120 20110-003 PRELIMINARY
Gemini/PD Technical Manual
5
Table 1: Tests and Adjustments Full & Half ChannelUnits
STEP
ACTION
EXPECTED
RESULTS at
25
°°°°
C
MEASURE
WITH
IF NOT?
1
Output Power
Press
PTT Channel x
40 watts
1
+10%, -20%
Service monitor
set to read power
Check the RSS maximum power
output setting: must be set to 255
(means 40W). User can however
reduced it down to 10 Watts.
Refer to factory tech support.
2
Frequency Error
Press
PTT Channel x
±300 Hz
Service monitor
set to read fre-
quency error
Adjust using the RSS
Freq Warp
setting (fine tuning adjust)
(Typical adjust range is ±1.5KHz)
If found outside limits, user is
to call factory technical sup-
port.
3
Deviation
Press
PTT Channel x
Carrier will be modulated
with a 1 KHz tone.
For any bit rate
speeds selected:
Full channel unit
±4.0 kHz
+5%, -10%
Half channel unit
±2.5 kHz
+5%, -10%
Service monitor
set to read
deviation
Using RSS, adjust TX deviation.
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. Open the top cover to access the radio (see 3.4.4)
To be performed only if a loss in system performance has been detected
5
12 dB SINAD
•
For Full channel unit, set
deviation to ±3 kHz.
•
For Half channel unit, set
deviation to ±1.5 KHz
•
Set service monitor IF
filter to mid (15-30 kHz),
no audio filter.
Measure taken at
J400 pin 21 (RX1)
and at pin 23
(RX2)
≤
0.5
µ
V
2
Service monitor
set for SINAD.
Connect to radio
connector J400
pin 21 (RX1) or
pin 23 (RX2).
Refer to factory technical support.
6
Distortion
Use same settings as per 12
dB SINAD
< 3%
Same as per
Step 5
Refer to factory technical support.
1 (unless you have set a lower value). Note that readings less than 40 watts may be due to losses in cables used for testing.
Check also your wattmeter frequency calibration curve. Do not be too ready to condemn the transmitter.
2
If a psophometrically weighted filter is available on the service monitor, use 0.35
µ
V.