The TAK-40 transceiver is designed specifically for the ARRL Homebrew Challenge contest. The
following is a list of the criteria for the contest and a brief description of how the TAK-40 meets the
The station must include a transmitter and receiver that can operate on the CW and voice segments of 40
meters. The TAK-40 covers 7.0 to 7.3 MHz.
It must meet all FCC regulations for spectral purity. All spurious emissions from the TAK-40 are at least
43 dB below the mean power of fundamental emission.
It must have a power output of at least 5 W PEP. The TAK-40 generates at least 5 watts PEP for voice and
CW modes. The ALC can be set as high as 7 watts.
It must operate from either 120 V ac mains or a 13.8 V dc power supply. The TAK-40 operates on a 13.8
VDC supply and draws less than 0.2A during receive and less than 3A during transmit.
It can be constructed using ordinary hand tools. Construction of the TAK-40 uses all leaded components
and assembly only requires hand tools, soldering iron, and an electric drill (helpful but not strictly
It must be capable of operation on both voice and CW. The TAK-40 operates lower and upper sideband
(USB and LSB) as well as CW. USB was included to allow the TAK-40 to easily operate in digital modes
Parts must be readily available either from local retailers or by mail order. No "flea market specials"
allowed. The TAK-40 is constructed from materials available from Digikey, Mouser, Jameco and Amidon.
Any test equipment other than a multimeter or radio receiver must either be constructed as part of the
project or purchased as part of the budget. The TAK-40 only requires a multimeter for construction,
extensive built-in setup functions are included in the software including a frequency counter to align the
oscillators and a programmable voltage source for controlling the oscillators.
Equipment need only operate on a single band, 40 meters. Multiband operation is acceptable and
encouraged. The TAK-40 operates on the 40 meter band.
Frequency control can be by VFO or crystal control. Some method of variable tuning is encouraged. If
crystal controlled, only a single crystal must be included in the $50. The TAK-40 has dual VFO’s with
memory functions including VFO to Memory and Swap VFO and Memory. Each VFO has it’s own
memory and the current VFO setting is retained during power off.
The total cost of all parts, except for power supply, mic, key, headphones or speaker, and usual supplies
such as wire, nuts and bolts, tape, antenna, solder or glue must be less than $50. The total parts required to
built the TAK-40 is $49.50
The TAK-40 also includes some features that make it very smooth to operate:
• LSB operation – interoperable with 99% of the voice communications on 40 meters
• Automatic Gain Control – regulates the audio output for strong and weak signals
• S-Meter – simplifies signal reports
• Digital frequency readout – reads the operating frequency to 100 hz
• Dual Tuning Rates – fast for scanning the band and slow for fine tuning
• Large tuning knob – just like commercial rigs
• Speech Processor - get the most from the 5 watt output
• Automatic Level Control – prevents overdriving the transmitter
• TX power meter – displays approximate power output
• Bootloader – accepts firmware updates via a computer (cable and level converter optional)