On Tuesday, February 13, 2024, one of my daughters had a dress rehearsal for A Midsummer Night’s Dream. The venue where the cast meets is a good 45 minutes from my QTH, and if I didn’t have POTA fever, I’d have to find something to do to burn four hours of time.
Since I do have POTA fever, I see these windows of waiting around as an opportunity!
An opportunity to spread the POTA fever, even.
On that particular Tuesday night, my dear friend Vlado (N3CZ) didn’t have any plans, so I invited him to join me on a short, late-shift activation. The idea was that he’d perform an activation, then we’d go grab dinner at a restaurant in Mills River.
Pisgah National Forest (K-4510) and Game Land (K-6937)
Quick note about park numbers: As of the time of publishing this article, we’re still using the “K” prefix for US parks. Tomorrow (March 20, 2024), all US park prefixes will change to “US.” Pisgah National Forest, for example, will be US-4510 starting tomorrow. Today, it’s still (barely!) K-4510, so that’s what we’ll use.
We drove to the Sycamore Flats Picnic Area where I performed a number of late-shift activations in February. What I love about the site is that it’s rarely busy (especially at dusk and into the evening), there are numerous spots to set up, and it’s pretty convenient to the Shakespeare venue.
Tufteln AX1 Antenna Stand
I’d mentioned to Vlado in advance that I was going to test “a new antenna support system.” I think he might have assumed I was packing a large tripod with a 1/4 vertical or something similar, so it was fun to pull out the AX1 and Tufteln AX1 Antenna Stand!
Vlado, like me, loves compact radio gear, and I knew he’d never used the Elecraft AX1 before, so I was looking forward to showing him just how capable of an antenna it is for POTA, even on 40 meters.
That day, it had been pretty gusty, and in the evening hours, while a little calmer, it was still a tad windy. I thought it would be the perfect opportunity to pair the AX1 with Joshua’s AX1 stand because it’s much more stable than the AX1 bipod in windy conditions.
Source: Tufteln.com
The stand consists of two parts: a base and an antenna sleeve. The sleeve screws into the base, and the AX1 simply slides into the sleeve. The height is perfect for the KX2’s BNC (indeed, it works with a number of radios). The stand will also accommodate the AXE 40M coil.
Source: Tufteln.com
When attached to the KX2, it makes for a very stable base. You can even use it as a stand-alone antenna support for the AX1.
Joshua has had this stand in his Tufteln product line for over a year, but I don’t think I’ve actually used it during an activation that I’ve also filmed.
New Mics!
Speaking of filming, this activation with Vlado gave me an opportunity to test my new DJI wireless mics. The system comes with two mics so both Vlado and I used them.
I filmed the activation, but in truth, was doing this more or less to test the mic audio. I believe I mentioned early on that this video might not ever be published.
In the end, I decided to publish it–the audio was quite good, and the wireless mics cut down on the wind noise dramatically.
Gear:
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My goal was to get Vlado on the air and give him a taste of POTA using the AX1 and 40M coil. I hadn’t planned to activate–since we were grabbing dinner afterward–but I did end up activating after the UTC day changed.
Without realizing it, I actually put a lot of pressure on Vlado.
He started his activation at 18:42 local (23:42 UTC). That meant, in order to log a valid POTA activation on February 13, he needed to log at least ten contacts in 18 minutes (using the AX1!).
Keep in mind that Vlado is a contester and DXer (also, very much a QRPer!). He’s used to operating CW at insane speeds when needed. In fact, he’s always one of the top people (if not the top) in the CW speed test at the W4DXCC contesting and DX conference.
I suggested he operate around 20 words per minute.
He started calling CQ POTA, and the first few contacts came in pretty slowly. I was getting nervous that I might have unintentionally made Vlado’s first POTA activation one that wouldn’t be valid.
Then the pace started picking up. (Whew!)
He ended up logging a total of 10 contacts in 12 minutes! Woo hoo!
Here’s his QSO Map, showing what the AX1 pushing 5 watts for twelve minutes can do:
Next, we decided that I would, indeed, perform a quick activation.
I spotted myself on the POTA site and started to call CQ, then it hit me: it was 23:58 UTC. If I worked one contact in that two minutes, it would be considered an activation on February 13 of only one contact.
Instead, we waited for a little over a minute for the UTC day to change!
I ended up working a total of 24 contacts in 21 minutes. Woo hoo!
Here’s my QSO Map:
And here are our logs:
Activation Video
Here’s my real-time, real-life video of the entire activation. As with all of my videos, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.
Since this quick little activation, he’s been out there hitting POTA sites regularly.
He hasn’t seen the doctor yet, but I’m positive he caught POTA fever. It’s incredibly contagious.
Also, the Tufteln AX1 stand worked perfectly in the wind. I’m going to keep this tucked away in my pack alongside my second AX1 to pair with a wide variety of radios.
Thank you!
Thank you for joining me during this activation!
I hope you enjoyed the field report and my activation video as much as I enjoyed creating them!
Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon, and the Coffee Fund. While not a requirement, as my content will always be free, I really appreciate the support.
As I mentioned before, the Patreon platform connected to Vimeo makes it possible for me to share videos that are not only 100% ad-free but also downloadable for offline viewing. The Vimeo account also serves as a third backup for my video files.
Thanks for spending part of your day with me!
Cheers & 72,
Thomas (K4SWL)
I might have mentioned in a previous post that I named my little Elecraft KX1 “Ruby.”
I name all of my field radios that are permanent; ones I never plan to sell or trade at any point in the future. Ruby is firmly in that keeper list.
Why do I anthropomorphize field radios? That’s perhaps a discussion for a different day but I reckon it’s because I feel they have a lot of character and are, quite literally, trusted companions. They go with me on travels, hikes, and all sorts of outings.
Ruby love
So Ruby is actually the second KX1 I’ve owned.
My first Elecraft KX1 also had a dedicated Pelican 1060 case. There’s even room to fit an external Whiterock paddle.
The first one I purchased in 2008 as a reward to myself for learning CW (see photo above). I enjoyed that KX1 until 2016 when I sold it to help fund the purchase of my KX2.
I immediately regretted selling it, although it helped that I sold it to an amazing person.
In October 2020, I purchased Ruby and wrote a post about how great it was to be reunited with this gem of a radio.
At the time, I had no idea what a great deal I had landed.
Ruby turned out to be a four band radio (it was advertised as three), included the built-in ATU, and the package came with a simple wire antenna, three different coaxial DC plugs, a Pelican 1060 waterproof case, earphones, and a set of KXPD1 paddles. All of this for $300 US shipped.
I took Ruby on a number of field activations and couldn’t have been happier
Intermittent issues surface
In the summer of 2021, I started noticing some odd behavior.
Sometimes, after turning on the power switch, the rig wouldn’t completely power up. Instead of the typical two clicks we KX1 owners are accustomed to hearing, I only heard one click and neither the display nor any of the functions worked.
This was an intermittent issue–the next day it might power up as it should.
I did a little troubleshooting: I completely disassembled it, visually inspected all of the solder joints, and removed/cleaned and reinserted the firmware chip. This had no effect at all.
So, I took Ruby to one of the best radio repair technicians in the world who also happens to be one of my best friends: Vlado (N3CZ). He actually does a lot of repair and even has a radio repair website.
Dr. Vlado
Vlado (N3CZ) draws a crowd during a joint park activation on the Blue Ridge Parkway a few years ago.
Vlado will be the first to tell you that the worst problems to diagnose are those that are intermittent; it takes much longer to trace the source of the problem.
A few days later, Vlado sent me a message notifying me that the patient (Ruby) was on the operating table and surgery was about to begin. (See why I call him “Dr. Vlado”–?)
Vlado checked the circuit board very carefully. He found a few solder joints that needed work including a couple on the chip holder. In fact, he completely desoldered the chip holder and soldered it back in properly. Keep in mind here that the KX1 was only ever available as a kit, so quality had everything to do with the skill of the original builder.
He re-assembled Ruby and she worked perfectly.
A second operation
I put Ruby back on the air for a few months, but then in December 2021, a variation of the same issue resurfaced. This time, the “two clicks” in startup took a couple seconds longer than it should. Then it simply stopped working altogether.
Vlado wanted Ruby back in surgery ASAP, so I dropped her off at his “Emergency Room.”
Since the problem was no longer intermittent, Vlado quickly sorted out the main issue: a faulty encoder.
I should note here that since the KX1 hasn’t been produced by Elecraft in many years, there’s always the fear that a replacement part might already be “unobtainium.”
I called Elecraft support and fortunately for KX1 owners everywhere, the encoder is one Elecraft uses in a few of their radios. They have a healthy inventory and the part costs less than $5.00. Woo hoo!
Admittedly, when I placed the order, I also order a few extra parts I thought could fail in the future and might be difficult to find: 3.5mm jacks, pots, and even the LED screen. If I was paying shipping anyway, why not add a few extras? The parts are all very reasonably priced.
The KX1 doesn’t seem to have a lot of unobtainium in it–I seem to recall though that the firmware chip can no longer be ordered from their website and neither can the pushbuttons. I bet you could find other pushbuttons if needed, though.
I had the encoder shipped directly to Vlado and he completed Ruby’s operation in short order. Thank you, Vlado!
To the field!
I’m so happy to have Ruby back on the air! We’ve chased numerous parks and summits in the past week and I took her on an activation Monday, pairing her with my recently-built K6ARK EFHW antenna.
I’ll post an activation report and video in the coming weeks.
KX1 advice
Elecraft KX1s have become as rare as hen’s teeth lately. You’ve no doubt noticed this if you’ve been looking for one. I’m sure I could sell my KX1 package in a heartbeat for twice more than I paid a year and a half ago. It’s a little insane, really, but I get it.
If you’ve been looking for a used KX1, I would offer the following notes/advice:
Since these were only available as kits, you might ask the seller about the original builder and/or have them take photos of the soldering work inside prior to purchasing.
Assume issues might arise with time. With radios like this, I mentally set aside at least a couple hundred dollars for future replacement parts and/or repairs.
Keep in mind that as with any other radio that’s a bit long in the tooth, you may find that some components are simply no longer available. That’s the risk we take being custodians of these cool little rigs.
Actively looking for a KX1 at time of posting (Feb 2022)? Note that interest in particular radio models waxes and wanes over time. With a little patience, you’ll eventually find one. I’ve seen this happen with so many other radios over the years.
The KX1, as with most Elecraft radios, comes in a number of configurations and you need to be aware of this if purchasing. Some only have two bands, some have three, and some have four. I’m not certain if band modules are still available via Elecraft, so you might get stuck with the configuration you purchase. Also, the internal ATU was an option; don’t assume the one you’re purchasing has the ATU.
KXPD1 paddles are very difficult to find these days. It’s a big bonus if your radio comes with them. Not everyone likes these paddles, but the version I have now seem to work really well, actually. N6ARA Tiny Paddles are a brilliant little replacement, but you might wish to make a 3D-printed holder to attach the the paddle point on the front of the radio to take a little strain off of the 3.5mm jack inside.
I should also add that Vlado is a brilliant repair technician and has worked on numerous Elecraft, Icom, Yaesu, Kenwood, and Ten-Tec models over the years–if it’s solid state, he can repair it. If you ever need his services he can be reached via his website HamRadio.repair.
Also, Dave (W8FGU) is an Elecraft employee that is devoted to their legacy radios like the KX1/KX1/K2, etc. He’s a great guy, brilliant resource, and I believe can also arrange repair, if needed.
Enough blogging: I think Ruby and I will chase a few summits now while I finish my morning cuppa’. 🙂
This past weekend, my good friend Vlado (N3CZ) and his wife came over to the QTH for the afternoon. It’s been a while since our families got together, so it was fantastic to hang with them.
I’ve been trying to tempt Vlado to do more field activations–we’ve done a number together in the past and it has always been loads of fun. Thing is, both of us have pretty active family/work lives, so it’s challenging to make schedules work out.
Nonetheless, our 2022 goal is to do at least one activation per month as a team!
MK-911
If you recall, a couple months ago, I posted an activation report and video using my buddy Eric’s 40-10 meter doublet. I called it a “stolen” antenna because it had been on loan to me for so long, I think Eric forgot it even existed.
Exhibit A: The stolen antenna.
Eric’s doublet was build around a Hughes Aircraft MK-911 Dipole Fixture that was designed and manufactured for the US Military and appears to have been part of the PRC-74 manpack radio-set.
I had assumed Eric found this as a one-off at a military surplus sale. Turns out Eric (and a few readers) made me aware that it was available at Fair Radio Sales in Ohio for $10.
Image of the MK-911 from Fair Radio’s product catalog.
I decided to buy two of them: one for me, and one for Vlado. The temptation was strong to purchase a few more just for the 30 feet of 72-ohm military-surplus twinlead, however I understand that there’s a limited inventory and wanted others to be able to purchase this gem.
I was also thinking this antenna fixture would pair beautifully with Vlado’s Yugoslavian RUP-15/PD-8 manpack or even his IC-703 Plus.
Doublet time!
While our wives were catching up, Vlado and I made our way to the storage shed and opened my antenna parts boxes.
I did a little digging and found what I was looking for: some wire I purchased at a thrift store many years ago.
This wire has a black jacket that’s quite slick. Guessing it might be 20 gauge and might even be teflon coated. It was ideal for antennas and eyeing it, I thought there might be enough for two doublets.
For a Norcal-inspired doublet–which covers 40-10–we would need two 22′ legs. I decided (prior to cutting) that I wanted our doublets to go as low as 60 meters (5,332 kHz) and cover everything above. 60 meters is such a useful band. Thing is, I hadn’t done research into suggested leg lengths in advance.
We decided to pick a longer non-resonant length and just give it a go. If it worked, great–if not, we’d cut them down to 22 feet and be happy with 40M and up.
We cut the legs to 31 feet, so there’d be a total of 62 feet of wire in each doublet. Many thanks to my daughter Geneva (K4TLI) for helping stretch, measure, and cut the antenna wire with us!
Assembling the antennas was incredibly simple as there are built-in binding posts attached to the twin lead on the winding fixture.
Vlado and I both decided to use the winder as the center-insulator of the antenna. This is actually how this military fixture was designed to be used. The negative, of course, is that the center insulator is relatively heavy. This isn’t a problem for me at all since I use super strong arborists throw lines to deploy my antennas.
From WD8RIF’s website.
Eric (WD8RIF), by the way, actually detached the twin lead from the fixture and posts on his unit and built a new center-insulator from a discarded 35mm film canister (see photo above). He wanted to keep the weight down so he could support the center of the doublet on his fiberglass masts.
Testing QRV!
I had planned to hook up the doublets to my RigExpert antenna analyzer, then I realized it was essentially an unnecessary step.
The big question for me was, “Will my Elecraft KX2 find impedance matches on 60M and above?”
Vlado and I connected the doublet to the KX2 and tuned to 5,332 kHz. After confirming the frequency was clear, I pressed the ATU button. The KX2’s internal ATU churned for a couple of seconds and confirmed a 1.4:1 match.
Score!
We checked all of the bands above 60M and the matches were even better.
Standing in the middle of my driveway, I asked Vlado to load the POTA.app website and look for CW spots.
I couldn’t put the antenna away without chasing some parks!
We then proceeded to work about three stations on the air in CW with 5 watts. All of them gave us 599 reports!
Vlado chasing a POTA activator.
It was serious fun.
As I mentioned to Vlado, it might have been the first time I’ve ever used an HF “Handy Talky” with a doublet antenna!
In the end, we both walked away with two effective military-grade field doublets. A perfect antenna for our monthly “Team Baklava” activations.
2022 Activation Challenge
Last year, my personal challenge was to validate all of my park and summit activations with 5 watts or less.
Since I’m very much a QRPer and primarily a CW op these days, this turned out to be low-hanging fruit; lower than I would have guessed in this part of the solar cycle.
For 2022, I plan to continue the 2021 five watt challenge and add another layer…
This year, my challenge will be to build a new antenna each month and deploy it at least once during that month during a field activation.
The MK-911 doublet will count as January’s antenna.
I’m going to allow myself to build these antennas from anything and everything. I might even cannibalize a few of my broken/worn-out antennas.
After two months in Canada, I’m pleased to make some time this weekend to activate PK01, the Blue Ridge Parkway.
I’ll be joined by my good friend, Vlado (N3CZ), and we plan to set up at the Folk Art Center on the parkway around 11:00 EDT and be on the air by 11:30 EDT (15:30 UTC).
[QRPers: Please note that the following is a re-post from my shortwave radio blog, the SWLing Post.]
Heard Island (Image: VK0EK)
Regular SWLing Post readers know that I’m a ham radio operator (call sign K4SWL). Being a shortwave radio enthusiast, of course, I spend most of my time on the air in the HF portion of the amateur radio spectrum. Contacting distant stations and connecting with other ham radio operators around our little planet gives me immense joy.
Thing is, my life has been so hectic lately, I’ve barely been home during the Heard Island DXpedition (March 29th – April 11th). And the days I have been home, VK0EK’s signals have been incredibly weak.
In short: timing and propagation were all working against me. And VK0EK was soon to pack up and come back home. I was becoming desperate…and beginning to lose hope that I’d make any contact with this unique and rare entity in the isolated stretch of ocean between Madagascar and Antartica.
“Antennas with a clearing” on Heard Island (Photo by Bill, AE0EE)
My hope was waning. Then, Tusday evening, I gave a presentation about shortwave radio at the Blue Ridge Amateur Radio Club. On the hour-long drive home, I stopped by my good friend Vlado’s (N3CZ) to confess my troubles to the radio doc.
Now it just happens that Vlado has a much better antenna set-up to work DX than I do, and what’s more, (close your ears, fellow QRPers) he has an amplifier.
Most importantly, though, Vlado is a keen DXer. He’s got 330 countries under his belt, and ever up for a challenge, routinely pushes himself to accomplish more with less. In January, with members of the local club, he entered a QRP challenge; he had 100 countries worked by the following month, all in his spare time. And a few years ago, Vlado actually built a radio of his own design and worked 100 countries within two months (you can read about that here).
So, of course, he was game to help me make a contact…even if it was a long shot. A very long shot.
Juan de Nova
When I arrived at Vlado’s QTH around 21:00 local, VK0EK was impossibly weak, so we focused our efforts on 30 meters and FT4JA: the Juan de Nova Island DXpedition (another all-time new one for me).
A portion of the FT4JA antenna farm. (Image: FT4JA)
After more than an hour of calling, FT4JA finally heard my call and (woo hoo!) I was confirmed in their log.
But what about Heard Island?
After working FT4JA, we moved down to 40 meters where VK0EK was slightly louder than before. Well, maybe it’s not impossible, I thought hopefully. Just next to it.
Between QSB (fading) and tuner-uppers, my ears were bleeding trying to hear Heard’s minuscule CW signal–so faint, so distant were they.
After only about ten minutes of steady calling, Vlado made a sign to get my attention, and we strained to listen, very carefully.
VK0EK came back very faintly with just one letter incorrect in my call–it was enough that I didn’t catch it at first. But Vlado heard it, and after sending the call back a couple of times, then the report, VK0EK confirmed my call with a signal report, and I reciprocated.
Vlad and I leapt to our feet, yelling, “WOO HOO!” (and hopefully didn’t wake up any of Vlad’s neighbors).
Heard Island is actually running an online log that is updated live. We immediately looked there to confirm I was in their log, and was greeted with this great circle map and a line from Heard Island to my call sign in the States. Vlado made this screen capture as a momento:
Here’s to good friends and mentors
In one incredible evening, I snagged two all-time new ones–and I owe it all to my good buddy, Vlado. Most importantly, I’ve been learning so much from him as he patiently coaches me through some weak DX with serious pileups. Plus it’s just always fun hanging around Vlado, the best broken radio doctor I know, to whom “challenge” is…well, a piece of cake.
Thanks Vlado, for your enthusiasm and patience–I’m lucky to have a friend like you!
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!
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Quick note about park numbers: As of the time of publishing this article, we’re still using the “K” prefix for US parks. Tomorrow (March 20, 2024), all US park prefixes will change to “US.” Pisgah National Forest, for example, will be US-4510 starting tomorrow. Today, it’s still (barely!) K-4510, so that’s what we’ll use.
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My goal was to get Vlado on the air and give him a taste of POTA using the AX1 and 40M coil. I hadn’t planned to activate–since we were grabbing dinner afterward–but I did end up activating after the UTC day changed.
I always enjoy hitting the field with Vlado.
Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon, and the Coffee Fund. While not a requirement, as my content will always be free, I really appreciate the support.
