Agilent Technologies 8564EC Service Manual page 467

RF Section
A9 Input Attenuator
Table 12-2 Attenuator Control Truth Table (W11 connected to A14J6)
ATTEN
Setting
(dB)
0
10
20
30
40
50
60
Table 12-3 Attenuator Control Truth Table (W11 connected or
disconnected from A14J6)
ATTEN
Setting
(dB)
0
10
20
30
40
50
60
606
A14U421
10 dB
Pin Pin
16 15
L H*
H* L
L H*
H* L
H* L
L H*
H* L
ON OFF
* reads ≈ 0.2 V (floating) when W11 is disconnected
H ≈ 28 V L ≈ 0.6 V
A14U420
10 dB
Pin 1 Pin 2
H L
L H
H L
L H
L H
H L
L H
OFF ON
H TTL High L TTL Low
30 dB 20 dB
Pin Pin Pin
14 13 12
L H* L
L H* L
L H* H*
L H* H*
H* L L
H* L H*
H* L H*
ON OFF ON
30 dB 20 dB
Pin 3 Pin 4 Pin 5
H L H
H L H
H L L
H L L
L H H
L H L
L H L
OFF ON OFF
Pin
11
H*
H*
L
L
H*
L
L
OFF
Pin 6
L
L
H
H
L
H
H
ON
Chapter 12