cumbria designs




2-Tone Test Oscillator

A battery powered 700Hz and 1900Hz Test Oscillator, with variable frequency single tone feature, for SSB transmitter adjustment

The 2-Tone kit employs DSP techniques to generate low distortion audio tones for transmitter and general communications audio testing. Two modes are offered, Dual Tone with composite 700Hz and 1900Hz outputs and Single Tone with an adjustable frequency from 100Hz to 3500Hz. In both modes output amplitude is adjustable in 1dB steps over a wide range. In Dual Tone mode the amplitude of either tone may be adjusted in 0.1dB steps to compensate for the audio response of the transmitter. The PCB is designed to be a slide fit into a Hammond 1455K1201 extruded aluminium box.

Jean-Claude Gerber, HB3YDH, has very kindly provided copies of his drilling templates for the Hammond Enclosure and component value overlay which may be found here; 2-Tone Enclosure Panels, 2-Tone Overlay Values. Thanks Jean-Claude!

2-Tone Kit

The 2-Tone oscillator is supplied as a kit and comprises of a single PCB populated with standard through hole parts. The kit is easily assembled by anyone able to solder and follow written instructions.


  • Composite 700Hz and 1900Hz output.
  • Harmonics better than -55dBc at full output.
  • Adjustable tone balance 0.1dB steps.
  • Variable Single Tone output 100Hz to 3500Hz
  • Output amplitude adjustable in 1dB steps over 40dB
  • Two outputs, nominal 600 Ohms, 0dB and -20dB to extend output range.
  • Battery powered (Single 9V PP3).
  • Rotary encoder control.
  • Three colour LED status indicator.
  • Phono (RCA) socket outputs.


  • Size L120mm, W75mm, H25mm
  • Nominal +9V operation (4V to 13.2V)
  • 15mA typical current
  • High quality double sided silk screened PCB
  • Comprehensive 12 page instruction manual.

(Battery for illustration purposes only, not included in kit due to shipping restrictions.)

Price 36.00 Inclusive of VAT at 20%

(Outside of the EC? Ex VAT price 30.00)