Option for 478A; 1MHz to 1GHz, SWR 1.05 at 50MHz. Std lab cal 1, 3, 10, 30, 50, 100, 300, 1000 MHz
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 include 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.
478A options
Keysight offers several options for the 478A, as can be seen below. Please note, the 478A is sold separately.
- 478A-H55 - 1MHz to 1GHz, max SWR 1.3
- 478A-H63 - 100kHz to 1GHz, max SWR 1.8 to 300kHz, 1.3 to 1GHz
- 478A-H72 - 1MHz to 1GHz, max SWR 1.2
- 478A-H73 - 1MHz to 100MHz, max SWR 1.1 except 1.05 at 50MHz
- 478A-H75 - 1MHz to 1GHz, max SWR 1.3 except 1.05 at 50MHz
- 478A-H76 - 1MHz to 1GHz, max SWR 1.3 except 1.05 at 50MHz. Std lab cal at 50MHz
- 478A-H83 - 1MHz to 1GHz, SWR 1.05 at 50MHz. Std lab cal 1, 3, 10, 30, 50, 100, 300, 1000 MHz
- 478A-H93 - 1MHz to 1GHz, max SWR 1.3 except 1.05 at 50MHz. Std lab cal at 50MHz and 100MHz
- 478A-H13 - 100KHz to 1GHz, max SWR 1.8 to 300KHz, 1.3 to 1GHz, std lab cal at 13 frequencies