QRP Radios I've Built


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Most QRP enthusiasts enjoy building QRP radios and accessories.  I'm certainly no exception as I've built many items through the years. Below are a few of the QRP radios I've built, many of which I have since sold. Of course, I almost always wish later I hadn't sold the item. Click on any picture below for a larger view.

Bayou Jumper

K4EQ Bayou Jumper Setup
The Bayou Jumper is one of the latest builds for me. It has a 40-meter, crystal-controlled transmitter and a receiver with a range of approximately 150 kHz. It's kitted and sold by the Four State QRP Group of which I am a member. The following is a description of it from the assembly manual.

"The kit owes its genesis to the imagination of Jim Giammanco, N5IB, who envisioned this project in homage to the classic "Paraset" transceiver (www.paraset.nl/), the legendary spy radio from World War II. Using the same circuit architecture as the original, Jim brought it up to date with solid state circuitry . . . . Jim named his creation the Bayou Jumper after the popular Knight kit Ocean Hopper regenerative receiver . . . ."

The transmitter in the Bayou Jumper is borrowed from the classic NC-40 transmitter by David Cripe, NMØS, which was also kitted and sold by the Four State QRP Group. It has an output of approximately 5 watts.

The picture above is of my typical Bayou Jumper setup, which includes a Palm Mini Paddle and a N8XAS UKA-2 Universal Keying Adapter mounted on top of an Ultra PicoKeyer. At the suggestion of NMØS, I changed the solid state relay in the UKA-2 to a AQV252G to be able to use the keyer with the Bayou Jumper. There's plenty of audio from the Bayou Jumper to drive the MFJ speaker.

This is a fun radio to play with and it brings back wonderful feelings of nostalgia to many of us who started out in ham radio as kids decades ago. It was especially fun working fellow Four State QRP Group member WØEB for my first Bayou Jumper to Bayou Jumper contact.

Cricket 30

Cricket 30 built by K4EQ
The Cricket 30 is a 30-meter transceiver kit designed by David Cripe, NMØS, and kitted by the Four State QRP Group. It's a follow up to the popular 80-meter Cricket 80.

According to the 4SQRP website, "A TX/RX offset is also included so that you can work other stations that have zero beat you, or are using a crystal on the same frequency. Full QSK and a sidetone complete the essential operating features. Dave's famous etched spiral coils are included on the PC board, so there are NO TOROIDS to wind. Additionally, a straight key is included on the PC board. Just snap it off, mount it on the board, and the whole rig is then self contained. Also included is an electronic keyer adapter--you can use your favorite keyer with the Cricket! These are many features for such a low parts count and inexpensive transceiver."


The Cricket 30 has a transmit output of approximately 700 mW
and runs on a 9-volt battery. How cool is that? Like most kits put out by the Four State QRP Group, the Cricket 30 is relatively easy to build. I just built mine in April 2019 and have some receive issues, so I'm reserving judgment for now on how well it it actually operates. I need to recheck all solder joints carefully and look for misplaced components.

 Splinter II

Splinter II built by K4EQ
At the 2017 OzarkCon QRP Conference in Branson, Missouri, I was fortunate to win four prizes, including a Splinter II 40-meter QRP receiver/transmitter kit. How great is that?

The Splinter II is kitted and sold by Breadboard Radio and, like the Bayou Jumper described above, is another one of those really fun radios to put on the air. Although the output of the Splinter II is quite low--somewhere between 400-650 milliwatts--that only increases the challenge and reward of making contacts. When you think about it, 500 milliwatts is only 10db less than 5 watts, which would be no more than two S units difference. Very workable!

Notice I painted the breadboard a MSU Spartan green. I'm a proud graduate of Michigan State University and a huge sports fan of the school. Go Green!

BJ, Splinter II, K2
On the left is a picture of my Splinter II and Bayou Jumper side by side. My Elecraft K2 is behind them, which gives you a good idea of how tiny the Splinter II is. Click on the picture to get a larger and clearer view of them.

The Splinter II packs a lot of goodies into a small package, including a sidetone, a VXO to pull the HC-49 crystals a few kHz up or down, a spot switch for zero beating, a built-in straight key, and an external key jack. One feature I like is the switching transistor, which allows the use of electronic keyers without having to use an external keying adapter. The kit also includes an unfinished breadboard to mount the PCB on. As you can tell, I love this little thing!

Heathkit HW-8
 
Promo Picture of Heathkit HW-8
In 1972, the Heath Company (Benton Harbor, Michigan) came out with the HW-7, a 2-watt CW transceiver kit. This was the first of three popular QRP CW transceivers produced by Heath, the other two being the HW-8 (introduced in 1976) and the HW-9 (introduced in 1984).

The HW-8 was the first QRP radio I built. It had a direct conversion receiver and included 80, 40, 20, and 15 meters (pre-WARC days). Depending on the band used, the output was between 1.5 and 2 watts.  My first contact with my HW-8 was with DK4KK in Germany on 20 meters. From that day on, I was hooked on QRP.

Tuna Tin 2

The Tuna Tin 2 transmitter is almost a requisite for all QRPers to built. For many, it's their first QRP project. It's simple to build and puts out around 500 milliwatts of power on 40 meters. Not much, but it works!

Tuna Tin 2 built by K4EQ

The TT2 was designed by Doug DeMaw, W1FB (then W1CER), who published an article in the May 1976 issue of QST magazine. It immediately became a hit. David Bixler, WØCH, writes, "The original Tuna Tin 2 was built in a tuna fish can and used two transistors, hence the name Tuna Tin 2. It used a crystal oscillator and a power amplifier stage and was capable of producing about 250 milliwatts of 40-meter energy. In 1996, Doug Hendricks, KI6DS (of NorCal fame), started work on building a TT2 transmitter. He soon discovered that some of the parts were not available anymore. He contacted Dave Mecham, W6EMD, who agreed to update the design to modern, available parts. KI6DS and W6EMD updated the circuit and designed the round circuit board . . . ."

Small Wonder Labs DSW 20/30

               
Inside of DSW 30/40                   
              
               DWS 30 built by K4EQ
Dave Benson, K1SWL, was the founder of Small Wonder Labs and produced some incredible QRP products. Among them were the DSW series of CW transceivers for 20, 30, or 40 meters. I built one each for 20 and 30 meters. Unfortunately for QRPers, Dave semi-retired a few years ago and closed Small Wonder Labs.

The DSW transceivers have a built in PIC-based keyer, audio frequency readout in CW, RIT, and two tuning rates. They have an output of 2 watts--enough for plenty of great QRP contacts. After a few years, I sold my two DSWs, but now wish I had kept at least one of them.

Small Wonder Labs Rock-Mite

Older K4EQ QRP Shack
Rock-Mites built by K4EQ
Another one of Dave Benson's QRP productions at Small Wonder Labs was a tiny crystal-controlled, direct-conversion transceiver called the Rock-Mite. I built three of them, one each for 40, 30, and 20 meters. The power output is approximately 500 milliwatts. They are another really fun and easy build and are now sold by Rex Harper, W1REX, at QRPme.

To get an idea of just how small these are, look at them in the picture on the right, next to a few other of my QRP radios from a few years ago. The QRP radios include a DSW 30, a NorCal 40A, an Elecraft K1, an OHR 100A, and two Rock-Mites. Click the picture for a much better view. Man, I sure love this QRP stuff!

NorCal 38 Special

38 Special built by K4EQ
The NorCal 38 Special was, indeed, a special little rig for me. When I built it in the late 90s, it rejuvenated my interest in QRP. It's a 30-meter CW transceiver with an output of around 500 milliwatts. I did the mod and beefed it up to 5 watts. Click on my article Rediscovering the Thrill to read about my experience with this fun radio. Suffice it to say, in the first couple of months I had it, I worked 29 DXCC entities and 24 states on 30 meters. Plus, I broke a pileup after half a dozen calls or so and worked 5N3/SP5XAR in Nigeria. What a blast!

I mounded the PCB on top of the dust cover for my Bencher Paddles. That made for a slick, little QRP outfit. Sorry about the small picture, but it's all I could find. I sold the radio a while ago, so I was unable to take another picture.

NorCal 40A

NorCal 40A built by K4EQ
Inside of NorCal 40A
This is another QRP radio I deeply regret selling. And, unfortunately, they are no longer being produced.

The Norcal 40A is a 40-meter CW transceiver designed by Wayne Burdick, N6KR and sold by Wilderness Radio. It has a superhet receiver with crystal filter, AGC, and RIT. I did a suggested mod and changed the 40 kHz band coverage to 150 kHz and added a 10-turn potentiometer. I also added the KC1 keyer/frequency counter. Depending on the supply voltage, the power output is 1.8 to 3 watts. This all made for a super duper, incredibly fun QRP radio.

OHR 100A

Inside of OHR 100A
OHR 100A built by K4EQ
The OHR 100A is a 5-watt CW transceiver kit produced by Oak Hills Research, a division of Milestone Technologies, Inc. There are 80, 40, 30, 20, and 15-meter versions available. Mine was the 20-meter version.

I enjoyed using this radio. My only complaint was the long warm up period before the VFO drift would stabilize. If I started a QSO before at least a 30-minute warm up time, I would be constantly turning the dial to stay on frequency. Otherwise, the radio was a solid performer.

 ELECRAFT K1

Elecraft K1 built by K4EQ
Elecraft has a reputation for producing some of the finest radios you'll find anywhere, and the K1 lives up to that reputation in the QRP world. Although it's marketed as a 5-watt CW transceiver, the output is adjustable from about 0.1 to 7 watts. Mine has a four-band filter board (40, 30, 20, 17 meters), although it is currently being sold with only two bands, and the four-band board is not available. The receiver is hot and it has three adjustable crystal filter bandwidths.

Inside of K1
There are a few accessories you can build and add to the stock version of the K1. I added the noise blanker, internal antenna tuner, and internal battery adapter. The tuner, which does an excellent job, is the top board in the picture on the left. I initially built an additional  two-band filter board for 80 and 15 meters, but after never having used it for about four years, I sold it.

Building the K1 is not overly difficult, but I wouldn't recommend this to be the first kit for a person to build. I did have to contact Elecraft a couple of times over a now forgotten issue during the build, and they were extremely helpful and courteous in identifying where I had screwed up.  😊

 ELECRAFT K2

Elecraft K2 built by K4EQ
The basic Elecraft K2 is a high performance, synthesized, CW QRP transceiver that covers 80-10 meters. The output is adjustable from 0.1 to about 12 watts (at least mine is). I added the SSB adapter, noise blanker, audio filter, K60XV 60-meter and transverter adapter, and 100-watt amplifier to mine. The amplifier would "un-QRP" it, but it is easily disabled for QRP operation through the menu.

I built my K2 a few months after I retired in 2013 and while I was still recuperating from two knee replacement surgeries. Perfect timing! It was definitely my most challenging build, but also the most rewarding. Without a doubt, the Elecraft K2 is one of the better QRP transceiver on the market. Elecraft continues to produce some incredible QRP transceivers.