User Manual

120 10503-201 PRELIMINARY T-96S Technical Manual
12
Table 5: Tests and Adjustments
full channel
units (25 KHz & 30 Khz models)
STEP ACTION EXPECTED
RESULTS at
25
°
°°
°
C
MEASURE
WITH
IF NOT?
1
Output Power
Press PTT Channel x
5 watts
1
+10%, -20%
Service monitor
set to read
power
Check T96HRSS maximum
power output setting: must
be set to 255 (means 5W)
Refer to factory tech
support.
2
Frequency Error
Press PTT Channel x
±300 Hz Service monitor
set to read fre-
quency error
Open the unit (see 3.4.4)
Adjust the Frequency Ad-
just control on the TCXO
2
3
Deviation
Press PTT Channel x
±4.0 kHz
3
+5%, -10%
Service monitor
set to read de-
viation with mid
(15 - 30 kHz) IF
filter.
Using T96HRSS, adjust TX
deviation with the up/down
arrows.
4 Set the service monitor to generate a -80 dBm signal on the selected receive frequency. The
signal should be modulated with a 1.0 kHz tone.
5
Demodulated Audio
• For 9600 b/s set
generator deviation
to ±2.5 kHz.
• For 1200 - 4800 b/s
set generator devia-
tion to ±4.0 kHz.
2.0 ±0.2 Vpp Oscilloscope
connected to
pin 4 of the data
I/O connector.
4
Using T96HRSS, adjust
receive audio level with the
up/down arrows.
6
12 dB SINAD
Set deviation to ±3 kHz.
Set IF filter to mid (15-
30 kHz), no audio filter.
≤ 0.5 µV
5
Service monitor
set for SINAD.
Connect to pin
4 of the data I/O
connector
4
.
Refer to factory technical
support.
7
Distortion
Set deviation to ±3 kHz.
Set IF filter to mid (15-
30 kHz), no audio filter.
< 3% Service monitor
set for Distor-
tion. Connect to
pin 4 of the data
I/O connector
4
.
Refer to factory technical
support.
1 (unless you have set a lower value). Note that readings less than 5 watts may be due to losses in the cables used for testing.
Check also your wattmeter frequency calibration curve. Do not be too ready to condemn the transmitter.
2
The TCXO adjustment is accessible through the hole next to the DIP switch on the logic board.
3
The unit is automatically set to 19200 b/s (Bt.3) for this procedure. If the unit is later used at 9600 b/s (Bt.5) or 4800 b/s, the
deviation be will automatically set to ±3.0 kHz and ±4.0kHz respectively.
4
Pin 4 is accessible by removing the cable connector hood. If you anticipate frequent need for access to this pin, solder a short
insulated lead to that pin on the cable connector and replace the hood. (The same signal is available at TP1 on the logic board
if the unit is open).
5
If a psophometrically weighted filter is available on the service monitor, use 0.35
µV.