Kenwood TS-570S Marine Radio User Manual


 
64
6 Adjust the TC500 trimmer to minimize the frequency
difference between the received 800 Hz tone and
the 800 Hz sidetone.
7 Re-install the protective cover on the PC board
(6screws).
8 Re-install the bottom case (8 screws).
ACCESSING THE INTERNAL FUSE
1 Remove the top case (8 screws) from the
transceiver.
2 Remove the 12 screws that fasten the inner cover to
the chassis.
3 Open the inner cover.
Be careful not to damage the speaker cable
connected to the PC board.
16 MAINTENANCE
INTERNAL ADJUSTMENTS
REFERENCE FREQUENCY CALIBRATION
Note:
The transceiver is adjusted at the factory prior to shipping.
Unless necessary, DO NOT perform this adjustment.
If you have installed the optional SO-2 unit, you cannot perform
this adjustment.
1 Set the following on the transceiver:
Mode: CW
AF control: Center
Menu No. 20 (CW RX pitch): 800 Hz
IF SHIFT control: Center
Receive bandwidth {page 38}: 600 Hz
RIT function: OFF
Break-in function (VOX): OFF
2 Remove the bottom case (8 screws) from the
transceiver.
3 Remove the protective cover installed on the PC
board (6 screws).
4 Tune in a standard frequency station such as WWV
or WWVH at, for example, 10.000 or 15.000 MHz.
Adjust the Tuning control so that the display
reads the exact frequency of the station.
•You should hear a beat tone of approximately
800 Hz.
For 800Hz:
faf = (fdisplay/20.000 x freference) + 800Hz
where freference is the shift from the 20MHz
reference frequency
5 Close your CW key and you will hear a transmit
sidetone of approximately 800 Hz.
This sidetone produces a double beat tone when
it combines with the received signal.
Adjust the AF control to hear the double beat
clearly.
For 800Hz:
fsidetone = 800Hz ±50 ppm (= 800 ±0.04 Hz)
where freference is the shift from the 20MHz
reference frequency
TC500
Fuse (4A)