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The Agilent 8648A is a synthesized signal generator with a frequency range of 100 kHz to 1000 MHz having a resolution of 0.001 Hz. The display resolution is 10 Hz. Typical frequency switching speed is <75 ms for frequencies <1001 MHZ and <100 ms for frequencies >=1001 MHz. The frequency accuracy is +/-3E-6 x carrier frequency in Hz. This can be improved with the addition of option 1E5 (high-stability timebase) to +/-0.15E-6 x carrier frequency in Hz. The standard internal timebase aging rate is +/-2 ppm/year, or <+/-0.1 ppm/year/<+/-0.0005 ppm/day with option 1E5. The timebase output is 10 MHz at >0.5 V rms (typical) into a 50 ohm load. The external reference oscillator input accepts 2, 5 and 10 MHz +/-5 ppm with a level range of 0.5 to 2 V rms into a 50 ohm load. The 8648A has low levels of spurious signals, with harmonic levels at <-30 dBc at an output of <=4 dBm. Subharmonics at the same output level are at -60 dBc. Nonharmonics with an offset level of >=5 kHz and an output level <=+4 dBm are at <-55 dBc on frequencies under 249 MHz, and less than -60 dBc for all other frequencies. Residual FM for frequencies under 249 MHz is <7 Hz, <4 Hz for frequencies under 501 MHz and <7 Hz for all other frequencies. The SSB phase noise at an offset of 20 kHz is <-120 dBc/Hz for a carrier frequency of 500 MHz and <-116 dBc/Hz for a carrier frequency of 1000 MHz. The output power level range can be from +10 to -136 dBm, with a resolution of 0.1 dB. The level accuracy with an output power level from <13 dBm to -127 dBm is +/-1.0 dB for frequencies <=2500 MHz. The output reverse power protection is 50 watts into a 50 ohm load. The SWR at output levels of <-6 dBm is <2.5:1 for frequencies <249 kHz and <1.5:1 for frequencies <=2500 MHz. The output impedance is nominally 50 ohms. Frequency modulation peak deviation for frequencies less than 249 MHz ranges from 0 to 200 kHz, 0 to 100 kHz for frequencies under 501 MHz, and 0 to 200 kHz for all other frequencies, with a resolution of 10 Hz at <=10% of peak deviation and 100 Hz for >10% to maximum peak deviation. Deviation accuracy is +/-3% of deviation +/-30 Hz. THe carrier frequency accuracy is +/-100 Hz for deviations <10 kHz. Phase modulation peak deviation at frequencies <249 MHz is 0 to 10 rad, 0 to 5 rad for freq. <501 MHz, and 0 to 10 rad for all other frequencies. Phase modulation resolution is 0.01 radians. The deviation accuracy is +/-3% of deviation +/-0.05 rad. Distortion is less than 1% at deviations of >=3 radians. Amplitude modulation ranges from 0 to 100% with a resolution of 0.1%. Amplitude modulation accuracy is +/-5% of setting +/-1.5%. Distortion is <2% at 30% AM and <3% at 90% AM. The Agilent 8648A offers an internal and external modulation sources. The internal modulation source outputs 400 Hz or 1 kHz from a front-panel BNC connector at 1 V p-p into 600 ohms. The external modulation source needs 1 V peak into 600 ohms for full scale modulation (High/Low indicator is provided for external signals <=10 kHz). There are 4 options available with the 8648A: 1EP (pager encoder), 1E2 (modulation generator), 1E5 (high-stability timebase), and 1CM (rack kit).
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