The 'Rock-Mite '
A simple CW transceiver for 80, 40 or 20 meters!

 

    The 'Rock-Mite' design grew out of my desire to offer a 'one-evening' CW transceiver kit which would be both affordable and easy to construct. It first appeared at 'Lobstercon' - a QRP gathering on the Maine coast- in early July, 2002, where it was provided to all attendees courtesy of Small Wonder Labs and the NorCal QRP club.


     The Rock-Mite is a crystal-controlled direct-conversion transceiver available for 80M, 40M, 30M or 20M.   It features an on-board 8-pin PIC microcontroller which controls a T-R offset on key-down. A brief tap of a pushbutton control switch reverses the offset to yield a second operating frequency. Pushing and holding on the pushbutton activates the speed adjustment routine for the built-in Iambic keyer. If you'd rather use an external keyer or straight key, there's a 'drop-through' mode which allows use of an external keying source.

You'll note in the image above that the Rock-Mite uses two crystals. The first is used in the local oscillator for transmitter and receiver. The second is used as a receiver front-end filter. This crystal significantly reduces the SWBC energy present at the receiver mixer; as a result, unwanted SWBC reception is dramatically reduced.

The Rock-mite uses one surface-mount part with fairly large spacing. There are no toroids to wind, so assembly should be a snap! The Rock-Mite uses subminiature epoxy-encapsulated RF chokes instead of toroids.

SPECIFICATIONS:-

- Double-sided PCB 2.0" x 2.5", plated-thru-holes, solder masked & silkscreened for easy assembly

- 0.5W power output at 12V supply.

- Supply voltage range 8-15V

AVAILABLE FREQUENCIES:

3560 kHz

3579 kHz

7015 kHz

7030 kHz (QRP calling frequency)

7040 kHz 

7122 kHz (US Novice/Tech+)

10106 kHz

 14060 kHz

 

-automatic T/R offset, reversible

-Built-in Iambic keyer, 5-40 WPM

-Built in sidetone, 700 Hz

- Includes assembly instructions and operating tips

- All on-board parts supplied in kit (as pictured above)

 

Check out this offering!

Dale Botkin, N0XAS, offers an economical upgrade to the RockMite functionality. The'PicoKeyer' provides memory-keyer functions, and with one added resistor, allows pot-based speed control. For further information, see:

http://www.hamgadgets.com

 

PRICE:

(See Order Form)

ENCLOSURE OPTIONS:

We do not offer an enclosure for the Rock-Mite. It's 'Altoids-compatible', however, so a source of enclosures is probably as close as your nearest market or pharmacy! For a beautiful custom-made enclosure, check out the 'MityBox' available from www.Americanmorse.com

CONNECTORS & CONTROLS

We now offer a complete set of controls/connectors for the RockMite. Includes:

BNC bulkhead, (2) 3.5mm stereo jacks, gain pot, knob, power jack & plug (2.1/5.5mm), power and interconnect wire, subminiature switch, reverse polarity diode, instructions. This parts set is 'Mitybox'-compatible.

Price:

(See Order Form)


Dave Benson, K1SWL

3/4/08