BIRD 43 - Page 12

Bird Model 43 Wattmeter
2
A shielded cable connects the RF line section to the rest of the
wattmeter. This lets you remove the line section from the wattmeter
housing for custom installation and still make measurements. The RF
line section is precision machined to provide the best possible
impedance match to the transmission line under test. A formed
phosphor-bronze spring finger protrudes into the element socket to
make contact with the element.
At each end of the line section are Bird Quick-Change RF connectors
that may be interchanged with any other Bird “QC” connector. The
wattmeter housing does not interfere with connector changes.
To make measurements, a Bird Plug-In Element is inserted into the
line section socket and rotated against one of the stops. A small catch
in the corner of the socket face presses on the shoulder of the element
to keep it in proper alignment. This assures good contact between the
spring finger and the element contact and between the lower edge of
the element and the line section body (see Figure 1).
Contacts on opposite sides of the element connect with the spring
finger when the element is in the forward or reverse position. This
occurs when the stop pin on the element is against either stop and the
catch is in place.
Figure 1
Securing an
element