For example: Agilent E4440A or Anritsu 68369
Keysight / Agilent YIG Oscillators (YTO)
Keysight / Agilent 5086-7500
Dual YIG Oscillator Assembly 2 - 20 GHz
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Manufacturer: Keysight / Agilent
Keysight / Agilent 5086-7781
YIG Tuned Oscillator 3.0 GHz - 7.0 GHz
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Manufacturer: Keysight / Agilent
Keysight / Agilent 5086-7786
Yig Tuned Oscillator Assembly, 3 - 6.8 GHz
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Manufacturer: Keysight / Agilent