Building the Cricket 40 CW QRP Transceiver

Last night (October, 2025) I finished building the Cricket 40 CW QRP Transceiver, a radio kit offered by the “Four State QRP Group.” I began building this kit back in May 2025. It sat on my shelf half-built for many months, and I finally completed it.

I’m fairly new to kit building but not a complete novice. The Cricket was a great next step on my kit-building journey.

Building the kit

Here’s the kit as it comes out of the package. One nice aspect of the Cricket is that you don’t need to wind any toroids. The toroids are built right into the PCB board.

The concentric circles on the Cricket’s PCB board are the toroid inductor coils.

I didn’t want to make any mistakes by mounting the wrong resistor in the wrong place. Taping the resistors directly to their listing in the instructions allowed me to triple-check before soldering them onto the board.

I checked resistor values with my multimeter. To do this, I set the multimeter to resistance (Ω) mode, placed the probes on each end of the resistor, and read the value on the display. This process was especially useful when the color bands were hard to read or could be confused.

Here’s my workbench.

I pushed the components through the board, bent the leads, and soldered on the underside.

Later, I bought a circuit board clamping kit. I like this better because I could flip the board back and forth while building. It was also more stable than the alligator “extra hands” device.

Here’s the radio fully assembled on my workbench.

Operating the Cricket 40 QRP Transceiver

I brought the Cricket down into my shack and attached my 40 meter EFHW antenna, straight key, and speaker. The Cricket transceiver is a crystal radio. It comes with two crystals for the frequencies 7040 and 7122 kHz. The PCB board has a socket that allows you to switch crystals.

To my great joy, as soon as I plugged it in and turned the Cricket on, I was receiving Morse Code. I transmitted, and you can see my Reverse Beacon Network results below.

My signal was picked up by a beacon as far as 460 miles away. Pretty good for about 0.7 watts.

A beacon 460 miles away received my 700 milliwatt signal!

QSOs with my Cricket

The next day, I reached out to some friends from my local radio club, PART of Westford, MA, and completed two QSOs with KC1UML and AA1N, each about 13 miles away.

I found that the Cricket’s side tone was super loud compared to its receive levels. For me the Cricket was more about the build than operations.

Going forward

I really enjoyed building the Cricket 40. It was super cool to build a radio and complete some QSOs with it.

I’ve ordered a QMX+ Transceiver and plan to build that kit next.