Kenwood TH-77A Service Manual page 51

ADJUSTMENT
TX-RX COMMON ADJUSTMENT
TH-77A/E
Measurement Adjustment
Item Condition Test- Specifications/Remarks
' Unit | Terminal Method
equipment
1. Reset 1) While holding the M key Display
down, set the POWER switch MAIN: 433.000 M, T, X, E
to ON. MAIN: 440.000 K, P
SUB: 144.000
SAVE: ON
APO:ON
2. Voltage 1) External power supply DC V.M DC IN Check
confirmation voltage: 9 V
PLL ADJUSTMENT
1. Transmit 1) FREQ.: 439.975 MHz: f. counter ANT TX-RX TC201 | 439.975 MHz] +200 Hz
frequency M, X, T, E Power meter (RFU) 449.975 MHz
449.975 MHz: K, P
HF RX ADJUSTMENT
1. BPF 1) Tracking generator output Tracking TX-RX ANT
: —40 dBm generator (RFV) TP2 K, P: 3 dB or Less
M, T, X, E:
Connect the spectrum Spectrum 4 dB or Less
analyzer to TP2. analyzer
ATT: 10 dB
LOG/DIV: 2 dB 156
an |
2. Receive SSG output: Oscilloscope ANT SINAD 12 dB or hgiher.
sensitivity —122 dBm/0.18pV AF V.M EXT SP
1) FREQ.: 146.05 MHz K, P, M, Xj Distortion
FREQ.: 145.05 MHz T, E1, £2 | meter
; SSG
2) FREQ.: 144,05 MHz Buininiy:Lesd
3) FREQ.: 147.95 MHz K, P, M, X
FREQ.: 145,95 MHz T, E1, E2
3. Squelch 1) FREQ.: 145.050 MHz T, E1, E2 Knob position 8:30 to
FREQ.: 146,050 MHz 11:00
K, P,M,X
SSG output: OFF
V SQL VR: At the point where
noise disappears.
Squelch is open.
3) SSG output:
—119dBm/0.25nV
V SQL VR: MAX
4. S-meter 1) FREQ.: 145.050 MHz T, £1, E2 Adjust so that all the signal-strength
FREQ.: 146.050 MHz segments go on then the last segment
K, P,M,X biniks.
SSG output:
—124dBm/0.14yV
2) SSG output: —91dBm/6.3pV All segments on.
3} SSG output: —127dBm/0.1 pV All segments off.
UHF RX ADJUSTMENT
1. Receive 1) FREQ.: 430.050 MHz M, x, T, | Oscilloscope EXT.SP Check SINAD 12 dB or higher.
sensitivity E1, £2 AF V.M
FREQ.: 438.050 MHz K, P Distortion ANT
SSG output: meter
—121 dBm/0.23 pV SSG
Dummy Load
2) FREQ.: 430.050 MHz M, X, T,
E1, £2
FREQ.: 445.050 MHz K, P
439.950 MHz M, X, T,
£1, E2
449.950 MHz K, P
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