Many thanks to Alex (W3AVP) who shares this photos of his homemade cootie/sideswiper originally posted on the POTA Faxcebook page. Alex notes:
I didn’t want to lug my Begali key to the parks so I made my own using the plans from KA8VIT. Worked great! I had a little QRP key but my fat fingers would make so many mistakes. The DIY aspect of this hobby is extremely entertaining!
And I bet your “cootie” serves you well in the field! I love the simple design and the fact it even has an adjustable action. At the end of the day, keys are merely switches so are perfect for homebrewing!
If you have a sideswiper/cootie or any other key you’ve built and would like to share it here on QRPer, contact me (K4SWL at QRPer.com).
Many thanks toPete (WB9FLW), who shares the following:
Don’t know if you are familiar with this project, a full blown 5 watt HF SDR Transceiver for less than $300!
No sound cards, DUC/DDC architecture.
Here’s the project description by Steve Haynal via YouTube:
The Hermes-Lite is a low-cost direct down/up conversion software defined amateur radio HF transceiver based on a broadband modem chip and the Hermes SDR project. It is entirely open source and open hardware, including the tools used for design and fabrication files. Over 100 Hermes-Lite 2.0 units have been successfully built.
The FOSSi Foundation is proud to announce Latch-Up, a conference dedicated to free and open source silicon to be held over the weekend of May 4th and 5th in Portland, Oregon, USA. Latch-Up: a weekend of presentations and networking for the open source digital design community, much like its European sister conference ORConf. Produced by NDV.
This is a simple and experimental modification that transforms a QCX into a (Class-E driven) SSB transceiver. It can be used to make QRP SSB contacts, or (in combination with a PC) used for the digital modes such as FT8. It can be fully-continuous tuned through bands 160m-10m in the LSB/USB-modes with a 2400Hz bandwidth has up to 5W PEP SSB output and features a software-based full Break-In VOX for fast RX/TX switching in voice and digital operations.
The SSB transmit-stage is implemented completely in a digital and software-based manner: at the heart the ATMEGA328P is sampling the input-audio and reconstructing a SSB-signal by controlling the SI5351 PLL phase (through tiny frequency changes over 800kbit/s I2C) and controlling the PA Power (through PWM on the key-shaping circuit). In this way a highly power-efficient class-E driven SSB-signal can be realized; a PWM driven class-E design keeps the SSB transceiver simple, tiny, cool, power-efficient and low-cost (ie. no need for power-inefficient and complex linear amplifier with bulky heat-sink as often is seen in SSB transceivers).
An Open Source Arduino sketch is used as the basis for the firmware, the hardware modification bypasses the QCX CW filter and adds a microphone input in-place of the DVM-circuit; the mod is easy to apply and consist of four wire and four component changes and after applying the transceiver remains compatible with the original QCX (CW) firmware.
This experiment is created to try out what can be done with minimal hardware; a simple ATMEGA processor, a QCX and a software-based SSB processing approach. It would be nice to add more features to the sketch, and try out if the QCX design can be further simplified e.g. by implementing parts of the receiver stage in software. Feel free to experiment with this sketch, let me know your thoughts or contribute here: https://github.com/threeme3/QCX-SSB There is a forum discussion on the topic here: QRPLabs Forum
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.
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
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.”
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.
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.
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.
As you can see from the photos, each piece is perfectly finished and has great character, as one might expect of real wood.
Dennis, being a hard-core QRPer, trekked with ham gear in tow; he brought his kits to FDIM:
There were a variety of keys and paddles to be seen, of course; offerings range from the home brewed to gorgeous Italian Begali designs:
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.
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:
Of course, FDIM featured loads of QRP transmitters, receivers and transceivers; here is Dwayne’s (AK4P) 40 meter transceiver, built in a SPAM container:
Terry Young, K4KJP, built a very cool pocket 20 meter transceiver in an Altoids tin:
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:
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–!
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)
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.
Returning 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)
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.
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Many thanks to Alex (W3AVP) who shares this photos of his homemade cootie/sideswiper originally posted on the POTA Faxcebook page. Alex notes:
