Furuno FS-1503 - 4. J3 E RX Total Gain; 5. J3 E TX Output Power

5-10
4. J3E RX Total Gain
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: Maximum
3. Applying 4.0 MHz + 1.0 kHz signal from the SSG, adjust the SSG output level so
that the AF output level is 1W.
The output should be –5 to + 1dB
µ
V.
(Rated output; 2Vrms for 4-ohm speaker; 2.83Vrms for 8-ohm speaker)
5. J3E TX Output Power
Refer to 4.4 Power Data Setting in chapter 4 for power adjustment.
1. Make a connection as below.
50
Ω
Pwr meter
50
Ω
ANT
(
50
Ω
Coax.)
FS-1503
AF OSC
MIC
(H)
(C)
13.6 V
AF OSC
ATT
200
Ω
200
Ω
200
Ω
600
Ω
+ 6 dBm
600
Ω
+6 dBm
600
Ω
– 46 dBm
3
4
1
2
PTT SW
(GND)
(PTT)
oscilloscope
Figure 5-4 Measurement of TX output power
2. Set the measuring instrument as below.
AF Oscillators: one for 1000 Hz and another for 1600 Hz, output level of +6 dBm
Attenuator: 46dB or microphone input of –46 dBm
3. While pressing the PTT switch down, read the power meter. (Output power meas-
urement with two tone signal) Double the reading for peak-to-peak power(Px).
References)
1) J2B(EIB): Power is measured by applying 0dB, 600 ohm.
2) NBDP : Measured in FEC-C mode.
3) DSC : Measured by transmitting DOT signal.