SG-2000 MANUAL
127
The SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
©1995, SGC, Inc.
TEL: (206) 746-6310 FAX: (206) 746-6384
21.4
Basic Tune-up Procedure (Alignment)
1)
Attach a wattmeter and a 50 ohm load to the antenna connector. Allow 10
minutes warm-up before proceeding.
2)
Set radio to a channel in the middle of its operating range. Current
production radios are aligned using ITU channel 1601.
3)
Confirm that radio is in high power mode by observing the front panel
LCD.
4)
Attach accurately calibrated frequency counter to pin 14 of IC608 and
Ground. Adjust the trimmer capacitors C639 and C640 to achieve 11.94
MHz +/- 1Hz.
5)
Adjust R41 and R42 on the LPA to maximum output power (fully clock-
wise).
6)
Set unit to CW mode. Key unit and adjust R119 on the exciter for 200 watt
output power.
7)
Readjust R42 to 150 W.
8)
Readjust R41 to 50 W.
9)
Change the channel to emergency frequency 2182 and set the mode to
A3H.
10) Adjust R338 on the exciter for a carrier level between -3 and -6 dB, (
37.5 to
75 watts)
.
11) Change the operating channel to channel 851 and set the unit to A3A
mode.
12) Key unit and adjust R337 on the exciter for a carrier level of -16 dB +/- 2
dB, (
2.3 to 6 watts)
.
Note: Bird wattmeter reads 40.5% on two tone test.