Op er at ing in struc tions. 17, Use and func tion of con trols. 17, Ini tial ad just ments. 17 – Bird Technologies 8890-400 Series Manuale d'uso
Pagina 27: Operating instructions, Use and function of controls, Initial adjustments, Zero adjust
Chapter 4
Operating Instructions
Use and
Function of
Controls
There are no operating controls for the Series 8890-400
Wattmeters. The Model BA-310 Blower Assembly, supplied
with some models, has a manual/automatic switch.
Initial
Adjustments
Before connection of the load, perform the following steps:
1. Wipe all conductors and insulator surfaces on
the transmission line face with a clean soft
cloth and check the RF input connector. Use a
self-drying, non-residue forming, contact
cleaner on the inaccessible portions of the con-
nector.
2. Check the 50 ohm input resistance of the load.
Refer to Section 1, Maintenance.
3. Zero adjust the meter. The meter should be
checked for zero set under no power conditions.
With no power applied, the meter pointer
should set exactly on zero. If adjustment is re-
quired, turn the adjustment screw until the
pointer is set at zero. Refer to figure 8.
17
Zero Adjust
Figure 8
Zero Adjust