HP 8920A, User Manual

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S:\HP892XX\USRGUIDE\manual\encoscrn.fb
Chapter 10, Signaling Encoder (AF Generator 2)
Using the LTR Encoder
To make a 12 dB SINAD measurement
1. Set Filter 1 to 300Hz HPF and Filter 2 to 3kHz LPF .
2. Decrease the Amplitude until approximately 12 dB SINAD is displayed.
3. Use the AVG (average) function to stabilize the measurement by positioning the cursor
in front of the SINAD dB field and pressing and releasing the SHIFT key, then the
INCR
×
10 key to access the AVG function, then press the ENTER key.
To Test Your Transmitter
To establish a trunked transmit channel on the home channel:
1. Connect the RF IN/OUT port of the Test Set to your radio’s antenna port.
2. Turn your radio on, and select the channel to test.
3. Press the PRESET key (to establish a known instrument state for this procedure).
4. Access the DUPLEX TEST screen.
5. Set the
Tune Mode
field to
Manual
.
6. Enter the home channel’s transmit frequency in the
Tune Freq
field.
7. Enter the home channel’s receive frequency in the
RF Gen Freq
field.
8. Set
AFGen1 To
to
Off
.
9. Set the
AF Anl In
field to
FM Demod
.
10. Access the ENCODER screen, and select the LTR mode.
11. Set up Message 1 with idle message data:
a. Enter your Area Number (0 or 1) in the
Area 1
field.
b. Enter the home channel number in these fields:
Goto 1
,
Home 1
, and
Free 1
.
c. Enter
255
in the
ID 1
field to establish an idle channel.
12. Set up Message 2 with transmit message data:
a. Enter your Area Number (0 or 1) in the
Area 2
field.
b. Enter the home channel number in these fields:
Goto 2
,
Home 2
, and
Free 2
.
c. Enter the Transmit ID number for your radio in the
ID 2
field.
13. Set the
Send Mode
field to
Cont
.
14. Set the
AFGen2 To
field to
FM
,
1 kHz
.
15. Set the
FM Coupling
field to
DC
.
16. Set the
LTR message
field to
Message1
.
17. Select
Send
to continuously output idle message.
18. Key the transmitter.
19. Select
Message2
in the
LTR message
field to tell your radio to transmit. If the
transmitter fails to establish a transmit channel before time-out occurs, try again using
these steps:
a. De-key the transmitter.
b. Select Message 1.
c. Key the transmitter.
d. Select Message 2.