Posts Tagged ‘engineering’

Pictures from KH8 (second trip)

I made another trip to American Sa’moa (KH8 for the radio amateurs in the audience) to deploy instrumentation.  It was a tight timeframe but the instruments seem to work and I managed to make a few ham radio contacts as well.

Flock of Pelicans in Honolulu.  Big overweight baggage bill. Waiting to board 767-300ER from HNL to PPG. Ubiquitous lizard Seascape on the road to Tula. Bell fashioned from a discarded gas cylinder, a common sight. Loading coil for the GU Special fashioned from wire I found on the side of the road (not joking).  This made the radio happy on 40 meters. Believe it or not, there's a C-130 in this photograph. Car says it was 90 F (32 C) outside. Traditional Samoan home or "fale." Requisite selfie from "today's office." Building infrastructure to support the experiment. Blockhouse for instrumentation (and radio shack) now with WiFi and GNSS antennas. We live in the future:  Raspberry Pi computer plugged into hotel TV. Crepuscular rays from Cape Matatula. Ham setup.  I spent a lot of time sitting on Pelican cases. Freezed-dried food is remarkably tasty...or I was hungry. Hammer (drill) time! Critter of the dark:  Coconut crab the size of a basketball.  Crabs this big are rare and prized for their tasty meat. Critter junior: coconut crab the size of a softball. Some of the research antennas. Research receiver instrument. Cable runs dressed. Beautiful. Yes, that is a jacked-up Corolla.

Custom Backshells for Cinch-Jones Connectors

What do you do to complete these hamfest bargains? 3D printing for the win!


The best thing about it is that you can color-code the connectors, too! Finally, props to a CAD-ninja coworker for whipping up the beautiful SolidWorks model in a couple of minutes.

There’s a new radio hobby magazine in town!

Recently, a number of hobby radio magazines have either retired, or have merged into a digital mix of several. Filling that void is the new The Spectrum Monitor, a creation of Ken Reitz KS4ZR, managing editor for Monitoring Times since 2012, features editor since 2009, columnist and feature writer for the MT magazine since 1988. Ken offers this digital, radio communications magazine monthly.  The web site is at

There's a new radio hobby magazine in town!  The Spectrum Monitor magazine - get your's, today.

The Spectrum Monitor magazine – get your’s, today.

Ken, a former feature writer and columnist for Satellite Times, Satellite Entertainment GuideSatellite Orbit magazine, Dish Entertainment Guide and Direct Guide, is also contributing editor on personal electronics for Consumers Digest (2007 to present). He is the author of the Kindle e-books “How to Listen to the World” and “Profiles in Amateur Radio.”

The Spectrum Monitor Writers’ Group consists of former columnists, editors and writers for Monitoring Times, a monthly print and electronic magazine which ceases publication with the December, 2013 issue. Below, in alphabetical order, are the columnists, their amateur radio call signs, the name of their column in The Spectrum Monitor,  a brief bio and their websites:

Keith Baker KB1SF/VA3KSF, “Amateur Radio Satellites”

Past president and currently treasurer of the Radio Amateur Satellite Corporation (AMSAT). Freelance writer and photographer on amateur space telecommunications since 1993. Columnist and feature writer for Monitoring TimesThe Canadian Amateur and the AMSAT Journal. Web site:

Kevin O’Hern Carey WB2QMY, “The Longwave Zone”

Reporting on radio’s lower extremes, where wavelengths can be measured in miles, and extending up to the start of the AM broadcast band. Since 1991, editor of “Below 500 kHz” column forMonitoring Times. Author of Listening to Longwave ( This link also includes information for ordering his CD, VLF RADIO!, a narrated tour of the longwave band from 0 to 530 kHz, with actual recordings of LW stations.

Mike Chace-Ortiz AB1TZ/G6DHU “Digital HF: Intercept and Analyze”

Author of the Monitoring Times “Digital Digest” column since 1997, which follows the habits of embassies, aid organizations, intelligence and military HF users, the digital data systems they use, and how to decode, breakdown and identify their traffic. Web site:

Marc Ellis N9EWJ, “Adventures in Radio Restoration”

Authored a regular monthly column about radio restoration and history since 1986. Originally writing for Gernsback Publications (Hands-On Electronics, Popular Electronics, Electronics Now), he moved his column to Monitoring Times in January 2000. Editor of two publications for the Antique Wireless Association ( The AWA Journal and the AWA Gateway. The latter is a free on-line magazine targeted at newcomers to the radio collecting and restoration hobbies.

Dan Farber ACØLW, “Antenna Connections”

Monitoring Times antenna columnist 2009-2013. Building ham and SWL antennas for over 40 years.

Tomas Hood NW7US, “Understanding Propagation”

Tomas first discovered radio propagation in the early 1970s as a shortwave listener and, as a member of the Army Signal Corps in 1985, honed his skills in communications, operating and training fellow soldiers. An amateur Extra Class operator, licensed since 1990, you’ll find Tomas on CW (see ), digital, and voice modes on any of the HF bands. He is a contributing editor for CQ Amateur Radio (and the late Popular Communications, and CQ VHF magazines), and a contributor to an ARRL publication on QRP communications. He also wrote for Monitoring Times and runs the Space Weather and Radio Propagation Center at  Web site:  Twitter: @NW7US  YouTube:

Kirk Kleinschmidt NTØZ, “Amateur Radio Insight”

Amateur radio operator since 1977 at age 15. Author of Stealth Amateur Radio. Former editor,ARRL Handbook, former QST magazine assistant managing editor, columnist and feature writer for several radio-related magazines, technical editor for Ham Radio for Dummies, wrote “On the Ham Bands” column and numerous feature articles for Monitoring Times since 2009. Web site:

Cory Koral K2WV, “Aeronautical Monitoring”

Lifelong air-band monitor, a private pilot since 1968 and a commercial pilot licensee since 1983, amateur radio licensee for more than 40 years. Air-band feature writer for Monitoring Times since 2010.

Stan Nelson KB5VL, “Amateur Radio Astronomy”

Amateur radio operator since 1960. Retired after 40-plus years involved in mobile communications/electronics/computers/automation. Active in radio astronomy for over twenty years, specializing in meteor monitoring. Wrote the “Amateur Radio Astronomy” column for Monitoring Timessince 2010. A member of the Society of Amateur Radio Astronomers (SARA). Web site:

Chris Parris, “Federal Wavelengths”

Broadcast television engineer, avid scanner and shortwave listener, freelance writer on federal radio communications since 2004, wrote the “Fed Files” column for Monitoring Times. Twitter: @TheFedFiles

Doug Smith W9WI, “The Broadcast Tower”

Broadcast television engineer, casual cyclist and long distance reception enthusiast. “Broadcast Bandscan” columnist for Monitoring Times since 1991. Blog: Web site:

Hugh Stegman NV6H, “Utility Planet”

Longtime DXer and writer on non-broadcast shortwave utility radio. Former “Utility World” columnist for Monitoring Times magazine for more than ten years. Web site: Blog: Twitter: @UtilityPlanet YouTube:

Dan Veeneman, “Scanning America”

Software developer and satellite communications engineer writing about scanners and public service radio reception for Monitoring Times for 17 years. Web site:

Ron Walsh VE3GO, “Maritime Monitoring”

Retired career teacher, former president of the Canadian Amateur Radio Federation (now the Radio Amateurs of Canada), retired ship’s officer, licensed captain, “Boats” columnist and maritime feature writer for Monitoring Times for eight years. Avid photographer of ships and race cars.

Fred Waterer, “The Shortwave Listener”

Former “Programming Spotlight” columnist for Monitoring Times. Radio addict since 1969, freelance columnist since 1986. Fascinated by radio programming and history.  Website:

Thomas Witherspoon K4SWL, “World of Shortwave Listening”

Founder and director of the charity Ears To Our World (, curator of the Shortwave Radio Archive and actively blogs about short­wave radio on the SWLing Post ( Former feature writer for Monitoring Times.


Latest Tinkering (or how Elecraft is taking all my money)


On Christmas Eve, I was sitting at my in-laws’ kitchen table with the Small Wonder Labs SW-40 I built as a high school kid in 1998 listening to beautiful music and I got the itch to come up with a radio smaller (and less expensive) than the K3 to drag around with me when I go places.  My mind wandered to the NorCal Sierra, which was a featured project in ARRL Handbook’s of my youth.  I was able to come up with a draft version of that Handbook article on the web—pause for a moment and think how revolutionary that is—my in-laws don’t have an ARRL Handbook, let alone the one that contained the Sierra article.  I looked at the bill of materials and realized that I had some 70% of the parts in my junkbox.  This seemed like a good idea until I went searching for a PCB.

Why PCB?  Well, I’ve done the dead-bug thing and it works great but it’s a pain to troubleshoot and unless you have decades of experience doing it, it looks like a Mexico City suburb, sprawling unpredictably in every direction with only the most tenuous connections to the core.  Since I was seeking a travel radio, I wanted it to be compact, easy-to-troubleshoot, and relatively rugged.  Due in no small part to the wishes of the Sierra’s designers (not coincidentally founders of Elecraft), boards are no longer available.  I looked into doing my own board, but if you don’t mix chemicals yourself, you’ve suddenly spent $150 on PCBs, plus the layout effort.  I toyed with making the board smaller (a win in several ways) by using surface-mount parts but even that was a non-starter since my junkbox parts are through-hole, requiring me to buy everything.

Astute readers can extrapolate what occurred next.  I went to the Elecraft web site to price the Sierra’s successor, the K1.  I had all but made up my mind to sell off some junkbox items and raise the capital to buy a K1 kit when something occurred to me:  fellow ham blogger Mike, VE3WDM, had recently moved to a smaller QTH and was offering a half-completed K2 kit for sale.  His asking price was only a little more than the K1 kit with some of the options I wanted and it was all-band.   The ad had been posted for some days by this point, so I fired off a sheepish e-mail to Mike asking if the radio was still available.  It was.  We sealed the deal and the radio made the somewhat tortuous ride (for us, not the radio—it sat in Chicago for two weeks) from his QTH to mine via the postal system.

I would not have bought a partially-finished kit from just anyone.  However, since this was Mike’s second K2 build and he was documenting it carefully in a blog, I figured it was a pretty safe bet.  So far, that is definitely true.

While I was eagerly awaiting the radio’s arrival, I redoubled my efforts to get a friend’s TS-930S off of my workbench, a task that involved replacing all 115 electrolytic capacitors on the cookie-sheet-sized “Signal Unit” board (similar to the K2 and K3 “RF unit”).  That radio still has low drive (it has ALC again and sounds like a million bucks), something I traced to a hard-to-find semiconductor that’s now on-order.  So, I gathered it up and started work on the K2 on Sunday afternoon.

Last night, I got it on 40 meters RX-only and peaked up the RX BPF.  Former K2 owner KL9A mentioned to me that it has some blow-by on strong signals but that he thinks it’s a pretty good radio.  I can confirm that based on my experience last night.  It sounds really really good on CW.

More on the build to come…including a look back at some troubleshooting of the BFO circuit.

At 522,000,000 miles per watt, Voyager 1 might be the ultimate in QRP.

At 522,000,000 miles per watt, Voyager could be the ultimate in QRP … if you have the right antenna.

For most HAMs the experience of seeing sub-one watt WSPR signals decoded from across the globe is enough of a thrill. However, the fine folks at the National Radio Astronomy Observatory have taken this a little further and used the Very Long Baseline Array radio telescope to precisely pinpoint the position of the Voyager 1 space probe.
While the layperson might see detecting the glimmer of 22 watts across the vastness of space miraculous, the amateur radio community can see this feat as the natural evolution and refinement of the technology and medium we know and love.
Earlier this year, the National Science Foundation’s Very Long Baseline Array telescope turned its gaze to NASA’s famed Voyager 1 and captured an image of this iconic spacecraft’s faint radio signal. The Green Bank Telescope also detected Voyager’s signal, picking it out from the background radio noise in less than one second.

Astronomers using the National Science Foundation’s (NSF) Very Long Baseline Array (VLBA) and Green Bank Telescope (GBT) spotted the faint radio glow from NASA’s famed Voyager 1 spacecraft — the most distant man-made object.

According to NASA’s Jet Propulsion Laboratory (JPL), the VLBA imaged the signal from Voyager 1’s main transmitter after the spacecraft had already passed beyond the edge of the heliosphere, the bubble of charged particles from the Sun that surrounds our Solar System.

Using NASA’s Deep Space Network, JPL continually tracks Voyager and calculates its position on the sky, which is known as the ephemeris. Since the VLBA has the highest resolution, or ability to see fine detail, of any full-time astronomical instrument, NRAO astronomers believed they could locate Voyager’s ephemeris position with unprecedented precision. This is unrelated to Voyager’s distance from the Sun or position relative to the heliosphere.

The initial observations, which were made on February 21, placed Voyager very near, but not precisely at its predicted location. The difference was a few tenths of an arcsecond. An arcsecond is the apparent size of a penny as seen from 2.5 miles (4 kilometers) away. The second observations on June 1 produced similar results.

“It is possible that these observations are at the milliarcsecond [one-thousandth of an arcsecond] level, or better,” said NRAO scientist Walter Brisken, who led the observations with the VLBA. At 11.5 billion miles — Voyager’s approximate distance at the time of the initial observations — one milliarcsecond would be roughly 50 miles across.

Voyager’s main transmitter shines at a feeble 22 watts, which is comparable to a car-mounted police radio or — in visible light — a refrigerator light bulb. Though incredibly weak by the standards of modern wireless communications, Voyager’s signal is astoundingly bright when compared to most natural objects studied by radio telescopes.

“The ability to pinpoint the location of Voyager and other spacecraft is critical as we explore the inner Solar System and beyond,” said Brisken. “The NRAO’s VLBA has the capability to do this vital task with unprecedented precision.”

Voyager 1, which was launched in 1977, is now headed away from the Sun at a speed of about 38,000 miles per hour.

In a remarkably sensitive complementary observation, the NRAO’s Green Bank Telescope (GBT), which is the world’s largest fully steerable radio telescope, easily detected Voyager’s signal, picking it out from the background radio noise in less than one second.

“Voyager is the first man-made object to penetrate the interstellar medium, and we really want to be able to receive the data from this new frontier,” said NRAO scientist Toney Minter, who oversaw the Green Bank observations. “This information will provide many clues about how the interstellar medium behaves and how the Sun interacts with it.”

“NRAO’s instruments have the capability to provide the most accurate position information of distant spacecraft like Voyager,” said NRAO Director Tony Beasley. “The remarkable sensitivity of GBT and VLBA’s sharp vision are essential for discovery but also have unique capabilities that have enabled us to make this contact with one of humanity’s most ambitious missions of exploration.”

The VLBA is a system of radio antennas located across the United States from Hawaii to St. Croix. The antennas work together as a single telescope nearly 5,000 miles across, giving the VLBA its ability to see fine details. Only seven of the VLBA’s full complement of 10 antennas were used to make these observations.

The 100-meter GBT is located in the National Radio Quiet Zone and the West Virginia Radio Astronomy Zone, which protect the incredibly sensitive telescope from unwanted radio interference. The GBT observations were made by NRAO scientists Toney Minter and Frank Ghigo, and Green Bank Director Karen O’Neil.

A Summer Trip to Greenland


A professional colleague who is the principal investigator of the Sondrestrom incoherent scatter radar facility announced at a conference that they no longer had a scientific high-rate GPS receiver at the site for making ionospheric measurements.  I enthusiastically volunteered to ship them one that I had on the shelf.  She suggested that instead I should come install it myself and I found some support to do it (the National Science Foundation heavily subsidizes U.S. Greenland and Antarctic scientific travel during their respective summers, making this trip possible).  Therefore unlike my previous trip in the winter, this trip did not involve travel with the most perverse of arrangements flying to Copenhagen only to hop on another plane and fly half-way back to the States.  I set off for my second trip to Greenland, leaving Scotia, NY, early on Monday and returning mid-day on Friday.

On the past trip, conditions were really awful for radio with plenty of visible Aurora.  I didn’t really mind that because the auroras were beautiful, but with only a small chance of NLC/PMC (noctilucent/polar mesospheric cloud) sighting in the summer, I was eager for some good radio conditions to sate my appetite for other nerdy activities.  I set up the radio equipment almost right away the first evening to make sure that everything tuned up and immediately made 10 or so QSOs on 20-meter CW before heading to bed.

Instrument installation is always a hairy business, especially when you can’t just run to a hardware store, let alone going to RadioShack or calling McMaster-Carr.  Sometimes, everything works smoothly; other times it doesn’t.  In any case a flexible attitude (and some good old ham practicality) goes a long way.  Wind gusts of 40-50 mph (18-22 m/s) on top of the hill made for exciting work, but having a couple of helpers made it go smoothly.  Here is a photograph of the installed instrument on its hilltop (the box and green antenna on the right-hand side of the pole, which also held a weather station).

Work, especially some recalcitrant Windows 7 issues (At one point, I was running Windows 7 in a VirtualBox virtual machine on a Linux machine and logging into the Linux machine from a Mac!), kept me pretty busy on Tuesday and Wednesday and I only managed a few minutes of operating on each of those days.  But, by Thursday, my schedule broke loose a little and I was able to operate for a few solid hours in the afternoon and evening.  I had no idea that Greenland would be so popular on 30 meters!  Wow.  That’s definitely the most intense pileup I’ve ever experienced.  Thanks for being patient.

There was some about S3 hash on 20 and 30 meters that the K3′s NR function would take care of but the NB function wouldn’t.  NR is not good for running pileups, so I often had to get the caller isolated to use NR.  On the receiving end, there was a lot of fast QSB, with a period of a few seconds (this is consistent with magnetospheric and plasmaspheric waves that impinge upon the auroral and subauroral regions.)  In any case, callers were up and down, often in the span of a call.  You all on the other end may or may not have observed the same from me.

Per usual, the setup was an Elecraft K3 and the GU Special vertical with 2x 1/4-wavelength radials for each of 20 and 15 meters.  Everything else was tuned by adjusting the length of the radiating section.  This is a substantial improvement in performance-to-size ratio over the previous station I carried in January 2012, which was a Yaesu FT-840, DK9SQ 10-meter telescoping pole, and a variety of wire antennas.  Below is a photograph of the GU Special deployed (it’s in the center, unceremoniously ty-wrapped to a wooden sign post sticking out of a barrel).  The diesel Toyota HiLux pickups are the most popular vehicle in town.  We gave a visiting graduate student lessons in driving a manual transmission.  Great vehicle to teach/learn on with lots of torque and low gearing!


Although I was unable to connect with them, we did drive past the OX2A/XP1AB site on Black Ridge that overlooks downtown Kangerlussuaq:

Thanks for the QSOs.  The log has been uploaded to LoTW this morning and QSL cards are ordered.  I never ordered cards after the last trip, so it will be a shared card with a photograph of the aurora.

Review: Array of Light (3rd Edition)

My friend Matt, KB9UWU, eggs me on to buy things.  Sometimes I listen.  Sometimes I don’t.  But, eventually he wins me over and I’m usually happy with the purchase (e.g., K3 and Hex beam, although I built the Hex from scratch, which reminds me that I owe the blog a discussion of that).  I like to think that I let Matt be the early adopter and then pick and choose based on his experience.  He convinced me to buy a copy of N6BT’s book Array of Light.  Here’s my review.

If there’s anybody that knows antennas in the amateur community, it’s Tom Schiller, N6BT, the founder of Force12 and now owner of N6BT Next Generation Antennas.  He’s also a member of the very successful Team Vertical contest team, who have revolutionized DXpedition and contest expedition antenna systems by replacing trapped tri-band Yagis like the TH-3jr(s), TA-33jr, and A3S, with arrays of verticals located at the water line.  Schiller’s work has been nothing short of revolutionary so I had high hopes for the book.

My copy, like every other copy, is signed by the author.  It’s a good-quality laser print and has the same spiral binding as the Elecraft manuals.  The book is a loosely-edited collection of articles and clippings that read pretty well in series.  But, it’s bear to skim or go back to find specific things unless you’ve read the whole thing cover-to-cover a couple of times.  But, that’s pretty easy to do because Tom is a good storyteller.  My only other complaint is that there are a couple of places where I think Tom has drunk his own Kool-Aid regarding the efficiency of his antennas, especially “linear loading.”  This is a topic that I need to revisit with a pencil and paper study at some point because there is a lot of misinformation floating around about traps, linear loading, and “multi-monoband” antennas.  It’s not clear to me that anyone has sat down and really examined this in a methodical way.  It was disappointing that he quoted numbers like “greater than 99% efficiency” without going into more detail about the efficiency of a full-size antenna versus the linear-loaded one, etc.  Of course, this is difficult, but it’s something that always makes me a bit skeptical.

Array of Light is worth the price of admission for a couple of reasons—the first is the stories and the second is the antenna designs.  I’m a big proponent of not reinventing the wheel on most of my homebrew projects and this book is sure to provide some proven designs to work with.  Especially if you want a good discussion of practical antennas for DXpeditioning and contesting I think it’s a real winner.

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