Service manual

10 Agilent 8495D/K Attenuators Operating and Service Manual
1 Introduction
Product Overview
The Agilent 8495D and 8495K are 50- ohm, dc to 26.5 GHz,
0 dB to 70 dB (in 10 dB steps), coaxial attenuators with APC 3.5
connectors. Each attenuator is made up of four attenuation
sections connected in cascade. Each section consists of a precision
thin- film attenuator card, a lossless thru- line, and a ganged pair of
edge line transmission lines. The edge lines are flexed to make
contact with either the attenuator card or the thru- line. The edge
line contacts are gold- plated leaf springs which ensure long life
and high repeatability. In the 8495D, the edge line controls are
flexed by low- torque cams. In the 8495K, the edge line controls
are flexed by solenoid plungers (see Figure 1).
Table 1 on page 12 shows the switching arrangement required to
increase the amount of attenuation from 0 dB to 70 dB in 10 dB
steps. In the 8495K, to ensure specified performance, it is
recommended that the attenuator sections shown in the table
below be used. Also, when changing attenuation, it is good practice
to insert the required sections before deletion of the unneeded
sections. With the attenuator set for 0 dB attenuation, only the
insertion loss (residual attenuation) remains.