Description - Keysight 478A Operating And Service Manual

General Information 478A Option H83

Description

Description
The 478A Option H83 is a standard 478A Coaxial Thermistor Mount modified to measure
microwave power from 1 µW to 10 mW over the frequency range of 1 MHz to 1 GHz. The
unit is then sent to the Keysight Standards Lab for calibration at the following
frequencies: 1, 3, 10, 30, 50, 100, 300 and 1000 MHz. The 478A Option H83 is tested to
have a VSWR ≤ 1.05 at the frequency of 50 MHz. The calibration is ISO compliant but
does not inlcude 17025 accredited cal. The calibration report will include Cal Factor and
RHO data with uncertainties.
The lower frequency is accomplished by the design of the RF input connector
(00478-62004) and thermistor assembly (00478-62005), which utilize a 0.1 µF cap for C1
and C2.
2 Thermistor Mount Manual Modifications