HP 8920A, User Manual

Page: 574 / 658

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S:\HP892XX\USRGUIDE\manual\connkeys.fb
Chapter 24, Connector, Key, and Knob Descriptions
Connector Descriptions
The pin numbers for the radio interface connector are listed on the connector and in figure
147 on page 573 . Pin assignments are as follows:
1. GND
2. No Connection
3. Audio Out
• This is an output for the audio sources, AF Gen1 and AF Gen2. It it also connected
in parallel to the front-panel AUDIO OUT connector.
• Set the
AFGen1 To
field, the
AFGen2 To
field, or both to
Audio Out
to select
this pin and the front-panel AUDIO OUT connector as the audio source output.
These fields are found on the RX TEST and DUPLEX TEST screens as well as on
the signalling encoder screen.
• All settings for the audio source affect the signal at this pin.
• Output specifications are the same as the front-panel AUDIO OUT connector.
4. Key Out 2
• This pin is a key relay contact.
• Key Out 1 and Key Out 2 are connected in parallel with the Key Out 1 and Key Out
2 pins of the front-panel MIC/ACC connector. They go to internal relay contacts
and can be used to key a transmitter. The relay contacts are closed, which connects
the two pins when the
Ext TX Key
field is set to
On
. This field can be found on
the TX TEST, DUPLEX TEST, or RF ANALYZER screen. ( See "MIC/ACC" on
page 568 .)
• Capacitance is 0.1
µ
F per pin (300 pF per pin after approximately 6
µ
s).
Contact Rating is 0.5 A, 50 V.
5. Audio Input
• Set the
AF Anl In
field to
Radio Int
to select this pin as the audio analyzer’s
input. This field is found on the TX TEST, DUPLEX TEST, or AF ANALYZER
screen, as well as various signalling decoder screens.
• Input impedance is 100 k
Ω
.
6. Key Out 1
• See pin 4. Also see "MIC/ACC" on page 568 .
7.
−
12.6 V
• Pins 7 and 8 can supply power to a low current device. The voltage is always present
when the Test Set is powered on and cannot be varied or turned on or off.
• Output current is limited by an internal 100
Ω
, 2 W resistor.
8. +12.6 V
• See pin 7.