Category Archives: Homebrew

New Product: Kev-Flex Stealth Kevlar Antenna Wire

My good friend David Cripe (NMOS) has recently informed me about a new product he’s offering to the radio community via his eBay store: Kev-Flex Stealth Kevlar Antenna Wire. Kev-Flex looks like a superb option for field antennas of all stripes especially since it has an incredibly high tensile strength. It’s available in 75′ bundles, but Dave can also cut custom lengths. NM0S is also a trusted retailer in the ham radio world, so you can purchase with confidence.

Here’s the product description and link:

Kev-Flex is a unique antenna wire manufactured exclusively for NM0S Electronics. The lightweight center core of the wire is made from Kevlar fiber, giving the wire its incredible strength. The Kevlar core is wrapped with six tinned strands of 30 AWG copper. The effective surface of the wire creates an effective skin area capable of handling well over 100W.

The cable is protected from the elements by a coating of UV-resistant black polyethylene. With a total diameter of only 1/16″ (incl. insulation) and a weight of just 16 feet per ounce, the tensile strength 125 lbs allows lengthy unsupported horizontal runs. Kev-Flex is ideal for extremely long LW-antennas and Beverages and is great for balloon or kite-supported antennas. Its low weight and high break-load makes it most suitable for SOTA activations and other field operations.

The outer insulation makes the wire kink-resistant, and its slippery finish makes it ideal for stealth antennas that must be passed through trees or other obstacles without snagging.

This antenna wire is sold in 75 foot long bundles, which is enough for a 40M dipole or EFHW. Two 75 foot bundles would make a great 80M dipole. Custom lengths are available on request.

Specification

– Kevlar fiber core wrapped with six 30 AWG copper strands
– Weather-proof black polyethylene (PE) insulation, 1/16″ O.D.
– Weight: 16 feet per ounce
– Breaking-load: 125 lbs
– Velocity factor 0.97

Click here to view on eBay.

A Simple and Low Cost FT8 Transceiver

Many thanks to Pete (WB9FLW) who writes:

Adam Rong BD6CR has designed a simple DSB Transceiver for FT8. Crystals are available for 7.074 MHz. and 14.070 MHz (which can be “pulled” with a trimmer to 14.074 MHz).

Using only 4 Transistors, 2 IC’s, 3 Toroids, 5 Diodes/LED’s and a handful of resistors and capacitors this one watt wonder will get you on the air in no time.

Click to enlarge.

One could build this on Perfboard (see above), or use Ugly/Manhattan style construction. There are no plans for a circuit board.

Adam posted this on groups.io crkit:

“I built this 7074 DSB 1-watt radio and made 6 FT8 QSO with JA stations in 15 mins last weekend. It is fun to operate by switching PTT manually to keep it simple and lower current consumption.”

For more info check out crkits groups.io.

Wow! Thank you for sharing this Pete. I’ll have to give this a go myself!

Bill’s 1 Watt Wood Box QRP Beacon

Many thanks to Bill (AA0RQ) who writes:

I’m running an attended beacon on 7041.8 kHz–the ID is VVV de AA0RQ/B AA0RQ/B AA0RQ/B 1 watt…

Often after running the beacon I plug the beacon crystal into the little 6L6 single tube transmitter.

Been having a number of QSOs with the bread boarded radio…

Below is the 40 meter 6L6 transmitter:

Thanks for sharing, Bill–I love the wooden box enclosure as it reminds me of early 1900s wooden box homebrew radios.

We’ll be listening for you on 7041.8 kHz!

micro-BITX: a homebrew general coverage SSB/CW QRP transceiver

Image Source: uBITX)

Many thanks to Pete (WB9FLW) who shares the following:

Farhan VU2ESE Does It Again!

http://www.phonestack.com/farhan/ubitx/ubitx.html

A compact 10 watts, easy to build, general coverage SSB/CW transceiver for HF bands

Homebrewers have traditionally avoided making multiband transceivers as they can get extremely complex and difficult to make. There have been some remarkable successes in the past, the CDG2000 (designed by Colin Horrabin G3SBI, Dave Roberts G8KBB and George Fare G3OGQ)is one such design. The SDR route as followed by several designs offer some simplification at the cost of bringing digital signal processing and a PC into the signal path.

On the other hand, many of the homebrewers do need a general coverage transceiver on the bench as well as as a base transceiver for bands beyond the HF. I ended up buying an FT-817ND that has been a reliable old warhorse for years. Two years ago, I attempted a high performance, multi-band architecture with the Minima transceiver. The KISS mixer of the Minima, though a very respectable receiver front-end, had serious leakage of the local oscillator that led that design to be abandoned as a full transceiver. Over months, I have realized that the need for a general coverage HF transceiver was wide-spread among the homebrewers. Most of us end up buying one.

While achieving a competition grade performance from a multiband homebrew is a complex task as evidenced by the works like that of HBR2000 by VE7CA, it is not at all difficult to achieve a more modest design goal with far lesser complexity. The uBITX shoots to fulfill such a need. It is a compact, single board design that covers the entire HF range with a few minor trade-offs. This rig has been in regular use on forty and twenty meters for a few months at VU2ESE. It satisfies for regular work, a few trips to the field as well.

A key challenge for multiband transceivers has been to realize a local oscillator system with such wide range. Silicon Labs has now produced a series of well performing oscillators that solve this challenge trivially : You connect the oscillator chip over a pair of I2C lines and it is done. The Si5351a is one such a part that provides 3 programmable oscillator outputs in a small 10 pin TSSOP package. We will exploit this chip to build the multiband transceiver.

Having exclusively used homebrew transceivers all the time, I get very confused whenever I need to use a commercial radio. There are too many switches, modes and knobs to twirl around. The uBITX use an Arduino to simplify the front panel while retaining all the functionality in a simple menu system that works with the tuning knob and a single ‘function’ button. The rig supports two VFOs, RIT, calibration, CW semi break-in, meter indicator, etc. In future, more software can be added to implement keyer, SWR display, etc.

Click here to read the full description of this project and download diagrams/schematics!

This is brilliant!  Thank you for sharing, Pete!

Build a cardboard stand for the Elecraft KX3

KX3-Cardboard-Stand-2

Many thanks to Tomasz Pabich (SP7Q) for sharing his simple Instructables project for the Elecraft KX3: a cardboard stand.

Click here to view on Instructables.

KX3-Cardboard-Stand-1

I love how simple and affordable this project is! Thanks for sharing, Tomasz!

Four Days In May: A look back at FDIM 2012…

Four Days In May is sponsored by the QRP ARCI
Four Days In May is sponsored by the QRP ARCI

One of the highlights of my trip to the Dayton Hamvention last year was attending evenings at Four Days in May (FDIM), a QRP convention sponsored by the QRP ARCI that rather conveniently coincides with the Dayton Hamvention, which I try to attend annually. Though scheduling makes it difficult for me to attend all of FDIM’s daytime presentations, the camaraderie and innovation one discovers at the evening sessions is wholeheartedly worthwhile.

Last year, I snapped quite a few photos at FDIM which I planned to post following the Hamvention. Unfortunately, shortly after the Hamvention, my laptop began displaying signs of an early demise.  In haste, I archived my photos on a portable drive, where they remained buried for a year.  I just rediscovered this photographic treasure, and thought I’d share it with readers; looking through them rekindled my enthusiasm for FDIM 2013, which starts next week!

A quick look at FDIM 2012

A great characteristic about FDIM is the array of QRP products offered by QRPers for the community. More often than not, these products are fairly priced, and often in support of the QRP community rather than major profit-making ventures.

For example, the North Georgia QRP Club produces affordable wood stands for QRP rigs. They’re incredibly simple, but fully finished and beautifully designed, just the thing to prop up your QRP portable at the right angle for desktop use.

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These wooden stands support the following rigs:

  • Elecraft K1, KX1
  • Ten Ten R4020/R4030/R4040
  • Yaesu FT817/FT817N
  • Hendricks PFR3

The club can even accommodate custom orders for other rigs. Check out and purchase these on the NOGAQRP website.

Speaking of wood products–one vendor last year featured an amazing array of wooden paddle pieces and even custom wooden tuning dimples (spinner knobs) for the Elecraft K2 and K1.

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As you can see from the photos, each piece is perfectly finished and has great character, as one might expect of real wood.

I also ran into Dennis Blanchard (K1YPP) and his wife, Jane, who were signing and selling their books. I wrote a review here on QRPer about Dennis’ story of the challenges and joys of through-hiking the Appalachian Trail. If you haven’t read Three Hundred Zeroes: Lessons of the Heart on the Appalachian Trail, you’re in for a treat. I’m hoping Dennis will attend FDIM this year.

Dennis, being a hard-core QRPer, trekked with ham gear in tow; he brought his kits to FDIM:

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There were a variety of keys and paddles to be seen, of course; offerings range from the home brewed to gorgeous Italian Begali designs:

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One paddle that really caught my attention was QuadraBug, a creation of WB9LPU. What makes this gem stand apart from other “Bugs” is that not only will it form “dits” automatically, but it also forms “dahs.” Truly, an amazing work of engineering. I searched the web for a video of the QuadraBug in action, but found nothing. [UPDATE:  Thanks, Yan for finding a video! See video below.]  This year, I’ll take a video if I’m fortunate enough to see it again.

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Home-brew galore

There were an amazing number of home-brewed projects on display, and even a home-brew contest. I didn’t capture photos of them all, but I did manage to snap a few.

One that really caught my eye (being a shortwave receiver enthusiast) was David Cripe’s (NM0S) version of Hutch’s Radio. The original Hutch’s Radios were built by US and British POW’s in WWII. Built in canteens, often from confiscated parts, these radios gave POWs hope by allowing them to tune in the outside world, via the BBC WS and Voice of America. In the spirit of the original, David challenged himself to build his version prior to FDIM, with original parts of the era, and in “secrecy.” Secrecy? As many of the components had to be purchased from suppliers on eBay, David tried to intercept all of the incoming packages without his wife noticing. His success was brief–alas, his wife discovered the mission–but fun; still, the end result was a very cool piece of historical recreation with a humorous story to match:

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Of course, FDIM featured loads of QRP transmitters, receivers and transceivers; here is Dwayne’s (AK4P) 40 meter transceiver, built in a SPAM container:

IMG_1382 IMG_1385 IMG_1386

Terry Young, K4KJP, built a very cool pocket 20 meter transceiver in an Altoids tin:

IMG_1379 IMG_1381

And Alan Shapiro, NM5S, should have won a prize for the most compact set of CW paddles.  These paddles are so small that they can be clamped onto your log book. Much to my surprise, they were amazingly easy to use, and would be a great addition to any field-portable radio:

IMG_1433 IMG_1436

FDIM 2013

If FDIM 2012 is any indication (yes), this is a mere sampling of the stuff you’ll see at Four Days In May 2013.  I encourage you to attend: if nothing else, make a little time either Thursday, Friday or Saturday evening to visit the evening displays at FDIM–they’re free and open to the public.

If you can’t attend, I hope you’ll earmark your calendar for a future date. I do plan to bring my camera again this year and will share some photos. Hopefully, I’ll post them a little earlier this go-around!

Hope to see you at FDIM and the Hamvention. For the third year in a row, I will be representing my charity, Ears To Our World (ETOW), at an inside exhibit at the Hamvention. We should be in booth 601 in the East Hall. Please feel free to stop by and introduce yourself! (And if you feel so inclined, you can even donate a few bucks to our worthy cause.)  See you there–!

Best & 72,
Thomas, K4SWL

Harold’s JA7HJ tower was not your average tower

Harold's JA7HJ tower (Click to enlarge)
Harold’s 30′ JA7HJ tower (Click to enlarge)

I meet some very interesting people in radio circles.  My friend Harold Johnson (W4ZCB) is undoubtedly one of them.

Last year at my local ham radio/DXer club meeting, members were asked to bring photos of shacks and rigs, and describe our evolution as ham radio operators. In the series of photos that arrived at the following meeting, one in particular stood out: Harold Johnson’s radio tower in post-war Japan.

Johnson’s tower stood almost thirty feet tall and supported a 20 meter Yagi which you can see in the above photo.  Johnson, who at the time operated under the callsign JA7HJ, also had a little ham shack built. The shack materials–including the tower, Johnson recalls–cost him “three bottles of Scotch for the army quartermaster…I paid the Japanese builder $15 or $20 for the complete  enchilada.” This tower was built entirely of wood: the vertical members were 2′ x 4’s, the slats were 1′ x 3’s.

Of course, the tower didn’t have a mechanical rotor; instead, Johnson climbed inside the tower, lifted the wooden boom, rotated it manually, and placed it back on the uprights.

When asked how he powered his station, Johnson pointed to the wheeled generator in front of the radio shack in the photo. “The generator was called a B6B–it produced 24, 120, 240, and 480 volts, and was rated 10 kW.” When I asked how he managed to procure the generator, he replied that he “borrowed it from the flight line, which was about 300 feet away.”

Johnson's Nashville, TN shack, circa 1955/56. (Click to enlarge)
Johnson’s Nashville, TN shack, circa 1955/56. (Click to enlarge)

I always enjoy hearing personal histories in radio and I didn’t doubt for a moment that Harold Johnson’s would be intriguing, so I asked if he’d tell us how his interest in radio began. So, here’s Johnson’s story in his own words:

As a preteen, (and poor as a church mouse during our previous
Depression), I would visit my aunt and uncle in the summer, likely due to the fact that they were farmers and had food to eat. They owned an old Philco radio that had shortwave bands and I was intrigued with the phone amateurs on the 80 and 20 meter bands. Often, I could hear both sides of the conversation, after I found out that they were on various different frequencies, being crystal controlled back then! My…How times have changed.

In high school, I found another afficianado, and can recall melting “Woods metal” in boiling water and floating a piece of Galena on it until it returned to a solid and [thus] made my own crystal set. WWII had started by then, and I would listen to the ground-to-air communications between ships in Lake Michigan and pilots taking off and landing on them. Great DX, perhaps 10 miles away.

In 1943, I had graduated from high school and joined the US Army Air Corps. Went through training and was still in training (…to be a pilot until they counted airplanes and pilots and decided they had enough of each […so instead] turned me into a B-29 gunner). The war was over whilst [I was] still in training and I “retired” in November 1945. Went home and found my high school sweetheart, married, went back to school to finish my education and started the Johnson family. Still married, and
to the same girl. What a sweetheart to have put up with me all these years. [No kidding, Harold!]

Went back in the US Air Force in 1949, this time became a pilot, and just in time to go to Korea for a year. However, during training, had to learn the Morse and if you learned to 13 WPM, you had a free hour and didn’t have to attend class. That overcame my obstacle to amateur radio, and I took the exams in 1950 and became W9PJO. Our rules at that time were that you had to hold a “class B” ticket for a year before you could take the “class A” exams. That year I spent in Korea and Japan and managed to obtain my first foreign call, JA7HJ.

W4ZCBqslReturning home to wife and by that time two children, I took the class A exams and became W4ZCB. I decided that I enjoyed flying, (at least most of the time), and decided to make it a career. The ensuing years, I was always on and in the air, and usually spent the winters in Alaska and the summers in the Canal Zone, anything to practice how to be miserable. Lebanon in 1958, Vietnam in 1968 and by 1969 decided that I should start doing something else before my luck ran out.

During my last 4 years of service I flew an Army four star around the world four times. Fortunately he was Ted Conway, W4EII, and we mutually enjoyed operating under a couple dozen different call signs from a lot of exotic (and several not so exotic) places. Had G5AHB back when the 5 was reserved for foreign nationals. We were good friends after we both retired (on the same day; I always liked to say that he couldn’t stand to serve without me) until his death in 1990.

I started a small company manufacturing electronic test equipment for public utilities; spent the next 20 years doing that (and enjoying a much more stable life with family and radio.) Managed to work all the countries (entities these days) there are, win a few contests from a contest station I built and operated for 10 years. (80, 40, and 20 in the front room, 15 in one bedroom and since 160 and 10 were seldom open at the same time, they shared the other bedroom. To change bands, you just changed chairs. Five big towers and Yagis, a VERY  high maintenance hobby in the lightning prone state of Florida. (Let’s not mention hurricanes!)

Retired again to the beautiful mountains of North Carolina in 1986. A much more modest station these days, but active on all the HF bands. I really enjoy building homebrew radios and maintaining daily schedules with friends worldwide. Can be found daily on 21.203 with G3XJP and often joined by other builders of the magnificent PicaStar transceiver designed by him. Sixty-three years a ham, still enjoying it. It’s guided my careers and interests. What a wonderful hobby!

W4ZCB's shack today is based around his home brew SDR transceiver, the PicaStar. (Click to enlarge)
W4ZCB’s shack today is based around his home brew SDR transceiver, the PicaStar. (Click to enlarge)

Over the past few years, I’ve gotten to know Harold Johnson; I must say, he has to be one of the very few hams I know who knows the inner workings of tube/valve radios as well as he does the highest tech radios on the market, a rare talent indeed. If you’re trying to learn a bit more about the BC-348 series of radios and trying to diagnose a problem with it, Johnson’s your guy. If you’re trying to build an SDR from scratch, he’s also your guy.  And clearly, if you want to hear a fascinating account of a life influenced by radio, this is most definitely your guy.

Thanks, Harold, for letting me share your story!

Check out Harold Johnson’s website by clicking here.

Author interview: Dennis Blanchard’s (K1YPP) “Three Hundred Zeroes: Lessons of the Heart on the Appalachian Trail”

Dennis Blanchard (K1YPP) at Four Days In May 2012

This year, at the Four Days in May (FDiM) Dayton QRP gathering, I had the pleasure of meeting Dennis Blanchard (K1YPP) and his wife, Jane, as Blanchard signed copies of his book, Three Hundred Zeroes: Lessons of the Heart on the Appalachian Trail. I had previously heard about Blanchard’s book, and it was great meeting the author in person.  Both he and his wife were most friendly, and I instantly felt a connection–after all, he is a fellow QRPer!

As a result of this meeting, I recently decided to purchased a copy of Three Hundred Zeroes on my Kindle eBook reader. Though I’ve always been a fan of turning pages on a traditional book, the eReader does afford one instant gratification, as you can order it on-the-go and start reading immediately.  And that’s exactly what I did…

The result? I’m very glad I took the time to read Blanchard’s Three Hundred Zeros.  Though I don’t like to spend much time away from my young family at present, I’ve always thought it would be a wonderful challenge and adventure to through-hike the AT (Appalachian Trail); reading this book was a vicarious opportunity to do so. Indeed, my favorite trail, the BT–the Bartram Trail, which follows the path of early American naturalist and explorer William Bartram–which I hike when I can, and whose NC chapter I’ve served as a board member for nearly 10 years now, parallels the AT at different points.  So the temptation to hike (and QRP, of course) continues.

“This photo was taken in NJ. Shortly after I took these photos, and walked down the trail about a 100 feet, a bear came over to check the table to see if I had left anything.” (Photo: K1YPP)

Blanchard’s book gives me hope. Three Hundred Zeroes is a well-documented, informative, and–despite his truly serious heart condition–often humorous journal-style account of his successful thru-hike of this 2176 mile trail. His writing style is very informal and likeable, focusing on the many personal interactions that make the trail hiker’s experience unique, and interweaving his day-to-day accounts with trail lore and history.

In contrast with the arduous journey Bill Bryson describes his well-known (and hilarious) book, A Walk in the Woods, in Three Hundred Zeros Blanchard calmly and routinely deals with misadventures and hair-raising encounters with wildlife, rolling with the punches and somehow emerging unscathed. He describes the journey as “long stretches of boredom, punctuated by brief moments of excitement” in the lively and unpredictable form of bears, mice, snakes, and even other hikers, to some degree. Blanchard was obviously a great hiking companion, thus rarely hiked alone–no doubt, other hikers sought his company.

A closeup of Dennis’ AT Sprint 3A taken at Four Days in May (Click to enlarge)

With QRP in mind, I had a few questions for Blanchard after reading his book.  He has kindly taken the time to respond to QRPer‘s questions, as follows.

QRPer:  I always thought that the AT would be a lonely place, but your book certainly changed my mind. Were there many stretches of trail where you were completely alone while trekking or camping at night?

Blanchard: There were times when I was alone for extended periods. However, “alone” is a relative term. Throughout the day I would encounter other hikers going in the other direction, or people that were slower or faster than I. In 180 days on the trail, I think I had three nights when I camped alone.

“2007-Damascus, VA was where I operated Field Day in 2007. It was shortly after this that I left the trail for the heart surgery.” (Photo: K1YPP)

QRPer: What was your favorite stretch of trail?

Blanchard: That’s difficult to answer…The trail is so varied and weather can change one’s views of any section. For me, it was a coin toss between the New Hampshire White Mountains and the 100 Mile Wilderness in Maine. The remoteness of both areas was just so spectacular. Of course the high altitudes made for great antenna opportunities as well.

QRPer: Did you bring a radio to listen to local AM/FM or shortwave?

Blanchard: For most of the hike, I carried a Yaesu VX-1R 2/440 handi-talkie. I think I used it about three times on two-meters. In a few situations, such as up in the White Mountains, I used the VX-1R to tune in NOAA for weather news. It also has AM/FM and on a few very rare occasions, I tuned into local stations for news. Would I carry it again? I don’t know. It is wise to have something for emergencies, and the radio wasn’t too big or heavy, but it was extra weight.

QRPer:  Specifically, what ham gear did you take with you? Do you have a photo?

Blanchard:As noted in the book, I did carry a home-brewed 80/40 meter CW rig for the first 600 miles. For the rest of the hike I carried Steve Weber’s ATS-3A. The radio was powered by six Energizer disposable lithiums, in a home-brewed battery pack. The pack could also charge my cell phone and power the 2-meter VX-1R radio. I used a 51 foot random wire for the antenna and some counterpoise wire, usually about 15 feet. Altogether, the gear weighed around two pounds.

QRPer: If you were to do the hike again, would you take the same equipment?

Blanchard: I’m not certain I would carry the VX-1R again. I didn’t use it much and it is extra weight. However, the NOAA weather, and 2-meter capability could prove extremely useful in an emergency.

QRPer:What was it like coming back off the trail once you completed it? Any especially notable things about how you perceived the world around you? Did it change you? Any culture shock?

Blanchard: The only real “culture shock” was riding in automobiles. Everything seemed to move so quickly. I much more enjoy walking and biking now. I would be happy if I never had to drive again.

“KD2VX, Kathy, was the trail angel that helped out with my hike up in New Hampshire. She is a QRP fan.” (Photo: K1YPP)

QRPer: How many other hams did you meet on the AT who were either through-hiking the AT, or hiking sections?

Blanchard: Since we [hikers] don’t wear being a “ham” on our sleeve[s], I can’t really say how many hams I encountered. The few that I was aware of were mostly section hiking. One benefit of setting up my QRP station along the way was public visibility for ham radio. On a number of occasions I inspired my fellow hikers to look into ham radio when they returned home. I’ve even had a few readers of the book write me to tell me they went off and got a ham license based on inspiration from the book.

QRPer: If any other QRPers are inspired by your story, and are thinking about hiking the entire AT, how much money should they budget for such an adventure? Based on what I read, there are a number of budgetary considerations for shuttles, food, gear, and the like.

“Duncannon, PA was were I operated Field Day. The station table was a few rocks I moved around.” (Photo: K1YPP)

Blanchard: The answer to this question depends on how many “creature comforts” one wishes. Hiking as I did, with stops along the way about every 5-10 days, can cost about $1-$3 a mile. Those on a tight budget could do it for much less, and those that enjoy getting to hotels and eating in fancier places could spend more. Most of the shuttles were really not that expensive, at least those that cater specifically to hikers. The hostels are a real bargain, compared to standard hotels, but one may have to tolerate annoyances, such as snoring and people coming and going at unusual hours. If you’re a light sleeper, this could be an issue.

QRPer: On zero days [based on your descriptions] it seems like hikers simply stuff themselves with food. I’m really curious what you typically ate on the trail?

K1YPP’s 2008 Field Day “table” in Duncannon, PA (Click to enlarge, Photo: K1YPP)

Blanchard:The short answer is: I ate everything. I’m not fussy, and don’t have any diet limitations. If someone is diabetic, or vegetarian, it is still possible to undertake such a hike, it just might require more preparation. My typical day was a few Pop Tarts first thing in the morning, or hot oatmeal on cold days, followed by an on-trail mid-morning snack, such as a Snickers Bars or trail mix.

Lunch was usually something that didn’t need cooking. Roll-up tortillas, or bagels with peanut butter won out most of the time. In the colder weather, bagels and cream cheese was a favorite. Gatorade powder mix, or hot chocolate in cold weather, was my favorite drink for lunch.

The evening meal was usually a pasta-based affair, or couscous. I really preferred the couscous; it is very light to carry, needs very little energy to cook, and is loaded with nutrients. I would usually stir in some dried vegetables with it, or dried meat. As a side I would carry a dried sausage, such as pepperoni, which could also serve as a snack for lunch. I usually carried some desert items as well, such as cookies or dried fruit. Of course energy bars would supplement all of this along the way. Many hikers preferred candy bars, but I tried to avoid them in the warmer weather since they melt.

Overall, even though the diet sounds bland, it wasn’t bad. Of course, whenever we hit a town, I would stuff on everything in sight. I actually did eat well, but couldn’t find enough calories to maintain my weight. I ended up losing 35 pounds at the end of the hike and looked like a refugee.

Well, Dennis–all I can say is that I hope you’ve gained back some of those lost pounds, continue to be in good heart-health, and are able to enjoy a little QRP on your forthcoming hikes.  Thanks very much for taking the time to answer our questions; we wish you the very best!

You can purchase Dennis’ book from Amazon.com or Barnes and Noble and visit his website at threehundredzeroes.com.

Vlado’s challenge: home-brewed QRP DXCC

Vlado (N3CZ)

My good friend, Vladimir (Vlado) Karamitrov (N3CZ/ZS6MG) is someone who likes to challenge himself. Perhaps this is why he’s such an accomplished DXer and contester.

Recently, at his QTH, he showed me one of his latest projects: a home brewed QRP transceiver. Vlado wasn’t content to simply build his own high-performance transceiver; no, he needed a built-in challenge.

Here is the story of his QRP radio, that he built mostly from junk parts, in his own words:


N3CZ's QRP rig front face

Challenge for all of us ….”Built your own radio”

By N3CZ / ZS6MG, Vladimir Karamitrov, 114 Russet Ln. Asheville, NC 28803 USA

Building your own radio is a challenge on its own. Using it to work DXCC is another challenge, probably less difficult. But combining the two brings a new spark and joy in our hobby. Isn’t ham radio about radios?

The purpose of this article is not to argue the need for building but to give ideas to those who have the time, like a new challenge and open up for ideas of building their own radios.

There are many different aspects to look into this. One is to build a radio from a kit. A search online will provide a list of manufacturers who offer these kits from basic thru intermediate to advanced designs.

The other approach is to build it your self. Yes, from scratch. Well, why not? Remember, time is what is needed most and of course some money and/or spare parts or junk parts. Time is not what I have available a lot, money is always on the agenda but having spare parts and stuff lying around your garage is another good resource.

N3CZ's workbench

So I decided to put something together. No time –means I can’t spend a lot on making this new rig look like a factory made, I have to use dead-bug design techniques and other easy methods to “glue” everything together. Available time is only after work and weekends and that is not much.

What kind a circuit and design to use? This was really the main question, because the answer will dictate what approach to take. First rule is check what parts and components you have available. There is something you have to remember here — when you go to a hamfest always bring some “junk” back home. You never know what you going to need. We all know this rule don’t we? Also don’t forget what your buddies have collected over the years, they will be able to help you with some of the missing parts if you need.

One of my passions is building my own equipment. Starting from antennas, to control boxes to switch them, pre-amps for the low bands and from time to time build a small QRP rig. Other interests are DX and Contesting, so while putting this radio together I cannot wait to hook it up to my antenna. This is where a little patience is required and I had almost none, hi. But I knew, bands are down for now, I have worked almost everything that was there to work, so will do this one little different and try to slow down a bit.

With my projects everything starts with the box. Few boxes I changed until the right one was in my hand. Next was to find a properly sized knob for the VFO. I then realized that it will take little more time to build all the components so I decided to use my $$ budget and get my self a nice DDS VFO. There are few different ones available online and for around $80. I got a nice programmable one with dual VFO’s and memories, with settable IF offset etc. This seemed to be the perfect fit for the project.

Transmitter

I thought I had all I need to start working on this project, but…..I wasn’t really sure about it yet. While looking for the “start” button and to actually take off with this project, I had yet to find that “trigger” that ignites the spark inside me, so I can say to myself, “yes I am ready, let’s just do this.”

You know the feeling – you feel a bit lazy at the beginning until that moment when that spark gets you. It’s like when you have to mow the lawn, and then you think, “no, it can wait another week, don’t feel like doing it now.” Well, I found my spark – it was not in the box, it was in the tuning knob that I got from a colleague also a ham and one who builds little QRP’s. I was actually explaining to him what I was planning to do, but not sure yet of the concept and how to handle certain parts of the circuit. While discussing all of this, he said he had some parts that he would bring for me and see if I could use some. He did not mention about any knobs, but when I saw them I knew I had what I was missing and now it iss the time to start working on this.

Transmitter PA

Now that I have the heart and the body, and the knob, I did some study of a number of different circuits published in ham radio literature including ARRL’s handbook and many online QRP resources. The goal was to build a simple radio easily reproducible, with reasonably good specifications so you can use it daily. Selection of IF frequency was the next and I decided on using 4MHz as I had access to a pile of some computer xtals of 4.032MHz.

Transmitter keying circuit and low pass filter

Junk stock provided the following:

  • Double balanced mixer SBL-1,
  • some 2N5109’s, J310 FET’s,
  • a few IF amps MC1350,
  • some toroids and
  • wire

I was ready to take on my own challenge – build it and work 100 countries with it!

Associated pictures with this article represent certain stages of the building process. As you can see I picked up an easy method for putting all together. I liked this approach for a simple reason that I can go step by step, keep adding components and test each stage as I move forward. There was no need for making PCB…who needs a PCB. In the old days, radios were built on a chassis and components hanging in the air and radio worked.

RX/TX antenna relay

On the other hand there was that perfection starring at me and making me feel a bit guilty, but I had no time to waste but hurry and build this radio in the short time I had available to me. Because you know what, the bands will just open up again, and then I had to do my other part – the DXing, hi so I may not be able to get this done.

I actually put the receiver in a working shape in one afternoon. I had the front end bandpass filter , double balanced mixed, post mixer amp, xtal filter, IF stage and audio section. All tested and worked first time. I spend the rest of the evening listening on 20m. Nothing much there but I found few stations up the band. There were few UA0’s as well. I managed to pick them up but signals were tiny. I decided to check my main radio and compare. I see now…signals were stronger, much stronger, S9 + on my TS850. So I checked few things and found few problems with my initial design: I had to amplify the input signal and my LO signal was too low to produce satisfactory mixing with SBL1. I used a J310 FET transistor for my front end pre-amp, and used single NPN transistor to boost the output of the DDS oscillator to appropriate level.

The receiver

I was ready to fire this thing and …wow, what a difference. I could still hear the UA0’s calling CQ and working others, and the signals were just incredible. Next obstacle was the Xtal filter. I had choose computer xtals that were somewhat matched in frequency, but the filter was way too narrow. I started experimenting with the capacitors around it and found a good medium that showed some good response on the signal quality and bandwidth.

Received signals now sounded “almost” like my ‘850. But I wasn’t happy yet. I was missing some “dynamics” in the signal. It was just a plain CW signal and nothing more to it. Next few days I experimented with an AGC circuit and variable bandwidth for the Xtal filter. After number of changes, I came up with a solid audio AGC circuit and S-Meter. That made a whole lot of difference. Everything was still sitting on the bench, loosely connected together and I was listening up and down the band. There were more stations now…hmm the bands must be opening up or something?

Receiver (left) & Transmitter (right)

For the xtals filter I ended up replacing the fixed caps with varicap diodes which I pulled out from an old TV tuner found at one of the local hamfests. You know that feeling when you can actually adjust xtal filter bandwidth. That is what was missing. I spend hours listening and trying to get into motion for my next step. I was simply amazed what I could pick up with the receiver and how I was able to select different signals, some of them very weak.

I went back and forth between my main radio and this little receiver that was sitting in front of me, still in pieces. “Not much difference is it?”–I was thinking to myself. I actually ended up spending hours in this year’s CQ WPX CW contest and only listening on my new receiver. I was able to pick every signal I wanted, even thru some heavy pile ups. It passed the test! Now I wanted to call these all these stations, so it was time for me to start thinking about the transmitter part.

Receiver front end and mixer

This was nother challenge. I tried one circuit and it worked. Straight forward a TX mixer, bandpass filter, couple stages amplification, low pass filter to the antenna. But I could not get the output power I wanted. I was getting something like 1 W barely making it to 2W. I figured out the reason. It was the transistors I used. Each stage must have enough gain to drive the next one. My final transistor was capable of producing an easy 10 watts out, but I was lacking drive power. I checked the complete circuit and components I had available on hand then decided to make few changes. Remember: the goal was to use what was available and not to go and spend any extra money. I ended up adding extra amplification after the TX mixer. Yep! That was it. That is what I was missing. I was now getting an easy 8W out. I couldn’t wait to hook up the antenna. I had no antenna switching circuit yet, so I hooked up my 3 element SteppIR on the little transmitter and used my vertical antenna on the main radio. Nothing easier than this. I was able to hear my transmitted signal and, at the same time, I could listen on frequency. First call and into UR land…559, “not bad,” I though. I then moved up the band and found a French station ending up a QSO, so I called him and worked him too. I got 579 for my signal. This was getting exciting. I ended up working 10 different countries that evening, mostly Europeans.

I spent the next week or so working on the box and figuring out how to implement the mechanical part of this project and get everything together. I tried using the little radio on 2 different bands (20 and 17M) with excellent results. These have been my main bands this year after they stabilized somewhat and we have them open after work until late. This is the perfect time for experimenting.

Receiver bandpass filter

Final touches can be seen on the rest of the pictures displayed here. I actually used this rig in the IARU CW contest for a while as well as in few QSO party’s on 20m, all with great success. The crown of everything was still to come.

It was getting close to the end of ST0R operation and I had them worked with my main station and KW into antenna on every possible band and mode I could hear them, but that one evening I was listening to their easy going pile-up on 20m working NA stations. The pile-up wasn’t that big and I was thinking,
“should I try this little rig and see if maybe somehow they will hear me?” I wasn’t sure this was going to work, but I hooked up my memory keyer and started pushing the button to send my callsign out. I did this for almost 2 hours. Yes, there was nothing else to do, while I was reading a magazine, I just used the preprogrammed call sign and kept sending it over and over.

Top view of N3CZ's QRP transceiver

Then I heard Lynn W4NL working ST0R with his QRP rig…NO WAY! What is he doing differently then me? And I am going crazy and about to give up, but….I was careful enough to check what frequency was W4NL transmitting so I tune up a little higher then he was. At the same time I received email from Lynn saying he worked ST0R QRP! Yes, I know I heard you Lynn…so I pressed few more time on the keyer. Guess what? It took couple more calls and there he was….smiling at me ST0R called me N3CZ 599 BK. There must have been another CZ I thought, so I send my call, then 599 and then my call again. Sure enough he came back with N3CZ TU. That was it! I did it! I just worked ST0R–a new country in a pile-up with my little homemade radio. I had them worked already on 20 CW , so what if it was a dupe? I knew I did it with my little radio and that was good enough for me. This is where I actually stopped and realized that I have accomplished my challenge. At least I have made it to a milestone, a major milestone. At that time I had well over 60 DXCC countries worked with the little radio, and it was barely 2 and a half months since I started working on this project.

I found this encouraging and I would challenge those readers who are thinking about a similar endeavor to not think twice–just do it!  Order yourself a kit at least and put it together. The reward cannot be described here or told by anyone. You have to feel it on your own. Put a challenge for yourself. Make a goal to work 10 states maybe or 10 DXCC countries, or 100. It doesn’t really matter. What matters most is that you give this hobby of ours another chance. A chance that makes it different from any other hobby on this beautiful planet we live on. What better can it be than communicating with others over a the vast emptiness of the space around us and bounce few signals now and then of the ionosphere?

“DX RULES” as my good friend Bill N2WB from Florida say.

N3CZ's QRP rig front face

I say “HAM RADIO RULES!” nourish it with everyday ideas, build your own stuff, don’t just buy that new radio and antenna, ready assembled and waiting for you to simply push few buttons and “work that rare DX”. There are many aspects of this hobby and like with anything in life we have to find it on our own. Sometimes we get help from another ham, sometimes a complete stranger to us, but with the same ideas.

Thanks to Dave K4SV, Phil W9IXX, Lynn W4NL and Carl N4AA who insisted on getting this article done [originally for The DX Magazine]. And all the stations who logged N3CZ/QRP. That was me who called you with this little homebuilt-junk parts radio. Drop me a note if you find this interesting and inspiring, because that was my intention anyway. By the way, I am already gathering parts for my next project. This time it really started with a nice box, but we’ll see. I don’t see that spark yet. I will let you know how it goes.

Until then,
73 & CU on the bands.
TU de N3CZ / ZS6MG / Z35C
Vlado

And thank you, Vlado, for sharing this article for QRPer.com readers! To contact Vlado, grab his email from QRZ.com.

If you have a home-brew QRP project that you would like to share with QRPer.com readers, simply contact us or comment!

Andy’s 6N7 Tube QRP Amp

In this Glowbug Times article, Andy shows us his very cool homebrew tube amp. Andy shares his motivation:

Once upon a time I’d decided to join a Big Guns Gang and made a Super-Duper Powerful Vacuum Tube QRP amplifier for my 800mW QRPP homebrew telegraph vacuum tube transceiver “3T” (I promise to write a separate article or two about this three tube transceiver project later). It was not an easy decision to me because for that legendary time I’d almost a year used the QRPPpower of less than a watt[…]

Read Andy’s full article here. Make sure to browse the many other articles he has published–his attention to design detail is simply inspiring.