5-9
CAUTION:
Do not transmit during the measurement on receiver circuit, otherwise SSG
may be damaged.
2. J3E Receiver Gain
1. Make the connection as below.
SSG
50
Ω
ANT
(
50
Ω
coax.)
FS-1503
EXT SP
(H)
(C)
4
Ω
or 8
Ω
13.6 V
Milli-
voltmeter
oscilloscope
Figure 5-3 Measurement on RX Circuit
2. Set the FS-1503 as below.
⋅
RF GAIN: Maximum
⋅
RX Freq.: 4.0 MHz, MODE: J3E, AGC: on
⋅
AF GAIN: 50 % of rated noise output (100 mVrms for 4-ohm speaker, 200 mVrms
for 8-ohm speaker)
3. Applying 4.0 MHz + 1.0 kHz signal from the SSG, adjust the SSG output level so
that the ratio between AF output and noise output is 20 dB. The output should be less
than 3 dB
µ
V.
With a 8 ohm speaker connected, the S/N is 20 dB when AF noise output is 200
mVrms and AF signal output is 2 Vrms.
3. J3E AGC Adjustment
1. Make a connection as shown in figure 5-3.
2. Set the FS-1503 as below.
⋅
RF GAIN: Maximum
⋅
RX Freq.: 4.0 MHz, MODE: J3E, AGC: on
⋅
AF GAIN: adequate AF output
3. Applying 4.0 MHz + 1.0 kHz signal from the SSG, adjust the SSG output level so
that the S meter start deflecting. The output shoule be +10 dB
µ
V. If not, adjust R210
on the TX/RX board.
SSG Output Level vs. S-meter Reading
SSG Output
(dB
µ
V)
10 20 30 40 50 60 70 80 90 100
S-meter + (1) 4 5 5 to 6 6 to 7 7 8 8 to 9 10 11
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