Transmitter Section - Kenwood TS-990S Service Manual

Transmitter Section

Item Condition
• Perform the following in the adjustment mode. Item 1 and 7~35 have been adjusted;
To terminate the adjustment menu in the middle, save your settings with Menu No. 128.
1. ALC refer- 1) Menu No. : 67 (14.1MHz,
ence voltage USB) Transmit
2. TX IF Gain 1) Main display f.:
18.100000MHz
Mode: CW
DRV: ON
Transmit
Connect the spectrum analyz-
er input to J700.
After the adjustment, discon-
nect the cable from J700.
3. TX IF Gain 1) Main display f.:
Check 18.100000MHz
Mode: CW
DRV: OFF
Transmit
Disconnect the cable from
CN800 and connect the spec-
trum analyzer input to CN800.
After the adjustment, discon-
nect the cable from CN800.
4. TX HF BPF 1) Main display f.:
(49~54M) 50.000000MHz
Check Mode: CW
Transmit
5. Final idling 1) Main display f.:
current 51.990000MHz
Mode: USB
Final unit (A/2) VR1~4: MIN
Transmit
Disconnect the lead wire with
connector (E37-1612-05) that
is connected between the
CN36 and CN16, and attach
jig cable (W05-1776-00).
When you adjust VR1, con-
nect each pin 1 of jig cable to
an ammeter. When you adjust
VR2, connect each pin 3 of jig
cable to an ammeter. (Refer
to page 162.)
After the adjustment, discon-
nect jig cable and reconnect
the lead wire with connector
(E37-1612-05) to its original
position.
ADJUSTMENT
Measurement
Test-
Unit Terminal Unit
equipment
DVM TX-RX TP1 Front
(A/2) (ALC) panel
50 J700 TX-RX
dummy (DRV) (A/2)
Oscillo-
scope
Spectrum
analyzer
CN800
Ammeter Final CN36 Final
(A/2) CN16 (A/2)
DC-DC
(A/3)
TS-990S
Adjustment
Parts Method
[UP]/[+] Set the adjustment 2.5V±0.1V
(F5) or value wiithin the limit
[DOWN] of the specifi ed volt-
/[-](F4) age.
L720 Output level max. –4dBm or more
L721
Check the output –4dBm or more
level.
Check the drive
output level.
Check the default
current (I ).
0
VR1 I + 650mA ±50mA
O
VR2 1500mA ±100mA
Specifi cations/Remarks
195