CW Transmitters

(Models DX 400, DX 400V, DX 500, DX 500V, DX 667 and DX 667V)

These transmitters are designed for mobile or base CW operation. Powered by the 12 volt vehicle battery or 12 volt regulated power supply, the maximum power output is less than 5 watts RMS. Frequency of operation is within the 10 meter band, determined by installation of a crystal into the oscillator board. The transmitters contain a transmit/receive relay and an output connector for the receiver to share the antenna and permit break-in operation.


  • Red "POWER" Button turns the unit on and off.
  • White "REC AMP" Button turns the receive amplifier on to provide 6dB of gain for your receiver. This will work independently of the power button -- that is, the white button may be pressed "on" even when the red button is "off." The oscillator may be operated without any output to the antenna. You will be able to hear the signal in your receiver. This may be useful to adjust your electronic keyer or to practice your Morse Code "off the air."
  • Green Button reduces power on all models. On models DX 400V and DX 500V, it also activates the RF Output Knob.
  • Yellow "DELAY" Button reduces power and adds delay to the transmit/receive relay to accommodate different transmission rates for break-in keying operation. On models DX 400V and DX 500V, this button adds delay but does not reduce power.
  • RF Output Knob controls RF output level when the Green Button is engaged. On the DX 667V only, the RF Output knob is operational at all times.
  • Meter is an RF Relative Output Indicator and lights during transmission.
  • A Crystal made for series operation must be installed into the holes labeled "X-1" near the top of the oscillator board. The frequency should fall between 28.0 MHz and 29.7 MHz.
  • Key Jack for 1/8" miniature phone plug is located on the rear of the unit for connection of the telegraph key.
  • Power Cables are also located at the rear. The red lead connects to the positive side of the power supply, and the black lead connects to the negative side.
  • Antenna Connector (SO239) for 50 ohm antenna is located on the rear.
  • Radio Connector (SO239) for 50 ohm output to the receiver is also located on the rear.  

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Frequency Range

28.0 MHz to 29.7 MHz


50 parts per million, 0-50 degrees Celsius with typical quartz crystal

Power Output

< 5 watts


13.6 volts DC


< 6


50 ohms

Duty Cycle

100% at full output


> 30dB down


3-1/4"(H) x 6-5/8"(W) x 10-3/4"(D)


6 pounds