The Hewlett-Packard Model 650A Test Oscillator is a wide
range precision resistance tuned oscillator covering from 10
cps to 10 me. It has a highly stable output signal level
that is adjustable from 30 microvolts to 3 volts into 600
ohms. Frequency response is essentially flat (±1 db)
throughout the complete extended range.
The output impedance is normally 600 ohms. Where a low
source impedance is desired, 6 ohms is provided by the
Voltage Divider Cable supplied with the instrument.
The Model 650A Test Oscillator output voltage is constantly
monitored by a vacuum tube voltmeter at the input to the
output attenuator system. This VTVM has two voltmeter scales
plus a dbm scale (o dbm = 1 milliwatt in 600 ohms). The
attenuator control, in conjunction with the AMPLITUDE
control, will produce a monitored signal of any desired
level when the instrument is resistive loaded with 600 ohms.
The flexibility and simplicity of the 650A Test Oscillator
find a wide variety of uses in audio, video, rf, and
alignment applications as well as laboratory wide band
measurements. This instrument was designed for such
applications as fast and accurate testing of filter
transmission characteristics, tuned circuit response,
complete receiver alignment, telephone or telegraph carrier
equipment, plus video and audio amplifiers.
The Model 650A Test Oscillator is well suited as a signal
source for af and rf bridge measurements. The wide range of
test frequencies necessary for repair and testing of
electronic frequency counters is also available from the
650A Test Oscillator.