The antenna I chose was a Comet CHA250B. This particular antenna is unique in that despite being vertically-polarized it has no ground radials, and it will also tune all bands from 80m to 6m. The coax feeds into a large black cylinder which acts as a matching network. This particular antenna has been alternately praised and vilified on review sites like eHam. People are either giving it a 0/5 or a 5/5. There doesn't seem to be a lot of rhyme or reason to this; although it's interesting to note that people giving it a 0/5 tend to compare it to a dipole which might be unfair.

For me, I was willing to try it out. Considering that my comparison point was my aforementioned $2 "Speaker-wire Special" I suppose anything would seem better. The real challenge in the antenna install was not so much the outside work, it was deciding how to get the coax up to the roof from my shack. Doing so entailed slithering around in my attic, which is a complete mess after a roof replacement earlier this year. There were also a few setbacks, such as a broken lag bolt and a too-small bracket on another antenna (my HDTV antenna) which is now needs to be adapted to the new larger mast.

In the end we got the Comet installed, and two extra runs of coax. I fudged up a temporary VHF/UHF antenna (until I can get a replacement lag bolt and the new mast installed) by slapping a magnetic mount down onto a metal attic vent. I may also sell the VHF/UHF antenna I had on Craigslist and get something else because it's a 6m/2m/75cm tribander and the Comet now covers 6m.

As expected the Comet performs better than the homebrew. I'm getting signals where there were no signals before, I don't have RF-in-the-shack problems like I did before, and the antenna is clearly quieter (lower noise floor) than the homebrew. It tunes a lot of bands, so all in all I'm happy with it. I'm not quiet sure why some people have panned it so hard on eHam. I suspect that it may have to do with unfair comparisons to dipoles, but also it might be the install makes a difference. The Comet's instructions call for it to be installed 32 feet off the ground. Perhaps if it's not installed at that height the matching network doesn't work?

JT65A-HF, we hardly knew ye...

A while back I wrote about JT65A, the amateur radio weak signal digital mode being used on HF bands. My best contact was just before Field Day 2007 when I logged ZS6WN in South Africa; over 10,500 miles using 50 watts and an antenna made of speaker wire at the bottom of the sunspot cycle. It was a very interesting and powerful mode. And yet I haven't heard anyone on the bands in over a month. Which leaves me to ponder; why?

WSJT (the software for JT65A) was originally written for weak signal paths such as Earth-Moon-Earth. As with most weak signal modes, a trade-off is made where the amount of information transmitted is intentionally limited in order to pull weak signals up out of the noise floor. In JT65A, the total transmission cycle was one minute (actually, about 48 seconds plus 12 seconds for the recipient to react and respond) and in this minute only 13 ASCII characters could be sent. Not exactly a rag-chewing mode. So once I'd worked a station and logged them, I was basically done. I'd see someone calling CQ, note that I'd already logged them, and so wouldn't respond. And once I'd worked ZS6WN in South Africa, working non-DX contacts was (to be blunt) boring.

So my theory on the premature demise of JT65A on HF is this; everyone worked everyone and once they were done there was no point in continuing. Radio amateurs like to rag-chew, talk about stuff, brag about their rigs and such. Hard to do at 13 characters per minute. And without a conversation, it's hard to make friends. Sure, you could always get to know folks by hanging out in the Ping Jockey web chat, and there's certainly a core group of people who do just that, but if you're going to chat in a chat room then why bother with a radio? So I think JT65A on HF has turned into the one-hit-wonder of amateur radio.

Echolink Follies

One of the developments we're seeing in amateur radio over recent years is the proliferation of VOIP and digital voice technologies. Examples of this are things like D-Star, IRLP, and EchoLink. The latter is sometimes a contentious technology, in that some amateurs don't consider it "real" radio because the audio/control interface is PC-based. Once while on a visit to San Diego I was having a pleasant conversation with a local repeater operator which turned very sour at the mere mention of the word "EchoLink" as he went into a tirade about the evils of the system. Normally hams reserve this sort of loathing for CB radio and BPL companies, so I was a bit surprised.

Since then I've encountered a few more instances of "EchoLink Enmity". My personal opinion is that there's little difference between controlling a radio/repeater with EchoLink versus using Ham Radio Deluxe plus Skype to control a rig remotely. The question of whether EchoLink users are higher or lower on the amateur food-chain is best left to the philosophers. I will concede however that there's an annoying element to EchoLink, but it's the fault of the developers and not so much the users themselves.

Allow me to explain: Most if not all EchoLink users are unaware that when they connect to a repeater or simplex link the server software by default transmits an announcement over the air which says "Connecting to EchoLink [callsign] -- Connected". Since a lot of EchoLink users are looking for QSOs (amateur-speak for conversations) they tend to hop from repeater to repeater looking for traffic. If a repeater's quiet, they tend to silently disconnect and go looking elsewhere. And again the server software by default transmits an announcement which says "[callsign] -- Disconnected". To the locals on the repeater, this can seem a bit rude. If the EchoLink user was looking for a QSO, then why didn't he transmit and ask if anyone was interested/available to chat? So throughout the day you hear a lot of Connect-Disconnect, Connect-Disconnect...over and over again. After a while, you might start to think that maybe EchoLink users really are bozos.

However I think the users are largely not to blame for this. The connection announcements are not played back to the EchoLink client's inbound audio, so users don't know about them unless they're listening to the repeater in question. Most EchoLink users connect to remote repeaters or links in other parts of the country or even around the world, so they often don't ever hear what goes out over the radio. I once sent a detailed email to the EchoLink developer team explaining all this. I was told that a repeater/link admin can turn off the announcements, but they're on by default. Most admins clearly don't bother to turn announcements off, and the users are unaware of them. I suggested to the EchoLink developers that they might want to add a note to the EchoLink FAQ/guide explaining all this, but they didn't. And so EchoLink users will continue to unwittingly annoy repeater users, and apparently the developers think this is OK. I don't understand this, but whatever. Therefore, here are my How Not To Be An EchoLink Bozo tips:

• Be aware that every time you connect/disconnect, your callsign is transmitted over the air.
• Knowing the preceding it should be no surprise why when I further suggest: Don't repeatedly connect/disconnect to the same repeater. It is amazingly annoying to the locals when you do.
• Try saying hello if it's quiet. You may be surprised at how many locals are listening and willing to come back and chat with you.
• Be careful about "calling CQ" on a repeater. CQ is traditionally used for simplex contacts, and a repeater is not a simplex system. Some people won't care, but others will think that you're a bozo. If the EchoLink node ends in "-R" it's a repeater and I advise against calling CQ. If the node ends in "-L" (a link node) then CQ is probably OK.
• Don't ask for a QSL card because you made a contact over EchoLink. People will think you're a bozo. For that matter; I will think you're a bozo. QSL cards are for commemorating simplex contacts. Would you send a QSL card to someone you chatted with over Skype?

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.