Dual Oscillator (DO-1) is a high performance
dual oscillator, including two identical proprietary
oscillators, that drive two quartz crystal
resonators simultaneously. The outputs provide series
frequency and series resistance of each resonator. The
parallel capacitance of the quartz resonator can be
cancelled in the range from 6 pF to 50 pF in each
oscillator. This is important for accurate
measurements in liquids and in soft (lossy) films.
An automatic level control (ALC) is employed and the
driving level in the crystal is choosen between 0.5 mA
and 1.0 mA.
The crystal face is in contact with the measuring ground,
but it is electrically isolated from the computer
ground, allowing an external current or voltage source
to be connected to it.
DO-1 can drive crystal resonators with
frequencies in the range from 1 MHz to 25 MHz. This
frequency shall be specified for each oscillator. The
oscillator can work with crystals in the range of the
specified frequency ±1 MHz. ( If an oscillator is
specified for 10 MHz, it will work with crystals from 9
MHz to 11 MHz).
Overtone operation is also possible in the range from 1
MHz to 25 MHz. This shall be specified.
The supply voltage (12 V DC) is taken from