Operating instructions

OPERATING MANUAL 2945A
46882-311D A-7
Features
This accessory for IFR instruments is used to measure forward power, reverse power and VSWR in
coaxial RF transmission lines and antenna systems. There are two versions as follows:-
Frequency range Part no.
1 to 50 MHz (HF) 54421-002L
25 to 1000 MHz (UHF) 54421-003J
There are no controls fitted to the Directional Power Head. There are RF line input and output
connectors, and a DIN socket for the lead to the Service Monitor. A 1 m lead assembly is available
as an optional accessory. As the Directional Power Head is bi-directional, it can be connected
either way round in the RF line.
The Directional Power Head is able to measure CW power or give an indication of peak envelope
power (PEP) for AM and SSB. The [PEP/CW] key on the directional power meter screen is used
to select the required measurement method.
A wide measurement range is available for both forward and reverse power. This can be from
10 mW to 400 W under certain some operating conditions. Range selection is automatic,
controlled by the software within .
A system of compensated peak responding detectors is employed to ensure fast response times and
a wide dynamic range. It should be noted that the instrument is accurately calibrated for signals
with low harmonic content and noise.