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Cricket 80a
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Cricket 80a
Designed by
David Cripe NMØS

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and Information Group
4SQRP
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Kitted and Offered For Sale By The Four State QRP Group        

RETIRED        
 
The Cricket 80a is an improved version of the original Cricket. For a more pleasurable operating experience, NMØS has added an on-off switch, more power and an improved oscillator permitting use of wider range of crystals. Click Here for the original Cricket documentation. The 80a has many improvements not found in the original. Like the original it is a low cost entry level minimalist CW transceiver for the 80 meter band. Both Crickets bear a family resemblance to the well known but much lower performing Pixie. However they are very different and vastly improved over the Pixie. They are NOT  Pixies, but are far superior! Low parts count, better components are featured, including MOSFETs for a better oscillator, more sensitivity and switching, and a modern NJM2113D audio amp. The 80a also puts out more power than the earlier version. This page is being written as though you landed here first, without prior knowledge of the original Cricket. The specs and info below have been updated to reflect the Cricket 80a performance.
 
ALL THROUGH HOLE parts make this kit very easy to 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 simple rig is fun and functional, and made many contacts at OzarkCon after the build session. A proven design and a great choice for your next rig, it is perfect for a group build with nets and contacts after the build. This is an excellent club project.
 
Clubs and Groups Please Note! Group discounts are available, 5 kit minimum order required. Contact the kitter at the email address below.
 
Join the Cricket Society! Earn Awards! Experience the comaraderie of the Cricket! More info here.
 
Specifications and Design Features
 
    General
    Transceiver: Fully functional transceiver.
    QSK Yes! Full QSK with fast, high speed switching.
    TR/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 Bander: 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 immediatly after assembly.
    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 doesnt.
    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.
 
    Documentation
    Assembly Manual
    Schematic
    Board Layout Part location.
    Part List BOM
    Photo Page Rig pix, part ID, and building tips.
    Introduction to the Cricket by NMØS
    Become a Cricketeer! Click here to join the Four State Cricket Society.
    Elecraft's Excellent Capacitor Identification Page  Posted with permission.
    Electronics 2000's Excellent Resistor Code Graphic Calculator  Posted with permission.
 

The Cricket is carefully kitted and shipped by Gary Lyons, WØGX
Please direct kit and part related questions to Gary
All proceeds are applied toward funding OzarkCon.   Thank you for supporting The Four State QRP Group.
 
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