What is it?

The Cricket is a low cost entry level minimalist CW transceiver for the 80 meter band. Chosen as the build session kit for OzarkCon 2017, it bears a family resemblance to the well known but much lower performing Pixie, but is higher powered, and has a much better receiver. It features low parts count, a MOSFET PA/mixer, and a modern NJM2113D audio amp. Originally developed for the Four State QRP Group, the kit has been retired by them, and now brought back into production by the designer.

A TX/RX offset is also included so that you can work other stations that have zero beat, or you are using a crystal on the same frequency. Full QSK and a sidetone complete the essential operating features. The PA filter inductors are implemented as 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 unusual features for such a low parts count and inexpensive transceiver.

ALL THROUGH HOLE parts make this kit very easy to solder together and assemble. It will make a fine, fully functional, and educational first rig for a new builder, the new ham, or seasoned veterans wishing to just have fun with a new rig at minimal expense and effort. Note that Novices and Technicians have 80M CW privileges from 3.525 to 3.600, same as everyone else - so they also can build and use the Cricket.

This kit was very favorably reviewed in the December 2017 issue of QST.

You can read the assembly manual here.

Why did you make it?

The Cricket was designed as a simple, low-cost CW transceiver that could serve as an excellent kit for beginners, but has performance good enough to get on the air as a usable radio.

What makes it special?

The Cricket kit is a self-contained CW transceiver, with built in battery holder, spiral PCB trace inductors, on-board morse key, and included crystal. You can literally be on the air making contacts within an hour of opening the kit envelope!

Features: Transceiver Fully functional transceiver.

• QSK Yes! Full QSK with fast, high speed switching.
• R/RX Offest: Yes! Can hear a zero beat station, with no offset they wouldn't be heard.
• Sidetone: Yes! Great keying aide, unusual in such a low parts count rig.
• Oscillator: Improved oscillator, now uses a MOSFET.
• Low Part Count: Only 36 total electrical components (the Pixie has 34).
• NO Toroids: NO toroids to wind, all inductors are etched on board spiral coils..
• Power Switch: An OFF/ON switch has been added to the 80a.
• Reverse Voltage Protection: Battery clips help prevent reverse connection.
• Self Contained: Both the battery and a straight key are board mounted.
• Keyer Adapter: An electronic keyer adapter is included - use your favorite keyer.
• Single Band: 80M only.
• Crystal Controlled: A 3579 KHz color burst crystal is included. Note ANY 80M CW Crystal, except dirty FT243s, may be used.
• Fast Assembly: Approx. 1-2 hours, depending on exprience level.
• No Alignment: None needed, put it on the air immediately after assembly.
• Tools required: Soldering iron and solder, flat and Philips screwdrivers, diagonal cutters, sandpaper.
• Size: The board is 6" x 3.5" including a 1/2" snap off piece that becomes the board mounted key.
• Power Supply: 9 volt on board battery.
• Current requrements Receive: less than 10ma, Transmit: less than 80ma.

Receiver

• Direct Conversion: No 60 cycle hum or AM BCB interference at most locations.
• Sensitivity: Minimum Discernible Signal (MDS) -110 dBm (~S3) well below the normal 80M noise level.
• MOSFET Mixer: Far superior to the Pixie's NPN mixer - better immunity to AM broadcast interference and 60 Hz hum.
• Current Requirement: Less than 10ma (!).
• QSK: Full QSK.
• Audio: Modern audio IC amplifier. Sounds good, and plenty of volume for headphones/earbuds.

Transmitter

• Chirps NOT Included Most Crickets chirp :o) this one doesn't.
• Power Output: 1 watt or greater.
• Final Amp: 2N7000 in Class E for cool efficiency. No heat sink needed.
• Spectral Purity: All harmonics and spurs are 50dB or more below the carrier.
• Current Requirement: Approx 111 ma.
• Robust: Will transmit into an open antenna jack with no damage.

NOTICE: If there are any missing or defective parts in this kit, contact me at nm0s@nm0s.com, and they will be sent out promptly!