4641V Elgar AC Source
- Output Frequency: 45 Hz to 70 Hz / 350 Hz to 450 Hz
- Output Signal Amplitude: Approximately 2 Vrms
- Harmonic Distortion: Less than 0.25% of oscillator output
- Decade Dial: ±1% of set value
- Narrow Range: ±-0.25% of set value
- Output Amplitude: ±.02%/°C
- Output Frequency: ±.02%/°C
The Elgar Series 400V variable frequency oscillators are plug-in units which provide frequency determining signals for the Elgar AC Power Sources. The Elgar 4641V provides a continuously variable frequency range of 45 Hz to 70 Hz/350 Hz to 450 Hz.
The oscillator frequencies are stable and accurate and the signal amplitude is stable, but uncalibrated. The signal amplitude is variable, at the front panel of the associated Elgar AC Power Sources, from zero to the full rated output of the power source.
The oscillator plugs into the front panel of the Elgar power source and is secured by two captive screws. Frequency output of the decade dial oscillator is selected by three decade switch dials and a vernier potentiometer which provides continuous resolution between the lease significant decade frequency steps. Pushbutton switches select ranges of 10-109 Hz, 100-1099 Hz and 1000-10990 Hz.
Frequency output of the narrow-band continuously variable oscillators is controlled by a calibrated vernier potentiometer on the front panel which gives continuous resolution between the lowest and highest frequencies of the operation frequency band. Two-band instruments have push-button selectors on the front panel for high or low frequency band selection.
Resistance programming is accomplished by connecting an external resistor between pins 11 and 12 of Connector J1, located on the rear panel of the AC Power Source. The value of the resistor is typically at 100 ohms per volt, referenced to the output of the AC Power Source on the 0.0 to 130V range.
The external resistor is in fact taking the place of the feedback resistor in the operational amplifier circuit of the oscillator. It is important to know that during initial calibration this resistor must be matched to the input resistor of the operational amplifier to obtain a gain of 1. Once this is accomplished the front panel amplitude control may be rotated to the desired full-scale output voltage on the AC Voltage Meter located on the front panel of the Power Source. The reading is typically 130V and in effect provides the 100 ohms per volt calibration.