This weekend, both of my middle school-aged daughters passed their amateur radio exams with colors flying. Volunteers with the WCARS VEC were kind enough to meet us at a local park to conduct the test in a covered picnic area.
At the test site I was more nervous than my girls were, but I really had nothing to fear. Both were hitting a 95% pass rate on practice exams in advance.
Even though the girls have obviously learned a bit about radio through osmosis in this household, they did all of the exam prep on their own. Funny story: I remember allowing them both to send CW to my buddies K8RAT and WD8RIF on my lap when they were maybe 2 years old? Of course, they had no idea what they were sending, but they loved playing with the “clicky thing” (my paddles). I think WD8RIF actually copied their code to paper. 🙂
I purchased both of them an FT-60R handheld radio from Universal Radio. I think these HTs should serve them well for many years to come!
I know one of my daughters is already chomping at the bit to pass her General now.
Anyway, thanks for letting me brag a bit here. I’m certainly a proud papa!
Many thanks to SWLing Post contributor, Frank (ON6UU), who shares the following guest post which expands upon his previous DB4020 article:
The EA3GCY DB4020 transceiver now has CW mode
by Frank Lagaet (ON6UU)
After telling you all about the DB4020 SSB build I’m here with the CW part of the kit, let’s say this is part 2. At a certain moment Javier let me know the CW interface kit was ready for shipment and some week later it was delivered to my QTH.
Again, a well packed kit arrived in a brown envelope, components and boards well packed in bubblewrap. I found even a board I did not expect which can hold a push button, a switch and the connector for your morse key. Javier thinks of everything it seems!
Unpacking the bubblewrap gave me this result, all components in 2 bags. In the bigger bag another 2 bags with 2 printboards, one for the CW interface, one for the CW filter. Great !! Checking the material bill resulted in all components there, another thumbs up.
I started, of course, immediately building it because I wanted CW in the transceiver as soon as possible. I don’t do much in SSB mode anymore and I already started missing CW on the DB4020, so I started my KX3 to listen to while I was populating the boards. I never thought CW was going to have this impact on me! …. ..
I started building the CW interface, again starting with all small items. I soon saw that the 2 relays which need to be soldered in were ideal to protect all components when the board is upside down, so I soldered them in very quickly. I then soldered in all other components ending with the elco’s.
Next phase was the CW filter. This board is small and came together in a blink of an eye, no problems there, the long legs of the 3 and 4 pin headers went in last.
The following day, I made all wire connections and soldered a 13pin connector, leaving one pin out since I want to have the option to choose the width of the CW signal I’m listening to. By cutting the FL CW + pin and adding an additional switch, I have now 500Hz or 2400Hz. Great option, for very little effort and simple. Another thumbs up here.
Now it was simply a matter of inserting the sub boards in the main board and all should be working. And it did! Hurray! The 500Hz filter works perfectly, filtering away all above or below stations nearby my operating frequency.
This is the result of the soldering work, 2 small boards which need to be inserted in the main board:
The CW interface still needs the 13pin header of which I cut one pin and mounted a switch to have the 2400Hz width.
The IC you see in the middle of the CW interface is the KB2 keyer which gives you several functions like 4 memories and beacon mode. The 4 potmeters are used to set the level on 40 and 20 meters, to set the delay between TX and RX switchover and to set side tone monitor level. The keyer also provides functions as keyer mode A or B, straight key function and can be set for speeds between 1 and 50WPM. WPM speed can be set in 2 different ways. Handy!
Here a picture of the CW filter inserted on the main DB4020 board.
The CW interface is inserted at the side of the main board, notice the 2 wires which go to the switch to allow switch-over between 500 and 2400Hz.
(Wiring still needs to be cleaned up in this picture.)
Finally, the result: a good working multimode QRP transceiver with 2 bands. It should be possible to make close to medium range with it as well as DX, even with QRP power.
And while I was building I also made a new key for this radio, it is made out of a relay and cost nearly nothing, looks good doesn’t it ? hihi.
The key, when in practiced hands (fingers hi), can do 50 WPM without a problem. My friend HA3HK does without blinking an eye at 40WPM with this kind of key and tells me that he can go faster if needed. Me? I’m going it a bit slower.
As this radio is only using little power (0.4A in RX, 1 to 2A in TX depending the power you set it) I thought, let’s make a battery pack for the radio.
The first plan was installing it in the box. I did not do that because the batterypack is also powerful enough to feed my KX2 and other QRP transceivers. Since I can use it with all of them, a loose battery works out better for me.
I started with an old laptop which had a broken screen and some other malfunctions, but still had a good battery, although I needed the battery connector of course. A piece of wood to mount the connector on was my next goal. And since I still have another laptop using the same batteries, I can charge the battery without problems. Simple, but good and it weighs much less than a gel cell battery.
The battery provides me with 12.5V and some 5Ah. Enough to last for hours on RX and for sure good enough to activate 2 SOTA sites in one day. It doesn’t look great but works great– that is what matters and to test it was more then good. Next will be getting the battery pack in a nice box. Better to re-use stuff than throwing it away I’m thinking.
I need to do something about the cover of the OLED display, there is still some work there to make it look nicer.
Some video can be seen on YouTube :
Finallym I’d like to thank you all for reading my articles about the DB4020. I had big fun soldering, tinkering with the box, making the key, and batteryholder/batterypack. My Hungarian friend HA3HK told me it looks a bit like a spy radio. …. ..
I also include one more time the link where you’ll find this kit :
Thank you so much, Frank. No doubt, you had a lot of fun putting this excellent little kit together.
Implementing a filter switch was a fantastic idea and, obviously, not terribly difficult to do.
Based on the videos, the DB4020 has a low noise floor and very good receiver characteristics. I’m impressed that the CW portion of the radios has so many features as well, such as a memory keyer and beacon mode.
I also love how you reused that 5Ah laptop battery! I think that could almost give you a full day of SOTA activations at those consumption levels!
Thanks again for sharing this with us, Frank! We look forward to your future articles!
At first glance, you’ll see a similarity between the ALT-512 and the LnR Precision LD-11/Aerial-51 SKY-SDR. The LD-11 and SKY-SDR, are very similar, save the LD-11 is marketed to North America (via LnR) and the SKY-SDR to Europe. The SKY-SDR had several iterative upgrades, most importantly the dual-threaded software used in the firmware, which cut CPU latency in half. Both the LD-11, SKY-SDR and now the ALT-512 are made in Europe.
The first article deals with buying used and new equipment, while the other article is a review of the uBITX QRP transceiver. Thanks go to Ken Reitz for graciously allowing these to be posted after their initial publication!
And thank you, Robert!
Readers, I highly recommend both of these articles. In his used equipment guide, Robert makes practical suggestions for navigating the world of pre-owned radio gear and shares some important tips. His uBITX QRP Transceiver article is essential reading for anyone who has considered building this incredibly affordable kit.
Battery Anker Astro Pro2 20000mAh Multi-Voltage (5V 12V 16V 19V)
Portable Charger External Battery Power Bank
Avoid look alike batteries and the next generation model from Anker. The newer Anker
battery is only capable of delivering 1.5A from the 12V supply. Two look alike batteries
I tried did not have the auto-off feature that the Anker does.
ACC2 and I/Q Jacks 2 x 2.5mm Stereo Jack Panel Mount (PH-666J-B)
Phone, Key, and ACC1 3 x 3.5mm Stereo Jack Panel Mount (High Quality) (PH-504KB)
Mic Jack 1 x 3.5mm 4 Conductor Jack Panel Mount (PH-70-088B)
12V IN and CHG IN 2 x 2.1mm DC Power Panel Mount Jack (PH-2112)
12V OUT 1 x 2.5mm DC Power Panel Mount Jack (PH-2512)
You also need plugs and wire for interconnects. I bought some 2.5mm (CES-11-5502)
and 3.5mm (PH-44-468 for stereo, PH-44-470 for 4-conductor) audio cables with right
angle plugs and just cut them to use for the signal lines going to the KX3. I did the same
thing for the 2.5mm (PH-TC250) and 2.1mm (PH-TC210) power cables. A couple of
caveats are in order. The Phone, Key, and ACC1 interconnects require low profile
right angle connectors. The cables I listed above won’t work. Vetco part number VUPN10338 will work. The power cables I’ve listed above use 24 gauge wire. This
is a little light, but the runs are small so I think it is OK. You can use higher gauge
cables if you can find a source.
USB OUT USB 2.0 Right Angle Extension Cable (RR-AAR04P-20G)
L Brackets 8 x Bracket Rt Ang Mount 4-40 Steel (612K-ND)
These L brackets are used to mount the KX3 to the panel and the panel to the case.
For mounting the KX3, I use a little piece of stick on felt on the bracket to protect the
KX3’s cabinet from damage. Replace the KX3’s screws with #4-40 Thread Size, 1/4”
Length Steel Pan Head Machine Screw, Black Oxide Finish (see below). For the panel
mounting, use #6-32 Thread Size, 3/16” Length self tapping sheet metal screw. You
may need to cut the tip off in order to not puncture the outside of the case.
RG316 BNC Male Angle to BNC Female SM Bulkhead Coaxial RF Pigtail Cable (6”)
This is not the original interconnect I used for connecting the KX3’s antenna output to
the panel. However, I think it is a better option for new designs. The caveat is that you
will need to verify the hole in the panel matches the bulkhead connector on this cable.
There will be a little loop in the cable when you are done, but that is fine.
This is optional if you want a built-in sound card interface for a waterfall display using iSDR. Make sure to eliminate the holes in the upper left corner of the panel if you are not installing. You will also need 2.5mm x 10mm screws to mount this to the bottom of the panel (see below).
In my opinion, the KX3’s noise reduction is totally ineffective for SSB communications. This external noise reducing DSP is one solution, albeit an expensive one, to that problem. It is only for SSB, not CW or digital modes. It is also available from GAP Antenna Products.
Scott: you have done a beautiful job here and have spared no expense to make a wonderfully-engineered and rugged go-box. No doubt, you’re ready to take your KX3 to the field and enjoy world-class performance on a moment’s notice.
Though I’ve never used them personally, I’ve noticed others who have taken advantage of the Front Panel Express engraving service–certainly makes for a polished and professional front panel.
Again, many thanks for not only sharing your photos, but also your bill of materials which will make it much easier for others to draw inspiration from your design!
Speaking of designs, when I looked up Scott on QRZ.com, I noticed that he also sports a QSL card (above) designed by my good friend, Jeff Murray (K1NSS). Obviously, Scott is a man with good taste!
NOTE: I am embarrassed to admit that I made a significant error in my original measurement methodology and the numbers originally listed below were inaccurate. I’ve redone all the measurements and the text and tables below reflect the corrected measurements. *
Your host, K4SWL, asked me to share my experiences in trying to find a small, lightweight, battery pack for use with my field-portable QRP station. While I’m looking for a battery pack specifically for my Elecraft KX1, what I’m learning should be useful for users of any low-current QRP transceiver.
Currently, I’m experimenting with a pair of ten-cell AA battery-holders, one of unknown provenance (photo) and a new, more rugged one from Batteries America (p/n 10AAT, photo). When filled with ten AA NiMH cells, the resulting battery-packs provide about 14v at full-charge. At the 2012 Flight of the Bumblebees, my KX1 generated an indicated 2.6w on 20m and 4w on 40m while being powered by one of these packs; the nearly four hours of low-stress operating during this event did not discharge this pack of 2,000mAh cells very deeply. The use of two AA dummy-cells will also allow the use of eight lithium primary or alkaline cells in an emergency.
I became concerned about using this style of spring-contact battery-holder when I found an article (link) by Phil Salas, AD5X, in which he reported that this sort of battery-holder is likely to display significant voltage drop under load.
I tested my original battery-holder with ten 2,000mAh NiMH cells and my KX1 transmitting into a dummy load. In addition to measuring whole-pack voltage-drop, I measured the voltage-drop of each of the individual 2,000mAh cells as I transmitted into the dummy load on 20m.
Original Battery-Holder / 2,000mAh cells
The sum of these individual drops was 0.52v, so I’m losing 0.24v in the spring-contacts and/or battery-holder’s “transistor battery” output connector.
After replacing the original nylon connector with a pair of Anderson Powerpoles, I tested the same 2,000mAh NiMH cells in the new, more rugged battery-holder, this time only on 20m:
New Battery-Holder / 2,000mAh cells
I’m losing about 0.20v in the battery-holder’s spring-terminals, slightly less than with the older battery-holder.
The 0.20v ~ 0.24v drop from the spring-terminals doesn’t seem excessive to me and the difference in these measurements between the two battery-holders is probably not significant. I am more concerned by the 0.53v ~ 0.54v voltage-drop I measured in the individual cells. It is likely that these older 2,000mAh cells, which have been cycled many times, are exhibiting greater voltage-drop than new cells would. To test this theory, I purchased new 2,100mAh cells to measure.
I measured the new cells as above, again on 20m into a dummy load, and found that with each of the battery-holders, the sum of the individual cell voltage-drops was 0.22v, so my speculation appears to have been correct–the new cells do have lower voltage drop under load than the old cells do.
Orignal Battery-Holder, 2,100mAh cells
New Battery-Holder, 2,100mAh cells
The new 2,100mAh NiMH cells are marketed by Polaroid and cost $6 per four-pack at Big Lots; the least expensive AA NiMH cells available at Batteries America, 2,500mAh Sanyo cells, cost $3 each at the time of this experiment. I don’t know if the Polaroid cells will last for as many cycles as the probably-higher-quality Sanyo cells would but trying the significantly less expensive Polaroid cells seemed like a a good gamble.
As indicated above, the new battery-holder (Battery American p/n 10AAT) is more rugged than my original battery-holder; it holds the AA cells more securely and and doesn’t use a “transistor battery” connector to connect to the load. I replaced the original nylon connector with a pair of Anderson Powerpoles. This battery-holder will be my preferred battery-holder for field operations with the KX1.
In his article (link), Phil Salas, AD5X, recommends foregoing battery-holders in favor of soldered/welded battery packs but I will continue to experiment with battery-holders. I prefer to charge my NiMH cells individually, using an intelligent MAHA charger, rather than charging an entire pack. In addition, my KX1 draws significantly less current on transmit than Phil’s IC-703 does so the the IxR losses I’ll experience will be less significant than that which Phil experienced.
* What had I done wrong? I discovered when testing my new battery-holder that the previous measurements of the old and new NiMH cells in the original battery-holder had been made with the KX1 transmitting into a 50Ω dummy load with the KX1 autotuner configured in tune mode instead of in bypass mode; because the KXAT1 autotuner doesn’t sense a mismatch and automatically tune, this meant that transmitter current–and the measured IxR voltage losses–might be also be significantly different than with the KX1 transmitting into a matched load. Comparisons of my original numbers to measurements made later of the new battery-holder wouldn’t be meaningful, so I had to do all the measurements again.
It’s time once again to join the Arizona ScQRPions at the annual Fort Tuthill QRP Conference in mountains of Flagstaff, Arizona!! Spend the weekend camping with us at a cool 7500′ playing radio and listening to our outstanding speakers present topics on using Microchip micro-controllers, troubleshooting, Software Defined Radios, and
Thursday afternoon, July 26, is for the early bird campers to arrive and get set up. Stake out your territory at our reserved campground site. Water is available, but no electricity. There are fire rings / grills for your outdoor cooking and no known fire restrictions inside
the campground at this time. Daytime temperatures should range from mid-70s to low 80s during the day and 50’s at night. Brief (usually) mountain thunderstorms with gusty winds are possible at all times especially during the afternoons.
Campground activities Friday, July 27, could include such things as easy expeditions to local SOTA peaks, operating, trading, renewing old friendships and making new ones, experimenting with antennas, and many other activities. There are plenty of tall Ponderosa pines for those wire antennas. Friday evening is our traditional group supper at one of the local restaurants.
Saturday, July 28, is our day for the technical forums at a nearby facility. We’ll adjourn about 3pm and head back to the campgrounds for our Saturday afternoon picnic. We have a covered ramada that will accomodate 70 easily. Water and electricity is available. You might want to bring a chair and/or table just in case as we don’t have quite the number of picnic tables as we’ve had in the past.
No tickets to buy. Prizes. No tickets to buy. All are welcome.
Bring your own entree for the picnic and we’ll do the rest! Look for many more details on our website at http://www.azscqrpions.com which is being updated. Watch for updates at the website or from @azqrp at Twitter. Send me your cell phone number if you want text updates.
This year, during our family’s summer holiday, I’m enjoying the hospitality of Prince Edward Island, Canada (hence, the lack of recent posts on QRPer). This is our family’s second visit to the maritime island, and each time we’ve been fortunate to stay at the same off-the-grid cabin on the eastern coast, less than twenty meters from the water.
Of course, staying in an off-grid cabin comes with its radio challenges—namely, supplying power—but also comes with one supreme advantage: no noise from the typical electrical devices that plague most of our homes. What’s more, this cabin sits on 60 acres, so not even a neighbor’s home appliances disturb my RX ears.
On our previous visit, I brought my (then) Yaesu FT-817, a 9aH gel cell, Micro M+ charge controller, 10W Solarex PV panel, some 300 ohm window line, loads of 22 AWG wire and an LDG ATU. Unfortunately, I found I had very little time for radio, and propagation was dismal. Indeed, it was during that trip that I discovered my FT-817’s finals had blown, so part of the time I was transmitting less than QRPpppp levels.
This year, since I knew the site well, I came better prepared.
My full 2012 setup consists of the following:
An Elecraft K2/10
An Elecraft KX1 (4 band w/built-in ATU)
Elecraft T1 ATU
LDG 4:1 Balun
One 35 aH gel cell
Two 9.5 aH gel cells
Two PowerFilm Solar foldable 5 W PV panels
My radio toolbox with various connectors, crimpers, cutters, wires, caps, multi-tester, etc.
Enough wire and 300 ohm antenna line to make a couple of wire antennas
So…how’s it all working out? Brilliantly!
In the past few years I’ve done a lot of QRP CW—mainly rag-chews with some buddies on the lower bands. I’ve done less QRP SSB phone. When I first arrived at the cabin and began the process of unpacking, I couldn’t find the jumper cable to attach to my Vibroplex single-lever paddle (the paddle being a Dayton 2012 find, by the way). So, I plugged in a microphone and tuned to the phone portion of the 17 meter band.
Talk about radio fun!
I’ve once again re-discovered the joy of operating QRP SSB. It’s challenging to make those DX contacts and to transmit a long call sign (“VY2 portable K4SWL”) across the ether, but occasionally the propagation gods smile upon you, and you’re able to participate in a good rag-chew or quick DX with a 57 to 59 signal report.
Being 20 meters from the salt water is a bonus I don’t usually enjoy in my US hermitage. Due to its excellent propagation characteristics, despite my lower power set-up, I have easily worked stations from Russia to North Africa, from the Caribbean to Japan. I am thoroughly reveling in it, and the process has re-connected me with my ham radio roots.
As Gunter, VA3GA, told me in a recent Canadian rag-chew, “ham radio holidays give you a chance to explore areas of the hobby you don’t normally think to enjoy.”
So true, Gunter. That’s what I love about ham radio in general– the hobby is so broad, you constantly discover and re-discover favorite elements about it.