Kenwood TS-870S - Manual (Page 76)

70
DRU-3 DIGITAL RECORDING UNIT (OPTIONAL)
RECORD LEVEL ADJUSTMENT
AT-300 EXTERNAL TUNER (OPTIONAL)
FUSE LOCATION
12 MAINTENANCE
INTERNAL ADJUSTMENTS
REFERENCE FREQUENCY CALIBRATION
Note: The transceiver is adjusted at the factory prior to shipping.
Unless necessary, DO NOT perform this adjustment.
1 Remove the top case (10 screws) from the
transceiver.
2 Set the following on the transceiver:
• Mode: CW
• MONI control: Center
• AF gain control: Center
• Menu No. 24 (CW PITCH): 800 Hz
• HI/SHIFT control: 800 Hz
• LO/WIDTH control: 1000 Hz
• RIT function: OFF
• Break-in Function (VOX): OFF
3 Tune in a standard frequency station such as WWV
or WWVH at, for example, 10.000 or 15.000 MHz.
Adjust the transceiver Tuning control so the Display
reads the exact frequency of the station. You should
hear a beat tone of approximately 800 Hz.
For 800 Hz:
f
af
= (f
display
/20.000 x ∆f
reference
) + 800 Hz
where ∆f
reference
is the shift from the 20 MHz
reference frequency
4 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 gain control and
the MONI control so you can hear the double beat
clearly.
For 800 Hz:
f
sidetone
= 800 Hz x [(20 x 10 6 + ∆f
reference
)/20 x 10 6 ]
where ∆f
reference
is the shift from the 20 MHz
reference frequency
5 Adjust the TC-800 trimmer to minimize the frequency
difference between the received 800 Hz tone and
the 800 Hz sidetone.
Remove the
top case.
TC-800
Remove the
bottom case.
VR3
Fuse for
AT-300
Remove the
top case.