SG-2000 MANUAL
187
The SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
©1995, SGC, Inc.
TEL: (206) 746-6310 FAX: (206) 746-6384
FONE connector to B.U.T. J4.
Audio connector replaces wires 9 and 10 of J1 remote cable.
Turn on the power supply and then the radio. Set the radio to the base station
frequency in A3J mode.
Set the Oscilloscope:
Vertical
= 1 volt/div.
Horizontal
= 0.2 msec/div.
Set the Distortion Analyzer:
Function
= Voltmeter
Meter Range = 1.0 VRMS
Set Audio Generator:
Load
= External
Frequency
= 1 KHz
Amplitude
= 0 VRMS
23.3.6
S Meter Test
Adjust the amplitude of the audio signal generator for a full scale reading on
the S meter. Full scale should correspond with a 10 dB increase from a 0 (no
segments) indication of signal strength. Record the VRMS amplitude and dB
level on the Distortion analyzer.
Full display
zero display
Amplitude
.3 to .4 VRMS
.03 to .05 VRMS
dB
-4 dB
-15 dB
Reduce the amplitude of the audio signal until there are zero bars on the S
meter.
Record the dB difference on the Distortion analyzer. This should be:
? dB
= 10dB ?2 dB
-4 dB - (-15 dB) = 11 dB
If test fails, check IC14 pin 2. For .5 VRMS Audio Input from generator, it
should read 2.7 VDC and for .05 VRMS it should read .2 VDC.