HP 8920A User Manual page 574

Chapter 24, Connector, Key, and Knob Descriptions
Connector Descriptions
574
S:\HP892XX\USRGUIDE\manual\connkeys.fb
The pin numbers for the radio interface connector are listed on the connector and in
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.
page 568.)
Capacitance is 0.1 µF per pin (300 pF per pin after approximately 6 µs).
•
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 kΩ.
6. Key Out 1
• See pin 4. Also see "MIC/ACC" on page
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 100Ω, 2 W resistor.
8. +12.6 V
• See pin 7.
(See "MIC/ACC" on
568.
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