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BK Precision 4070A User Manual Rev.2.2
39
5.26 Voltage Controlled Oscillator (VCO) Mode
Introduction
The Voltage Controlled Oscillator mode generates signal, where frequency could be vary between two specified
values using externally supplied -5.0V/+5.0V voltage. The control input bandwidth is DC to 35 KHz. Start, End
frequencies, output level and DC offset values could be manually entered from the front panel keypad in this mode.
External signal gating options is available in this mode. External Sweep (VCO) mode could be entered by pressing
“Mode”> “Sweep” >”2” key at any time.
VCO Mode Parameters
The Voltage Controlled Oscillator mode has the following front panel display:
Figure 5.26-1: VCO mode display
1. Start Frequency
This is the output frequency when -5.0V is applied to the External Modulation In connector (rear panel). You may
enter from 0 Hz (DC) to 21.5 MHz in 0.01 Hz steps.
NOTE: You are not allowed to enter a start frequency that is greater than the end frequency.
2. End Frequency
This is the output frequency when +5.0V is applied to the External Modulation In connector (rear panel). You may
enter from 0 Hz (DC) to 21.5 MHz in 0.01 Hz steps.
NOTE: You are not allowed to enter end frequency that is less than the start frequency.
3. Level
In this field enter the output level, from 4 mVp-p to 10 Vp-p in 1 mV steps or from -44.0 dBm to +24.0 dBm in
0.1 dBm steps.
NOTE: The level specified is a 50O loaded level. This is the level of the signal will appear across a 50O load
connected to the SIG Out connector. Intoau open circuit, the output swing will be twice the value entered.
Offset
You can enter an offset voltage for the output signal. For more information on output offsets refer to section 4.4.
External Modulation In
Apply the control voltage to this connector. For this mode, the input signal may be in the -5.0V to +5.0V range.
Levels outside this range will be clipped by limiting circuitry.
*** Caution***
Levels outside ±25V may damage the 4070A.
VCO
Start: 0 Hz
End: 1,000,000.00 Hz -10.0 dBm
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