Kenwood TS-870S Internal Adjustments, Maintenance, Reference Frequency Calibration, Fuse Location

12 MAINTENANCE

INTERNAL ADJUSTMENTS DRU-3 DIGITAL RECORDING UNIT (OPTIONAL)

RECORD LEVEL ADJUSTMENT

REFERENCE FREQUENCY CALIBRATION

Note: The transceiver is adjusted at the factory prior to shipping. Unless necessary, DO NOT perform this adjustment.

1Remove the top case (10 screws) from the transceiver.

2Set 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

3Tune 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:

faf = (fdisplay/20.000 x ∆freference) + 800 Hz where ∆freference is the shift from the 20 MHz reference frequency

4Close 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:

fsidetone = 800 Hz x [(20 x 106 + ∆freference)/20 x 106] where ∆freference is the shift from the 20 MHz reference frequency

5Adjust the TC-800 trimmer to minimize the frequency difference between the received 800 Hz tone and the 800 Hz sidetone.

Remove the top case.

Remove the bottom case.

VR3

AT-300 EXTERNAL TUNER (OPTIONAL)

FUSE LOCATION

Remove the top case.

Fuse for

AT-300

TC-800

70